Ed,
Sorry, I didn't mean that to come off as confrontational as it probably did.
I'll be happy to address all your points because I know in the end I will win you over with logic and facts.
> In the frequency ranges that bass traps are supposed to take care of, there was not any difference in what I heard, nor in the mixes referenced on many other systems. <
I really wish you told me what kind of bass traps they were. Lots of people buy foam corner blocks and think they have bass traps. But maybe you understand the purpose of bass traps, at least in a typical control room, which is mainly to flatten the low frequency response rather than reduce reverb time. I assume you haven't yet read my Acoustics faq at Recording.org so I urge you to do that. It's a long piece, but an easy read with no math or physics.
> the only time I have read much talk about "bass traps" is either from you, or companies that build them. <
Then you're reading the wrong material In another thread in this forum John Sayers told me yesterday how he built an entire wall of 2x2 foot bass traps. I was at Avatar studios in NYC a few weeks ago and they asked me to bring by a set of traps to help them with bass problems in one of their control rooms, because the traps they have now do not work well enough. Nearly every major pro facility has low frequency absorption, often built into the room behind a fabric screen. Saying that nobody cares about bass traps except the people that sell them is like saying nobody cares about cars or instant coffee or breakfast cereals except the people that sell them.
>the discussion about controlling the listening environment revolved around the low mids, NOT the lower frequencies. <
Then maybe it's just a matter of semantics. A lot of folks don't realize that 100 Hz.
is a low frequency. To me, anything that absorbs at, say, 250 Hz. and lower is a bass trap.
> John Sayers, who has designed studios that bands I have heard recordings from, actually supported my comments. <
John said that adding bass traps to a control room doesn't make any difference? Please show me were he said that!
> MY experience has been that bass traps installed have done little to improve the overall listening experience in most environments <
Again, please tell me what type of bass trap you are talking about. ASC tube traps? Foam corners? Panel traps like mine? Modex corner traps?
> On a RT calculator, when all room dimensions and materials were entered in, I got this for RT times: <
You're looking at the wrong information. What you need to do is find where the response peaks and nulls are, and how severe they are. Variations in the low end frequency response as large as 15-20 dB. are common, and these are
far more damaging to your ability to record and mix than a little extra LF reverb.
> I see a glaring problem of balance in the RT times of a room like this! <
Yes, that's important too, and I surely don't mean to imply that frequency response is all that matters.
> I use Event 20/20's. While they go fairly deep in response as near field monitors go, I don't EXPECT them to give me much useful info below say around 70-80Hz. <
Those are rated down to 50 Hz. +/- 3 dB., right? Then you should be able to get that response from them. In fact,
this is precisely what bass traps are intended for - to reduce the acoustic reflections that cause holes at the lowest frequencies.
> What earth shattering improvements will bass traps give me in this room that would make me put a priority on building them over say some mid absorbers and some possible diffusion? <
All of the above explanations, plus the section about bass traps in my Acoustics article - especially the graphs of before and after low frequency response.
--Ethan
). Enuff said.
SoMm
