The end of my room tuning adventures

[Dean Roddey]

Just wanted to post the results of a long and ongoing process of tuning my room, just so that folks who have small, non-optimal rooms like mine will have hope that they can get really good results. My room is lke 16' long, about 11' wide the ceilings are only about 7' 8". So it's pretty worst case.

Here is the latest measurements I did tonight. This is from 40Hz to 300Hz:



I've drawn a line down it about -10dB. Except for my one remaining, PITA, cancellation around 65Hz, everything is pretty much within about 1.5dB of that line. I could actually set up a Phase Linear EQ preset that would knock down those two small peaks and that would make it flat to within about 1dB other than the one cancellation issue.

I'm not sure what results other folks are getting, but as I understand it, that's pretty dang good. The remaining cancellation, I just don't think I'm going to be able to get rid of. There's no more space for broadband traps. I guess perhaps a tuned trap at the cancellation frequency is a possibility, but they are pretty costly and if it did really nothing for me, I'd be seriously PO'd, and there's not really any good place to put one if I had one, given the room size limitations. The part of it that's down more than 3dB from that line is probably only about 5Hz across, so it would only really affect a few notes badly, but I can hear it of course if a prominent bass line runs down through it the right way.

But, I guess I can live with it. It's still probably overall way better than many more expensive rooms.

It required a pretty bodacious amount of trappage. Just for reference, in case anyone reading this later wants some estimate, I've got:

1. A raw box of 703 on its side on the floor behind the speakers, so that's 12" thick.

2. On top of that, standing up on end, are two sets of 4" ones with a couple raw sheets behind that, so 10"s coming up behind the speakers.

3. A 6" trap on the wall/ceilng corner behind the speakers.

4. There are two 6" traps side by side (so 4x4') as a cloud overhead, but then 5 raw sheets slipped down the middle between them, so 16" down the middle line overhead.

5. In the left/right corners are two raw sheets thick with 4" bagged traps over those, so 8" from floor to ceiling.

6. On the left/right wall/ceiling corners are 6" traps with antoher raw sheet behind them, so 8" there, plus some 703 scraps thrown up in there.

7. On the wall/floor corner to either side are 6" and 4" traps, so 10" each there.

8. And there's a 6" on the wall ceiling corner in the back.

9. 4" ones on the two side walls for the first reflection point.

I don't have rear wall/wall corners that can reflect back to the listening position, so nothing to do there. Note that, other than #8, there's no treatment on the rear wall. It's a big sliding glass door with curtains and blinds, so it would be hard to treat. I could put a couple back there on stands I guess, but they'd be pretty intrusive. And I've stacked up beaucoup trappage back there and it's had no really measurable effect, so I've concentrated it elsewhere anyway.

That's a lot of 703 for such a small space. And huge amount of time spent rearranging them and moving the desk around and trying monitor orientions and positions, since theory doesn't always translate to reality in the complexities of a non-rectilinear room. So I did a huge amount of experimentation, measuring each change. I used a dbx measurement mic and a simple little clean pre-amp for the measurements, and a RS SPL meter to sniff around for energy buildup.

So that's it. I think it shows that you really can get good results in very sub-optimal rooms with enough trappage and enough trial an error. The result sounds fantabulous in terms of the clarity of the low end. The bass is so smooth and full and consistent. It's quite a pleasure to listen to CDs in there now just for fun. I didn't do any listening after tonight's binge. I was too tired and sweating like a pig. So I'll take a listen tomorrow night and it should sound even better than before. I managed to narrow up the remaining cancellation considerably this time and get the rest even tighter than it was.

[Ethan Winer]

Originally Posted by Dean Roddey

It required a pretty bodacious amount of trappage.

It always does.



Excellent, thanks for the report.

--Ethan

[Dean Roddey]

Oh, and I forgot to add:

9. 4" ones on the two side walls for the first reflection point.

[Scoobz]

I'm struggling with a similar sized room (but with a lower ceiling! )

Any chance you could post a pic of it?

[Dean Roddey]

Maybe so. I recently upgraded to Vista on my bedroom machine and haven't gotten the Nikon capture stuff working yet in order to get pictures sucked in from my ancient Coolpix 990 camera. I'll have to get motivated and do that.

[Scoobz]

nice one, I'm very interested to see how you managed to fit all that absorption in!!!

[Dean Roddey]

OK, here are some pictures. Definitely not Better Homes and Gardens, but it has good bass response...

[Scoobz]

Thanks for doing that it was interesting to see, from the way you described it, it sounded like a narrow tunnel you could walk down in the middle of all this absorption, then a pair of speakers and a chair in a cave of rockwool! lol
It's not that bad at all, you can tell things are there for a purpose.
That's how I'm getting with my room, at first I was only concerned with appearance, it gotta look sharp but after actually measuring my room for the first time in 6 years sharp is out the window!



Since that was taken I've got 4inch tiles all over the ceiling, I'm making ceiling/wall corner traps, I'm building some 4inch treament for the back wall.... the list goes on.....

Glad to hear you got it how you want it, and there's many professional rooms that would be envious of +/- 1.5db. My room, looking like it did in the pic was about +/-9db!!!!! Down to 4.5db now and hopefully when I'm done with the last wave of treatment about +/-3. Thanks for the motivation

[Dean Roddey]

Your room looks to be a lot larger than mine, so it should probably be amenable to good treatment, given sufficient bucks and fiberglass.

[Scoobz]

Nah, I was in the corner when I took that! It's 15x14x6.5 nearly square, with a low ceiling!!! Lovely!

[danbronson]

Craziness!

What's your RT60? That's important too, especially when working with reverb (too high an RT60 and you don't use enough reverb, too low and you use too much).

[Dean Roddey]

I'm sure it's quite dead. But I sanity check reverb and whatnot using headphones so that I know if I have too much.

[elan]

i dean i'm curious to see a your freq response graph, maybe with room eq or similar

thanks!

and compliments for the work!

[Glenn Kuras]

Originally Posted by elan

i dean i'm curious to see a your freq response graph, maybe with room eq or similar

thanks!

and compliments for the work!

Here is a link for it Dean
Room EQ Wizard Home Page

[Bender412]

Originally Posted by Dean Roddey

OK, here are some pictures. Definitely not Better Homes and Gardens, but it has good bass response...

LOL all those bass traps and 703 panels look like big bullies next to the scrawny little acoustic foam squares on the wall!!