Hang on! This is a long one.

Many topics ago, the subject of exhadurated low end, and changing EQ in different parts of the control room came up. At first, people were wondering if the da7's sound characteristics were to blame. I was experiencing a similar situation. I think one of the Jeremys even went to a movable partition, instead of a fixed wall with a window. I solved my problem, with the help of a guy in L.A.

I consulted John at Steven Klein's Sound Room in Van Nuys, CA. They design studios and sell thick, dense acoustic foam, etc. In fact, Steven engineered a lot of the Bee Gee records.

I put 2'x 4', 4" thick panels on the wall (the front wall) directly behind each monitor, and centered the panels vertically. The monitors are on pedistals 15 degrees above ear level, and about 9" from the front wall. On the side walls, I placed 3" thick panels of the same size, and centered them vertically at ear level, ending just past where I sit.

Then, one 3" thick 3'x 4' piece went on the ceiling between the monitors and where I sit (a per the audio room guy's recomendations).

Man, it's beautiful ... night and day. It's a whole new deal. No bass build up in the back of the room (a 7'x 14' space) and the sound is consistant everywhere. I also spread the monitors to about 5.5' apart (my max in this room)and about 4" from the side walls, and positioned myself further away from them and the console.

The stereo imaging is now unbelievable. The smearing and imprecise, moving imaging that I experienced when I moved my head and/or changed my position slightly is gone also. I feel like I'm painting a mural on a huge canvas.

Basically, reflections and build-ups from the front wall (and secondly,the ceiling) were responcible for the bass problems, even though I had sound board and some acoustic tiles up. The stereo imaging was messed up by the mids and highs bouncing off the side walls and ceiling (and the fact that I needed wider spacing between the monitors).

Moving the monitors back closer to the front and side walls, in front of this dense foam, allowed the foam to suck up the low end before it became a bigger problem. And, the fact that the foam panels met in the corners, eliminated the bass build up there (a bass trap).

The foam panals are not cheap, but even if you only treat the front wall in back of the monitors, I think it worth it. I believe it's the best money I ever spent (except for the da7, of course). There's nothing wrong or abnormal about the da7's bass responce, it's the damn room.

I hope this is helpful, and once again, I apologise for being so long-winded.

Thank you Clegs.
I like this kind of advise.
I too consider that monitor positionning is fundamental. Have to try several small displacement.
Night and day, that's true.
Philippe.

The DA7's low end is huge. Monsterous.

Putting absorbent material on the side walls is the conventional wisdom, but Dave Moulton (Golden Ears audio eartraining, one of our writers, Grammy nomination for best engineer of classical recording [go Dave go!], audio guru, etc. - not in any particular order) makes a persuasive argument that the side wall reflections actually help imaging.

And he's demontrated this to me with his wide diffusion monitors, so it's not just talking out of the rear end. I'm now officially convinced that diffusion from the side is sometimes a good idea, but absorption isn't.

LEDE is definitely a good idea, though. Absorption behind the speakers definitely helps. Windows with thick curtains (to remove reflctions) work well as bass traps, by the way. A lot of people don't realize that and block off their windows.

Wow, LEDE! Can someone refresh my memory of LEDE? Which end should be dead? Isn't it the end where the monitors are (...cause the early reflections aren't "heard" as discrete reflections but instead combine with the direct sound from the loudspeaker and thus skew frequency response)?

I believe Chip? Davis pioneered this LEDE technology thing. I think you're right, dead end is the monitors and live end is the rear of the studio (where the important folks sit!).

- Greg

Actually it was Chips Davis and Don Davis (no relation). The back of the room isn't just LIVE, but refractive.

The monitors should also be phase or 'time' aligned. The early LEDE rooms used Urei 813 monitors where the high frequency driver was delayed slightly to compensate for the voice coil of the woofer being behind the voice coil of the HF. By delaying the HF, the concept was that the HF and LF are aligned together in TIME!!

A present day example of this would be the larger Tannoy monitors where the HF driver is actually inside the woofer and both voice coil are aligned. It's an incredible difference in sound!! The difference was very obvious in a LEDE room done correctly, too.



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ERIC SEABERG • San Diego, CA
eseaberg@turningpointradio.org

When I first started treating the walls of my studio with very expensive foam( not the
kind you can blow air through) I way over did it. I covered every square inch so there was no wood paneling showing.Then I had a session with a drummer. It sounded horrible.
The cymbals sounded dead, no life or high end, it was boomy and thuddy. I tore it all down, reinstalled it this time with about 4 inches of reflective wood showing. It helped but the room still didn't sound rite. Eventually I ended up with 1x1 ft. squares
3 thick with about 5 inches of reflective wood between them. The room sounded better. It is quiet but not totally dead. I don't think it's a good idea to have all surfaces
absorbant, you need some reflective surfaces
for high end. A good friend of mine who is a acoustic engineer says listen to how music sounds in a room as your treating it. Is it really bright or dead, mid rangey and boomy?
Place the treatment untill it's neutral sounding. Sinse i've opened up my room, it's now 15 ft. x 26 ft. , the monitoring is great.
Very even frequency responce. And the drum sound is much improved.

Good feed-back. My comments that follow are what I was told by the guys at Steven Kleins, and also what I've gathered over the years.

Each room is a different challenge, and one's approach and limitations are different too when you piece-meal a studio of your own together (like me), on a reduced budget. In addition, and I believe this is probably true for most of us nowdays, we're using near-field monitors instead of those monsters we used to use. Those dinosaurs really needed space and sophisticated studio design.

Yes, the back of the studio should have defussing surfaces (shelves, racks, and other uneven surfaces of varying density, and angles).

Density is the only thing that's going to absorb low end energy (and curtains really aren't going to do it as far as "boom" goes). On my front wall (behind the monitors) I had two layers of sound board on top of the standard studio wall (sheet rock, sound board, sheet rock, air space, then repeat). I didn't start to cure the bass build up until the 4", super dense foam with the egg-crate defuser surface was place behind the monitors and on the ceiling. Unlike the thinner foam, which abosorbs only high end and upper mids, this thick stuff absorbs more evenly across the tonal spectrum.

Jeremy mentioned that after treating his walls with foam, the drums sounded dead and lifeless. Perhaps this was due to the foam he used not being dense enough, and as a result, it was mostly absorbing only high end. Also, maybe the dull and lifeless sound was really more representative of the source material ??? If this was the case (or a contributing factor) the fact that the monitor and room weren't "hyping" your sound was a good thing in that it cound make you strech for different mic choices and/or placements.

Jeremy, your acoustic engineer's comments made no reference to the type of foam being used and it's density, or the size of the room being treated. In large studios and control rooms (especially with higher ceilings), you can use more wood and other more reflective materials(on the walls, floors, etc.) because the sound has space to blossom, defuse, and disipate before the reflections reach the mic or (in the case of the control room) one's ears. In monitoring, what we want to hear is the direct sound first, and as little of the first reflection(s) as possible.

An even, balanced representation of what's coming out of our montitors should be what we are striving for. If your room's walls, floors, and ceiling are collectively allowing you to hear the direct signal first, and are modulating the reflections (especially the first reflection) and returning the reflections to you in a tonally balanced way (collectively), you're going to have a good monitoring room.

I think what I found is it's easy to absorb high frequencys, more difficult to absorb lows. As a general rule of thumb, you can get a pretty good idea of what the treatment is doing by how the room sounds when you listen to some music in it. Reguardless of what type of foam your useing. It makes sense. The foam i'm useing is very dense.
What happened when I recorded the drummer was that the foam absorbed all the high's leaving the mids and low mids to make the room sound boomy. You can't absorb everything
in a smaller typical basement, so you have to find the best medium for the most even absorbtion. Covering all surfaces with no reflection can kill all the highs. What worked for me was useing the 1x1x2"s 3 thick
so they stuck out from the walls about 5 inches with gaps of about 8 inches between them. This way easyly absorbed the low mids and highs but didn't make the room totally dead sounding. The drum sound now is fantastic.