At what distance do different freq. reflections not cause CF

[TomM]

To better explain that subject line..

If you hit a drum close to a wall (hard), how far do you have to get for each of the frequencies to have week enough reflections to NOT cause comb filtering?

So for example...

At 3 feet away, would you have to only worry about 500HZ and below? Would you have to worry about all frequencies? Would 1500HZ be OK? Or 15000?

My concern is that my studio will be quite thin (aprox 10 feet wide and 18 feet long). Wherever I place the drums they will be close to the side walls. I'd like to minimize comb filtering though, but I don't want it to be unpleasently dead sounding.

The ceilings are only 7' 6" and I do plan on putting absorption on the ceiling above where the drums will be.

What do I do about the side walls? Should I just worry about bass trapping the corners? Or will the walls closest to the drums need absorption as well?

Should I get lots of bass absorption that reflects higher frequencies?

[Ethan Winer]

Tom,

> If you hit a drum close to a wall (hard), how far do you have to get for each of the frequencies to have week enough reflections to NOT cause comb filtering? <

50 feet?



Sorry, I got carried away!

Seriously, as you get farther and farther away, the first frequency gets lower, and the peak and null pairs get closer together, and the reflections also become softer making the peaks and nulls less severe. There's no hard cutoff point - it's all a matter of degree.

> I'd like to minimize comb filtering though, but I don't want it to be unpleasently dead sounding. <

That's always a problem in any small room. There is no good solution aside from getting a larger room or resigning yourself to adding all ambience electronically. My current catch-phrase is "Small room ambience is bad ambience."

> The ceilings are only 7' 6" and I do plan on putting absorption on the ceiling above where the drums will be. <

Yes, that too.

--Ethan

[TomM]

Hi Ethan,

What mix of acoustics should I use for this room...keeping in mind it's a mix room/live room in one.

I have four of your mini-traps. I already plan to get some of the HF mini-traps for above the drums. Can you recommend how many it would take? Maybe 3? that would give a 4' X 6' coverage.

I like the specs on the soffit traps you have and I was thinking of doing all four corners with them..

Is this what you would recommend?

I may keep some of the traps on stands so I can move them around... maybe remove them for recording... but because of being so close to the walls, i'm not sure. I'll have to experiment when I get everything set up.

I will also have mini-traps above the mix position... how many would you recommend?

Then what type of product should I place on the side walls?

Since the room is fairly long at 18 feet... I think I may use diffusion on the rear wall for mixing. I'm afraid that leaving it there for tracking (because it will have to be close to the drums) will do more harm than good..

Thanks!

[Ethan Winer]

Tom,

> I have four of your mini-traps. I already plan to get some of the HF mini-traps for above the drums. Can you recommend how many it would take? Maybe 3? that would give a 4' X 6' coverage. <

Yes, three HF MiniTraps will help a lot. I'd put one over the drums above where you'll place your overhead microphones, and one on each wall behind the drums (assuming the drums are near a corner).

> I like the specs on the soffit traps you have and I was thinking of doing all four corners with them. <

Most rooms do better with broadband absorption, so getting more of the standard MiniTraps is a better choice. SoffitTraps work really well, but only below 400 Hz or so. They're great for audiophiles and others whose spouse objects to the look of our regular traps. I assume you don't have that restriction?

> I will also have mini-traps above the mix position... how many would you recommend? <

The main goal is to treat the first reflection points, so most near-field monitoring needs only one or two on the ceiling, depending on how far apart the loudspeakers are. For this use you also want the HF type.

> what type of product should I place on the side walls? <

Other than the first reflection points on the side walls, I'd aim to treat more of the corners before worrying about the side walls. Unless you have large areas of bare parallel walls. In that case I'd use standard MiniTraps spaced off the walls 3 or 4 inches.

--Ethan

[TomM]

Yep...no wife restrictions... this part of the house is all mine


The reason the soffit traps were of interest is because I read that the bass in small rooms is hardest to smooth out because of not having enough space for bass traps. So they seemed really effective for absorbing the bass in the corners...

So OK, broadband absorption is better. Would the mondo traps be a better choice for the corners than standard mini-traps?

[Ethan Winer]

Tom,

> Would the mondo traps be a better choice for the corners than standard mini-traps? <

Yes, when the cost difference is not an issue MondoTraps absorb twice as much as MiniTraps below 100 Hz. But we should probably move this to email since many people object to sales talk in the public forums. You know where to reach me, yes?

--Ethan

[TomM]

Yep, i know where to reach you..

by the way, those video clips on your website are great! thanks for them!

thanks