Speaker placement (a must read for Belles and La Scala owners!)

[Mad Bat]

Ok, just a little bit of my history in order to let understand. Being back in the Hi-Fi passion after lot of years, two months ago I purchased a pair of Belle Klipsch, that have been in my dreams when I was a student and could not afford them. Then, I installed them in my house with a Rotel 966 Preamplifier-processor (I set up an home theatre with 3 Heresy II for surround and central channels). Anyway let's forget the home theatre, what I' m going to speak about is only stereo use. I attached the Rotel pre to my old glorious Luxman M-4000 (180W ch/ 8 ohms, a lot for the Belles, but ok), and I started play a CD. The sound was good, very good, but...I was missing something; the bass was very thin and someway "muddy". I started to think that the problem was the Luxman or the Rotel (I tried different cd-players, but nothing changed), so I went to a McIntosh 6450. The bass was better now, also the sound was more warm (good for the horns), but.... I was not really satisfied, still missing the "punch" I remember very well I heard from the big Klipschs when I heard them 15 years ago. The worst thing is that I could not tolerate the poor way they reproduced some kind of music (rock, disco, pop, etc.) and I was going to listen only to jazz and classical because this music was better reproduced with my Belles (this is not a bad thing, but anyway I would prefer to listen to some kind of music I was not used to because I want, not because my speakers ask for it). I tried every possible other solution to get better and more clean basses, but nothing worked. I was so frustrated I was starting to think about buying a couple of very big JBL monitors with two 15" woofers to put on side of my Belle's for rock music. Then... yesterday I started to think: maybe the acoustic of my room is so bad (the room is atypical, "cathedral" roof)? May I change something? What about the PLACEMENT OF THE SPEAKERS? So, I started a research on the net about how to place the speakers. Until then, I had my belles along the short wall of the room (like a lot of people, I think), about 3 feet from the wall (measuring from the front of the Belle's to the wall behind them), and 2 feet from the side walls (from the centre of the woofer to the wall). I look at various websites for what they suggest for placement, until when, through TNT-AUDIO (a very good Italian Hi-Fi net review) I went to this article in Genelec website (Genelec is a producer of studio monitor loudspeakers, if somebody don't know):

http://www.genelec.com/faq/faq20.htm

(The title is: I am not getting enough bass?)

This FAQ article really opened my eyes on a reality (cancellation frequencies) that I didn't know neither existed as a problem. Putting together all the information found in this article and in others, I tried firstly to put the Belles as close to the wall behind them as possible, even if I had already tried it as it is the common solution suggested to improve the bass. The result, as expected, was not good; bass even more "muddy" and still thin, and a lot of resonance. So, I tried what seemed strange to me, but was suggested: put away the speakers as much as possible from the wall behind them and from side walls. I put the speakers at 6.5 feet from the wall behind them and at 4' from side walls. My listening position now become quite near (8 feet from the front of the speakers), I was a little bit intimidated by having so big speakers so near, it seemed strange (and "unnatural") to me not to have them more far away. Anyway, I put on one of my CD and...... WOW!!! I really could not believe in what I was hearing! It seemed to have a BIG subwoofer in the room, but with a quality of bass sound that subwoofers I have heard (also some of the best) can neither dream to achieve, and also the mid and the high were a lot improved...Everything was really a lot, lot better (soundstage, musicality, smoothness of the mid-high, dynamics, detail, etc.) but the bass improvement was so terrific I really cannot find the words to express it. This is by far, far, far the biggest improvement I have had in my audio equipment, just moving the speakers some feet away from the walls. I enjoyed so much the really new sound (it seem now to have completely different speakers) that I spent almost all the night listening to all the different kind of music I have in my CD's collection, as all of them sound so much better. This morning I ask a friend of mine, another audio-enthusiast who has listened my Belles lot of times, to came and listen, and he too was absolutely impressed, said he never heard anything like this (the improvement). I am now writing this while listening to some now wonderfully reproduced rock (reproduced? It seems live now!) and my floor "rattle" as if I have a really big subwoofer while my McIntosh vu-meters tell me I am putting 0,1 watt in my Belles. This is ridiculous! All you Belles and La Scala owners, please try it moving the speakers far away from the walls according to Genelec, and who is luck enough to have a very big room and could keep the Speakers at 10 feet from the rear wall (this would be the optimum distance), could also have deeper bass! (Be careful anyway to the wall behind the listening position, it must be far too due to the "half wavelength cancellation frequency"). The thing that I like more is that this is the first scientific and predictable change I could do on my audio equipment (other than mysterious results using "magic" cables or other things!); we can calculate exactly where we will have "Quarter wavelength cancellation frequencies" and "Half wavelength cancellation frequencies", as well as the "minimum distance of the monitor to the wall" in reference to the -3dB low cut-off frequency of our speakers, and we would know exactly where we are going to put the notch on the frequency response of our speakers depending on where we put them in our rooms!

I hope not to give headache to Klipschorn owners that cannot move speakers away from the wall, but I think they are just perfect in the corners where they have been engineered to be, they are different from Belles.

Sorry for my poor English and for my length, but I really cannot keep only for me what I am hearing now (and also the biggest improvement I have ever had COST ME NOTHING! Funny, uh? Thanks a lot to Genelec that proves again, if needed, to be a respectable professional monitor producer).

Now, I really LOVE my Belles!

[Steve Phillips]

MB,

great post,enjoyed it a lot.I have K-Horns so not much movement there.

A friend has K-Horns using the Luxman M-4000,has used it since the early 80's.usually has the watt meters at 18.Yes loud!s>

My couch is 11'from my Horns and I've noticed on my spl meter w/test cd and just by moving a foot forward or backward that the bass improves.Good(or bad)old frequency cancellations hard at work.

The couch is in the middle of the room and I'd move it back some,but my side surrounds are there to stay.O Well!

[wired1]

Awesome article!!! I am looking to buy a pair of Belles or K-Horns and am not sure which. I have heard and love the K-horns but they are $5k and maybe to big for my room. I have never heard the Belles but they may be better for my room placement??? Any advice? Thanx!

[stormin]

Very nice article. Wonder how the chorus II's fall into the equation. Seems there are 2 extreme opposites for improved bass. (1) being as close to the rear wall as possibe and (2) being at a very large distance from rear wall. Being that the chorus II's use a passive radiator, wonder if that has another effect to the equation? Might be an optimum distance from corner for passive radiator as to let the pass breathe. Anyone else find a formula for the optimum distance from corner or rear wall with passive radiator? Thanks and again great post Mad Bat

[soundog]

I have found speaker placement made a big difference with my LaScalas ...when I acquired my K=horns I was forced to learn how to adjust room acoustics through use of diffusion, reflection and absorption. A lot of reading on the net and experimenting with materials in the room. Bad acoustics can make a great speaker sound bad.

[Kevin Merritt]

If you're looking at Belles, you NEED a big room. I've got a set in a 13 x 16 room mounted about 9 feet apart on the long wall. They sound 100 times better than when I had them on the short wall. For years I have worked with speakers and design... the Bells are , by far, the most temprimental speaker to place. The sweet spot couldn't be much smaller. Let me repeat, you need a big room. I would guess that a good size would be 20 x 30 or so. I would be upset if I paid full price for these bad boys. Granted, they sound very good in the sweet spot but only "fair" outside that small area. I wish I had a bigger room to take full advantage of them.