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POSITIVE FEEDBACK ONLINE - ISSUE 16
 
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Our readers respond…we respond right back!

Send your comments to either drobinson@positive-feedback.com or dclark@positive-feedback.com

 

 

Hi David,
Thanks for forwarding this. I'll do my best to respond, and if you want to post it, that would be great.

Kudos to Bruce Beckner for his interesting and thoughtful letter on the subject of bass response in typical rooms. I'd be happy to jump into the fray and offer a few more thoughts on this topic.

First, Bruce is correct that most rooms will have at least one large resonant mode in the bass, and quite often several. "One-note bass" is a pretty common affliction. I would encourage anyone with an interest in this subject to buy an el cheapo Radio Shack SPL meter and a Stereophile Test CD with LF warble tones (am I allowed to recommend another magazine's products here?). For less than $50, you will have a very powerful tool at your disposal; just don't get too upset when you discover how uneven your room's response is. Many rooms will have severe problems in the 60-80Hz range, well above the roll-off of typical speakers, which makes Bruce's main room mode just below roll-off a "lucky accident" that cannot be counted on in most rooms.

Having said that, there are several issues here. One is that it is possible to minimize this problem by choosing both a good room and good placement within the room. Quite often, I find that the best results are obtained with what I call the "back-wall" setup, where the listening chair is pushed up almost against the back wall. The speakers are placed very far out into the room (typically 1/3 of the way from the front to the back wall, or more), and the back wall is heavily treated for absorption and diffraction. While not very wife-friendly due to the way-out-in-the-room speaker placement, this can yield a quite flat response in the bass, along with superb imaging.

The use of "bass traps" for typical room-mode eigen frequencies is almost impossible in most homes, due to the physical size of trap required to actually make a dent in the problem without "killing" the rest of the room's response from the midbass on up.

The other issue is the one I touched on in my earlier "reply". That is, most loudspeakers on the market are high-Q ported boxes, and as such, will automatically give "one-note bass" on their own. Before you get your feathers in a ruffle over this statement, study the physics behind ported boxes. They are resonant systems with a Q of typically 1.0 or more, and as such, will "ring" at a specific frequency when stimulated with an impulse signal. This is an unavoidable consequence of any high-Q system, whether it's a loudspeaker, a tuning fork, or a car with blown shocks. As such, any transient they see, regardless of whether it's at their resonant frequency or not, will produce a ringing at the resonant frequency. (For a graphic illustration of this phenomenon, refer to Loudspeaker Handbook by John Eargle, ISBN 0-412-09721-4, pp. 64 and 73, which shows impulse response data for sealed and ported boxes published by Richard Small in the 1970's.)

In addition, this high Q causes a "hump" of several dB in the frequency response at the resonant frequency. With an overblown time-domain response and an overblown frequency-domain response, if their resonant frequency also happens to coincide with a room mode, things can get ugly in a hurry. And they often do.

That is one of the many reasons it is so advantageous to use low-Q sealed-box loudspeakers. Not only do they have far superior transient response, but their frequency response is inherently flat, so it does not exacerbate room modes. In addition, their roll-off is twice as shallow as a ported box, meaning that they tend to give a much flatter response in combination with the natural LF boost in typical home listening rooms. While a ported box will sound much more "impressive" initially, because it has "more bass", it gets very fatiguing in the long run. The constant one-note assault is just too much to take, and it makes you want to get up and turn the volume down, or the entire system off.

The Ultimate Monitor / BOMB system is a rather unique case, because it isn't every day that you see a small sealed-box monitor with a -3dB point (anechoic) of 32Hz and a system Q of 0.7. While these numbers don't mean much to most people, this is every bit as deep as typical midsize floorstanders, and much flatter and faster to boot. So in this regard, I must disagree with Bruce. The intent in our case was never to limit the bass response, but rather to extend it as far as possible given the physical excursion limits of the drivers, and to keep the system Q low enough to preserve excellent transient response. The tradeoff, as I've stated, is in limitation of the maximum attainable SPL.

I would also say that it is exceedingly rare to find any small speaker with a useful response much below 40Hz. Most of them are ported boxes with a resonant frequency in the 40-50Hz range, along with the typical sharp "hump" in the frequency response at resonance, and they fall like a brick below that. As such, they are missing more or less the entire bottom octave, and yes, any "bass" in that range will often be due to a bad room mode, which is not the same as real bass. The only exception to this was the Sonus Faber Extrema, but it would be a real stretch to call it a "small" speaker. The Extrema was also rather unique in its ability for users to adjust the system Q "on-the-fly", and trade off frequency extension vs. transient response by varying an electrical resistance applied to the passive radiator.

On the subject of subwoofers: Those who have visited our website will note that I strongly recommend the use of subwoofers rather than the BOMBs for all applications requiring maximum extension and SPL's. Specifically, I recommend the use of RELs or others of a similar design, which allow the main speakers to run full-range without any high-pass crossover. I very strongly believe that this is the best approach to subwoofing, and gives results far superior to those employing high-pass filters for the main speakers. There are two main reasons for this, in my opinion:

First, I strongly believe that any "sub-sat" system should use a crossover point below 80Hz, because once the crossover goes above 80Hz or so, it becomes highly audible. So there is no need for extra high-pass filtering if the main speakers are chosen correctly, because no one should ever be using a 100Hz crossover point anyway. The Ultimate Monitors were designed for this approach from the start, and work extremely well with the subs set at around 50Hz (+/- 10Hz depending on the room), which is ideal.

Second, the Ultimate Monitors are a sealed-box design, and as such, have very linear power handling all the way down to the infrasonic range, along with a 12dB/octave roll-off which automatically matches the second-order low-pass filters used in most subwoofers. Thus, they are an ideal match for subwoofers "as is", without needing further protection from LF over-excursion. The same cannot be said of ported speakers, which have a 24dB/octave roll-off and are at high risk for LF over-excursion as well.

There are many who still adhere to the traditional view that a subwoofer should "relieve" the main speakers from reproducing bass, via a high-pass filter. I will state very strongly that this particular benefit not only is of dubious value in our case (due to the extraordinary performance of the ScanSpeak "Revelator" magnet system in a sealed-box loading), but is also overshadowed by the damage done to the main signal's fidelity when it passes through that high-pass filter. It is not just that it's another piece of electronics, although that undoubtedly cannot be beneficial. The real damage is caused by the midbass phase shifts the filter introduces, which are unavoidable and wreak havoc on the musical realism of the system.

I would urge anyone who has never heard a good "sub-sat" system, using high-quality sealed-box monitors and high-end RELs or similar subs, to audition one at your earliest opportunity. I firmly believe that this approach will almost invariably give results that are superior to those attainable with typical 3-way floorstanders of equal cost. The setup can require weeks or even months of effort, but when integrated properly, they truly do give the "best of both worlds". They combine the unbeatable "disappearing act" of monitors with the unbeatable extension and flatness of dedicated subwoofers, and they do it at a bargain relative to full-range speakers of comparable quality. When the setup is right, it simply sounds like the little monitor speakers have seamless extension flat to 15Hz, which is an amazing experience.

Finally, I would venture a guess that Bruce's suggestion for a "shootout" will be a very challenging task. First, the variables in setup alone are enough to make one wonder about the legitimacy of the results. Setting up subwoofers optimally is a far harder task than is generally appreciated. On top of that, the system-to-system variables would be overwhelming-- how do you compare Vandy 5's to a set of Ultimate Monitors plus REL Stentor III's? They're completely different beasts. And I think the Vandys are excellent speakers; it's just that you're no longer comparing apples to apples. The "qualitative" variations between different bass-loading techniques (sealed, ported, passive radiator, ARM, TL, etc.) could easily swamp out any differences between the in-room performance of the various systems. Lastly, as Bruce pointed out, six different listeners are going to have six different opinions about what is "best", so what's good for the goose might not be right for the gander. Having said that, I'm firmly in the camp of adjustable subwoofers, whether they're attached to the mains ala Vandy 5's, or stand-alone units like the RELs. No traditional 3-way will allow the same level of in-room tuning as a sub-sat system, and it shows.

Best Regards,
Karl Schuemann
AudioMachina


David,
First, let me thank you for your efforts and the apparent success of PFO. It's on my very short list of on-line audio publications that I read regularly. (There are some on-line audio publications that I don't read at all!)

The dialog between you and the designer of this speaker was particularly illuminating in that it gave us an insight into how this designer managed the inevitable set of trade-offs associated with building a loudspeakereven at the rather elevated price level at which he chose to work. While any six randomly selected audiophiles likely will have six different sets of preferences as to what to optimize, it's nice to know what this designer was thinking and why.

The most interesting part of the discussion to me was the colloquy between the two of you on the subject of bass reproduction. I don't think there it can be seriously disputed that the concept of "high fidelity" audio reproduction must include the reproduction of bass frequenciesthat's part of the music. But the tradeoffs associated with doing that are particularly nastyprimarily because nearly everyone's home listening room is of a size that's going to have a resonance peak somewhere in the bass range. Therefore, no matter how "flat" the speaker measures, if it reproduces even as low as 40Hz, what we're going to hear in our room is, to some degree or other, "one-note bass" at that resonant peak, which can be as much as 6 or 8dB. I don't believe that resonance can be killed by careful speaker placement; although it might be attenuated by a lot of bass traps, but they are large and pose "decorating issues."

Your apparent preference is to put up with some room resonance in order to hear the bass in the music (and perhaps to limit the loudness level of your playback to avoid exciting that resonance too much). Mr. Schuemann, and many owners of standmount speakers, chooses the opposite trade-off, which is simply to limit the low-end extension of the speaker and avoid exciting the "room boom." If the owners of standmount speakers are lucky (as is the case with my speakers in my room), the low frequency roll-off of the speaker is complemented by the lift of the room resonance; and the net result is a slightly more extended bass response, without any peak. However, that does not cure the other limitation of standmount speakersevident to the ear and visible in any distortion test (such as those published by SoundStage!)which is their inability to reproduce the lowest 1/2 octave of their bass response loudly. Typically, the standmount speaker's last half octave of bass response at moderately loud levels has a high proportion of second harmonic. This is relatively benign; but the lack of the fundamental deprives the music of the sense of weight that true bass imparts, whether the instrument being reproduced is a cello, a double bass, a Fender bass, or even an acoustic pianoleave alone a bass drum.

It seems to me that the most promising solution to this problem is either a subwoofer with a parametric equalizer (as the Velodyne Digital Drive subs) that also has a line-level cross over to move the (unequalized) main speakers' response out of the bass range (regardless of their inherent bass reproduction capabilities) or a full-range speaker with a self-powered bass reproducer that includes a parametric equalizer, such as the Vandersteen 5. Either type can then be custom-tailored to the particular characteristics of the room in which the system is operating.

It would be interesting for PFO to precipitate a discussion on this topic among designers and, even better, to run a comparison of the different alternatives (conventional full-range speaker, full-range speaker with parametrically adjustable bass, stand mount speakers with parametrically adjustable sub) in the same room. The test wouldn't be so much about which combination goes the lowest, but about which has the most satisfying bass reproduction.

Anyway, that's my suggestion.

Regards

R. Bruce Beckner

Hello Bruce...

I want to thank you for a thoughtful and literate response to the dialog between Karl Schuemann and me. Positive Feedback Online seeks to stimulate a true creative forum for fine audio, as our subtitle suggests; your letter is an excellent example of what we seek to stimulate in the audio arts.

You are correct as to my preference: I accept a degree of room resonance in order to have the deep foundations of the music. I have a couple of ASC tube traps in the rear corners to knock this down a bit, and have vents placed in the side rear walls behind speaker to allow bass overflow to go into spaces on either side of the listening room. It helps; so do the cambered side-to-ceiling interfaces, and the very solid construction (2" x 6" studs, wall-within-a-wall left and right). The room is by no means ideal...far from it...but it sounds much better than you'd expect. Nevertheless, there are certainly trade-offs, and I have made my choice quite willingly.

Your suggestion of a comparative evaluation of alternative designs is an excellent one. If both the candidate designs and the logistics could be resolved, I'd certainly be willing to have PFO host such a project.

I'm cc:'ing Karl Schuemann so that he can respond to your comments. Karl, if you do so, make sure that you cc: me; I'll see that this exchange is published in "Reverberations," extending our original interview and dialogue.

All the best,

david

David W. Robinson, Editor-in-Chief, Positive Feedback Online


Dear David,
I have to agree with Chip Stern’s review of the Joseph Audio RM25si Mk.II loudspeakers in Issue 13. I’ve owned a pair of original marque RM25’s for several years, and just upgraded the crossovers to the Mk.II version about 6 months ago. I’m glad to have some indirect corroboration of what I observed about the Asymmetrical Infinite Slope crossover vs. the original iteration.

My subjective experience is that the deep bass is slightly more pronounced. It remains as tight as before, so there is no downside to this change. The midrange around the crossover point is cleaner and smoother. The small hint of a metallic ring on some music is gone. My contention regarding Joseph Audio products has been that the entire line offers an unbeatable bang for your buck. Since the upgrade of the entire line to MK.II status, my contention in this regard is even stronger.

The RM25si cabinet is not small, but isn’t any more imposing than a really good compact monitor mounted on a sturdy stand. The black grilles are what tend to make the speakers imposing. With the naked cabinets, the wood finish (mine are cherry) moderates the visual impact. The aluminum drivers are a little disconcerting initially, but the message that you aren’t looking at any ordinary speaker comes through loud and clear.

I can verify that these speakers are easy to drive. I had to resort to using a 25-year-old Akai receiver as power for my system for a week and found that the top and bottom ends were a little less robust, but the JA sound still came through loud and clear. I’m not sure what sonic characteristic to ascribe to these speakers. They aren’t ‘fast’, ‘warm’, ‘lean’, ‘rich’ or any of the other usual buzzwords that are used to quantify transducers sonically. The closest I can get is ‘neutral’.

I finally own a pair of speakers that can be used as a comparison point for every other speaker that is available for audition in my part of the world, and my RM25si’s keep coming away with their figurative heads held high. The best competition for this speaker is the RM33si at over twice the price. Maybe someday…

A brief criticism of Chip Stern’s review has to be made. There was too much description of his room, the location, power conditioning, etc. I was getting impatient to get to the damned speaker review! If you know the room and know the associated equipment, it should be easy to let your brain and ears filter the sonic anomalies out and get to the heart of what is different about the setup: the speakers! Otherwise it was a great, insightful review. Way to go, Chip!

Regards,

Graham Moore

Vancouver, BC


Dear Editor,
Regarding Karl Lozier's review of the Esoteric DV50s. I have been using version without the DVI input and upgraded video DAC for some time now and agree that it has excellent sound, especially on redbook CD. It also does an excellent job on SACDs. The multi-channel SACD reissue of "Dark Side of the Moon" played in two channel mode sounded great but was bested by the recent vinyl reissue. Currently, I only have a small handful of DVD-As and from that selection my experience with the player is mixed. I am not yet set up for multi-channel sound and this may contribute to my mixed impression of DVD-A. I look forward to when I can make some meaningful comparisons in multi-channel. One DVD-A disc that sounded most excellent on the Esoteric was a Ray Brown two channel disc a friend brought over that was recorded at 192kHz.

In my system the Esoteric replaced a Theta Gen Va 24/96 DAC and Data Universal transport. I initially thought I might end up keeping the Theta DAC to use for redbook playback but the DV50 did so well on CDs that the Theta didn't beat it so I changed my mind. The Theta gear sounds slightly different in it's presentation. It has a smoother sound across the entire audio band. On some CDs the DV50 can sound a bit sharp but this is usually not a problem with judicious downward adjustment of volume. I like to rock out a bit and sometimes get carried away. The Theta gear is up for sale if anyone is interested.

There are a couple of things that Karl didn't mention about the DV50 that are worth noting. From the remote you can choose several display brightness levels, including completely off, which is how I use it, to minimize the possibility that the display circuits might generate noise. For the same reason I usually also use another feature available from the remote. The video circuits can be completely disabled. Unlike some DVD-A and a few universal players the DV50 does not require that a display be connected in order to play a DVD-A disc. It treats it just like a CD or SACD in it's ability to skip forward or back on tracks, etc. There are, however, some setup features that do require a display, including setting the player for two channel operation with multi-channel SACDs and DVD-As. Once set it remains so. Failure to make this change in a two channel setup will affect what you hear.

As far as I am aware, no one is yet offering hotrod mods for this player. The single ended multi-channel output stages might benefit from such efforts. I have made direct comparisons of the DV50 with a well regarded Pioneer universal player brought over by a friend. Don't recall the exact model number but it was a comparably priced unit. The Esoteric slightly bested this player with a more open sound and slightly better detail. I'd love to hear the Esoteric up against the EMM DAC6 and EMM transport. That would be a fun comparison.

Will Wright
Seattle, Washington


JohnPearsall,
I was recently perusing a reprinted article of yours concerning the history of the hobby. There was a mention of the early digital recording work by Denon in the early 1970's. I thought you would be interested in another bit of history from a few years later.

I was a college student in New Orleans in the mid 70's. During that time I worked part time as a salesman at a local store. Alterman Audio was your old style five man operation, we mostly sold mid-fi to keep the doors open but had some higher end stuff (my favorite was our huge bi-amped full range electrostatics). Anyway, we were the main seller of Sony audio in the city during those pre-chain days and consequently got to play with some R&D projects that were sent over from Japan. The relevant one for this discussion was the first A/D-D/A converter I had ever seen. Hell, it was the first one I had ever heard of (I was a biology major not electrical engineering). It was built on a Betamax chassis, as near as we could tell, and you recorded and played back using one of the first generation Betamax videotape machines. We actually got permission to record Richie Havens at a club he was playing at. We only had the thing for a couple of weeks so that tape, if Hank (Henry Alterman was the owner of the store) still has it, is totally useless except as a historical trivia document. This would have been sometime in late 1977 or early 1978. As far as I know this prototype was never marketed to the public although it might have been released as professional recording engineer product. I never heard of the thing again. I suspect that it was more of a proof of principal exercise for the engineering types but if memory servers it certainly didn't look kluged together.

Hope this added a bit of fun to your day. If you already knew about it, sorry for taking your time.

Steve

Stephen Bentivegna, Ph.D.


To the editors
Thanks to Mike and PFO for sharing his experience on building a music-only room.

Our fantasy is his reality.

Two simple questions:

1. I know the room measured well everywhere, but I was curious as to how many people he has had in at one time for serious listening (as opposed to just looking), and if the number of people changed the sound.

2. Also, could you provide a complete list of all audio equipment in the room?

Thanks again!

Jay Valancy

Hello Jay,

You're welcome.

I'm glad you enjoyed my journey. It doesn't seem real to me yet either... and I'm not sure I mean that in relation to the performance, or that the damn thing is finally done (relief or awe???).

In any case, to answer your questions:

I have had as many as 10 listeners at a time so far. Unfortunately, when I have had more than 3 or 4 listeners I have not spent any time in the sweet spot myself... so I have not had an opportunity to judge the effect of 10 bodies on the acoustics. My opinion (guess) is that there would be a difference... but not substantial... due to the fact that all the listeners are away from the walls, and therefore not dramatically affecting room energy (all the 'live' surfaces are still working). I would say that you do get a slightly diminished sense of 'space' and 'openness'... but not in a musical sense. It's more of a feeling.... like any room, empty versus full. How much of that 'feel' is acoustics, and how much is human psychology is beyond me.

In the future, I plan to get further into details of the room's performance; when I do that, I'll try to consider a better answer to your question.

2. My system is listed on the 'Meet the Staff' page listed on the Table of Contents page of PFO. Scroll down; mine is the fourth system listed. Here is a link http://www.positive-feedback.com/staff.htm .

Best regards,

Mike Lavigne


Dear David,
All the endless columns, interviews, reviews, awards and comments about SACD not withstanding, do you really think SACD is ever going anywhere?

We get it, you like SACD. Most of us don't. I've tried it, twice. No, I haven't tried it with a $10,000 player but I have had a Sony XA-777 and a Marantz SA 8260 and frankly neither sounded good at all on redbook and overly bright on SACD.

SACD just sounds so artificial, multichannel belongs in Home Theater. After all when you go to a concert does the band play behind you? SACD two channel is nice- for about 5 minutes until your ears start bleeding from the overly high frequencies. Lastly, there still is almost no content available. Even Sony seems to be backing off, witness www.sonystyle.com where there is almost nothing listed under SACD.

Give us a break and stick to two channel regular reproduction for a while.

Hank

Hello Hank...
Actually, it is my belief that SACD is already going places. In an increasingly fragmented format market, with many more alternatives than ever existed in 1982-1983 when Red Book CD was launched, I think that DSD and SACD have done very well.

Would I like to see many more titles? Sure.

Do I wish that Sony Music would get its bloody act together, move towards inventory conversion to hybrids, and quit acting like a schizo-cat gone off its medications? Absolutely. (Betcha that Sony wishes that too!)

Would I like to see more pop/rock on SACD. No kidding!

Do I wish that the DVD-A gang and the Dual Disc folks would get a clue? Yep.

Would I like to see WEA/Time-Warner make a commitment to quality audio and SACD? Naturally.

Do I wish that the music industry wasn't run by so many bean-counters and corporate airheads who have no interest in superior quality, but only in the lowest common denominator? Undoubtedly.

But despite all this, I do think that SACD is making slow, steady progress.

Gee, I get it: you don't like SACD. I don't know which "most of us" you're claiming to represent; "most of" the people I know do find SACD properly done to be a truly superior format (which it is, your unfortunate experience to the contrary). And your description of SACD playback sounds to me like whatever you were listening to wasn't done well at all.

Consider the possibility that any fine audio format (turntables, open reel tapes, SACDs...heck, even mere CD playback) requires attention to detail, quality components, and a system-wide approach to sound reproduction and synergy. If you don't do so, you're likely to get mediocre results very much like you describe. And what you describe is not a condemnation of the format... but it may well be a condemnation of an implementation of the format.

So....we shall have to agree to disagree, Hank. I categorically reject your categoric rejection and blanket dismissal of SACD...and that, my friend, was a no-brainer!

You'll get no "break" from me on the topic... if you read my work in PFO, you're going to get to hear my enthusiasm for SACD and its audio possibilities whenever I'm so moved. 

If you want a "break" from that, you'll have to read something else, eh?

All the best,

david

David W. Robinson, Editor-in-Chief, Positive Feedback Online


Dear Mr. Clark and Mr. Robinson,
I'm referring to the A Simple and Effective DIY Rack by Ed Morawski in your Issue 16 Nov/Dec 2004 issue.
That article goes to great lengths to explain how to make this rack and in the end I get the feeling that Ed Morawski is the inventor of this rack!!

That couldn't be further from the truth as the rack that he built has been a design that has been in existence for a long, long time on the TNT-Audio website l-o-n-g before Ed Morawski even considered building it! The TNT-Audio design is the original design. In fact, the rack that he built is the TNT-Audio FleXy-rack.

Ed Morawski made NO mention of the fact that his rendition is his version of the TNT-Audio rack using 4 feet (the original TNT-Audio FleXy-rack uses 3 feet). Very unscrupulous and very ungracious of Ed Morawski!!

Here is the weblink to the ORIGINAL TNT-Audio Flexi-Rack: http://www.tnt-audio.com/clinica/flexye.html

The article is dated 1998, clearly well before the Nov/Dec 2004 issue.

Regards
Manbir Nag
(Audio Enthusiast/Audiophile, Positive-Feedback regular reader)

Hello Manbir...
Actually, Ed Morawski makes
explicit mention of the prior TNT-Audio design in his very first paragraph... to quote that passage (see http://www.positive-feedback.com/Issue16/diyrack.htm):

I hate spending my audio budget on things that don't produce music, like equipment racks. Until recently, I got along quite well with inexpensive coffee tables from Ikea, but they had been in my music room for a while and took up a lot of space. I was ready for a change. The "flexy" rack has been around for some time, both in the commercial market (Salamander Archetype) and the DIY market (tnt-audio.com). The design is excellent and very flexible, as the name implies, but I wanted to make a few changes. I wanted four legs instead of three, and I wanted a bit more class, so I decided to use acrylic instead of MDF for the shelves. I have a great source for many raw DIY materials: http://www.mcmaster-carr.com This vendor is a real treasure trove of fasteners, tools, plastic, metal, and just about everything else. They sell precut sheets of acrylic in lots of sizes and thicknesses, but I selected .472-inch sheets (18 x 24 inches) that sell for only $23.57 apiece.

The TNT-Audio site mentions the use of MDF; one of their readers (Arnold Z. Cruz) did an acrylic variation on the TNT-Audio design, but with three legs. Ed is describing an acrylic version with four legs, and telling readers how to do it.

Since Morawski quite properly cites two earlier sources, including the very source that you are pointing out, and does not claim intellectual property or authorship, I do not see any evidence of the "unscrupulous and very ungracious" behavior you describe.

I therefore must say that I believe your criticism of the article is without merit.

All the best,

david

David W. Robinson, Editor-in-Chief, Positive Feedback Online

Dear Mr. Robinson,
Upon receipt of your email reply, I re-read the article in question. Yes, you are correct and Ed Morawski has mentioned the original TNT-Audio FleXy rack in his article (which somehow eluded me yesterday).

My bad! Please accept my apologies. (good thing that I’m not in Journalism!)

Regards

Manbir Nag

Thanks for the follow-up, Manbir. These oversights do happen...no harm, no foul.

And we are glad to see that you are a regular reader.

All the best,

david

David W. Robinson, Editor-in-Chief, Positive Feedback Online


David,
Is the Dartzeel in the same league as the Wavac 833?

Thanks,

Mark Senior

Hello Mark...
That's a fair question, though perhaps not a fair comparison. You'll have to remember that the darTZeel is an MSRP $14,000 amp, while the latest rev. of the WAVAC HE-833 is running around $59,000, last time I looked. They are radically different approaches to the challenge of providing 100 Watts per channel of amplification. As I noted, the darTZeel is a real category buster, and a very satisfying stereo amp.

Having said that, and given the choice, I would prefer the WAVAC HE-833 over the darTZeel. There's a remarkable coherence at all levels with the WAVAC... a more definite roundness... greater transparency...slashing quickness with transients...and incredible authority in the bass. (Think of it as "Godzilla meets Glass!") The sense of presence with the HE-833's is exceptional; a single directly-heated triode with this kind of power combined with all the nuance ot triode-based amplification, is simply the best thing that I've heard so far.

That's why I'll be reviewing the WAVAC HE-833 1.3's after CES 2005; these monoblocks use the same tube, but are rated at 150 Watts per channel.

Given my prior experiences with the WAVAC line, I expect that the results will be heavenly.

All the best,

david

David W. Robinson, Editor-in-Chief, Positive Feedback Online

David,
BTW, forgot, do you have any listening experience with the MD-805's? A more cost effective amp with perhaps some of the 833 magic?

Mark

I have heard the MD-805's briefly at CES a couple of years ago in the tmh audio room with my old audio friend Jim Ricketts, but it wasn't long enough to come to any final conclusions, Mark. Like all WAVACs of my acquaintance, the quality of the sound was superlative... a great deal of the magic of the 833's... but given my speakers I generally like more than the 55 Watts per channel that the 805 monos develop.

If you have reasonably efficient speakers, however, these strike me as a very worthy way to go. I do know that my audiobud Steve Hoffman has used WAVACs continuously over the past three years, and is currently a very enthusiastic user of the 805s. He loves them!

Hope this helps you; enjoy your audio journey!

All the best,

david

David W. Robinson, Editor-in-Chief, Positive Feedback Online

 


Dear Sir,
I don't want to take anything from the Life Time Achievement Award for Mr. Meitner, but what about the poor guy, at the time working as a wage-slave at the R&D of Royal Philips Eindhoven (the Netherlands) who invented the compact disc in the 60-ties in the first place??

Kees.

Hello Kees...
You make a point with potential validity about the "poor guy" (name?! or was this a group?), but I'd have to know a lot more about this person or persons.

The PFO Lifetime Achievement Awards are given by me for people whom I definitely know are worthy of such recognition. The case that you suggest is without details, which makes it impossible for me to do much with it.

As for me, I would be far more likely to award a Brutus to the folks who developed DSD and SACD as formats, which are true fine audio specifications. PCM done at the Red Book level is, in my opinion, inherently flawed...a step backwards from microphone feeds and master tapes...and so is not of as much interest to me as DSD/SACD (or LPs, or open reel tape, for that matter).

Your comment is appreciated, however; thanks for sending it along.

All the best,

david

David W. Robinson, Editor-in-Chief, Positive Feedback Online


David,
First thanks for the heads up at the asylum (http://www.audioasylum.com/forums/hirez/bbs.html) about the Verve Japan Supreme Sound SACDs. I just got three by FED EX. How the heck do they get them to California in just four working days—what service! Then there is the sound.

I was not prepared for how great they sound. I just couldn't believe how alive and musical they sound. They define the term PRAT (Pace, Rhythm And Tempo—Thanks, Art Dudley!). I have put up with how bad the CD of Mac the Knife sounded for years because I loved this album. So it was the first one I put on, and man, I couldn't stop listening until the end. I have a few questions though.

1. How did you know about these and how can you tell by looking at them that they are the Supreme Series?

2. I am assuming there is something special about how these are done by what you said in your other post at audioasylum.com, am I right?

3. Are there only 10, and do you know if there are more planned?

4. On the Getz/Gilberto why is it so different from the previously released Verve SACD? The earlier one sounds anemic, and is panned much harder left and right. What gives?

Thanks again. I know the rest of what I want for Christmas now: the other seven.

Jack Roberts

Hello Jack...
Glad that you found these SACDs to be as fine as I did. PRATfull and running over with audio ju-juiciness, for sure.

I think I told (warned!) readers that the HMV Japan delivery service, while a bit spendy, sets the bar for speed, packaging, and excellence (including very fine auto-email updates on order status).

Regarding your questions:

1. I ran across a reference to the series online... perhaps through Brian Moura's excellent reporting (see the link below), maybe via Stephen Best's sa-cd.com site. Verve doesn't use the Supreme Series designation on this JSACD packaging... in English, anyway. The gold-toned packaging and the designation (in English) as a "DSD remastering" project are the only cues I see.

2. Yes, these SACDs were all mastered directly from the original master tapes in NY to DSD without any intermediate bogosity, according to Verve. Brian outlines the project in the article below. They certainly sound quite clean via the EMM Labs playback system here at PFO River City.

3. There are only 10 of these titles in the series right now. I haven't heard that more are planned; it would require another trip to the tape archives in NYC, if they were to do more from the Verve vaults (please!).

4. This could be a matter of taste; Brian Moura says that he favored the earlier pressing. (I'm still comparing, so won't comment on my choice yet.) The earlier pressing was Verve/UMG Europe, as I recall...could be a different source playback, different mastering chain (dCS? Meitner? Some PCM in the earlier?), different engineer, different EQ, some combination of any/all of them—and if the soundstaging/imaging is different, could be a different tape (shudder).

Yes, I already treated myself for Christmas this year... I bought all ten.

My credit card company is pleased with me....

All the best,

david

David W. Robinson, Editor-in-Chief, Positive Feedback Online


David,
I want to thank you so much for all your work on the different SACD mods. I have heard the Meitner, but it cost more than I paid for my entire system (Audio Note ANE speakers, the ones that go for about $8000, the 777 SACD player with Kern mods, a WAVAC MD 300B that I purchased from a dealer closing his doors for $3500 and some audience au24 wire) which means the mods really interest me.

Well, just after you so graciously answered my letter about the mods Richard Kern had added to what I had done earlier (Superclock II, power supply for clock, power supply, Black Gates and new resistors) you reviewed a newer Kern 777es and the VSEI Sony DVP 9000ES. I was so surprised to see that Warren Gregoire (a really nice guy by the way), the west coast tech, lived less than 5 miles from me.

Well, based on your review I couldn't wait to call him, but he didn't have anything I could listen to right then. A few days later he called and he had a 777 that he had just finished. He had called the customer and asked if he could bring it over to my place for me to compare to my Kern modded 777.

We simply pulled mine off the Sistrum stand and plugged in the VSEI unit. We listened for about two hours, and the differences were pretty obvious. The bass was quicker and tighter, but not deeper. The unit was more transparent and clearer. Gone was the little bit of thickness in the mid-bass that my system had. So he left with my unit.

Well, I've had it back for a few days. He liked the Kern mods, so he left the Super Clock II, its power supply, and the new power supply mod for the unit that Kern had put in. The VSEI mod does bypass some of the Black Gate caps and new resistors that Kern put in. Warren dropped it off at the house and hooked it up to be sure everything worked. He said he thought I would be pleased because he thought the combination of the two mods sounded even better than the unit I had listened to (it should for an extra $1500).

Well I've had it back a few days and I think it's a winner. Now the 777 with the Kern mods I had was no slouch. In fact, if you had ask me for the weaknesses in my system the only thing I would have mentioned would have been that the bass could be a bit thick on some recordings, and even occasionally a tad boomey on a few recordings.

But with the VSEI mod added, the thickness in the bass is gone, but that's not all. My system is more transparent and clearer. I ever hear some details that I have never heard before. It is even more dynamic. The Kern mod wasn't fatiguing and after the VSEI mod it still isn't, and it doesn't bring in any negative effects on the Kern's excellent soundstage, and wonderful imaging. There is now something very, very special about voices. Well, as you said it deserves a rave.

By the way, I think mine with the Kern mods and the VSEI mods is better than the one that Warren brought over that just had the VSEI mods. It seems better on voices, and even more transparent. Thanks again. Look what I was missing, and it was only 10 minutes away.

Jack Roberts

Hello Jack...
I'm very glad to be of service to you, and to many other PFO readers over the years, on this truly intriguing topic. It's become increasingly clear that there's a very important world of fine audio performance to be attained by the creative exploration of audio modifications. This is no new revelation; audio artisans have been doing it for years! (Just think "Pooge"!)

But its virtues have become particularly obvious to those of us who have invested the time and money to modify our SACD players. The possibilities of DSD playback become much clearer when even relatively modest players are carefully hotrodded.

Your report is a good description of the characteristic improvements that I heard with Allen Wright's VSEI mods. I can well believe that the combination of the Kern mods with the Vacuum State mods would yield a very gratifying improvement in performance...you must be pleased.

Thanks again for taking the time to write up your impressions, and for reading Positive Feedback Online, Jack. Drop in any time.

And by the way, your system sounds like a very sweet combination...Wavac, Audio Note, VSEI/Kern Sony 777ES SACD player, Audience, Sistrum...very well done, indeed!

All the best,

david

David W. Robinson, Editor-in-Chief, Positive Feedback Online


Dear David,
First thanks for the heads up at the asylum (http://www.audioasylum.com/forums/hirez/bbs.html) about the Verve Japan Supreme Sound SACDs. I just got three by FED EX. How the heck do they get them to California in just four working days—what service! Then there is the sound.

I was not prepared for how great they sound. I just couldn't believe how alive and musical they sound. They define the term PRAT (Pace, Rhythm And Tempo—thanks, Art Dudley!). I have put up with how bad the CD of Mac the Knife sounded for years because I loved this album. So it was the first one I put on, and man, I couldn't stop listening until the end. I have a few questions though.

1. How did you know about these and how can you tell by looking at them that they are the Supreme Series?

2. I am assuming there is something special about how these are done by what you said in your other post at audioasylum.com, am I right?

3. Are there only 10, and do you know if there are more planned?

4. On the Getz/Gilberto why is it so different from the previously released Verve SACD? The earlier one sounds anemic, and is panned much harder left and right. What gives?

Thanks again. I know the rest of what I want for Christmas now: the other seven.

Jack Roberts

Hello Jack...

Glad that you found these SACDs to be as fine as I did. PRATfull and running over with audio ju-juiciness, for sure.

I think I told (warned!) readers that the HMV Japan delivery service, while a bit spendy, sets the bar for speed, packaging, and excellence (including very fine auto-email updates on order status).

Regarding your questions:

1. I ran across a reference to the series online... perhaps through Brian Moura's excellent reporting (see the link below), maybe via Stephen Best's sa-cd.com site. Verve doesn't use the Supreme Series designation on this JSACD packaging... in English, anyway. The gold-toned packaging and the designation (in English) as a "DSD remastering" project are the only cues I see.

2. Yes, these SACDs were all mastered directly from the original master tapes in NY to DSD without any intermediate bogosity, according to Verve. Brian outlines the project in the article below. They certainly sound quite clean via the EMM Labs playback system here at PFO River City.

3. There are only 10 of these titles in the series right now. I haven't heard that more are planned; it would require another trip to the tape archives in NYC, if they were to do more from the Verve vaults (please!).

4. This could be a matter of taste; Brian Moura says that he favored the earlier pressing. (I'm still comparing, so won't comment on my choice yet.) The earlier pressing was Verve/UMG Europe, as I recall...could be a different source playback, different mastering chain (dCS? Meitner? Some PCM in the earlier?), different engineer, different EQ, some combination of any/all of themand if the soundstaging/imaging is different, could be a different tape (shudder).

Yes, I already treated myself for Christmas this year...I bought all ten.

My credit card company is pleased with me....

All the best,

david

David W. Robinson, Editor-in-Chief, Positive Feedback Online


Dear David,
Because of some questions I've received, in order to eliminate a possible ambiguity, the RealityCheck™ CD duplicator burner doesn't have any analog or digital inputs for recording from external sources.

Sincerely,

George


Dear Clark,
I enjoyed your article about improving the state of CD playback by improving the physical bit structure of the discs themselves. I agree with you that this is a very important topic, and is of great potential benefit to all music lovers. It is something I have been interested in for quite a while, and I have found some very powerful tools that allow all audiophiles to make what are often dramatic improvements in our own CD collections.

Because of my own interest in obtaining the best-possible CD music reproduction, I have been experimenting with CD-R blanks and ripping / burning software for a number of years. Quite recently the Mobile Fidelity label has introduced a new type of CD-R blank called "Ultradisc" which is designed expressly to improve the quality of the "pits" created during the burning process (as well as being a truly archival disc). The point of this exercise is - as your article emphasizes - that a better-defined pit structure produces a cleaner eye pattern with reduced jitter for improved time-domain performance. Because of the analog nature of this part of the CD system, this should result in audibly improved performance.

In my experience, they have succeeded brilliantly. The CDs that I have mastered or copied with Ultradisc blanks sound to me very much like your description of the improvements wrought by the various companies mentioned in your article. In many cases, the degree of improvement is rather startling. If the companies you mention are able to produce even better results with conventional CD technology, then we are all in for a real treat!

In the meantime, Ultradisc CD-R blanks are available from www.mofi.com and www.amusicdirect.com. Using programs like Exact Audio Copy (available as freeware from www.exactaudiocopy.de) to properly rip your CDs, and Feurio (available as freeware from www.feurio.de) or Nero (www.nero.com/us/) to burn your Ultradiscs results in a CD that sounds very much like your description of the "RealityCheck" discs - and anyone with a computer can do it. True, you do have to have some computer savvy to do it properly, and it is possible that the type of burner used might affect the outcome, but my point is that this is not technically difficult.

In truth, I find it hard to understand why more audiophiles aren't doing this regularly - especially given our collective propensity for tweaking. One possible reason could be that those who tried this in the past (using other software and CD-R blanks) were disappointed with the result. If so, I would offer the following observations: 1) the type of blank used is fundamentally important, and it is only recently that truly good blanks for audio have become available, and 2) most of the burning software assumes that the user wants the finished product in their hands ASAP and so defaults to the highest-possible burn speed. Higher burn speeds give the laser less time to form the pit, and work against the goal of accurate pit formation. Using Ultradisc blanks with the above-mentioned software burned at 1X on a good burner (like a Plextor or Lite-On) usually results in a CD copy that is an obvious improvement over the original. I should note that the outcome is somewhat variable because the quality of the original CD pressing is extremely variable. Most are mediocre at best, so the level of improvement can be startling. Using a good CD to begin with (XRCD, for instance) still results in an improvement, but it's not so dramatic.

So, perhaps the companies you mention have developed a better system for creating CDs, and that is good news for all of us. But I would suggest that we all have the ability to create a similar result in our own homes, and I sincerely hope that more audiophiles will give this a try. I think they will be pleasantly surprised.

One final note: I have no affiliation with Mobile Fidelity or Ultradisc - I just think it is a remarkably good product that achieves exactly what the MoFi engineers had in mind.

Best regards,

Steve McCormack
www.SMcAudio.com


Dear Mr. (?Dr.) Kennedy,
I have 2 pairs of speakers very similar I assume to your "Rhodes." The exception is that they have the slightly smaller D131 12 inch drivers (? coaxial?) and the annular ring 075 tweeters. For many years I thought these were called "JBL Signatures." The earlier model I believe is called the C-32 cabinet and were my father's. They were bought in1959 according to my mother. The second pair I bought off ebay as D-36s. I believe these are about 5 years younger maybe 1964.

My question is where do I learn more about this series? The JBL historical section ignores them completely except for a hand written note by J. Lansing re the 130 driver. Any help would be appreciated.

BTW I bought Sherwood integrated amps ( I think he had the S5000-II eventually) to replace my father's which my mother kindly threw out while in good working order.

Sincerely,

Steven A. Mechanic

Hi Steven,
I would be delighted to share what little I know of these excellent vintage speaker systems. First off I need to mention that all of the information here came directly from http://www.audioheritage.org - which I think is the place to find anything on any of the Lansing companies.

Catalogs for the JBL line of speakers can be found here: http://www.lansingheritage.org/html/jbl/catalogs/jbl-catl.htm There is a lot of additional technical information on the JBL line on this site as well as board.. I would recommend joining to anyone seriously interested in Lansing. (Altec or JBL) I have tried to be as accurate as possible given my
limited knowledge, but please don't assume that this is even close to the whole story.

The last reference to the C32 I can find is in the 1955 catalog where it is described as a larger version of the C33 corner loaded horn, with smoother low frequency response. Recommended driver packages included the D130 woofer and the 001 or 050 options - all of which are based on variations of the D130 woofer. At 120lbs each these cabinets would have been massive, and I believe this is just the /cabinet/ weight as the buyer had several different driver package options to choose from.

The C37 Rhodes was made from the very early 1950's until the end of the line around 1967. Mostly new products were featured starting around 1968 - 69. The Rhodes and C35 Fairfield are identical except for the cabinet orientation and are reflex based designs. These systems were available with the 12" D123 and 075 ring radiator as well as quite a few variations with D130's - too numerous to mention here.

The 12" D123 is listed as an extended range driver and is substantially shallower than the D131 which is the top of the line 12" driver based on the 15" D130 extended range driver. As far as I know Signature referred specifically to the line of JBL drivers and not the actual completed speaker systems themselves.

Early JBL speaker systems represented the very cutting edge in speaker design for the time, and indeed today JBL drivers are still regarded as some of the best drivers out there. JBL pioneered very tight tolerance manufacturing, 4 inch edgewound ventilated aluminum former voice coils, the annular ring horn tweeter - which I think is about the best sounding horn tweeter I have ever heard, amongst other things. These old systems will give any modern high end speaker system a good run for the money, and are an ideal match for low powered SET amplifiers. Cabinets by today's standard are not /exactly/ attractive, but still work well. Also mine are completely original, including the cross-overs so I guess at 40+ yrs old we can say they are reliable as well.

There were so many variations available in the early 1960's that I cannot identify the specific model you have without seeing them, however there should be enough information available at Audioheritage to allow you to do so..

Regards, Kevin Kennedy


Dear Editor-in-Chief,
I want to clarify my offer to make RealityCheck™ CDs for $5. (Our readers should note that this product is discussed in Clark Johnsen's column elsewhere in this issue at http://www.positive-feedback.com/Issue16/RealityCheck.htm.) If equipment is subsequently purchased, then I credit the $5 against the purchase. Additionally, if an individual isn't satisfied with the RealityCheck™ CD then I'll refund their $5 and they keep the RrealityCheck™ CD. Therefore, they're only risking the postage to send me the original CD for reprocessing to a RealityCheck™ version.

Hear the Music Not Just Notes™ and Listen to Music Not Measurements™.

Another addition to Clark Johnsen's article is as follows: the RealityCheck™ CD Reprocessor-Duplicator is a stand-alone dual drive burner that can also be used for making compilations. It doesn't connect to computers or have an internal hard drive, but that's offered as an option.

Thank you for your interest and consideration. Congratulations, because your e-magazine article has sparked a lot of interest and controversy, so your magazine carries a lot of weight and obviously has a very large following.

Best regards,
George Louis, CEO
Digital Systems & Solutions
georgelouis@georgelouis.com


Hi Greg
Loved the P.F. (nostalgic) piece on "Opus One" and Tasso Spanos. Contact me if you like, and we can reminisce; I practically lived at Opus One during the decade of the seventies, and received my early audio education at Tasso's knee, so to speak.

To answer your musing on the subject, the microphones in the store were without a doubt Tasso's Sony C-37 tubed mics, his absolute favorites and now very rare. He later sold them to a friend of mine who owned a recording studio, but sadly, they no longer exist; they were destroyed in a fire.

Opus One was the finest audio "salon" I have ever known, and your recollection went straight to my heart.

All the best,

Larry Mehal,

Larry
How nice to hear from someone with similar memories of that era in general and that particular space in time specifically! Thanks for the info on the Sony mic's! We will publish that info as I feel it is relevant to the work. It is so rewarding to hear such wonderful feedback. This type of response is the major motivation keeping me coming back to the computer pounding out my opinions and observations…

Do you still find yourself frequenting audio stores and salons? If so, hasn't the experience changed dramatically? I so long for the purity of those days. While I have to admit that, for the most part, affordable products today have come LEAPS AND BOUNDS closer to providing high fidelity than they did in that era, especially in the past 3 to 4 years, the widespread passion and the professionalism of those days has long vanished…

Thank you so much for taking the time to write, and for reading my rantings at Positive Feedback Online! Have a great weekend. I know your letter has assured me that I will.

Greg Weaver, Associate Editor


Dear Sirs,
You have featured two reviews of the recent Berlioz Requiem recording on Telarc with the Atlanta Symphony Orchestra and Chorus. I find it astonishing that neither offers a comparison to the earlier recording on the same label with the same forces under their founder, Robert Shaw. That recording has often been cited as of demonstration quality. A comparison of musical and audio qualities would have been most welcome.

Mel Meer


David
Hi Mr. Robinson, my name is Gary and I have been reading your on-line magazine for about one year now.

The reason for my email is related to a series of reviews you have done on modified Sony CD/sacd players. I have read many reviews in a variety of audio publications including yours and am very confused about which players actually stand out. My question to you with that in mind is this: of the modified Sony units (Dan Wright, Allen Wright, and Kevin Kearns) seems best to you? And do you think it is better to buy a Sony have it modified or just to by a good quality stock player like an Ayer cx7 for example?

My system is comprised of a Quicksilver preamp with Quicksilver 90 mono blocks; and I am currently using a Jolida 100 CD player.

Thanks for your work and I hope you will have the time to respond to this inquiry.

Thanks Gary Schuch

Hello Gary... I can understand that you might be feeling confused; there's certainly a lot happening in the world of modified SACD players.

First off, I have to say that I am not familiar with either the work of Kevin Kearns or the Ayer CX7, so I cannot comment on those.

I can say that I've never heard a stock player (other than the EMM Labs line) that was as good as it was when intelligently modified by artisans like Allen Wright, Richard Kern, or Dan Wright. (I have not heard the work of Alex Peychev or Ric Schultz, so cannot comment on them the way I can with the three I've listed.) Purchasing a good stock player that can be modified, then having it modified, is a cost-effective alternative for those who simply cannot afford the EMM Labs solutions (which continue to be the best that I've ever heard).

Of the modified players that I've heard in the past year, the one that comes closest to the reference-level virtues of the EMM Labs system is Allen Wright's VSEI Level 4 mods with balanced output on the Sony DVP-9000ES. Note that this is a stereo-only solution, but you can have something like this for approximately $2500, which is a truly exceptional level of performance in my experience. The VSEI mods are available on several players; check with Allen's site (http://www.vacuumstate.com) for more information.

The best solution for six-channel surround sound continues to be either the Linn Unidisk 1.1 or 2.1, or (top o' the heap) the EMM Labs DAC6/DAC6e via the EMM Labs SWM-3 preamp. I hope that this clarifies things for you, Gary.

All the best,

david

David W. Robinson Editor-in-Chief, Positive Feedback Online


 

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