[bpape]

I don't think we suggested that your products did not work.  Anything that one can do to kill a corner and it's horn effects is a positive thing.  Also, PROPERLY absorbing sound does not end up with rolled off frequency response.  I think if you look at the specs on both the GIK and the Real Traps, you'll find that they're specifically designed not to overdo it.

The thing that is of concern is that the bass control seems to be ignored.  That is just as or more important IMO.  THAT's why a lot of rooms sound dead and rolled off - because it's a bunch of upper mid/high frequency only absorbtion with the vocal range down basically left to run wild causing an imbalance in decay time through the room.

Bryan

[Big Red Machine]

What type of surface does the reflecting?  Plywood, a composite, hard foam?

[8thnerve]

What type of surface does the reflecting?  Plywood, a composite, hard foam?

The reflective surface in the Adapt line is a wood laminate.  Any hard material will work, but look for something that is not resonant, or brace it.

[8thnerve]

I don't think we suggested that your products did not work.  Anything that one can do to kill a corner and it's horn effects is a positive thing.  Also, PROPERLY absorbing sound does not end up with rolled off frequency response.  I think if you look at the specs on both the GIK and the Real Traps, you'll find that they're specifically designed not to overdo it.

The thing that is of concern is that the bass control seems to be ignored.  That is just as or more important IMO.  THAT's why a lot of rooms sound dead and rolled off - because it's a bunch of upper mid/high frequency only absorbtion with the vocal range down basically left to run wild causing an imbalance in decay time through the room.

Bryan

The Adapt products show measurable improvements down to 40 Hz.

[bpape]

In decay time?

Again, I'm not bashing the product in any way.  Many people have the product and they like what it does.  I don't believe I've ever said any different.  I just want to consider all of the things that are key to improving room response.  Frequency response is just one.  Overall decay time, balanced target decay curve, impulse response, etc. are also important elements of a balanced treatment plan.

Bryan

[Ethan Winer]

The Adapt products show measurable improvements down to 40 Hz.

Nathan, I don't want to seem like I'm bashing you either, but I'd like to learn more about the test data you show on your site because it makes no sense to me. Looking again at the data on your Methodology page, the peak and null frequencies are not exactly the same for the before and after graphs. They are similar, but at 80 Hz there's a null without treatment and a slight peak with. The only way I can see that happening is if the measuring microphone is moved between tests. In which case the entire test is invalid.

Do you have more detail you can share about how the tests were done, photos of the room showing microphone and speaker placement, software used, and so forth?

--Ethan

[darrenyeats]

The Radio Shack SPL meter is not as accurate as it should be, you should take the following into consideration when plotting your curve.

http://www.subwoofer-builder.com/SPL-corrections.htm

I have an RS SPL meter and it has a socket marked 'Cal.'. I assumed this meant the meter could be calibrated...and HAD been calibrated at the factory (?!)

It makes sense this should have happened...considering the purpose of the device.

It also has an RCA socket labelled 'Output'. Even IF the meter were calibrated, I am not sure the calibration would be applied to this output.

Any comments?
Darren

[bpape]

I believe the cal setting is only to set the level at a reference tone.  The overall balance of the mic across the whole frequency spectrum can only be accounted for by implementing a .cal file matched to that one specific meter after it has been measured against a reference.  You can get in the ballpark by using the generic compensations. 

Bryan

[dnd]

Big Red Machine - Might I suggest something crazy & unique here?

You have a great looking set-up and very nice gear.  I was in the same boat as you wanting to get my room right once and for all.  I did TONS of research and experimentation over the years, and needless to say spent a lot of money and time (I'm also a DIY'r).  Earlier this year I finally hired Terry Montlick to acoustically analyze my room (after threatening to do so for several years).  Obviously there are other qualified people for this, but my experience is with Terry.  Here's his site:

Goto: http://www.softwaredesign.com/

For a modest fee, he helped me more than I could have hoped for, and most importantly, saved me a lot of time and money by way of keeping me from making some very big mistakes.  It was absolutely the best money I've spent in audio, and it was less than the price of many power cords.

Your room response might be problematic, but there is more to it than just room response...so I have learned.  By hiring an expert like this, you still get to do the DIY part, if you want too, but you'll save money, and you’ll more quickly begin to enjoy your set-up in a way you never thought possible.  Since Terry does not make or sell acoustic products, you’re more likely going to get an unbiased resolution, and let’s not forget he is educated as an acoustician and has a lot of real world experience to boot.

[satfrat]

Big Red Machine,,, awesome room you got there. My hat's off to ya.  Looking at your room treatment, looks like a ton of foam to me but tastefully done, and looking at your chart, my guess (and that's all it is) would be that you don't need more absorption but maybe more undistorted reflection. I believe Eighth Nerve's Adapt Rectangles do this best with the least amount of obstruction in a room. I have 4 Rectangles in each wall/ceiling and I have their Response Rectangles in each wall corner( and that's only because they came out first and I don't want to go theu the hassle of selling and replacing them with Adapt Rectangles). For me, in my room, I can't praise these Adapt Rectangles enough. I haven't done all the tests that you guys do, I have no charts but I do remember the sharp improvement in clarity & detail when using the Response Rectangles but it was nothing compared to what I got with 4 Adapt Rectangles on each ceiling wall. Simply incredible. I also use 2 Real Traps Soffit's, (1) 4' plant stand and (1) 2' subwoofer stand, both definitely tightened up my bass. I don't think any 1 product is a cureall for all room quirks. But they all are better than nothing.

Good luck with those flucuating highs! 

Robin

[bpape]

I don't think any 1 product is a cureall for all room quirks.

Amen to that.  Every product has it's own forte.  A combination of things is usually the best answer.

Bryan

[Glenn K]

IronLion wins the prize of course.  As I've consistently stated, the Eighth Nerve products are NOT designed to be absorbers.  They are designed to trap most of the corner return wave.  That alone reduces echo and reverb, and flattens the frequency response.  They are not absorbers at all in the general sense, so therefore do not suffer from the most egregious side effect of every other acoustic product, over absorption of high frequency information.  As you should be able to see from my diagram, the whole "trapping of the corner return wave" is not a gimmick or feature of the product, it is the product.

So if your idea of great acoustics is rolled off high-frequencies and tons of huge panels on the walls and century old science, then by all means believe that size is all that matters.  After all, that's "how acoustic products should work."

Sorry for the glib response, but as you can see from the responses (no pun), they do in fact work and they work well.  Years of unanimous positive feedback supports this, as well as technical measurements.  Glenn and Ethan, you guys do a great service here helping people out with acoustics.  There is no reason to suggest that my products are somehow not effective because they don't work like yours.  I'm not selling snake oil, there is real science behind these designs.  You won't find it in Everest's tome because it's not old science.  Can't we all just, get along?

Love and kisses,
Zaphod

Nathen,
I am sorry if you took my statement as though I was saying something bad about your products. I honestly was not.
Have you thought about sending your products off to be tested? I know the people at Riverbank and would be more then happy to put you in contact with them.  Trust me I totally understand customers feed back is very importanted, but you may want to think about testing though. I think you would  see a pretty good jump in sales also. 

[8thnerve]

In decay time?

Again, I'm not bashing the product in any way.  Many people have the product and they like what it does.  I don't believe I've ever said any different.  I just want to consider all of the things that are key to improving room response.  Frequency response is just one.  Overall decay time, balanced target decay curve, impulse response, etc. are also important elements of a balanced treatment plan.

Bryan

Yes, in decay time as well.  I don't have measurement data breaking down into a waterfall plot, so the decay time reduction was measured broadband.  Subjectively, it is very apparent that there is a reduced decay time at low frequencies.  I would love to have new measurements done at an independent facility, unfortunately, all testing facilities are designed to measure absorption ability, not overall frequency and phase data as a systems approach.  Essentially, it'll happen at some point, but it will be a large endeavor as it will require the right set of circumstances.

[8thnerve]

The Adapt products show measurable improvements down to 40 Hz.

Nathan, I don't want to seem like I'm bashing you either, but I'd like to learn more about the test data you show on your site because it makes no sense to me. Looking again at the data on your Methodology page, the peak and null frequencies are not exactly the same for the before and after graphs. They are similar, but at 80 Hz there's a null without treatment and a slight peak with. The only way I can see that happening is if the measuring microphone is moved between tests. In which case the entire test is invalid.

Do you have more detail you can share about how the tests were done, photos of the room showing microphone and speaker placement, software used, and so forth?

--Ethan

That's right, eliminating the return corner wave changes the frequency response dramatically.  The distortion from the corners couples with the sound energy in the room, reinforcing and canceling waves causing the frequency balance to change.  Depending on the shape of the corner, the size of the room and many other factors, these changes can be very significant, even exacerbating existing bass problems due to the geometry of the room.

I don't have any photos, but the Phonic PAA2 used was mounted on a tripod at the listening position, and the small amount of treatment was measured with white noise and averaged over 4 subsequent readings.

[Ethan Winer]

I don't have any photos, but the Phonic PAA2 used was mounted on a tripod at the listening position, and the small amount of treatment was measured with white noise and averaged over 4 subsequent readings.

The key is if the microphone was moved between tests, which you didn't confirm or deny, and also the resolution of the measurements. Could you please elaborate a bit more? I'm sure I'm not the only one here who is fascinated by this stuff!

Also, I agree with Glenn that you really need to have your products tested formally in a lab. You wrote:

I would love to have new measurements done at an independent facility, unfortunately, all testing facilities are designed to measure absorption ability, not overall frequency and phase data as a systems approach.

I'm afraid I have no idea what that's supposed to mean. If your products can improve the decay times and frequency response of a room, I assure you this can be measured by an acoustics lab! Heck, I will gladly measure your products for you, just as I did for the Cathedral Panels guys. However, my tests show only a change in response and ringing, not absolute performance values. Which is why acoustic labs exist. So unless you have truly invented a "new physics" (unlikely), I can't see why your products couldn't be tested at a lab just as all other room treatment products are.

--Ethan

[Big Red Machine]

Changes are being made to the room this week.  No sweeps yet (assuming I can get them done properly).  Preliminary listening is good.

[8thnerve]

I don't have any photos, but the Phonic PAA2 used was mounted on a tripod at the listening position, and the small amount of treatment was measured with white noise and averaged over 4 subsequent readings.

The key is if the microphone was moved between tests, which you didn't confirm or deny, and also the resolution of the measurements. Could you please elaborate a bit more? I'm sure I'm not the only one here who is fascinated by this stuff!

Also, I agree with Glenn that you really need to have your products tested formally in a lab. You wrote:

I would love to have new measurements done at an independent facility, unfortunately, all testing facilities are designed to measure absorption ability, not overall frequency and phase data as a systems approach.

I'm afraid I have no idea what that's supposed to mean. If your products can improve the decay times and frequency response of a room, I assure you this can be measured by an acoustics lab! Heck, I will gladly measure your products for you, just as I did for the Cathedral Panels guys. However, my tests show only a change in response and ringing, not absolute performance values. Which is why acoustic labs exist. So unless you have truly invented a "new physics" (unlikely), I can't see why your products couldn't be tested at a lab just as all other room treatment products are.

--Ethan

Ethan,

The mic was not moved, I figured that the use of the tripod would suggest that, but I didn't specify.  Unfortunately, the resolution was only 1/3 Octave, so your standard set of measurements apply.  I've been on the lookout for better software for measurement, specifically one with phase options and speech intelligibility.  Have any recommendations?

Nathan

[95bcwh]

Pete, what kind of changes are you making??

barry

Changes are being made to the room this week.  No sweeps yet (assuming I can get them done properly).  Preliminary listening is good.

[Big Red Machine]

Patience   I'm doing what I can after dinner, homework, and honey-do's each night.

[Ethan Winer]

I've been on the lookout for better software for measurement, specifically one with phase options and speech intelligibility. Have any recommendations?

I use ETF and R+D which cost $150 for both. Here's an article describing how I use such software:

http://www.realtraps.com/art_etf.htm

There's also the Room EQ Wizard which is free yet it quite excellent:

www.hometheatershack.com/roomeq/

--Ethan