John Sayers' Recording Studio Design Forum

Hi Guys,

Here's two measurements from my home recording room - The Green is without my treatment in the room, the Red is with the room empty.

I have 2 4" floor to ceiling traps that straddle the front corners made from tontine acoustisorb 3, and six 4" 60cm x 90cm panels (filled with fluffy insulation' placed at the first reflection points; two on each side wall, two on the back wall, and two on the front wall.

I also have a few 3" slabs of acoustisorb which are laying in the wall/floor corners

But as far as I can tell, it's not really making much difference? not sure what I'm doing wrong but I'd love some advice. It is making difference to the reverb time, which is something, but the frequency response doesn't seem that different, and looks like it's having an effect on the mids at around 2khz.... is that normal?

I used Fuzz Measure and a Behringer ECM 8000, through a FF800 to measure the room, with the mic at my seating potation pointed towards the ceiling... so I'm a noob at this, and could really use some help

Thank

Pete

Actually, there's quite a difference between those two graphs, so it is making some difference! You can see an overall smoothing, and some of what could be modal issues seem to be getting better. But there also seems to be another issue (I'll get back to that).

However, acoustic treatment is not going to magically make the graphs dead flat, especially in a small room (what size is yours?). Acoustic treatment can iron out some of the major problems, but no amount of treatment will flatten the curve totally. That would be unrealistic. In fact, both of those curves are pretty normal for a small room. If you can get the curve flat to within +/-6 dB, then you are doing great, and even +/-10 dB is reasonable.

However, going back to that "another issue": Are you absolutely certain that you had the mic in the identical position for both readings? It seems to me that we are looking at different parts of the same room, so the comparison is not valid. It is imperative that you physically measure the exact location of the mic for every test, and that the mic is always in precisely the same location for every test, accurate to within about half an inch (1 cm). If you don't do that, then you cannot compare the readings, as you are looking at a different set of acoustics.

Also, did you have the speakers set up in exactly the same way, and did you do the test with just ONE speaker turned on? Actually, you should really do tests with first one speaker, then the other, then both at once, but the most useful readings will come from comparing the results for just one of the speakers.

So the mic should be positioned at the location of your head when you are mixing, and you should use the same speaker in the same place set up the same way, for all your readings. The same applies to the rest of the room: Don't do one test with just you sitting in there, then the next test with three other people standing around the room, a different console on the desk, and a new sofa in the back! Keep the room the same each time, in order to have results that you can compare validly.

It's not that each measurement is wrong if you don't follow these rules! All measurements are valid and tell you useful things about the room, but only for the specific location where the mic was for THAT test. The issue is that you cannot validly compare graphs from tests done at different points in the room, since you are looking at different acoustical patterns. You can test at any point you want, provided that it is always the same point, and since the most important point is the one where your head will be located while mixing, it simply makes sense to us that point as the reference point for all your acoustic testing.

So if you can, repeat the tests as outlined above, with the mic, speakers and room itself set up identically, using just one speaker (either left or right: it doesn't matter too much), first with no treatment at all, then with the treatment, and post those two graphs. Or better still, do separate measurements for each speaker, so you'll have before/after curves for the left speaker, and also before/after curves for the right speaker. Post all of those, so folks can take a better, more accurate look at how things are working out.

- Stuart -

_________________
I want this studio to amaze people. "That'll do" doesn't amaze people.

What "things" are you referring to? Please be more specific. Also, why do you think this is about "establishing ways for interaction with people"? What exactly does that have to do with building a studio? Are you even posting on the right forum?

- Stuart -

_________________
I want this studio to amaze people. "That'll do" doesn't amaze people.

Why do you think he needs to determine room modes (I guess you mean "modes", not "nodes") by calculation when he already has done actual acoustic tests and no major modal issues are present?

In what way would knowing the modal response of a room help you to design bass traps? Please explain.

Also, why would you need to re-calculate the modal response of a room after installing bass traps? The modal response will not change due to adding bass traps: the modes will still be present at the same frequencies. The only way to change the modal response is to change the positions of the walls. Treatment does not affect modal response much.

Why would you make that assumption when the OP never even mentioned drums? And what difference would drums make to the response of the room, especially considering that we are talking about a CONTROL room here, not a live room!

Why would you think that he is only recording guitars, when he said no such thing?

so your solution to treating the modal, RT-60, frequency and time-domain response issues of a control room is to throw a blanket over the amp??? Hooookay...


- Stuart -

_________________
I want this studio to amaze people. "That'll do" doesn't amaze people.