I just spent the last couple of days dialing in my Velodyne DD-15 sub with auto EQ with the rest of my system. My room is a dedicated Home Theater with a Paradigm 7.1 setup. I did treat the room walls up to ear level with Linacoustic on the side and back walls and the entire front (screen) wall). After the EQing the DD-15 I have noticed a definite improvement in the sound--especially the bass. Simple things like a car door slamming, etc that would have went un-noticed before, now have sharp and crisp sounding bass. Here is my room's response as graphed by the DD-15.

http://farm1.static.flickr.com/124/369223724_80ba6d7145_d.jpg


I had always planned on adding bass traps. However, this looks relatively flat. Does anyone think that adding bass traps to my room would result in better results that would be noticeable?? Is it possible that the design of my room doesn't call for bass traps?? Thanks - Andrew

Andrew,

> Is it possible that the design of my room doesn't call for bass traps?? <

No. :D

Seriously, all rooms benefit from bass trapping. Generally, the more trapping the better. Understand that raw low frequency response is only half the story. Just as important is reducing modal ringing (excessing decay times) which is hidden in simple response graphs like the one you show.

--Ethan

Ethan is spot on.. The ringing in the room is going to give a "one note" bass sound. With bass traps you will get a clearity on the bass that sounds punchy and well defined.

Glenn

And you won't know what is being added by the room in terms of ringing and boominess until you have the bass traps to get rid of it.


Also, your graph could still use a little smoothing. Plus, the deep extension doesn't seem to be getting very much boost. Do you have the sub in or near a corner? I would expect a DD-15 to have a lot of slam down low...

Thanks for the responses.

I have a false screen wall (GOM in front of the speakers) about 6 feet from the true back wall. The sub is in the front corner of the theater, but one of the walls is a false wall...so it is really about 6 feet up on the side wall. I did try and place the DD-15 in the true front corner (behind the screen wall) but it shook the screen too much :)

What would deeper exetnsion down low look like on my response? Higher dbs?

Since I do have a false wall with about 3 feet on space in the middle and 6 feet on the sides, I definitely can easily place bass traps behind the screen wall. However, corner bass traps would be only a few feet from my L and R speakers. Is this enough room?
L&R Speakers are Paradigm Studio 100's V3 and they do port out the the back.

Is it worth placing bass traps directly behind the screen itself (it is not perforated) on the floor? I didn't know if the screen would hinder the performance of the bass traps. I was thinking on the floor behind the screen if it was going to help.

edit...here's a picture of the theater layout:

http://farm1.static.flickr.com/42/85249649_a0e3d0d0f1_d.jpg

>Since I do have a false wall with about 3 feet on space in the middle and 6 feet on the sides, I definitely can easily place bass traps behind the screen wall. However, corner bass traps would be only a few feet from my L and R speakers. Is this enough room?<

That should be fine. Just make sure the trap is not touching it.

>Is it worth placing bass traps directly behind the screen itself (it is not perforated) on the floor? I didn't know if the screen would hinder the performance of the bass traps. I was thinking on the floor behind the screen if it was going to help.<

You can put some there, but it is always better to put bass traps in the corners.

Glenn

Glen,

What about the extra two corners that are located where the room extends out behind the screen (fireplace above). Would these be considered true corners as well?

I just spent the last couple of days dialing in my Velodyne DD-15 sub with auto EQ with the rest of my system. My room is a dedicated Home Theater with a Paradigm 7.1 setup. I did treat the room walls up to ear level with Linacoustic on the side and back walls and the entire front (screen) wall). After the EQing the DD-15 I have noticed a definite improvement in the sound--especially the bass. Simple things like a car door slamming, etc that would have went un-noticed before, now have sharp and crisp sounding bass. Here is my room's response as graphed by the DD-15.

http://farm1.static.flickr.com/124/369223724_80ba6d7145_d.jpg


I had always planned on adding bass traps. However, this looks relatively flat. Does anyone think that adding bass traps to my room would result in better results that would be noticeable?? Is it possible that the design of my room doesn't call for bass traps?? Thanks - Andrew

the auto-EQ of the SMS-1 is not sufficient to get a flat FR, all it does is adjust gain of the original filters. you should be using the manual EQ and properly set FR, gain , and Q.

Glen,

What about the extra two corners that are located where the room extends out behind the screen (fireplace above). Would these be considered true corners as well?

On my first post I did not notice the fireplace behind the screen. :o Yes that would be a great place for bass trapping also. In fact I would stuff the hole fireplace with fluffy fiberglass.

Glenn

Plincoln,
Thanks for the reply. Do you know anywhere online that outlines how to use the manual EQ to adjust those parameters. The user's manual doesn't go into too much detail in those areas.

Glenn,
I have several left over bags of Roxul Safe N' Sound (mineral wool) from building the theater. Would I be ok stacking them in their plastic bags in the fireplace cutout?? Or would I need to open them up? Should I leave any space on the sides or back of the mineral wool?

For the corners, would one of your standard traps placed at an angle be as effective as the corner model? Since it will be behind a false wall, the looks of a angled trap won't matter. Or do the corner models perform that much better?

Plincoln,
Thanks for the reply. Do you know anywhere online that outlines how to use the manual EQ to adjust those parameters. The user's manual doesn't go into too much detail in those areas.


http://pdf.outlawaudio.com/outlaw/docs/sms1guide.pdf

That's a great guide to read through...starting on page 16 is what you are after, but I would go ahead and just start at the beginning...some of it will be old news for you, but it can't hurt.

I had always planned on adding bass traps. However, this looks relatively flat. Does anyone think that adding bass traps to my room would result in better results that would be noticeable?? Is it possible that the design of my room doesn't call for bass traps?? Thanks - Andrew
Bass traps are not very effective in the subwoofer range. EQ is your best bet at these very low frequencies. The bass trap sellers will of course tell you otherwise. :) After EQ to balance the levels, ringing (even 2 seconds duration) is not perceptible below 100 Hz. See Karjalainen et al., "Perception of temporal decay of low-frequency room modes," AES 116th Convention, 2004.

- Terry

Bass traps are not very effective in the subwoofer range. EQ is your best bet at these very low frequencies. The bass trap sellers will of course tell you otherwise. :) After EQ to balance the levels, ringing (even 2 seconds duration) is not perceptible below 100 Hz. See Karjalainen et al., "Perception of temporal decay of low-frequency room modes," AES 116th Convention, 2004.

- Terry

Interesting.... Do you think something like the GIK 244 sound panel is worth it for frequencies above 100hz? Or is the equalizer the best thing here too?

Interesting.... Do you think something like the GIK 244 sound panel is worth it for frequencies above 100hz? Or is the equalizer the best thing here too?
Conventional porous bass traps, of the type sold by Glenn and Ethan, can be quite effective above 100 Hz when their area is a good fraction of the room surface. At subwoofer frequencies (below 80 Hz), do not expect much. The laws of physics are against you.

Equalization above 100 Hz is not very effective in dealing with individual room modes. There are simply too many of them, and our modal decay time discrimination is more sensitive at these higher frequencies. Acoustic treatment is the way to go for these frequencies.

- Terry

Terry,

> The bass trap sellers will of course tell you otherwise. :) <

Not me, and I've stated many times that I use the one-band cut-only EQ on my big SVS subwoofer to tame the most prominent length mode in my room around 40 Hz. And I know you agree that EQ is not useful for bass nulls, and those are at least as big a problem as bass peaks and modal ringing.

But to say that porous traps are not effective below 100 Hz isn't accurate either. The demo video on my company's site show eight bass traps making a real improvement all the way down to the 40 Hz lower limit we tested. You are correct that most of the improvement is in the mid bass range and up, but there can still be a big improvement down to fairly low frequencies.

Just to be clear on what's possible with "porous" bass traps, the ETF waterfall plot below shows the response and ringing in my living room using only that type of trap. Okay, I have a lot of traps. But there's still less total surface coverage than in many pro-designed rooms. And you can see the response is very uniform, with little ringing, at all but the very lowest frequencies.

--Ethan

http://www.realtraps.com/ethan-ht.gif

But to say that porous traps are not effective below 100 Hz isn't accurate either.
I did not say that. I said, "Bass traps are not very effective in the subwoofer range," and "At subwoofer frequencies (below 80 Hz), do not expect much."

As for ringing below 100 Hz, even if bass traps could substantially effect it, this is not a perception issue to begin with (see above cited paper).

You don't really want to bring up the subject of bass trap subwoofer frequency effectiveness, do you? :D In the tests we did together, just bass traps (even filling the room to the rafters with them) failed miserably in flattening the uneven subwoofer frequency response. This was the conclusion of the simplest possible objective flatness test -- a standard deviation calculation. This analysis is freely available to anyone on the Realtraps web site.

- Terry

I have several left over bags of Roxul Safe N' Sound (mineral wool) from building the theater. Would I be ok stacking them in their plastic bags in the fireplace cutout?? Or would I need to open them up? Should I leave any space on the sides or back of the mineral wool?

I'd put as many of those leftover bags as you could behind your false wall. If need be get more bags. Fill it, the more the better. You can leave them wrapped in plastic, bass doesn't care about a thin layer of plastic - it will go right through.

Terry,

> I did not say that. I said, "Bass traps are not very effective in the subwoofer range," and "At subwoofer frequencies (below 80 Hz), do not expect much." <

Which is exactly why I posted the response and ringing for my living room. You can clearly see that all the way down to ~45 Hz the response and ringing are quite exceptional.

> As for ringing below 100 Hz, even if bass traps could substantially effect it, this is not a perception issue to begin with (see above cited paper). <

I disagree with that research based on my own experience. Let me guess, the tests were not done in a domestic size room, yes? Just like the "research" that says it's okay for a room to have a long reverb time at low frequencies. :D

Of course I'm not dissing research, but a lot of research in the past did not consider that small rooms behave very differently from large rooms. Also, just because something appeared in the AES Journal does not make it so.

> You don't really want to bring up the subject of bass trap subwoofer frequency effectiveness, do you? :D <

Sure I do! :eek:

> In the tests we did together, just bass traps (even filling the room to the rafters with them) failed miserably in flattening the uneven subwoofer frequency response. <

Or put another way, In the tests we did together, just EQ (even using all 12 bands) failed miserably in flattening the uneven subwoofer frequency response.

So now where does that leave us? :D

Seriously, as we both know, it's impossible to make any room perfectly flat with no excess ringing. It's not even possible to get close to flat. So we do the best we can, using all of the tools at our disposal, and hopefully eventually can ignore all the tech nonsense and start enjoying the music.

I'll still take my room with 40 traps over any other room in a house I've ever heard. <g, d, r>

--Ethan

Terry,

> I did not say that. I said, "Bass traps are not very effective in the subwoofer range," and "At subwoofer frequencies (below 80 Hz), do not expect much." <

Which is exactly why I posted the response and ringing for my living room. You can clearly see that all the way down to ~45 Hz the response and ringing are quite exceptional.

Actually, the frequency response of this room is not very good at all. More than 12 dB range from 20-200 Hz? I wouldn't be showing that graph around very much if I were you.


> As for ringing below 100 Hz, even if bass traps could substantially effect it, this is not a perception issue to begin with (see above cited paper). <

I disagree with that research based on my own experience. Let me guess, the tests were not done in a domestic size room, yes?

Wrong as usual, Ethan. :D

Your lip service to the scientific method, and yet your disdain for the science of acoustics and ignorance of the acoustic literature would be entertaining if it wasn't so sad. :(

- Terry

Terry,

There's no need for that sort of tone. I don't insult you, and I see no reason for you to insult me. :mad:

> Actually, the frequency response of this room is not very good at all. More than 12 dB range from 20-200 Hz? I wouldn't be showing that graph around very much if I were you. <

That's preposterous and I'm sure you know it. Some months ago you and another regular here tried to dismiss my claim that with bass trapping you can never have too much. At that time I asked you both at least three or four times to show me some hi-res waterfall graphs for rooms you've done. You never did. So I'll ask you now, yet again, to please show me results of rooms you've been hired to improve.

--Ethan

Terry,

There's no need for that sort of tone. I don't insult you, and I see no reason for you to insult me. :mad:

Sorry, but that was not an insult. It was a sad statement of fact. :( As far as I can tell, you are not at all versed in the professional literature, even that on bass absorption. I once tried to explain the key results of Mechel's important 1988 paper to you, but was unsuccessful.


> Actually, the frequency response of this room is not very good at all. More than 12 dB range from 20-200 Hz? I wouldn't be showing that graph around very much if I were you. <

That's preposterous and I'm sure you know it.


If you knew how to read a waterfall graph, you would see this uneven frequency response quite clearly. :(

- Terry

Quit it guys...

Get back OT!

Actually, the frequency response of this room is not very good at all. More than 12 dB range from 20-200 Hz? I wouldn't be showing that graph around very much if I were you.

- Terry

To me that doesn't look bad at all. I wish my living room measured that well.

I have a few questions:
Ethan, why do you think you have that broad peak around 160hz. Without that you'd be +- 10db (which I think is pretty darn good).

Ethan, what happens above 200hz? Is that the bottom of your hole? My room has a frustrating dip in the same general area. I probably need more bass traps, more positional tweaks, more time, more money, more sex, more something.

Terry,
Specifically what don't you like about Ethan's waterfall. There is some weird stuff going on below 80hz, but I don't think it is too bad. In fact, I don't think I've seen anything better (except in a specially built room with TACT room correction on all channels). What do you think is wrong with his setup. What would you do to make it better (using lower resolution measurements doesn't count)?

Terry, I assume you provide your customers with before and after treatment plots. Do the after treatment plots typically look better than Ethan's? If so I better start saving up, I'd like you to come over and visit ;-)

Terry, I assume you provide your customers with before and after treatment plots. Do the after treatment plots typically look better than Ethan's? If so I better start saving up, I'd like you to come over and visit ;-)
OK, start saving now. :)

Here's a waterfall plot (same 200 ms window size, ~30 dB amplitude range, and 20-200 Hz frequency range as Ethan's) of a typical theater we did:

http://www.tmlaboratories.com/treated.jpg

Notice the flatness of the frequency response (the uniformity of the horizontal "mountain peaks" at t=0). We would have hammered down that resonance at around 20 Hz via EQ, but it gave the room a little extra visceral "oomph"!

- Terry

Terry, looks nice !

Looks better - largely because of the scale used. It's down to about 6db (which is very good) if you ignore the 20Hz - but...

while I agree that EQ can help with ringing:
-IF you get the center exactly correct
-IF you get the Q exactly correct
-IF you're only worried about one seat

Taking the same measurements in a different seat in that room without changing the EQ would have the ringing right back again - as happened during your and Ethan's experiment and the center frequency wasn't spot on. The FR would also vary I strongly suspect.

As to whether or not subwoofer range ringing is detrimental, I don't know that a single paper that you cited is enough to get me to ignore 2 second decay times fom 80Hz down.

I'll agree that for frequency abberations that are consistent across seats and peaks in nature, EQ is the way to go - after you've done what you can with treatment.

Bryan

.Ethan, why do you think you have that broad peak around 160hz. Without that you'd be +- 10db (which I think is pretty darn good).

Actually, the span is 10 dB - each division is 3 dB.

The response at any given location in the room is the sum of the direct sound from the loudspeakers plus many competing reflections from the floor, ceiling, and all the walls. If you move the microphone even one inch the response changes dramatically. Even at very low frequencies, and especially if there are no bass traps.

In a room the size of my living room - 25 by 16 by 11 feet high at the center peak - this is as good as it gets. Well, okay, I could put in another 40 traps and make it even better. :D But as it is now this room sounds fabulous. Better than a lot of very expensive professional studio control rooms the same size.

> what happens above 200hz? Is that the bottom of your hole? My room has a frustrating dip in the same general area. I probably need more bass traps, more positional tweaks, more time, more money, more sex, more something. <

Again, what "happens" above 200 Hz depends on where I measure. Most of the bass problems in most rooms are at the lowest three or four octaves.

> Specifically what don't you like about Ethan's waterfall. <

It's not my waterfall plots, it's me personally. Though I have no idea why he takes that attitude! Especially the personal insults. You should ask Terry the size of the room in his graph, where the measuring microphone was placed, if he used any EQ, and how many bands of EQ. :eek:

--Ethan

Hi Bryan,

Found another measurement where we had leveled off that LF peak:

http://www.tmlaboratories.com/treated-3.jpg

I have scale this more tightly to the 30 dB range to be directly comparable to Ethan's graph.

Actually, there was no EQ above 80 Hz. It was just used for the subwoofers. And because of the long wavelengths of the subwoofer EQ, it was quite robust with respect to listening position.

Above 80 Hz, you are seeing the result of a whole lot of acoustic treatment!

- Terry

Bryan,

> Looks better - largely because of the scale used. <

Yes that, and there's no time span or anything else on the graph. :D

> while I agree that EQ can help with ringing:
> -IF you get the center exactly correct
> -IF you get the Q exactly correct
> -IF you're only worried about one seat

I'm working now on a brief article that will put this to bed for once and for all. Empirical evidence trumps theory every time, and I now have bullet-proof empirical evidence.

> As to whether or not subwoofer range ringing is detrimental, I don't know that a single paper that you cited is enough to get me to ignore 2 second decay times fom 80Hz down. <

Of course I agree. There's research and then there's research. I've seen a few howlers in the AES journal over the years. Even if the research Terry cited is valid for one room, how well does it apply to my room and to your room?

One huge thing missing from a lot of the "expert" opinions I see are they rely too much on reading stuff someone else wrote, and not enough on first hand practical experience. I've been playing with pro studio gear for 40 years now. I know exactly what 1 second of reverb added to a bass track sounds like, and it's not a pretty story. I also know what a 12 dB boost with a Q of 0.9 sounds like. And so forth. I have all of these tools available in front of me as I write this. So I can test almost anything in 10 seconds on my very accurate home studio system.

--Ethan

Terry,

> Above 80 Hz, you are seeing the result of a whole lot of acoustic treatment! <

Obviously! I'm glad to have had such a large influence on you! :eek:

So please tell us more about this room. How big, how much treatment, where the treatment is placed, how thick it is, and so forth.

--Ethan

Terry,

> Above 80 Hz, you are seeing the result of a whole lot of acoustic treatment! <

Obviously! I'm glad to have had such a large influence on you! :eek:

???
Most of what I do is design of acoustical treatments. It always has been. I use EQ when I have too -- at frequencies where bass absorbers are not effective.


So please tell us more about this room. How big, how much treatment, where the treatment is placed, how thick it is, and so forth.

--Ethan
The room is 2300 cubic feet. And no, I will not tell you where and what type of treatment was used. This is my intellectual property, and I do not give it away. It is what I do for a living, the results of working in the acoustics profession for a few decades! :eek:

- Terry

.

Actually, the span is 10 dB - each division is 3 dB.

--Ethan

My mistake. I should have said +- 5db.

You have to admit Terry's measurements look better.
I have to wonder how he got those measurements. I also wonder how
the room actually sounds. I've heard a room with mix of Helmholtz
absorbers tuned to the room, and 6-12" broadband absorbers almost
everywhere else. It sounded good. But too dead for my tastes.

I think in the end there is no perfect room, and what sounds
best to the user depends on what they like (i guess that could be called
personal phyco acoustics)

As to whether or not subwoofer range ringing is detrimental, I don't know that a single paper that you cited is enough to get me to ignore 2 second decay times fom 80Hz down.

I should explain more carefully the experiments done in this paper. The authors distinguished between two types of modal EQ. There is the precise parametric inverse filter method, where you have to match and cancel the center frequency, Q, and gain. There is also a non-parametric, less critical method where all you do is equalize the magnitude response to reduce the mode amplitude without trying to match its exact characteristics. You are not going to clean up the modal decay with such a cruder method, because you are not matching and precisely cancelling the resonance.

In the experiments, a synthetic room mode was added, and the the second type of EQ was done on it. At most frequencies, subjects could readily discriminate the EQed synthetic room mode vs. no added mode when the modal decay time was only 0.2 to 0.3 seconds. Sound reasonable? There was no amplitude peak at the modal frequency because it was EQed down, but the pesky decay tail remained. Although softer, this could still be heard.

But several modal frequencies were used, and an interesting thing happened at very low frequencies. To quote the authors:

"Below 100 Hz the value [discrimination threshold] exploded so that at 50 Hz in these listening conditions the subjects could not notice systematically any difference within the given samples even for a synthetic mode decay time of almost two seconds."

More experiments are planned, as these listening tests were done with just single room modes and 8 subjects listening to only four types of sound (speech, bandpass noise, drum hits, and rock music) at a single listening level of 75-80 dB.

I encourage anybody interested in the science of acoustics to read the original literature. Don't take my word for it. Read any paper carefully, and judge for yourself!

- Terry

Terry, can you tell us approx. how many traps were used in the room where you measured that waterfall plot?

You have to admit Terry's measurements look better.
I have to wonder how he got those measurements.
Terry got those measurements the same way I made the REW measurements below. :D

Both of the graphs below show the response in my large (34 by 18 by ~10) home recording studio, using identical gate times and all other parameters. One is measured the proper way, and the other was measured using an improper (read: disingenuous) method. This is the very same room, and these are real measurements taken 15 seconds apart. Yet one reflects reality and the other surely does not.

I have no need to hide anything, and I'll be glad to show how I made my studio appear far flatter and tighter than it really is. But first Terry needs to answer Tukkis' question about how many traps there were, and also reveal what speakers they were, where the sub was placed, and where the measuring microphone was in relation to the speakers and sub.

I find it amusing that Terry is now the champion of using "a whole lot of acoustic treatment" after he criticized me many times for telling people that more bass trapping is always better. The only legitimate ETF graph I have ever seen that looks even remotely like what Terry posted was for a home studio control room that was 1/3 filled with rock wool. Not 1/3 of the square footage, but 1/3 of the room's entire volume!

--Ethan


http://www.ethanwiner.com/misc-content/studio_34a.jpg

http://www.ethanwiner.com/misc-content/studio_34b.jpg

Terry, can you tell us approx. how many traps were used in the room where you measured that waterfall plot?
I didn't use discrete traps, except for a couple of custom tuned absorbers which had only minor impact. It is all integrated into the overall acoustical treatment, which in this case varied in thickness from 2 inches to nearly 2 feet. But even 2 feet of depth is not enough to thoroughly correct the lowest bass frequencies. That's where parametric EQ is necessary. For this room, an independent set of parametric equalizer channels was used to optimize each sub -- yes, there were multiple subwoofers.

This room had approximately 10% of its volume taken up by acoustical treatment. That is the sort of commitment you have to make when you are serious about achieving high performance home theater acoustics. Barhoram has some great space behind his screen for placing low frequency absorption.

- Terry

Bump.

Regards,

???
Most of what I do is design of acoustical treatments. It always has been. I use EQ when I have too -- at frequencies where bass absorbers are not effective.


The room is 2300 cubic feet. And no, I will not tell you where and what type of treatment was used. This is my intellectual property, and I do not give it away. It is what I do for a living, the results of working in the acoustics profession for a few decades! :eek:

- Terry

So, would it be fair to say that you're here on this forum not so much to share your experience with others in the hope that they will learn from it and be able to improve their system, but instead you're here just to promote your business?

So, would it be fair to say that you're here on this forum not so much to share your experience with others in the hope that they will learn from it and be able to improve their system, but instead you're here just to promote your business?That's an unfair statement, especially from a new arrival to these forums. Terry has shared his knowledge and experience with us for a long time, including ideas and theory about room acoustics. OTOH, expecting him to provide free the specific services from which he makes living is unreasonable.

That's an unfair statement, especially from a new arrival to these forums. Terry has shared his knowledge and experience with us for a long time, including ideas and theory about room acoustics. OTOH, expecting him to provide free the specific services from which he makes living is unreasonable.

It wasn't a statement. It was a question. And the implied relevance of my being a new arrival is childish.

Terry's implied claim that he's using some sort of secret methodology is rather humorous. Perhaps he's using some fantastic new speaker cable he read about in Stereophile? Let's see, you make a plot of all the nulls in the room, feed the data into some secret formula, and the formula tells you where to tie the speaker cable in knots which then cancel all the nulls! ;-)

It wasn't a statement. It was a question. And the implied relevance of my being a new arrival is childish.It is certainly relevant since, had you been around for a while, you would know more about him.

...More than 12 dB range from 20-200 Hz?....
I read those graphs as about 10dB, but aside from that, I'd ask if those frequencies need to be flat for the perceived tonal qualities. Yes, I prefer something flat above that for voice and music, but for bass, can we distinguish a flat response...without a "golden ear"???

Terry, Ethan, and a host of others provide general guidance. The amount and specificity of the comments they provide are peculiar to their own, individual, comfort levels. If you find it useful, that's great. If you need more information, then perhaps posting in other areas might garner what you're looking for. IMO, the effort they expend in promoting their own endeavors is next to nil.

I am kind of curious if I missed something as this thread is pretty old, and then bumped and then a person responds to a post made over a year ago questioning their posts as advertising. What am I missing here?

I am kind of curious if I missed something. . .[snip]

Nope.

Regards,

I read those graphs as about 10dB, but aside from that, I'd ask if those frequencies need to be flat for the perceived tonal qualities.

What is important to understand is that a flat measured response is not the same thing as a perceptually flat response. That probably didn't question your question. Uh. .

A flat measured response will mean that the recorded material is faithfully reproduced but -- not quite. In order for the material to be faithfully reproduced (as in 100% faithfully reproduced) the frequency response would need to measure flat with an identical RT60 time in the bass range as per the mixing engineers requirements.

Good luck with that. A flat response is overrated as it doesn't necessarily mean that it will be perceptually accurate but rather a measurably accurate duplicate of the recorded material. :)

Regards,

Most bizarre thread bump ever.

I have seen more bizarre thread bumps in my time here but I digress. Perhaps something good can become of it. Or not.

Regards,

Thanks for your explanation!

You are most welcome.

Regards,

Bumping a thread without explanation after 18 months of inactivity is poor form. and bad boarding.

Bumping a thread without explanation after 18 months of inactivity is poor form. and bad boarding.

No offense but your opinion on what constitutes bad form and bad boarding matters very little to me.

Regards,