Looking for some advice - one sided bass

J

james14

Guest
Hi,

Looking for some advice as I'm having some trouble with the bass from my system.

I'm currently using a B&W 675 forward facing sub, on the right hand side of my room (central isn't possible), and while I've read that low level frequencies are often hard to pinpoint where they are coming from, I hear a lot more bass in my right ear at mid volume levels, than in my left.

Not going deaf, as if I face the sub rather than my screen, it sounds fine ;)

My previous sub was a downwards firing one from the kef 2005.2 kit, and I can't say I ever noticed it with this sub.

Since I can't put the sub centrally (fireplace), I'm looking for alternate solutions.

Should forward facing vs downwards facing make any difference? If it does, I think my first choice would be to swap out for a different one.

Failing that, I'm considering running extra cables to put a sub on both front sides. Though it does seem like a bit of a waste of money, as I'm usually only able to listen at mid volumes anyway. That said, the imbalance is driving me mad, so I've got to do something!

Thanks for any thoughts,
James
 
Hello,

what is your crossover setting? Are you using the crossover of your receiver, or that of the subwoofer?

If it is below 120Hz, it should not be possible to tell where the bass is coming from.

If you could measure the response of the subwoofer alone (i.e., all other speakers disconnected at the amp side), it would help knowing which frequencies are being reproduced from the sub.
 
I've always had to have my sub at the extreme left or right side of my rooms for some time now. I always use 80hz as the standard crossover and I get the same slight sideways effect. I think its most noticeable at upper end of the scale (more towards 80hz). I've been meaning to try out a lower crossover setting, but since my only other option is 40hz, I'm not so sure it will integrate any better.

A lower crossover setting (if you are using 80hz) could be worth a try for you.
 
I must admit, I've not looked at the crossover. I set the dial on the sub itself to max, as advised to do on the Audyssey setup, so it could be pumping out anything at the moment.

I did set up RoomEQ wizard a while back to get the trace graphs, though never did much with it due to lack of knowledge. I'll try and get a trace of the subwoofer output on its own. Will then try some lower crossovers and report back.

Many thanks,
James
 
Chris / James

I have the same issue too - I started a thread about it the other day too but am still stugling :thumbsdow

Keep us posted with any progress you make :smashin:
 
I have no idea if this will work, but would be easy enough to try. If the sub is firing directly at you, across the room for example, could you turn it 90 degrees (say) so it is firing down a different axis of the room ?

Dave
 
I have no idea if this will work, but would be easy enough to try. If the sub is firing directly at you, across the room for example, could you turn it 90 degrees (say) so it is firing down a different axis of the room ?

Dave

I'll give that a go tomorrow ... nice idea :smashin:
 
Ok, I unplugged all my main speakers and ran the trace through RoomEQ wizard. It showed my sub starting to drop off around 115hz.

I've tried changing the crossover dial on the sub and have got this down to around 90hz.

By the time I got all the speakers plugged back in, I didn't have much time remaining. But after a quick listen I must admit that the effect does seem a bit less noticeable now, but I still get the feeling that its mostly coming into one ear. I'm starting to wonder if its down to the room shape, and the sound just not filling both sides of the room well.

Will listen to it some more this evening, as well as trying some different placements for the sub.
 
I've tried changing the crossover dial on the sub and have got this down to around 90hz.

The crossover is controlled by the amp, that's why it asks you to set it high on the sub. If you set it lower on the sub you may get a gap in the frequency range. Best to set it lower in the amp and leave the dial on the sub as high as poss.

80hz should be fine as long as your speakers can do 80hz and upwards. I have mine set to 100hz and in the right position isn't noticable.

You're more likely to improve the situation by trying different locations for the sub.
 
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James: I tried 40hz on my processor last night and it really messed up the room response. So I'll have to live with the sideways effect for the time being. I'm sure lowering the crossover would help, but it may or may not be workable for you. You'll have to check your REW graphs and your ears to determine if its right.

I think for those of us that have to put up with less than ideal placement, effects like this are unavoidable. LFE is more 'locateable' than many would have us believe.
 
It's because the LFE channel is not the same thing as a subwoofer/bass channel. If you switch off the crossover on the sub and let the amp handle everything the .1 channel (the LFE) on a movie can go up to 120Hz. What someone else may be able to confirm/refute is whether that still gets through when the crossover on the amp is set to 80Hz.

Dave
 
The Onkyo amps have setting for "LPF of LFE", which can be wound up to 120Hz.

I'm assuming that this is the cutoff setting for the .1 channel and would bin anything else above it's setting.

I would guess that it is independant of the other speaker crossovers, as my amp at least has 4 crossovers (fronts/centre/surrounds/surround backs), which can all be set individually.
 
The Onkyo amps have setting for "LPF of LFE", which can be wound up to 120Hz.

I'm assuming that this is the cutoff setting for the .1 channel and would bin anything else above it's setting.

I would guess that it is independant of the other speaker crossovers, as my amp at least has 4 crossovers (fronts/centre/surrounds/surround backs), which can all be set individually.

Hi mate, yes it is just the range for the dedicated LFE channel, anything lower than the set frequency will pass through to the sub .. although I thought I noticed directional bass when set to 120hz during certain material, so have mine on 80hz now .. tbh I can hardly tell the difference between 80 & 120 with the bass content when watching a movie, it's just being able to locate certain content that put me off :(
 
Hi mate, yes it is just the range for the dedicated LFE channel, anything lower than the set frequency will pass through to the sub .. although I thought I noticed directional bass when set to 120hz during certain material, so have mine on 80hz now .. tbh I can hardly tell the difference between 80 & 120 with the bass content when watching a movie, it's just being able to locate certain content that put me off :(
One one side, that is really strange. If I setup a certain crossover level, is because I want the bass to be divided like that, right? Specially because otherwise, the LFE content will not behave the same (for example, in my case, I "treat" a resonance with the crossover).

OTOH, LFE is special, because it can include louder sounds than those typically sent to speakers (IIRC, it has 20dB more dynamic range :confused:), so that's a way of protecting "less capable" loudspeakers.

No way to test it, I believe, unless you can prepare a dvd in DD with test tones in the various channels.
 
One one side, that is really strange. If I setup a certain crossover level, is because I want the bass to be divided like that, right? Specially because otherwise, the LFE content will not behave the same (for example, in my case, I "treat" a resonance with the crossover).

OTOH, LFE is special, because it can include louder sounds than those typically sent to speakers (IIRC, it has 20dB more dynamic range :confused:), so that's a way of protecting "less capable" loudspeakers.

No way to test it, I believe, unless you can prepare a dvd in DD with test tones in the various channels.

The independent crossovers for the 5/7 speakers will not be affected by changing the Low Pass Filter .. as it is just the .1 of the channel :smashin:

Try the Pod Race scene with it set to 120hz, then try it again at 80hz .. there is certain content in there that seems easily located while not adding anything to the experience (I can't remember exactly which part you need to listen to .. but can re-listen later to confirm if needed) :)
 
The independent crossovers for the 5/7 speakers will not be affected by changing the Low Pass Filter .. as it is just the .1 of the channel :smashin:
Yes, but then you are somehow "trowing away" content... Maybe in the specific movie you quote it does not matter, but I wonder if this is generally the case...
 
Yes, but then you are somehow "trowing away" content... Maybe in the specific movie you quote it does not matter, but I wonder if this is generally the case...

I will give it a try set to 120hz on another movie later on, and see if I can locate anything or try to notice content that wasn't noticed before :smashin:

Edit: I forgot, it was King Kong not Star Wars pod race where I noticed the problem, as the pod race was the test disk afterwards but I soon realised that being a THX movie it would have had the LFE content cut off at 80hz anyway .. so it turned out to be a useless test disk in the end .. but I ended up setting it back to 80hz anyways as that is what it had always been on.

Does anyone know if Audyssey sets this or is it's default setting 80hz ?
 
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My sub is behind me in the right rear corner of the room. Front speakers are set to small and cross over is 80Hz. Listening to some music a couple of weeks ago, I noticed that on one of the tracks on the album, the beat appeared to be coming from the right rear part of the room. This annoyed me and I've been thinking about moving the sub to another part of the room.

But, yesterday while listening to the same track, I pressed the "source direct" button on the amp (which cuts off the sub and runs the fronts full range) and to my suprise the beat still appeared to be coming from the right rear part of the room (with a slight change in the tone of the beat).

So it wasn't the sub after all but probably some room interaction with the base that particular track was putting out and one or two other tracks I've noticed this effect on as well.
 
Does anyone know if Audyssey sets this or is it's default setting 80hz ?

On the Onkyo amps, the manual states that Audyssey does not control this setting - I beleive my Onkyo came defaulted to 80Hz

After a firmware upgrade and reset my Denon was set to 120Hz as a default
 
On the Onkyo amps, the manual states that Audyssey does not control this setting - I beleive my Onkyo came defaulted to 80Hz

After a firmware upgrade and reset my Denon was set to 120Hz as a default

It's not the sort of thing that Audyssey would be able to set as it is a cutoff on the LFE track not a crossover, where as it sets the various crossovers on what it thinks the frequency response of the speakers are.
 

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