[Tyson]

Hire Brian and get the room treated properly.   Best move I and my customers did was to hire an acoustic engineer and change the room, speaker placement and the like. With a 10K preamp why are you fooling around ? Eh! Eh!

charles

Well if he's like most audiophiles I know, it's because he spent $10k on a preamp and now is broke!  Haha, I'm only kidding

[dB Cooper]

Find a used pair of Allisons, which discussed your exact problem in their technical documentation. You can see the 'suckout', in the exact frequency range you're having the problem, in the measurements shown on this page of their catalog. I don't know why this approach isn't more widely adopted as the Allison patents are expired.

Short of that unlikely approach, a small sub or two, located strategically, may offset the 'suckout'. I say 'small' because it's not a huge room and I assume you're not trying to create a 'boom room'.

[artur9]

Roger Skoff has been writing a series on getting better bass.  Here's part 1 (he's up to 5)
http://audiophilereview.com/subwoofers/how-to-get-better-bass-part-1.html

[veloceleste]

I see no mention of bass traps. I had a similar problem with suckout and after doing a lot of reading/research ended up trying ASC tube traps. Huge improvement; smoother, tighter, more tuneful bass, and less suckout.  Bass went from being boomy or nonexistent depending where you are in the room to relatively even through out the room. Also, as mentioned earlier, try adjusting speaker position within the parameters of what is functionally practical for your your room. 

[poseidonsvoice]

 

I see no mention of bass traps. I had a similar problem with suckout and after doing a lot of reading/research ended up trying ASC tube traps. Huge improvement; smoother, tighter, more tuneful bass, and less suckout.  Bass went from being boomy or nonexistent depending where you are in the room to relatively even through out the room. Also, as mentioned earlier, try adjusting speaker position within the parameters of what is functionally practical for your your room.

I mentioned it earlier in the thread: http://www.audiocircle.com/index.php?topic=151187.msg1617107#msg1617107

Advising is one thing. Whether the OP is able to implement the advice, based on his or her budget, and patience is another.

I don't see anything ground breaking here. This is SBIR (or the Allison effect), pure and simple. And the methods that curtail SBIR have been published for decades. It's so common in home Hifi that I frankly find it boring to talk about so I post links instead as I did previously.

http://www.gikacoustics.com/room-setup-speaker-placement-201-part-one/



Best,
Anand.

[JLM]

I mentioned it earlier in the thread: http://www.audiocircle.com/index.php?topic=151187.msg1617107#msg1617107

Advising is one thing. Whether the OP is able to implement the advice, based on his or her budget, and patience is another.

I don't see anything ground breaking here. This is SBIR (or the Allison effect), pure and simple. And the methods that curtail SBIR have been published for decades. It's so common in home Hifi that I frankly find it boring to talk about so I post links instead as I did previously.



Best,
Anand.

+1

So little new under the sun, yet most audiophiles fixate on funny little technical tweaks while ignoring basic physics. 

[gtaphile]

I relocated the speakers on the opposite wall (flipped the room entirely) and positioned the speakers in several locations (all that one could live with and leave room for a love seat and a single chair) and adjusted for toe in. This affected imaging considerably and had little effect on the suck out.

How do I know that its a 10 out of 10?  Many world class speaker designers and engineers have listened in this room and they marvel at the performance of the room. It is a no holds bar assault on the science of a 2 channel listening room.   

My room issues have not baffled the designer of the 10 out of 10 room or myself.  We are trying to improve the in room response  without subs and without building a floor to ceiling custom absorption/diffusion system that will make the room uninhabitable and might not work.       

I appreciate everyone's assistance and comments. I am going to try some ceiling treatment such as the 244's to minimize ceiling bounce. I did plug the numbers into Kens audio page for normal sitting position and leaning forward and found that one null went from 137 Hz to 122 Hz and another from 410 to 367. If they do not reveal a significant ceiling bounce they can be reused elsewhere. 

 

Have you tried repositioning the speakers and/or listening position?  Wondering how you know the above referenced set-up and treatment was "10 out of 10" in another room when you can't solve the apparent SBIR issues in your own room.  You mentioned above trying a setup along the wide side of the room and that moving forward (versus normal position) helped.  What was "forward" and what was "normal"?  Again, diagrams/images would help.

Agree about not jumping into subs.  Subs are over-applied by some and over-avoided by others.  A true subwoofer works at frequencies below typical speakers (say under 50 Hz).  The frequencies you stated having problems are low to middle C (120 - 240 Hz, lower midrange).  So subs aren't the answer.


I see three possible solutions: move the speakers (recommended), replace the existing treatments with more effective ones (something similar to GIK 244 panels), or a mid-bass module like these -

http://www.hsuresearch.com/products/mbm-12mk2.html

http://www.diysoundgroup.com/midbass-module/mbm-12.html

[bpape]

Find a used pair of Allisons, which discussed your exact problem in their technical documentation. You can see the 'suckout', in the exact frequency range you're having the problem, in the measurements shown on this page of their catalog. I don't know why this approach isn't more widely adopted as the Allison patents are expired.

Short of that unlikely approach, a small sub or two, located strategically, may offset the 'suckout'. I say 'small' because it's not a huge room and I assume you're not trying to create a 'boom room'.

Allisons' on-wall placement is designed to miminize any front wall SBIR.  The same can be done with moderately thick bass panels between the speakers on the front wall.

[nickd]

I have a $7500. preamp and the matching mono amps sitting on the floor (out of service) in my listening room.

I ended up using the Lyngdorf recommendation of placing the speakers on the font wall (14' wide) of my 14 x 21 room because I couldn't get rid of a bump and a suckout at the listening position. A bit of DSP correction from a TDAI 2170 and I finally have punchy, deep, tight bass at almost all listening levels after many years and countless speaker and component changouts.

Roy Allison was on to something. Really good DSP takes it to the next level.

Over the years, I also came to believe you need a quick light paper 12" or 15" driver to really hit hard in the bass and have great tone. Early American designers understood this. I knew this in my teens and twentys. I spent 20 years coming full circle.

Danny Ritchie has commented on this thread. His stacked OB 12" drivers are the only modern system that I have heard that make serious "American style" bass. That they have to be 3' from the wall is their only possible drawback.

Not trying to stear you in any direction. Just observations from my own personal journey.

[Audiophile58]

The room is always s large factor in nulls, and reflections in rooms. That is why A good room correction
System works as well as some sound panels.  I  did this the easy way bass busters in corners behind the speakers as well as several acoustic panels, having s carpet in front of speakers is a must to avoid bounce reflections. I just bought Martin Logans New 11-A  from their masterpiece series ,and not only
Transparent,and Totally seamless . the bass has Anthem room correction  built in
Which eliminates any Bass nulls in the room ,and having dual opposing  powered drivers per speaker
Cancels out vibration issues,24 bit DSP guarantees everything is Seamless .this may be their least expensive
Model in this series  but competes and beats many speakers at 2x the cost .yes room correction
Absolutely works . Underwood wally  has a very good one under $1k.

[Audiophile58]

Depending on system for the money spent this DSpeaker  product has won many awards and just may be
The ticket  there are many DSP  products out there, for under $1k non better
Unless you have a fully Active system  from tweeter on down, then a DBX system can get much more complex.

  http://www.underwoodhifi.com/products/dspeaker

[Audiophile58]

Also the 8033-S2  DSpeaker  is strictly for Subwoofers. For just over $400.
Now you do have options !!

[JLM]

I use a DSPeaker Anti-Mode 2.0 Dual Core (long name, small piece) for DAC, preamp, and DSP.

I'm ready to give up on this thread.  The OP indicates that the room is a "10 out of 10" and that "world class speaker designers and engineers have marveled at the performance of the room" yet he also complains about "non-existent" mid-bass response.  Seems like something coming out of the WH. 

[Letitroll98]

I think the 10 out of 10 room was another room with similar speakers, not his room.  I believe he's trying to get to a facsimile of that room, but I may have missed something.  You've provided a lot of good advice on this thread JLM, maybe you might stick around?

[gtaphile]

Exactly. The 10 out of 10 room is another room entirely and mentioned as a reference. The same speakers that I have with the same playlist heard in that room are a reference for what the end to end performance could sound like in my room.

JLM and others - your comments are useful. They have caused me to purchase some specific room treatments to check for ceiling bounce. I have tried and cannot move the speakers to the wall. That location collapses the wonderful image entirely.  I have also exhausted moving the seating positions.     

I think the 10 out of 10 room was another room with similar speakers, not his room.  I believe he's trying to get to a facsimile of that room, but I may have missed something.  You've provided a lot of good advice on this thread JLM, maybe you might stick around?