Charlie,

I did a bunch of tests this weekend running pink noise through the system. I also did tests using sine wave sweeps, and 1/3 octave pink noise bursts. The results were very conclusive. The room is 129.5"x90"x94.5". Axial modes are at 52 Hz (long dimension), 75 Hz (width dimension), and 72 Hz (height). According to Auralex consultants I also have a really bad tangential mode at about 92 Hz. I really should post some plots of my room so you guys can realy see how *BAD* things are in the low end. We're talking huge crater. What I end up getting is a peak at 52 Hz. Then due to the 72/75 axial modes and the 92 tangential mode, I get this huge deep wide dip that looks to be centered around 83-85 Hz (if you average 72/75 and 92 you get about this). Then I have another peak at 143 Hz. This is mode due to the height dimension again. It's bad stuff. The rest of the frequency range looks pretty good in comparison. I do have a random sharp dip at 531 Hz but I believe this may be due to a reflection coming off a rack located too close to the mix position (just to the side of it).

I calculated 1/4 wavelengths for my mix position to see if I was sitting at the null of any of these modes. I wasn't. If anything it's helping me out by smoothing out some peaks. I moved the monitors around, and some acoustic treatments around, documenting each small change with a new frequency analysis plot. I pushed the monitors closer to the front wall and it naturally brought up that huge dip...now instead of being a crater its a valley--still sucks though. If anyone is interested I can post some plots.

Brad

I sit in the first third of the room. The monitors are about a foot from the front wall (I moved them to smooth out the huge dip I was experiencing--see my last post). High frequency absorption is not overdone--most of the absorption in the room are broadband absorbers. So there is roughly equal energy being absorbed across the whole frequency range, not just in the high end. I wish I could find another space...but I live in the San Francisco Bay area--rent isn't exactly what I would call cheap around here!

Brad

Jeremy,

I intend to work the acoustics of the room as best as possible before resorting to tuning with an EQ. But even guys such as Bob Hodas admit that the best solution is often a combination of the two. But you are right--no room is perfect. I'd be much happier with "kind of crumby" as opposed to "absolutely pathetic" though.

It's not really fair to say that the Mackies had an erratic frequrency response when you checked them with a spectrum analyzer. What you really measured was the room/monitor system response, not just the monitor response. I would say your room was probably the component exhibiting the strange dips and high end response. It's usually a safe bet to assume that the average small room is going to have inconsistent response. Althought the Mackies I'm sure aren't ruler flat, they are much more so than my room which has a acoustical abyss smack dab in the low-end--you can't change physics.

Brad

ASC makes a good little package called the Mix Station for making small rooms usable: www.tubetrap.com. You don't have to install it the way they suggest, but the materials are great. For example, putting the side baffles on the sides is controversial (I've done it but may change when some wide dispersion speakers I've been waiting for come out), and you can adapt it to your room (I have the front baffle overhead).

The Mackie monitors are very nice to listen to but have a definite smile curve. It's not just the room.

Brad -

Yep, that's a small room for ya. I feel your pain.

If you do go down the EQ route, please share the info & results - I have the feeling that my next place will have some, uh, challenges as well. Maybe we could trade acoustics geek stories - get out the Everest books and draw frequency plots over dinner. |:-)


charlie

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charlie bonnell
www.copperdalton.com

Charlie,

We definitley should exchange some information--it seems like we are experiencing similar problems in similar size rooms. Feel free to email me at bradmcgowan@yahoo.com and I can give you more details about my room and some of the tests I've done and the recommendations I've received from Auralex. I'm going to try building some diaphragmatic absorbers before I resort to EQ. On a side note Bob Hodas said in an email response to me regarding using EQ for room tuning: the [Symetrix] "552 is the best low end solution I know."

rawk on,
Brad

Brad, ARE YOUR MIXES TRANSLATING OVER TO OTHER SYSTEMS WELL?? Isn't that what it's all about? I can make a mix sound good in any room, the problem is it won't sound the same anywhere else.

I disagree with your assesment of what I said about it not being the monitors. I changed out my monitors and they were flat in the same room, in the same spot, where as before they wern't. It may be your monitors.

BTW, what are you useing for monitors???

Jeremy,

If you refer to my post nine messages back, I believe I answered your questions. But to reiterate:

Mackie 824's
mix translation not good

I used to have Event 20/20p's before the Mackie's. The Mackie's are head and shoulders better sounding than the Events. I agree with you that the response of the monitors do play a part, but in my particular case the room is the dominating factor. I'll really try to get up those plots I was referring to so you can see what I'm referring to. I think when you see them you'll be hard pressed to say that any kind of monitor substition will alleviate the problem. Unless of course you know of a speaker that has a 15 dB boost centered at about 83 Hz!

thanks,
Brad

My bad Brad, missed that one. So do your mixes have to much bass on other systems or is there a lack of?

Brad...

you know... it's all written in chapt. 19+20 (pages 399 - 428) of "The Book". Guess you gotta resort to calling the Everest directly... it's a long an' winding climb but it may be well worth it...

Cheer up...

Paul