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I write again to explore further some new "findings" from my previous posting. I have been exploring bass response of my two speakers--Quad ESL-63s and B&W Matrix 801 Series IIs using the two power amps from my previous postings, each 100w/ch, one solid state the other tubed. I am not a scientist and these measurements were made just by ear.
Today, I started testing the depth of bass response using Stereophile's Test CD (STPH-002-2) using tracks 25-31 which were all warble tones at -20dB.
The relevant tracks were:
25 @ 80Hz
26 @ 63Hz
27 @ 50Hz
28 @ 40Hz
29 @ 31.5Hz
30 @ 25Hz
31 @ 20Hz
I would expect the B&W Matrix 801 Series II to exhibit much deeper bass, but that turned out not to be the case. Nor was the depth of bass I got different from one power amp to the other.
I played the warble tones through each amp into each speaker, switching between them until I could no longer hear the tone, recording the lowest tone I could hear before there was a sharp drop off in audibility.
Here's what I got:
SS amp Quad: 40Hz
SS amp B&W: 63-50Hz
Tube amp Quad: 40Hz
Tube amp B&W: 63-50Hz
One respondent mentioned damping factor of the amp.
The damping factor of the tube amp was listed as 11.
That for the solid state amp was 300 to 1kHz into 8 ohms; 60 to 10kHz into 8 ohms.
I wonder what comments you might care to make with regard to the findings.
I am wondering why the B&W bass response was the way it was when I expected it to go lower than the notoriously bass-hobbled ESL?
Were both amps just too underpowered to show the B&W's real bass abilities? Or, another way, if I used a much more powerful amp, say a 200-300w/Ch solid state amp with a very high damping factor and much more current capability, might I expect the B&Ws to best the ESLs in depth of reproduced bass frequencies?
George
Follow Ups:
Ah, measurements....they say so much and yet they mean so little! Unless you are a connoisseur of warble tones of course;)
dave_b
Pretty sure that's room-related. Electrostatics and dynamic drivers have very different room interactions, the latter generally affected much more by boundary reflections and room modes. Try moving the B&Ws around a bit - even a few inches can make a big difference. If there's a bad room mode, you might not be able to get rid of it.
The amp power (lack of) is probably contributing, but I'd guess the room interactions are more important.
Cheers,
Dunc
Is intimately tied to the quality of its output transformers. If a tube amp is using big enough iron then it won't saturate and then it won't create a lot of distortion. Most of the bloated sound of some tube amps is due to this transformer saturation and NOT the damping factor.
An article some years in Audioholics showed that a damping factor of 5 or greater is sufficient for basically any loudspeaker...except for a ridiculously poor design with a Q of 1.5 or greater.
OTLs don't have transformers so they don't have the saturation problem. However, if they are a totem pole design then they have problems with complex impedances and the tubes become unbalanced causing a lot of distortion. The circlotrons fare much better and give a nice tight bass normally even with a not very high damping factor.
What an extremely high damping factor can do is take a speaker that is already optimally damped and make it sound overdamped and a bit dead.
-in terms of simple tones you are not going to hear a lot.
The ear hears spectrums of sound much better than it does individual tones.
Did you read that article at the link I posted? It is at the bottom of this post as well. You can design a speaker to take advantage of the higher output impedance of a tube amp. For example you can move the port frequency of a bass reflex such that you can extend the bottom octave by as much as 1/2 and octave if you know what you are doing.
The Voltage paradigm and the Power paradigms have different ways of going about things. The Voltage Paradigm favors flat frequency response over distortion; the Power paradigm favors low distortion over flat frequency response (because it assumes that the ear/brain system converts distortion to tonality).
First can you tell us what analyzer and mic you are using to see the results? Also did you calibrate by starting at 1K at 80db as a reference.
Meaning get your first reading of 1K at 80db then don't change the volume for the rest of the tones....
Those B&W should have no problem going under 30 at maybe -3db at most...
My experience with Tubes vs SS. I have a PASS X250.5 and Manley Snappers.
there is a big difference in power 250 vs 100 watts.
I love both amps, the Manley has a sweeter sound, but the PASS is faster sounding. My guess its the Damping factor.
I'm happy with both as they are quality products, but like the power of the PASS.
As I said in my original posting, I did this by ear. I used no test equipment.
Thank you for your response.
I would expect a little speaker repositioning (or, easier, microphone repositioning) would yield different results......
It is POSSIBLE that the B&W, depending on model, has a very low impedance coupled with a high phase angle at some of your test frequencies. The result would be VERY much less delivered power.
OOOPS! My bad. STereophile, who is good for this kind of measure tells me quite otherwise.
Look elsewhere, perhaps room or setup for bass issues!
Too much is never enough
Sensitivity aside, it may be an easy load for an SS amp, but not for a low powered SET amp. It is generally too low and while it doesn't have any large negative phase angles, it is still "bumpy". A sensitivity of 87dB dB, or as low as 83dB, is not a difficult load for a 8-9W SET if the curve is non-reactive (flatter), and always above 8-10 ohms in the audible range. There are conventional 2-way speakers like this.
But such a speaker may have a true bottom end in the 50-60HZ range, unless it is a horn.
Observe, before you think. Think before you open your yap. Act on the basis of experience.
I've been playing Double Bass since 1958 and a brand new 1962 Fender Jazz Bass. Obviously, I haven't listened to every "full range" design out there but I have heard many of the established brands. I have yet to hear a single cabinet passive design that reproduces realistic extra low bass in real world conditions.
In 1984 I purchased a Velodyne ULD-18 and I haven't considered a speakers bass response ever since. Not only does a speaker need to have the bass response but it needs to load the room which usually requires more energy from a given frequency on down to sound realistic.
Keep the tube amp. A modern quality subwoofer offers ultra control and will last through many speaker upgrades, then queue up some Prince an forget about it.
An interesting response and perspective. I have been considering a subwoofer for use with my Quads. I'd probably go for an REL sub for use with my ARC tube amp though the Velodyne DD series with calibration software is attractive!
That Velodyne ULD and the subsequent DD18 were heavy monsters yet there's a lot to be said for 18 inch drivers. I'm now into the fourth generation Velodyne using two DD12 plus. In hind sight two DD10 plus would have been preferable. Two subs require much less EQ and the timing and presentation seem tighter.
A few years back and with the help of a few friends we did a half assed comparison between a JL Audio F113, REL Studio III (made in the UK), and the Velodyne DD18. The owner of the Studio was so amazed by the other two he sold it soon after.
In the end the comparison showed us the benefit of two subs and the necessity of calibration for the room and the integration with the main speaker system. Using the proprietary high level connection between the amplifiers and the main speakers the Studio interfered with the mains performance slightly. Its cabling limited room placement. Feeding it a low level EQd signal from the DD18 and better room positioning helped a great deal but it still fell short of the other two. Keep in mind the Studio was a much older model and I'm not trying to steer you away or to any particular brand sub. There is now a great selection of smartly designed yet affordable subs on the market and it doesn't take much to augment a hifi in a normal sized room.
We all agreed that two subs are better for the room and the better a sub is integrated with the main system and the room the less noticeable it is, if at all, and consequently more musically enjoyable. So weather you use a sub with built in EQ or something like a DSpeaker controller the key is dialing the sub/s into the main system.
I appreciate the additional information.
To be honest, I had originally considered the Velodyne DD+ range because of the calibration system, which is very appealing, and because of the reviews in Stereophile by Larry Greenfied where he showed graphs of the subs performance with Quad ESL 989s.
I was steered towards REL by a recommendation from Audio Research who like REL's hook up to the power amp's inputs.
I have only one main out on my preamp. Does it get connected to the Velodyne and, from there speaker cables go to the main pair?
George
Below is a PDF of the User Manual. I think on page eight shows the connectivity options which are very extensive including High Level speaker connections. There is another manual devoted to calibration.
Unfortunately, the price on these is fairly high. There are more affordable alternatives with similar connectivity out there. I believe JL Audio has an economical line thats had terrific reviews. I think SVS has added equalization to some of their products.
http://velodyne.com/pdf/digitaldriveplus/63-161_DD+%20Users%20Manual_web_Rev%20A.pdf
Have fun.
Without it, the 801s bass drops off pretty quickly below about 50 Hz.
Certainly shows in the Stereophile measurements
No, I'm not using the filter. I have one on the way to test soon.
Intuitive investigating George-
I must say that the best B&W auditions that I have experienced over the years were w/ Classe' power amps (big ones).
2-300 watts for the 801 for sure .....
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