Subwoofer Problems

[Chrisdraper85]

Hi all,

Last weekend I got my new surround receiver after my old one broke down (upgraded to the Onkyo TX-NR509) and in testing it this weekend with a few different Blu-Rays & Xbox games, my subwoofer (it is a downward-firing Jamo A102HCS5 sub & surround system) made a flat *pop* sound and has since been much less ‘full’ sounding – i.e. to my ear, it still picks up the sub bass but some of the warmer notes that the subwoofer normally picks up at the top end of its range are missing.

I looked underneath and somehow a random plastic plug cover was under there – I’m worried that the diaphragm has oscillated itself against this and broken it.

There is no obvious damage to the diaphragm but wondered how easy it is to damage in this way, and given that it is now out of warrantee, the likelyhood of being able to repair it.

The alternative is a new subwoofer (money permitting) & I have been looking at the Wharfedale Diamond SW150 as this is now £140 on Amazon.

Has anyone else had this happen & easily been able to repair the sub, or am I better putting my money into a new unit?

 

[chrisup]

Chris,

Have you run the Audssey set up on the Onkyo with your speakers? It is improtant that you get the crossover setting right. I looked at the manual online and it said your satelite speakers only go down to 150 HZ. I assume your speakers need to be set as small so the sub needs to handle the bass so set the sub crossover to 150HZ and this must match the LFE setting in the Onkyo menu. When setting up my B&W 685 Theatre I have my sub volume set at 12 o clock on the sub (its also set to Auto) and then I ran Audssey setup. I used this as a starting point for my system. Try experimenting with the sub crossover eg 140Hz to see what works for you in your room.

Best Wishes

Chris

 

[Andrew Everard]

Last weekend I got my new surround receiver after my old one broke down (upgraded to the Onkyo TX-NR509) and in testing it this weekend with a few different Blu-Rays & Xbox games, my subwoofer (it is a downward-firing Jamo A102HCS5 sub & surround system) made a flat *pop* sound and has since been much less ‘full’ sounding – i.e. to my ear, it still picks up the sub bass but some of the warmer notes that the subwoofer normally picks up at the top end of its range are missing.

I looked underneath and somehow a random plastic plug cover was under there – I’m worried that the diaphragm has oscillated itself against this and broken it.

There is no obvious damage to the diaphragm but wondered how easy it is to damage in this way, and given that it is now out of warrantee, the likelyhood of being able to repair it.

Highly unlikely that the sub cone vibrating against the stray plug cover would do any damage, even if it has enough excursion to hit this cover with any force (which I doubt)

Are you sure the sub is actually operating? The symptoms you describe suggest to me that the auto-standby has been triggered by too little signal coming from your receiver: it might be worth either overriding the auto-standby, or turning down the sub's own gain control and cranking up the receiver's sub level to compensate. If there's too little signal, the sub 'goes to sleep'.

Conversely, there is a limiter in this sub, and if you are overdriving it this may cut in to protect the amp and drive unit from clipping damage.

 

[Chrisdraper85]

Thanks both,

I used the Audyssey set up originally (what a godsend for a newbie like me!), and my next step will be to repeat this process with your suggestions to see if this fixes the problem. The sub is definitely operating, as when it's on auto-standby mode the LED on the front does not light unless it is producing a signal.

It sounds like I might be overdriving the sub in this case so some experimentation with settings will hopefully do the trick.

Will report back & let you know my findings!

:cheers:

Chris

 

[moonfly]

Audyssey will clean up the sound of the sub which is likely the missing upper bass effect you notice, something is missing, and thats probably distortion or a peaked response in the upper frequencies. Audyssey will also maximize the subs low end performance, which at greater volumes may be pushing it to hard, and this is what I reckon your experiencing. You have probably outgrown your old sub now and its time to upgrade, and for the money the SW150 is a good buy.