Trapping sub bass

[MJGreene Audio]

You can cover them with reflective material if you want to retain the highs. I covered them with 3"703 and cloth and it works great.

these hangers would fit perfect in your ceiling and if you trap the corners with 4" of 703 and built a 24" deep trap on your back wall filled with the hangers that would make a Huge difference.

Hangers do tend to work better at High SPLs,

they are super quick and easy to build

You can hang them with rope , chain, heavy wire or plumbers tape.

I did this in the 4 foot space above my drop ceiling in my old room. It worked wonders. It really fixed a bunch of issues very quickly and easily. With some cosmetic work also you could do this above your mix position and get great results.

ake an hour or two, get some long xlr's, and just move those damn adams all around that room with a good ref recording playing, and have no regard for practical concerns such as 'mix position' or 'basic human esthetics'. just move them everywhere.

as you're doing this, move yourself around and listen to everything. make them really wide and sit twice as far back as you normally do. set them up catty-corner, set them up near the middle... go nuts, and listen to what's going on.

somewhere, somehow, you should find lots of places where the bass is deep, if uncontrolled. if you don't, the problem is not your room. i'm with thrill, a total dropoff sounds like something else is going on. even the tiniest rooms with the most horrendous nodes and nulls still have lots of audible energy sub-60, it's just untamed.
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I think this should be your first plan of attack. Ethan can tell you for sure but I think the mix position should be 30-34 % from the front wall. I can tell you from personal experience that this works most of the time but not all the time. My room ended up being a bit under that. And my biggest point? When it was at 30% I had huge bass null problems. Much like you are having. I hate to say it but as much as a couple of inches can make a HUGE difference in the response.

I am curious about your bass trap design. Did you come up with this on your own or did you find it somewhere. I ask because after spending a year of research before I built my room I never saw any kind of design like what your using. I don't want to burst your bubble but I don't think they are doing squat. You need brute force corner trapping and lots and lots of it. It isn't so much about tuning it for your frequency's. It you trap the corners as high as you can with deep and massive amounts of 703 or mineral fiber you will probably find a number of your problems go away. With the problems you mention it sounds like your going to have to take a bit of a brute force approach to get started. You have some serious bass phase issues and its driving you nuts.

Do you know about the John Sayers site? http://www.johnlsayers.com

It is a gold mine of information and John is very helpful. Between the people on his site and Ethan's help I was able to get my room working in very short order.

The room I have now is a Studio Bauton room and the bass trapping is amazing. All the corners are trapped with 703 boxes about 3 feet deep and also there are boxes built along the ceiling edges from front to back about 2.5 feet deep and 3 feet wide. The bass in my room now is stupid tight. Just incredible. Its not that big but it has become the perfect mix room for me. The best part is the priciples they used are basically everything I have mentioned above.

I know you have put a lot of time and money into your room already but I think it might be time to rethink your approach.

Michael Greene

[djui5]

Originally Posted by MJGreene Audio

I did this in the 4 foot space above my drop ceiling in my old room. It worked wonders. It really fixed a bunch of issues very quickly and easily. With some cosmetic work also you could do this above your mix position and get great results.

Michael Greene

This is my plan of attack, something similar to Steve's hangers....sorta.

The "bass traps" I built were based roughly off Ethans wall trap designs on his site, the low freq one with the front board, then the sheet of insulation, then the space between the insulation and the wall. I changed it a little though, as there is no wall, so I used a 1/2" sheet of plywood instead, and the space is more like 5", and I didn't use 703, I used that attic crap.
It did help a little. I noticed a touch of a difference. I can slightly hear the sub bass, were as before I couldn't hear anything at all...literally. Now, if I turn it up loud enough I can hear a touch of it. Filling the speaker stands helped a touch too.

My thought behind the big black thingees was that the bass was traveling to the back of the room, bouncing back and canceling out. I thought if I built those things, it would stop it and I'd hear the bass. Although it helped a touch, it was quite a disappointment. Maybe I build them wrong? Or maybe that wasen't the problem in the first place...who knows. They did help, so I'm not taking them down...plus they look nifty....

I'm gonna fill the corners with more mineral wool (the corners that are fabric wrapped now), throw some "hangers" in the ceiling, and 2 4'x8' traps on the wall behind the speakers.

As for moving the speakers around, I've done that many times before. Nothing helped much. The only think I haven't done is turn the whole rig 90 degrees, and I would prefer not to. I'll address it as it is.

[stevep]

I'm gonna fill the corners with more mineral wool (the corners that are fabric wrapped now), throw some "hangers" in the ceiling, and 2 4'x8' traps on the wall behind the speakers.

If you fill the back wall with hangers make them 2'wide 8'tall 1/2" and 3/4" thick mdf or particle board and use linoleum or Masonite for the ceiling hangers (lighter and easier to hang) and fill your corners with 703, that will make a big difference !

You need to fill the space completely, just so the fiberglass touches , but the wood can not touch, it must hang freely so it can vibrate.
And stager them or use a haring bone pattern so the waves get mangled.

I think i forgot you don't really have a back wall...........

with that window and a door there it will limit your trap size,........

Hmmm..

You could build a weak wall say 5 feet in front of the entry way and then that would act as a trap and also give you some privacy from the luneys outside



Email me and ill give you my phone # if you want.
Also i can send you some links that might help


steve

[DirkB]

Originally Posted by stevep

You could build a weak wall say 5 feet in front of the entry way and then that would act as a trap and also give you some privacy from the luneys outside

That sounds like a very good suggestion. Since your room is pretty deep, you have the space for it. Why not build a foot deep of 703 type of stuff. That will definitely help a bit. Although I am not certain with a cavity of 5feet or something how much there performance is diminished.

I hate to say it, but I first impression was also that, although the traps look great, even if they work, can't be doing much.
Filling the corners and adding hangers seems the right way to start. Important though with any kind of basstrapping though, is that you need a substantial amount of traps relative to the room to really make a difference.

Why post your situation over at John Sayers forum? You'll get plenty of solid advice for free!

Good luck,
Dirk

[Ethan Winer]

> How do you go about tuning your deep bass traps? By increasing the spacing between the insulation and the wall? <

You lower the frequency by using a larger space, or a more massive front panel, or both. The formulas are in Everest's book, and Phil O'Keefe also posted a link here in my Acoustics at MusicPlayer.com:

http://www.musicplayer.com/ubb/ultim.../t/000826.html

Click the link in the second post down.

> What if there was no back to it? If it was only a front panel, insulation, and no back? How would that effect the response? <

A wood panel trap will not work right, or even at all, if it's not sealed air tight.

--Ethan

[djui5]

wow...this is crazy.

I flipped the S3A's over (the mid was on the bottom, now the sub is) and the bass is a LOT better. I also switched them too, to keep the ports inside. Amazing...

[stevep]

Nice !

Its good to hear you got some progress.....




Ive been working on some sub nulls so i feel your pain,

even with all the trapping still ....... nothing is perfect

but a 60" subwoffer might help



steve

[djui5]

Originally Posted by stevep

but a 60" subwoffer might help

http://www.audioheritage.org/images/...cts/maxell.jpg

[rara114]

Originally Posted by djui5

wow...this is crazy.

I flipped the S3A's over (the mid was on the bottom, now the sub is) and the bass is a LOT better. I also switched them too, to keep the ports inside. Amazing...

I just moved my S3A's from my room into a new room and they just dont sound they way I remember them sounding... I'm gonna try all the in/out/up/sideways combinations and see what happens... I remember the last I did this.
What sounded the best didn't translate the best. The best translations came from horizontal b on the left and a on the right. Vertically with a on the left and b on the right they sounded BadAss but it was more of a hi-fi audiophile music playback setting than a studio reference setting. TRANSLATION IS WHAT WE SEEK. I understand that difference now. I find the S3A's do different things when you are off axis vs. on axis triangulation, sometimes good, sometimes bad. Every room will be different. Tweak the postions until you gt good results. An inch here and there and a few degrees this way will make all the difference.

good luck!