Thread: 86%

Last weekend I attended the monthly Suncoast Audiophile Society meeting. It was held at Sleepysurf's (Alan) place. He had invited Nyal to give a virtual presentation on bass management. In the presentation, Nyal cited a recent study from Harman corporation which discovered that 86% of what we hear is influenced in one way or another by the room.

Perhaps Alan or Nyal can chime in with more details. But I will say, the presentation was fascinating. I will try to post pictures of the presentation.


















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Looks like an interesting presentation too. I wonder if Nyal could provide an on-line link?

You would buy treatments for higher frequencies (Vicoustics for example), but NOT bass traps. He showed that adding 10 bass traps ONLY had an impact of 3db on the biggest sub 100hz problem. A 20-30db bump at 73hz like I had would require 100 bass traps.

I love my Vicoustics - they worked wonders, but my ASC bass traps were a huge waste of f'ing money. I tried to work with the folks at ASC, but all I got was BS excuses on why my 10 traps weren't doing a damn thing. Yeah, I'm bitter. They weren't cheap.

To be fair, the bass traps did some nice things for imaging - but they did not even come close to fixing the problem - which is why I bought them! Only my DSPeaker 2.0 Dual Core TRULY, 100% measured, unequivocally fixed my problem at 73hz.

As a side note, I received the DEQX and I'm looking to compare that to the dual core. But let's just say, if you have a nail, the dual core is the hammer.

Nyal is a big believer in a multi stage approach - measure, position speakers, remeasure, reposition speakers, measure and so on. Next, DSP and multiple subs to even things out. He mentioned a new product from MiniDSP that looks interesting.

http://www.minidsp.com/dirac-series/ddrc-22a


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Originally Posted by Mike

my ASC bass traps were a huge waste of f'ing money. I tried to work with the folks at ASC, but all I got was BS excuses on why my 10 traps weren't doing a damn thing. Yeah, I'm bitter. They weren't cheap.

Wow.I'm shocked.

I love my Vicoustics - they worked wonders, but my ASC bass traps were a huge waste of f'ing money. I tried to work with the folks at ASC, but all I got was BS excuses on why my 10 traps weren't doing a damn thing. Yeah, I'm bitter. They weren't cheap.

To be fair, the bass traps did some nice things for imaging - but they did not even come close to fixing the problem - which is why I bought them! Only my DSPeaker 2.0 Dual Core TRULY, 100% measured, unequivocally fixed my problem at 73hz.

Interesting, Mike. As it just so happens, I've also got ten ASC Tube Traps and, like you, put a DSPeaker Anti-Mode 2.0 Dual Core in my system (months ago) and was very impressed with the results. It's a nice little unit with a lot of features for not that much cost.

My ASC tube traps help with imaging focus and soundstage. But in my room, they measurably did sweet bugger all on bass node problems. Before and after measurements show no difference. Maybe 3-4db tops.





The DSPeaker 2.0 Dual Core fixed ALL of the bass problems, didn't negatively affect sound one bit and cost 1/10 the cost of the bass traps. Before and after measurements go from "big problem" to "fixed"!



I look forward to trying the DEQX in the next week or two. I have it, but need to work with the experts at the company to set it up and configure it.


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I cannot speak to other products, but if they have been lab tested and show to work below 100hz, then they will, and you do not need 100 of them. Keep in mind that frequency response is only one small piece of the puzzle. Decay times and ETC is just as important, if not more important, IMO. Also your room measurements look a bit strange. Not saying they are wrong, but to have all those spikes in the low end with no real nulls is strange to say the least. I would recommend you test with a program like REW, which will give you much more usable information.

Thanks Glenn. Hopefully Nyal will chime in with his data. For me, no further testing is needed. Just listening, you could tell the traps sharpened up the image and a few other things, but they clearly did not have any impact on the problem areas below 100hz.


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Well like I said I am not 100% sure your measurements are correct. But if that spike, for example was coming from the back wall then you would need to treat the back wall. The same would go for the ceiling, side or front walls. For the most part you will notice a much higher impact on the decay times (think of this like low end reverb) when bass traps are but in corners, which as I said is just as important if not more important then frequency response.

BTW I lived in Sarasota for a number of years. MISS IT BIG TIME!!

Originally Posted by Glenn Kuras

Well like I said I am not 100% sure your measurements are correct. But if that spike, for example was coming from the back wall then you would need to treat the back wall. The same would go for the ceiling, side or front walls. For the most part you will notice a much higher impact on the decay times (think of this like low end reverb) when bass traps are but in corners, which as I said is just as important if not more important then frequency response.

BTW I lived in Sarasota for a number of years. MISS IT BIG TIME!!

If you ever get back here, swing on over for a listen. I have 10 big ass ASC tube traps and I worked with the manufacturer on several placement ideas. They did nothing to solve the real problem. When people have a small bump, a much shorter delay problem, then maybe bass traps will help. But a 73hz spike will go right around bass traps and laugh at them. DSP (DSPeaker 2.0 Dual Core - which is a bass only DSP solution) combined with multiple subs was the only thing that worked. And it worked.


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Mike what is the dimensions of the room? Actually I have found that if the spike is high like that it is easier to start to tame, but it is those last few db that can be a "bitch" (very technical term ha ha) to fix. If the tests are right I wonder if just moving might be in order. I am not up to 10 posts yet so I can't post a link but I have HAMMERED a 70hz problem with 8 traps.

BTW what you did worked for the spike, but still would be interested to see the decay times.

Originally Posted by Glenn Kuras

BTW what you did worked for the spike, but still would be interested to see the decay times.

I have the software (XTZ) and mic, but haven't yet been able to bring myself to buy a copy of Windows to run it.


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REW will work on a mac also.
Room EQ Wizard Tutorial - GIK Acoustics
.

I can post that link now so you can see the impact
http://www.gearslutz.com/board/7597560-post146.html

Hi Mike, often times for specific low frequencies a Helmholtz resonator is one of the only answers, along with dsp. Bass traps are a misnomer as low frequencies have very long wavelengths so the traps need to be huge the typical 16" traps won't do much in that frequency to tame the fundamental energy though they will help with the decaying energy. Digital parametric eq with high Q set at that specific frequency will help

Originally Posted by Mike

My ASC tube traps help with imaging focus and soundstage. But in my room, they measurably did sweet bugger all on bass node problems. Before and after measurements show no difference. Maybe 3-4db tops.





The DSPeaker 2.0 Dual Core fixed ALL of the bass problems, didn't negatively affect sound one bit and cost 1/10 the cost of the bass traps. Before and after measurements go from "big problem" to "fixed"!



I look forward to trying the DEQX in the next week or two. I have it, but need to work with the experts at the company to set it up and configure it.


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The other issue with Bass Traps that no one seems to mention is that they kill dynamics.

Originally Posted by Myles B. Astor

The other issue with Bass Traps that no one seems to mention is that they kill dynamics.

No argument here. In the end, the dual core just left the system lifeless.


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Originally Posted by Adrian Low

Hi Mike, often times for specific low frequencies a Helmholtz resonator is one of the only answers, along with dsp. Bass traps are a misnomer as low frequencies have very long wavelengths so the traps need to be huge the typical 16" traps won't do much in that frequency to tame the fundamental energy though they will help with the decaying energy. Digital parametric eq with high Q set at that specific frequency will help

Adrian - since I sold the Alexia's, I don't have any bass issues.

To be fair, I've had other speakers that were problematic in that room.

Speakers with a bass chamber like the Strads or downward firing port like the Salon 2's, work best. Any speaker that excited the corner where the back wall meets the side wall AND the sloping down roof is a nightmare.


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Originally Posted by Mike

No argument here. In the end, the dual core just left the system lifeless.


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Hi Mike, can you clarify? Are you saying that with the DSpeaker the system became lifeless?

For what it's worth, this may not necessarily be the DSP's fault... excess bass energy (as long as it's not boomy) can give a great sense of increased dynamics; not accurate but can be very enjoyable. High Q peaks in the bass can do that. When bass peaks are lower Q and also cause boominess, the result is terrible for articulation and detail.

I'm happy for you that the Strads work better in your room.

Adrian - too much A-D-A-D-A going on. The magic was lost in translation.


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ok. Are you using any DSP now or all passive

I saw something similar at the NYC show this past weekend. A before and after graph of bass response in the room. I think it was in the Martin Logan room, but maybe it was somewhere else. They took 8 measurements around the room then digitally applied correction. The after graph was almost flat and the before was all over the place.

The bass did indeed sound tight and accurate without the usual bloat at one frequency or another.

I'm not sure how DSP can fix bass response all over the room, I was under the impression that it could only be corrected for 1 or 2 locations without causing more issues elsewhere.
With that said I use DSP also, in J. River before any D/A conversion takes place. That employed with multiple subs seems to work best in my room for the time being.
The plan is to next give dipole bass supplimented by a large sealed sub(below 40) a try.

One of the best DSP products I've used is the Lyngdorf RP-1, now discontinued, but available in a modified version as the McIntosh MEN220. I like it very much because it really works well to judiciously smoothen out the major room issues (you still have to treat highly reflective rooms as DSP won't solve that). Also, because it is automated, you don't need to be an acoustician. According to the designers, the difference between the Lyngdorf/McIntosh system and others is that the system is able to discriminate between the response of the speaker versus the room. I'm not sure how it does that. Perhaps it's due to the multiple random microphone placements in the room. By doing so, the processor reads the response of the room and discriminates between the speakers' response vs the room's response. Apparently, this allows the processor to leave the character of the speaker alone while dealing with the room.

Does it work? Again I can only speak for myself. Yes, it works very well. We once exhibited at the Montreal audio show. The hotel room was terrible, causing huge (+15-25 dB!!) spikes between 50-150 Hz. Even the RP-1 shut down the first few times when we were trying to read the room, until we lowered the initial set up level (it wasn't high to begin with!). The result was amazing. Switching the processor in made everything clearer, much more linear. Switched out, the bass was more impressive, much more powerful, but definitely not real. More fun? Perhaps. More dynamic? Yes, depending on the cut you played. The bass issues of the room seemed to be mostly high Q so boominess was not as big an issue, but it was still there.

Here's a link to the designer talking about the Lyngdorf RP-1
https://www.youtube.com/watch?v=uYMAVbw6tLc

Originally Posted by Face

I'm not sure how DSP can fix bass response all over the room, I was under the impression that it could only be corrected for 1 or 2 locations without causing more issues elsewhere.
With that said I use DSP also, in J. River before any D/A conversion takes place. That employed with multiple subs seems to work best in my room for the time being.
The plan is to next give dipole bass supplimented by a large sealed sub(below 40) a try.

I think you are correct, DSP needs to work together with passive treatments, though in my experience and knowledge, passive bass treatment can only really be effective with Helmholtz Resonators tuned to the particular frequency that is most annoying. Employing multiple subs (3 or more) in various parts of the room will help smooth out the bass response as well, assuming that you don't create even more issues! haha.

However, my experience with the Room Perfect is very positive overall. In the sweet spot (Focus setting), bass is definitely more accurate virtually every time, and you can also set the processor up to do a Global response so it widens the sweet spot; the sound seems better for more people.

Originally Posted by Adrian Low

I think you are correct, DSP needs to work together with passive treatments, though in my experience and knowledge, passive bass treatment can only really be effective with Helmholtz Resonators tuned to the particular frequency that is most annoying. Employing multiple subs (3 or more) in various parts of the room will help smooth out the bass response as well, assuming that you don't create even more issues! haha.

However, my experience with the Room Perfect is very positive overall. In the sweet spot (Focus setting), bass is definitely more accurate virtually every time, and you can also set the processor up to do a Global response so it widens the sweet spot; the sound seems better for more people.

I've also tried Helmholtz Resonators, multiples are still needed to fix the problem IME.

Here's an interesting paper on multiple subs: http://www.harman.com/EN-US/OurCompa...s/multsubs.pdf

Originally Posted by Face

I've also tried Helmholtz Resonators, multiples are still needed to fix the problem IME.

Here's an interesting paper on multiple subs: http://www.harman.com/EN-US/OurCompa...s/multsubs.pdf

Great article. Saw that. Thanks!
Was first thinking about multiple subs around 2005/6. We were doing a big home theatre installation. Just out of curiosity we measured the room with one sub, then another, until we had 4. We expected the bass to be more powerful but we had no clue the bass would actually smoothen out! Then shortly after, we became a Sonus Faber dealer, and one of the owners came by to train us. He also mentioned the benefits of multiple subs. I believe that same year I went to CEDIA and Velodyne showed graphical evidence of multiple subs. I think that might be the first time I began to fully realize that it could be a good option to bass issues.

You are right re multiple resonators needed, especially if it is a serious issue, with many peaks at different frequencies. Unfortunately when it comes to bass, there isn't a magic bullet.

I have a client who LOVES bass. Absolutely LOVES it. He is fortunate that both his rooms do not suffer from boominess. When he plays his electronic dance music, your chest cavitates, and you literally feel every deep note.

Originally Posted by Mike

.... but my ASC bass traps were a huge waste of f'ing money.

Easy to see your problem..footers. You need stillpoints under bass traps before they can truly be effective.

Other than DSP, that we audiophiles all hate. The only way to fix bass problems is to build another room. I agree Mike, tube traps are a waste of money if you think they will cure big bass issues. If you are ok with subs (obviously yes if its home theatre) Adrian is absolutely correct, multiple subs is the answer.