Lack of bass. 2 12 subs small room.

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ssmokeyy

Junior Audioholic
Finally I have my min parts needed to do my dirac live calibration and after almost 2 hours I test the sound and low end sucks. Room size 12.5 x 15 x 7 basement room. 4 layers of 5/8 rock with green glue. Avr integra drx 8.4 with a custom anthem mca 50 that I recapped with top of the line nichicon/ pansonic caps. Subs are 12 I ch martin logen dynamo. 600 rms each. Used rew to level match the subs. 94 dB at seat. But I can't hear it there. By the wall yes. Also both subs are on sw1 output on the integra. Im building a 15 inch box to install in the rear for sub 20hz. Right now I would like to get the 12's Dialed in. I do not have many options for placement in this room. I could sell these 12's and do a small 15 inch box if that would fix any problems. Dirac live graphs added here also. Subs and front tower graphs
 

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shadyJ

Speaker of the House
Staff member
Are you sure that Dirac isn't EQing the subs to have that shape? I am pretty sure that MartinLogan would high-pass those subs as well. They never were low-bass monsters. If you want subs that will have better deep bass and aren't much larger, look at some Starke Sound SW15 subs.
 
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ssmokeyy

Junior Audioholic
So I have had these subs for years. In our last house we had them in they sounded 10 times better. There rated to 20hz I know that's not realistic but I do know they sound damn good. There is a problem here. Next to the wall bass is crazy loud that u can hear. In my seat no bass but the mic picks up 94db in my seat when setting levels on setup.
 
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shadyJ

Speaker of the House
Staff member
So I have had these subs for years. In our last house we had them in they sounded 10 times better. There rated to 20hz I know that's not realistic but I do know they sound damn good. There is a problem here. Next to the wall bass is crazy loud that u can hear. In my seat no bass but the mic picks up 94db in my seat when setting levels on setup.
Sounds like an acoustics problem. If you really don't have freedom of placement to move the subs, you might be out of luck. The sound character of bass is overwhelmingly determined by the room acoustics. Are you able to try near-field placement, like having the subs right behind your seat or on the sides like endtables?
 
William Lemmerhirt

William Lemmerhirt

Audioholic Overlord
Was the previous room on a suspended floor? Or also on concrete?
 
AcuDefTechGuy

AcuDefTechGuy

Audioholic Jedi
So I have had these subs for years. In our last house we had them in they sounded 10 times better. There rated to 20hz I know that's not realistic but I do know they sound damn good. There is a problem here. Next to the wall bass is crazy loud that u can hear. In my seat no bass but the mic picks up 94db in my seat when setting levels on setup.
Do the subs suck with vs. without Dirac? Do they suck with any room correction? Does room have carpet/rug?
 
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ssmokeyy

Junior Audioholic
Last room was concrete with thin carpet half wall open. Smaller it was like 9 by 15 x 6.5 ceiling. Subs center of room. Sucks with or with out dirac. Little more with.
 

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ssmokeyy

Junior Audioholic
Also this is a older picture. There is only one center its a rp 504c
 
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ssmokeyy

Junior Audioholic
Moved the subs all over and stacked them. The mic says it's better but still lack if bass on my seat. The first graph is the mic 12 inches from the subs stacked and the other graph is from my seat 5 ft away. Graph doesn't change much when I move the subs or change the phase
 

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ssmokeyy

Junior Audioholic
I also did change the phase. Best output was when both subs were on 180 phase Switch. Also the right side is 3db less than the left with the same settings. I also swapped subs side to side to make sure one wasnt better than the other. No problem found there.
 
TLS Guy

TLS Guy

Seriously, I have no life.
Moved the subs all over and stacked them. The mic says it's better but still lack if bass on my seat. The first graph is the mic 12 inches from the subs stacked and the other graph is from my seat 5 ft away. Graph doesn't change much when I move the subs or change the phase
Your mains look capable. By the look of you last plot you should change your bass management to LFE + main. In other words run you main speakers full range as well as the subs.

A lot of times perceived loss of bass is above sub range.

I think members do not run their mains full range as often as they should. It is often the best setting. The whole problem comes from the fact that bass management is a generic off the shelf crossover. That is never a good way to design a speaker system. Ideally subs and the front three should be designed as an integrated system. When you do that you will probably have to alter the sub phase setting, most likely by 45 degrees. Set the receiver crossover frequency to the F3 of you main speakers plus 50%.
 
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ssmokeyy

Junior Audioholic
I have been trying to find out how to turn that on. When I logging to my integra drx 8.4 I can see the option for double bass but it won't let me click it. When I lower the front speakers crossover under 80hz it starts removing that from the subs. Also would ported subs fix this problem at out?
 
TLS Guy

TLS Guy

Seriously, I have no life.
I have been trying to find out how to turn that on. When I logging to my integra drx 8.4 I can see the option for double bass but it won't let me click it. When I lower the front speakers crossover under 80hz it starts removing that from the subs. Also would ported subs fix this problem at out?
In my view ported subs are a much better bet. Sealed subs really are a 'brute force and ignorance' approach. The ported subs couple much better to the room.
I'm not familiar with Integra, but there should be a way to do it. Set speakers to large in the menu first. Then set just the sub, may be that will do the trick.
 
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ssmokeyy

Junior Audioholic
i tried that. I'm going to call Integra and ask. Is there any per built 15's around 600-800 that would be worth a look. I have a stereo integrity sql I'm building a box for in the rear of the room. to save time I would like to buy something built but if its more than 800 I would pass and build a second one. I was looking at the emotiva xs15 looks ok but i hate the port on the rear. Also there is a deal on the osd black 15 for $500 700rms.
 

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