|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
66.51.146.158
In Reply to: Time for some quotes posted by Duke on March 10, 2007 at 12:22:59:
Blind tests?
You have none.
Sighted tests?
You have none.
Measurements of a specific sweet spot listening position in a variety of rooms?
You have none.Measurements of a specific sweet spot listening position in ONE room?
You have none.All you have is a variety of "experts" with contradicting subwoofer advice for surround sound audio in print (and no similarities seen in the homes of those who have invited me into their homes).
You cherry pick very general conclusions from experts who do not agree with each other, and then extrapolate them to ALL two-channel audio sweet spot listening positions in ALL rooms?
Don't make me laugh!
This is nothing more than desperate data mining to defend a strong belief about subwoofers ... or to elevate a subwoofer quantity/locations choice that works well in your room into a broad audio rule of thumb for all two-channel audiophiles!
= jumping to conclusions
= baloney
.
.
.
Richard BassNut Greene
Subjective Audiophile 2007
Follow Ups:
Richard,In my opinion it is much more productive to put our energy into discussing acoustics instead of arguing about arguments. But this is the direction you have chosen to take the discussion.
You insist on data that is not yet available. Controlled listening tests are expensive, and deliberately asymmetrical placement of multiple subwoofers is a new paradigm.
Yet when I do produce data and quotes from genuine experts in the field that clearly supports my position, and you accuse me of "desperate data mining".
Seems I can't win with you.
In some circles, my having produced expert data and references to support my position would actually mean something. You have not rebutted any of the expert testimony I've introduced - you've merely called it "BS". I assume if you had a better argument than that, you'd have made it.
You wrote:
"You cherry pick very general conclusions from experts who do not agree with each other, and then extrapolate them to ALL two-channel audio sweet spot listening positions in ALL rooms?
"Don't make me laugh!"
Mocking me isn't the same as making an argument. Show me some evidince or construct a good argument based on linking together acoustic principles to demonstrate that, as a general principle, scattered multiple subwoofers does not result in smoother in-room bass response as compared to conventional (symmetrial) placement of one or two subwoofers.
Maybe there is a room where a certain asymmetrical placement of multiple low frequency sources would result in less smooth bass than symmetrical placement of one or two low frequency sources. If it's possible, it will be because of acoustics. So give me a well thought-out acoustics-based argument on how and why that could happen.
If you undertake this exercise, I think you will find that scattered multiple subs are more likely to have exactly the results I have claimed.
Turning up the emotional volume with things like "don't make me laugh", "quotes can be BS too", and "baloney" will definintely score you points with some people. Some will read it and say, "Duuuuude, BassNut sure body-slammed the Dukester with that one!" And some will be reading for information rather than WWF-style entertainment, and will be interested in the evidence presented and arguments made on the subject of acoustics.
Duke
"This isn't an argument!"
"Yes it is."
"No, it isn't!!"
This is a two-channel audio forum.Subwoofer recommendation for home theater may not apply to a single two-channel audio sweet spot.
Subwoofer recommendations vary among experts and among manufacturers such as REL and HSU.
The Welti research makes assumptions that rarely apply to two-channel audio (equalization) and he admits in writing there is no way of knowing if his measurements correlate with subjective impressions of real audiophiles!
So the obvious answer to whether adding a third or fourth "scattered" subwoofer will benefit the sweet spot seat in a two-channel audio room is "I don't know".
That has been my answer all along.
From a transcript of: "Multiple Subwoofers for Home Theater" originally presented by Tom Nousaine at the 103rd Convention of the Audio Engineering Society, September 1997 (preprint 4558)
" ... in the subwoofer range, a single one (subwoofer) in the corner beats the pants off five-in-the-round ... So in summary, at least this experiment showed that one sub in the corner beats any combination placed elsewhere. ... If you have two or three subwoofers and you want the best performance, stack them all up in the same corner ... So the best thing you can do is to put your subwoofer in the corner and excite as many of the modes as you can as hard as you can!! What that does is give you the smoothest possible response in that room, although it may not be perfect."
So which expert is right?
You seem to know.
I don't.
.
.
.
.
Hi Richard,Thank you very much for the Tom Nousaine reference.
I printed out a copy of AES Preprint number 4558 and could not find that quote you gave anywhere in the paper.
However, Nousaine does clearly state that one subwoofer in a corner measured smoother than five placed where his left, right, center, and two surround speaker normally go in his home theater system.
Nousaine is showing in-room measurements of plus or minus 3 dB from corner placement of a subwoofer. Richard, that simply does not sound right to me! Does that sound right to you? Is it really that simple - just put the subwoofer in the corner??
I once tried designing a speaker specifically for corner placement, and I am absolutely convinced that any speaker measuring plus or minus 3 dB from 100 Hz on down when placed in a corner had to be designed (or equalized) specifically for corner placement. Imagine moving a Klipschorn out into the room like a normal speaker. What would happen to the bass response?
The only way I can see Nousaine's subwoofers measuring so smooth in a corner is if they were designed specifically for corner placement. If that is the case, then no wonder they measured poorly when placed elsewhere (weak lower bass, as would be expected).
Also, you earlier made a strong case for scattering subs in the vertical plane (if multiple subs are used) to smooth out the floor-to-ceiling mode. Did you notice that the shape of the frequency response curve did not change when Nousaine stacked five subs in a corner? Only the amplitude changed. That is very, very strange - the implication would be that changing the height of a low frequency source has absolutely no effect on the floor-to-ceiling mode. With apologies to the bald-headed bad guy in The Princess Bride - inconceivable!
I did a search to see how widely Nousaine's paper is being cited as a source. Since its publication in 1997, one paper mistakenly attributes a statement on "envelopment" to Nousaine's paper, and another cites him as a "supplemental source". No papers are citing Nousaine's amazing "discovery" that corner placement results in the smoothest possible in-room response. Zero. If Nousaine was considered a credible source on the subject of subwoofer placement by the academic community, you'd think someone would have used his monumental findings in the ten years since his paper was published.
In contrast, Welti's "How Many Subwoofers Are Enough" has been cited in 17 papers since it was published in 2002.
So... my expert's friends can beat up your expert's friends!
The Nousaine quotes were all taken from an 11-page Nousaine article in the February 1988 issue of the Prairie State Audio Construction Society newsletter SOUND BYTES. The article was said to be a transcript of Nousaine's presentation to the audio club a few weeks after his AES presentation on the same subject.I can't find my 4558 preprint to quote from it.
If I wanted the loudest bass possible in my room, then one or more subwoofers in a corner with parametric EQ to eliminate all bass peaks at my sweet spot would be the answer. But my main speakers are 8 feet from the front wall and five feet from the side wall, so using a one corner subwoofer makes it sound like a bass player is standing alone in the front corner of my room!
Subs "stacked" in a corner may really be side by side in a corner rather than all stacked vertically to the ceiling.
All the measurements we have don't mean much if they are not confirmed by real audiophiles experimenting with subwoofer locations/quantities in their own rooms.
The ONLY conclusions I have from 25 years of experimenting iare:
(1) parametric equalizers are great "band aids" for subwoofers,
(2) a dozen bass traps are good if the wife will allow them (two don't make much difference), and
(3) side and rear subwoofers are much less likely to be sonically invisible than front subwoofers located near or between the two front speakers of a two-channel audio system.I can't even say for certain that adding a second subwoofer will benefit the two-channel sweet spot seat in a particular listening room, much less a third or fourth!
I'm sure "experts" who claimed the world was flat were cited many times ... before people found out they were completely wrong!
My current tube subwoofer places a 15" driver behind my left speaker, four feet off the floor, firing up at a slanted ceiling that is about nine feet tall above the driver. This location requires three bands of parametric EQ. If I reverse the subwoofer 180 degrees so it is downfiring at my cement slab floor, the frequency response becomes so bad that after an hour of trying to equalize it, I just gave up.
This worst sub driver position I'd found since 1987 ... was a mere 4 feet away from the best sub driver position I had found.
Who could have predicted that?Okay it's long past time for us to reverse positions and start a new argument. My new theory is that if your home has a street address that is an even number, then you should use an even number of subwoofers. I could cite many studies for this hypothesis ...
if there were any.
Well Richard, my horse has long since been beat to death, and yours ain't lookin' too healthy neither.Seriously, I learned a lot from this. Thank you.
Except Welti who took his toys and went home mad.
,
,
,
Richard BassNut Greene
Subjective Audiophile 2007
This post is made possible by the generous support of people like you and our sponsors: