Siting SBLs in room

There are lots of topics on here about setting up SBLs and getting them to perform well, all very interesting and useful. I have a pair against solid walls, all set up correctly with new gasket and pads, and sound great. When I move around the room it is noticeable that the only place I get really good low base, the lowest part of the sound of a kick drum or bass guitar, is if I stand in line with the speaker. In my listening position, equally spaced between each speaker the sound stage is great, the music fills the room, but the low bass is only there when I stand, or sit, in line with the speaker, and then… no sound stage. I am not saying I have no bass, its just the very low bass that is missing. SO I am thinking the speakers are performing correctly but, maybe, they are just not positioned correctly in the room. They are 3m apart and 0.3m from the corners of the room. I am sitting in directly between them so that I am 3m from each speaker. Speakers are as close to the wall as they can go, about 5cm and are not toed in. Rest of my system is LP12, CDX, NAC82, Supercap, 135s. NACA5 Looking forward to some suggestions based on your experience. Thanks

3m apart seem a lot. Have you tried moving them closer to each other


Thanks for your reply. I did have them about 2m previously before setting up properly and didn’t have low bass or soundstage, probably as were not set up properly! Perhaps I should try them closer together again.

Sounds like you might simply be sitting in room mode null. Half a meter back or fourth might make all the difference.
Don’t know if SBLs want to be closer together, but an equilateral triangle is a common recommendation in general. FWIW I have a 2.6 meters equilateral triangle in a quite large room and this in itself is definitely not what causes missing low end.


Are the sbls sealed properly? Are the screws set at the correct torque,? you could also try toeing them in slightly. Just some further thoughts

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Yep, set up as well as I think they should be using all guidance from Naim. New gaskets and ali pads. Crossover recapped. What is niggling me is that the low end is there, but I have to stand inline with the speaker, whether 2m or 4m away from it. I move to the left or right of speaker and low end is gone. Screws to correct torque, are these the ones for the spikes of the ones supporting the tweeters? Both are tight and a bit more! :slight_smile:

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You have nailed it exactly. THE low end is there, just not where I am sitting, I moving towards the speakers makes no difference, I can only go .5m backwards and I am agains t the wall, again no difference. Everywhere is low base free, except in direct line with the speakers.

That’s a pity as it limits options. I guess best to move forward then (which would also get you closer to the magic 1.7 meters runtime difference for the reflections from the back).

This might or might not mean that you are too close to speakers if they stay 3m apart - only listening will tell if you get a hole in the center. But anyway, it sounds as if you have the space to move them closer together, which will also get them out of the corners and away from the side walls. I’d try with a 2.5m triangle or so, sounds like a possible win-win-win.

Unless the SBLs are special in this regard, I would personally not easily give up on an equilateral triangle. If set up well, the center will be well filled and the soundstage is big and can extend well beyond the speakers. I am very happy with my 2.6m triangle (but am lucky with the room)

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Some great points there, thanks, will give it a go, something is either absorbing the low before it gets to me, or it is being cancelled out in some way I guess. The I get an hour or 2 I will clear the room and see from there how the sound is and start trying to move the speakers a little closer too, if needed.

Keep us posted! I would recommend small steps, a few centimeters in speaker position can be all the difference.

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If you found a way to absorb low bass, you can order a Statement as hifi nuts from all over the world will soon start throwing money at you :slight_smile: I would bet it is the latter

3m apart does seem a lot. Over 30 years of ownership 2m ish always seemed to deliver. I always seem to prefer them on the longest wall too.

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Longest wall tends to maximize side wall distance, always a good thing. I have it there, too. But in most rooms this will be limited by the distance to back wall then being too short, so it’s a tradeoff.


I had a good result when I wound the spikes on the speakers so that they came as close to the floor as possible and were well tightened.


Haha, very true, it was late when I said that :wink:

My system is similar to yours and I’m happy with the bass produced even though the room is far from ideal. I agree with some others that 3m may be too far apart as you may be sitting too far off the optimal axis of the speakers. Away from this point a speaker’s performance deteriorates. When standing in front of one speaker you are central to that axis so hear a fuller sound.

My SBLs are 1.7 m apart (inside edges) and I am sitting 2.8m away from the front of the two speakers. I’m happy with the bass. The SBLs are a bit odd in being designed to sit close to the front wall so a lot of the general advice around speaker positioning does not really apply.

Check the cabinets are level in all directions. Small adjustments in positioning can make a big difference.

It’s always worth checking that the left and right signals haven’t been reversed - I’ve managed to do this so many times when moving things around.

In terms of tweaking positioning stick with one or two pieces of music you know for certain there is a strong bass line. Many recordings have very little low bass information and all too often we blame the system for faults in the recording. It’s all a compromise, though so don’t sacrifice midrange quality to improve bass extension.

You can also have fun if you download some bass tones in the 40-80khz range and play the tone on repeat and move around the room or adjust your seating position back and forward to get clues about the optimal position.

Low frequencies need a long room to fully propagate, nearly 7m at 50hz so room reflections can be a problem, cancelling or enhancing the bass at particular positions.

Sound travels at 343m per second and I often marvel at our ear’s abilities to ignore the problems this causes in small rooms. It’s worth asking google about bass frequencies in small rooms as there’s a wealth of information.

Our problem is that a 40hz sound wave is 8.5m long so it can’t fully propagate in a small room. The peaks and troughs of the wave interact at high speed and cancel or reinforce as they bounce around the room. This is why people apply absorption to the back wall but to absorb bass frequencies you need thick panels that are mainly unacceptable in our living rooms.

SBLs can go down to 37hz which is good for a fairly small speaker - very clever design on Naim’s engineers part. When you stand in front of the speaker you are probably at a point where the bass note from the speaker is reinforced by the return bounce from the rear wall or the corners of the room.

I’ve resisted the temptation but if you really want to go down the rabbit hole you can buy a calibrated microphone and install RAW on a computer to analyse what’s happening in your room.


Hi Pete,
I would definitely move them away from the corners and much closer to eachother. At all times maintain equal distance to the sidewalls whilst experimenting. My guess with a listening distance of 3 metres the inside edges should be no more than 1.60 mtr. apart with 135s up them. Personally I would only entertain a wider distance between them, unless you say were running 52/ 4x135s and gear beyond that. The 82 pre could also be your weak link for bass weight.
What is your room dimensions and how far to the back wall from your golden ears? ATB Peter

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Room is 4.5m into 1930s bay window, by 3.7m, 2.6m high. The speakers are either side of a tiled 1930s fire place, which isn’t ideal but only place for them really.I’ve moved he speakers so they are 1.5m apart, but are now getting a bit close to the fire place. The fire place sticks out 150mm, the speakers are now 500mm from the corners. What I am finding is that the bass increases the further I get from the speaker and closer to the rear wall. Not sure if it really is much better in my speaker position, but will keep on with fine adjustments.

Thanks for all your detailed explanations, not sure I am ready for the RAW route yet, I have moved the speakers to 1.5m apart as I explained further below, or is that above!

Hi Pete, yes aren’t domestic constraints just bliss :roll_eyes:. Just checked your room dimensions on The Amroc Roommode Calculator and it’s actually a really good room dimensionally. Always a good start! :+1:t3:
Excuses if a haven’t read your OP properly ( somehow that seems to be happening my end at the moment), but have you recently moved your system into this room and now finding what you are finding, or has anything else within the system changed?
Going back to your dimensions and as both speakers have to go either side the fireplace, does this mean that the fireplace is centered mid wall in the the main bulk of the room and then there is the added bay window bit only on one side of the room - now it would be rude not to ask for a photo? :wink:
ATB Peter
As you started with a 3 meter distance and now down to 1.5 meter, how come your speakers are now only 500 mm from the corners, surely you should have gained 0.75 meter each side, no?? :thinking: