Positioning Vandersteens


This is a two-part question and since the parts are related I think one post is appropriate. First part is regarding a recent thread about speaker placement in dealer showrooms in which a couple of folks commented on the difficulties in properly placing Vandersteen speakers. This is interesting since I am in process of trying to get my 3A Signatures properly located in my somewhat small room. I’m having difficulties, primarily with a bass boom, and was hoping someone might be able to relay their experiences with siting Vandersteens. Comments on whether these speakers are appropriate for my room (see below) would also be appreciated. The second part of the question relates to the room itself, I recently measured the room with my Radio Shack SPL meter (using the Rives Audio test procedure and the Stereophile Test CD) and found, to my amazement, that the room was only flat from 400 Hz to 1000 Hz, the readings dropping off steadily such that at both 100 Hz and 10,000 Hz the readings were 20 dB down. This seems rather extreme to me, anyone else have similar findings? Specifics on the room, overall it is 17’ 3” by 14’ 8” with 7’ ceiling, however, it is reduced in size by a partial, full height wall through half the width making for a 13’ 4” by 14’ 8” space where the speakers are. To make matters worse there is some ductwork (boxed in and insulated) running along two walls. Because of the odd shape most or all of the acoustic software for siting speakers won’t work. Particulars of the system: Audio Research SP-9 MK II, Audio Research Classic 60, CAL Tercet MK IV, VPI HW-19 MK II, McIntosh MR-71, and PS Audio P-300. Some assistance in this process from those who’ve been there done that would be greatly appreciated!
pmotz
1. For bass control try experimenting with distance between speakers and the wall behind them, and with placement of your listening chair, relative to the wall behind it.
2. In the room you describe, I would concentrate on optimizing a near field listening position. I own a pair of Vand. model 3s, and prefer them in the near field.
I agree with Judit. I used to have a pair of Vandersteen3A Sigs and found that the instructions that Vandersteen provides work very well. To minimize some of the problems you are having with bass control, I would suggest moving the speakers away from the wall (I had them about 38" away, rear of the speaker to the wall) and aiming them towards the listener, with the speaker axes crossing just behind my head. The vertical tilt of the speakers is extremely important, since the vertical band in which they sound good is extremely narrow (only about 6" high!).
Pmotz, for acoustic modeling software that works in odd shaped rooms take a look at CARA CAD. My room is L-shaped, has a cathedral ceiling w/beam, irregular end wall heights, etc. and CARA modeled it just fine. The results match fairly closely those from an SPL meter and test tones.

CARA doesn't completely replace experimentation. It does provide useful insight into what is happening acoustically which aides in decision making and "what if" scenarios.
I also agree with Judit & Kweifi, I moved my 3A sig 4 feet from the rear walls and added 2wq's, It's heaven when you get it right! Tilt is the tough part, I had to order extra spacers to get the angle right with my listening height. But it's worth the trouble, I never think about my speakers any longer, I just listen to the music, never been happier with any purchase as I am with the Vandersteen 3A sig. Take your time and listen, when you get it right you'll be pleasantly rewarded, well you already know, that's why you bought them!
Good Luck.