SBL's How far from Wall
Posted by: greeny on 21 March 2002
I've recently had a move around and changed the position of my SBL's to fire along the room rather than accross the room (20ft * 14ft room)
Now, when firing accross the room I had them 2-3 inches from the wall approx 8-9 ft appart, and bass was excellent, deep and punchy.
Having moved them to fire along the room I'm having difficulty getting controlled punchy bass, it seems to be boomy. I started with speakers 9ft apart just over 2ft from each side wall (I used a room modes spreadsheet written by someone here for suggestions), this was miles too boomy. I now have them approx 7.5 ft appart, just over 3 ft from the side walls, this was also much too boomy so I've started moving them away from the back wall. They are now 7 inches from the back wall and this is better but still boom with heavy bass lines.
The question is does anyone else use their SBL's some distance from the back wall >7 inches?. Obviously I can move them further into the room but will I lose out on anything else?
Could this by a symptom of a damaged seal? (I've not rebuilt them after the move).
Another complication is I had been using 135's and an LP12 front end, but the 135's are going for service and I'm awating a new cartridge for my TT, so the source is my seldom used CD3, and I have an old NAP110 as the power amp. But I'm not compaining about other sound quality aspects here, just bass strength. In my experience bass will not be reduced with 135's/TT though it could be more controlled.
Posted on: 21 March 2002 by Bosh
I had problems getting mine to sound right at the new place, mainly due to the dry-lined cavity and fireplace between them causing excessive bass boom.
I have still not fully resolved this but found moving speakers away from wall helped but loses definition and especially snappiness. Moving further apart (6ft to 8ft) did the same but put a hole in the middle. The ideal was 7.5ft apart, 4 inches from wall, with the resultant slight hole in the middle closed by slight toe-in
Interestingly a quick dem with a Supercapped prefix (in lieu of HCap) totally resolved this.
Good luck with the experiments.
Posted on: 21 March 2002 by ken c
i have my sbl's very almost hard up against the back brick wall, about 3". the only reason they are not closer is the skirting board and the fact there is stuff around the speaker that makes any reconfig very hard. i would play with one variable at a time --
enjoy
ken
Posted on: 21 March 2002 by Bruce Woodhouse
Hard to generalise but with every centimetre furher away from the wall I find the sound progressively 'falls apart' with my recently re-installed SBLs. I was playing with this yesterday! and ended up 4cm away and no-toe-in where they now fill my (smaller room) with effortless sound.
Simple I know but check the spikes are tight and making good floor conatct on all four corners-this does make a lot of difference. I am not sure how you can check the seals easily without taking them apart but I reckon that this is quite a possibility
Bruce
Posted on: 21 March 2002 by ebirah
I was recently comparing shahinian Arcs and SBLs in the same room and for reaons I wont bore you with, had to have the SBLs about 12 inches away from the back wall at one point in the dem - I was surprised at how good they sounded in that particular environment. They were better hard against the back wall though, but the difference was less than I had thought it would be. I'd just place yours where they sound best, even if it flies in the face of accepted Naim doctrine...
Steve
Posted on: 21 March 2002 by garyi
If you have lifted the speakers for placement then I suggest a look at the seals as you have pointed out.
Posted on: 21 March 2002 by greeny
I may check this.
Raises a question though. If you can't move them at all, how do you find the best postion?
Posted on: 21 March 2002 by garyi
I would say that you can move them within reason, luckily I have wood block floor so they can be slid on penny peices with little effect on the seals. However if you havn't touched the seals in a long time then heft them about the place and then get boomy bass from whense there was none then its resonable to check the seals first. remember the washing up liquid for gawds sake.
Posted on: 21 March 2002 by Rico
quote:
Could this by a symptom of a damaged seal? (I've not rebuilt them after the move).
Absolutely. This is the first place to start.
Rico - SM/Mullet Audio
Posted on: 23 March 2002 by J.N.
I've had mine for seven years and love 'em.
I've also humped them around the room a fair bit and tried to deal with similar room problems.
Careful lifting and re-siting should not upset the seal. They are designed for boundary placement and if they are booming, I would say that's it's almost certainly a room problem because I've been there.
My experience teaches me that although one cannot disregard the laws of physics; I've given up on mathematical computations or computer programs coming up with the answer.
There is no substitute for (gently) humping them around the room. Is the room sparsely furnished?
'Busy' rooms tend to sound best. More sofas/soft chairs is a good place to start.
Don't overlook the fact that good quality system supports can alleviate/cure 'room problems'. Give the gear a fighting chance.
Good luck.
Posted on: 26 March 2002 by Rico
how did you get on, Greeny?
Rico - SM/Mullet Audio
Posted on: 27 March 2002 by greeny
I still get the same problem. I cannot get rid of the boom even with the speakers 12 inches from the rear wall. I have moved them all over the place.
I currently have my 135's and HI-Cap in for service when they get back Audio Councel are going to come round to install them and check everyhing is OK.
I don't want to take the speakers apart until I get my proper system setup back, though I suspect this will be necessary.
Not enjoying music at all at the moment.
Posted on: 27 March 2002 by John
My experience:
With an 82/Hicap the SBL sounded best about 8inches from the wall.
Inserted a Supercap for the Hicap and the SBLs sound best about 2 inches from the wall.
The height of the spikes also makes a difference. The metal frame of the SBL shouldn't be making any contact with the carpet. Same with the nuts that tighten the spikes. This also causes a boomy effect.
Reseal, reseal, I can't overstate. If you move them. Get them positioned correct and reseal.
John
Posted on: 29 March 2002 by Steve Crouch
When measuring the distance from the back wall to the speaker, where on the speaker are we talking about, ie to the metal suppoting structure or the speaker cabinet?
Posted on: 29 March 2002 by Greg Beatty
...is your kit sitting on?
I've heard Naim CD players go from boomy and rolled off to thin and brashy only with a change of support surface.
- GregB
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