Sub virtually silent when wired to speaker outputs on amp

[SOLVED]


Good afternoon all,

I used to run my subwoofer through line in, it was very loud so used with the volume set near zero.

When I listen through headphones the sub was still active as only the speakers muted, also the phono cable was very short limiting the positioning.

I brought some speaker cable to run the subwoofer off the speaker terminals from the back of the amp to address the aforementioned issues however now it is virtually silent (in comparison to the bass from the speakers) even with the volume turned right up on the back of the subwoofer?

Any ideas?

I can't really hear any differences between most of the settings on the back, could it be incorrect choice of wire making it so quiet?

I have tried running it with one speaker only to try and hear if I'd wired the speakers out of phase etc but not much joy so far.

Any advice would be greatly appreciated!

 

You say you have now connected the sub to the speaker output on the amp. Is this the same output as the main speakers? Sometimes, amps have two sets of speaker outputs and there's usually a switch on the amp to select either output (or both). If this is the case then the output needs to be on.

Can you tell us the make and model of both the amp and the sub and maybe post a couple of pics of the connection panels.

I would recommend using the sub's line level input if possible. Using the speaker input has potential problems e.g. if it gets shorted out it could easily blow up the main amp.

 

The wire choice will make no difference, pictures are needed.

 

I wouldn't be surprised if I've made a mess of the wiring on the binding posts, I'm quite willing to rewire them if needs be..

I wired the sub and amp as per fig. 6 of the manual (page 3), before I had it wired as per fig. 5.

The sub is a B&W ASW 608, its used with a Roksan Kandy KA-1 MkIII integrated amp and B&W DM602 S3 standmounters.





Earlier I tried 'Dream is collapsing' from the film Inception and 'Like A Dog Chasing Cars' from the Dark Night, the bass level actually seems about right but it still seems strange that I have volume level of the sub set to maximum and for non movie stuff it sounds a bit thin. As opposed to having plenty of headroom when using the line in input.

 

I'm tempted to split up the bi-wire cable sending one pair to the speakers and the other pair to the sub and see if that makes a difference, IMO it looks like a bit of a bodge how I have it wired at the moment.

 

In the photo of the amp, the wire going to the R+ connection has writing on it. On the left output, the wire with the writing is on the negative (L-) connection.

Usually, the writing is only on one of the two conductors so, depending on how it's connected at the sub (can't tell from the photo), you might have the L & R connections out of phase.

 

I see the sub has stereo speaker inputs. These will be summed inside, so if the left speaker connection to the sub is reversed compared with the right, the signal will actually be reduced. Double check the left and right connections going to the sub have the same polarity.

 

Thanks BiffoBear & Tenson, your quite right, just pulled it all out and checked the wiring again, I had one the other way round on the subwoofer, I even doubled checked the wiring. Doh

Problem solved, operator error. Thanks for pointing that out, I am indeed a pleb!