B&W ASW608 Sub problem

[stonehound]

When I set the speakers up using Audessy, the sub was set too loud so the sub produced a rattling noise when playing any loud explosions, etc. I have turned the sub down gradually but still get the same problem when turning the volume up on the amp. Its reaching the point now where if i turn the sub down anymore i won't be able to hear it all whilst watching films. The rattling noise is very annoying and sounds like something in thecabinet is loose.

Wondered if anyone else had experienced this?

 

[Tom Moreno]

Do you have an SPL meter?

What reading do you get for the speakers and the sub when using the manual test tones from your receiver?

 

[stonehound]

I dont have an SPL meter but the test tone does not sound overly loud.

I cranked the sub up so it was making the rattling sound on the test tone then gradually reduced the test tone volume until the rattling disappeared. The problem is that the sub is very quiet now but still rattles during loud bass sequences.

 

[Tom Moreno]

stonehound:
I dont have an SPL meter but the test tone does not sound overly loud.

I cranked the sub up so it was making the rattling sound on the test tone then gradually reduced the test tone volume until the rattling disappeared. The problem is that the sub is very quiet now but still rattles during loud bass sequences.

Right,

I would recommend getting an SPL meter as it is one of the most important tools in setting up your system. Audessy does a good job of auto calibrating your system, but sometimes it does throw up interesting curveballs and if you have an SPL meter you can easily correct any discrepancies. You can get the Radio Shack one via amazon.co.uk for like £23 and this is almost the standardised tool. When looking at SPL meters don't be fooled into getting a digital one as these are rubbish for measuring subwoofers in particular. The level playing tone on a sub wavers so you set it based on the middle of the needle's movement.

First thing to check is what the crossover on the back of the sub is set to, before running the Audessy it needs to be fully opened up (set to the highest frequency or >120hz) if it is rolling anything off it will confuse the measurements. the next thing to note is that if you were to use an SPL meter and toggled the test tone around the channels a properly setup sub should sound a bit softer in the room as it isn't giving you full frequency bandwidth. As a guide I usually try to set the sub's volume control so that when the channel setting on the receiver is set to 0 dB the sub is close to the reference level for the room (usually about 75dB). This is hard to do and that's why I say try to get close and then use the receiver's channel setting up or down 1-2 dB to get it spot on.

Once you've got your sub's levels set, check your different surround modes and be sure that the settings are the same for channel levels. I found it interesting on my Denon that after I made adjustments to the Audessy channel levels, the system snapped back to the incorrect Audessy settings when I played a blu-ray with PCM. I had to set the tweaks for PCM separately from DD/DTS!

 

[Anonymous]

It may sound daft but, have you checked the isolation spikes on the underside of your sub???

I run ASW610's and one of mine started rattling during a loud viewing of The Dark Knight.

Turned out it was a loose spike. Frightened the life out of me!!!

Might be worth checking.

 

[Tom Moreno]

stan007:
It may sound daft but, have you checked the isolation spikes on the underside of your sub???

I run ASW610's and one of mine started rattling during a loud viewing of The Dark Knight.

Turned out it was a loose spike. Frightened the life out of me!!!

Might be worth checking.

Wow that's a new one!

It's not like there isn't enough to keep you uncomfortably perched on the edge of your seat during that one as it is!

 

[stonehound]

Cheers fellas, I best get myself a SPL meter. Tom - what Denon amp do you have?? I have the 1909 so may be a similar set up. i do notice that it rattles more though Sky HD as opposed to HD audio throughthe blu ray so I have tweaked the db's on the amp for each source.

Btw, I checked the spikes and they were all tight.

 

[Tom Moreno]

stonehound:
Cheers fellas, I best get myself a SPL meter. Tom - what Denon amp do you have?? I have the 1909 so may be a similar set up. i do notice that it rattles more though Sky HD as opposed to HD audio throughthe blu ray so I have tweaked the db's on the amp for each source.

Btw, I checked the spikes and they were all tight.

I have an AVR-3808A but I'm willing to bet that you've found the same thing in the software that I have.

 

[denislours]

I know it is an old tread, but i was wondering if you ever found out what was the problem, i have the same problem, i can't crank the volume on my ASW850 cause it will rattle, i keep the volume very very low kind of 1/10 and still, on some low pass, it will rattle.

I have tested it on 3 differents preamp, same problem!

I'm going to make it check if something have unglued on the driver....

 

[Tuomas]

I had the same rattle problem with asw 608. Turns out that it was caused by loose screws on the back of the sub. Loose screws made the amplifier back plate to vibrate.