Axiom Home Page Forums General Discussion Home Theater Room Treatments

I'm looking for any one with experience that can lead me in the right direction about room treatments. I have been looking at some of the Auralex roomanator kits and bass lenrds. I was told that foam doesn't do anything acoustic wise, so I was looking at the Owens Corning 705 FRK and thinking about doing 48"X24"X2" panels. I want to frame them with wood, but what would be a good backing and front covering. Any input would be appreciated or give some suggestions on something. Thanks

Muslin or similar open weave cloth. If you can blow easily through the cloth it will be acoustically transparent.

I used reg 703 with no FRK for my first reflection panels and for my corner bass traps. Here is an old thread.

http://www.axiomaudio.com/boards/ubbthreads.php?ubb=showflat&Number=144079&fpart=1

cool thanks, so just drawing the fabric tight front and back should work. 24" is a little wide for wall to ceiling so cutting them in half and doubling them up in the corners.

so 703 would probaly be cheaper? Did you just hang any on the wall flat or just corners. I'm getting a bad null between 50ish hrz up to 70ish. The test tones rise in db's and then around 50 it drops off to almost nothing and then starts rising again around 70. Thats why i'm not getting the mid bass. Room treatments are first then getting the Velodyne sms 1 this summer.

I never priced the 705, but I'm sure the 703 is probably cheaper. I think I paid about $120 for 12 sheets of 12 x 24 x 2 at a local insulation distributor. My side "first reflection zone"(FRZ) panels are hanging on the wall. I had my son sit in the primary seat while I slide a small flat mirror along the walls/ceiling, when he saw the tweeters I placed a sticker at that point. This is where the middle of my FRZ's are mounted. Just used some heavier picture frame wire and some eye screws to hang them.

For corners you can either use the 12 x 24 x 2 inch panels to straddle the corners, but Ethan from Real traps says you need at least 4" for corner bass traps to be effective. I decided to cut triangles and fill the entire corner.

In my opinion, the treatments should help, but you may never get rid of the dips. I had a SMS-1 also, but sold it as I found that with proper sub placement, and ordering multiple subs placed around the room, you get great reponse and don't need the SMS-1.

I should have my new Denon 3808 soon, then I can start experimenting with Audyssey.

I have 6 sheets of 703 left over, but I"m sure you don't live near Iowa.

I am no expert on room treatments, but from what I have read you will need panels thicker than 2" to treat problems in the 50 -70 hz range. I would go with 4" panels and/or corner traps.

yeah i found some 48x24x4 panels of 703 fairly cheap, 24" wide is kind of large for wall to ceiling so I was going to cut it to 48x16x4. Then do the same for the front corners. I was going to get the sms 1 eq because i'm very limited as to were I can put the sub only the 2 front corners will work, the other corner I tried seem to be a giant null totally, sub sounded like it was in another room. So the panels and the audessy should help I hope.

Hi gtpsuper,

As Sir Quack has pointed out, probably the most cost-effective solution for getting much smoother distribution of deep bass throughout a room to most listening seats, without the severe nulls and peaks common to most rooms used with a single subwoofer, is to use two subwoofers carefully placed.

I'd also point out that a home theater is NOT a recording studio control room, and that setting up panels to absorb the first reflections will considerably reduce the spaciousness of the front main speakers--their ability to image beyond the boundaries of the speakers. Lateral reflections in concert halls (and outdoors) are what cue our ears and brain to the "size" of the front image, and absorbing those first reflections will reduce the apparent width of the musical source.

There may be exceptions if you have an extremely "live" and reflective space with too many bare surfaces, but generally, despite the wrong advice doled out by "room treatment" vendors and manufacturers, you do not want to absorb lateral first reflections from the front speakers.

Regards,

Alan

So I guess what your saying is that by putting of "room treatments" will not really improve sound, but make it worse? Someone told me that my sub is already overkill for that size room 15x9 a SVS 25-31pci. If I could find a way to make a graph of in room response, I will post it and see if anyone can give any info. The main speakers are just bookshelfs M2's right now, so I just need to smooth out the freqencies below what the M2's are capabiliby of, I have them set for 100hrz cutoff with the sub cut off at 120hrz, but the 50-70hrz is drasically rolled off to almost inaudible levels using DVE audio test 15-300hrz.

Hi,

I'd suggest trying an 80-Hz crossover frequency for the M2s and your subwoofer and see how it sounds. The M2's bass response is quite strong and smooth down to 70 Hz, as you can see from these NRC anechoic frequency response curves:

http://www.soundstagenetwork.com/measurements/axiom_m2i/

To your first question, while I'd acknowledge that every room is different, if you have a reasonable mix of both reflective and absorptive surfaces--carpet or area rugs, some upholstered furniture, some bookshelves or objects on the side walls to just break up the reflections a bit (not absorb them)-- there's an excellent chance that you don't need any room treatments. You certainly don't want to overtreat a room so that it ends up being quite dead. I've heard some "professionally" treated rooms that were so dead it was like listening on headphones. Very peculiar, with the surround signals appearing in the middle of my head because there were no natural reflections taking place in the room near and around the surround speakers.

Alan

Thanks for the help everyone. I just ran audessy on my receiver (onkyo 605). But I noticed that its 2EQ, which according to Audessy's site "2EQ measures 2 room positions, uses a basic resolution filter for the satellites and does not apply a filter to the subwoofers." It did set the fronts to 80hrz, the center vp150 to 150hrz, surrounds to 60hrz. The sub crossover is still at 120 but it set it to -8Db. What I am thinking about now is going ahead and getting the SMS-1, put the sub in my seating area and use the mic to do the sub crawl, take a picture of the screen of what it read and then go to next spot and so forth. Then put sub in the best spot and run sms1 again to fine tune. Does these seem like a good idea?

Hi gtpsuper,

Yes, a good idea, but don't rely on Audyssey so much. It's very error-prone. The VP150 has good bass down to 90 Hz. I have no idea why Audyssey wants a crossover at 150 Hz --clearly, it's in error, as is the suggestion for setting the surrounds at 60 Hz. That should be at 80 Hz.

Regards,

Alan