# need advice to improve room acoustics



## pietsch288 (Sep 10, 2006)

I have all 4 corners trapped (I used the fluffy pink , r19 aprox 25-30'' thick and compressed so I could get as much back there as I could) so looking at the www.ethanwiner.com/density.html comparisons between insulation.... I feel my traps are just fine. I have 4 svs cs ultras running off of a ep2500 and a few people have told me that I should be able to get 105db @ 10hz and I'm nowhere close I'm barely getting 105 @ 25hz. So where's my bass at? I have noticed that when I put the sms mic up high (towards the cealing), I have much more output up there. I was thinking about getting a 15 or 18 to play with the boys but maybe all I need to do is trap where the walls meet the cealing or something, maybe a big ol 6" think trap right above my head? So what else can I trap/absorb to get most from my subs. 

One question on first reflection absorbtion. Right now I am using 2" rockwool on the sidewalls and the cealing but I feel like my klipsch rf7's still get a little brite on action scenes and the diolog could be a little better. I also have the pink fluffy (r11 6") on the front wall floor to cealing. Here's the question ....what should I take off and re-do..... and what can stay...... and if I do need to replace something what do I need to do IT RIGHT.

A little background on the room... its 15.5 X 23 X 9.5 I have the seating @ 60% of the room (closer to backwall). The subs are run in pairs (I have to wire them in series to show the amp 4 ohms) so two are strattling the center on the front wall and two dead center of the back wall. I am using an sms-1 for eq duties and xover settings. I have my front speakers as close to the screen (and as far out of the corner) as I can, but I have a 92" screen so there still somewhat corner loaded....I am crossing them over at 120hz that helps with smoothing of the subs. 

I feel like my room is still a little brite (reflective), and I should be getting more bass from my subs. I know I'm probably being critical but I think it could be better. Besides its a hobby and I need to work on something.


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## bpape (Sep 14, 2006)

Don't want to burst your bubble but the CS Ultra is down about 20db at 10Hz vs where it is at 40Hz

http://www.svsound.com/products/subs/charts/pc13_ultra_new_FR_popup.jpg

Even with 4 of them, if you're at 105 at 10Hz, you'll be at about 130db at 40Hz. 

As for overall bass, sitting with ears at 60% will put you in some serious problem areas. Try more like between 62 and 66% from ears to front wall.

Where are the subs placed in the room? To get a smoother response, try one centered on each of the 4 walls.

Bryan


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## pietsch288 (Sep 10, 2006)

so I need to xover lower to get rid of what I don't wan't. For example I've been xover at 23hz @ 18db slope.....which makes the bass more tolerable. So for the most part I just need to keep with the trial and error of xover and slope until I figure out what I like?

Ok.... well how about taming those klipsch speakers?? Would covering the front wall with 2" 703 help? Is the 2" rockwool good enough for first reflections? Do I need some diffusion on the back side walls? 
thanks rich


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## bpape (Sep 14, 2006)

6" on the front wall is an awful lot. 2" should be sufficient. Also, try some 4" mineral wool with an FSK facing bonded to it in the middle of the rear wall.

2" 4lb on the side walls for reflections should work just fine.

Bryan


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## pietsch288 (Sep 10, 2006)

So what would happen if I trapped where the cealing meets the walls???


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## bpape (Sep 14, 2006)

It'll help with overall decay time in the low end. May or may not help anything from a frequency response perspective.

Bryan


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## pietsch288 (Sep 10, 2006)

ok, thanks Brian.....I think I'll give it a try.


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