• New Patreon Tier and Early Access Content available. If you would like to support AVForums, we now have a new Patreon Tier which gives you access to selected news, reviews and articles before they are available to the public. Read more.

My sub makes no sound

gamingdave

Established Member
My sub appears to be faulty but can anyone help diagnose the possible fault?

It is a (nearly) 10 year old Acuostic Energy AE108s - link

It hasnt been uesd in a number of years, as I simply havent had room for it, untill now. It is plugged into a Yamaha RX-V3800 via the sub out on the amp, to one of the inputs on the sub. I haev tried both inputs on the sub, and several cables from the amp.

When I switch it on at the mains, it lets out a low thud, which sounds like the amp switching on, coming from the speaker. However when running either tests from the amp in the setup, or playing content, I hear absolutley nothing from the sub. I have tried changing the crossover and volume levels, but they do nothing. This is the same whether the amp is set to On or Auto.

Can anyone suggest any tests I could do to verify what may be the problem?

Many Thanks
 

PeteW123

Established Member
since you are getting a thump from switch on it sounds like you should be getting something at least when you run it.

So, maybe a silly questions, but are you sure you have enabled the subwoofer on the amp?

Otherwise it could be the internal fuse, on the back of the amp there may be a balck plstic cover, either circular to twist off, or square by the on switch, behind which is a fuse.
 

gamingdave

Established Member
I am pretty sure that I have enabled subwoofer on the amp, It is set to on in the setup menu, and when running the signal/tone test it show the speakers on the display, and the sub is one of them. The amp has an autosetup, and when that runs it detects no sub, so I manually changed this to on.

There is a fuse on the back, but I assumed if this was blown I wouldnt here the thud when switching on.
 
Last edited:

Andori

Prominent Member
Silly question :)

You have checked it is in the Sub Pre-Out (8th from the left when looking from the back, under the BD/HD DVD video ins), not the Sub Pre-In (5th from the left when looking from the back, under the MD/Tape ins)? As shown on page 7 of the manual (page 11 of the PDF)
 

gamingdave

Established Member
Yes, its definately in the right socket on the amp.

Keep the silly questions coming, it could be something silly after all.
 

PeteW123

Established Member
sounds to me like the connection from the amp is faulty, either at the amp or on the sub.

Can't think of anything else it could be - the fact that it is not detecting the sub automatically definitely suggests this.

can you take it somewhere to be checked?
 

Andori

Prominent Member
Thought I'd check as that one is a favourite problem :)

Potentially can check the sub with a PC using a jack to RCA lead with relevant test tones, and possibly the other way going from the amp output to a PC (soundcard line in), though not tried that way myself.
 
P

Peter Galbavy

Guest
Just connect a CD player phono directly to the sub (a disc with some bass mind, no classical :) ) and then turning down the sub gain, play the disc, raise the sub gain gently and see if anything happens. The audio out of a DVD player would do just fine. There is no issue connection a normal L/R audio input to the sub, it will just ignore anything with high frequencies.
 

gamingdave

Established Member
Thanks for all the advice. I will try and plu some other devices into it tonight, and see what happens. I would hope its not the output on the amp, as its brand new.
 

gamingdave

Established Member
Tonight I tried to plug it in via other outs on the amp, and its just doing nothing. :(

Looks like its going to need repair or replacement. Any advice on where to start looking at repair. Im in London, so could take it somewhere, but I guess sending it somewhere (like to AE) may get costly.
 

gamingdave

Established Member
Tried to get it up and working again last night. The sub has inputs and outputs for left and right, via speaker cable. I took the cable currently running into the front left, and plugged it into the sub, and I do get sound :)

Now im thinking of trying a few different connections, but dont want to do anything that could damage my speakers or amp.

I assume I can take the cables currently running into my fronts, and connect them into the sub, and then use the outs on the sub to wire in the fronts. But what will this actually do? Will the subs amp still be used to power it, or will I essentially just have added an extra bass cone to the fronts? Will the signal coming out of the sub be adversly affected? I dont run the amp at anywhere near full volume, so it could drive a lot more than it currently does.

My amp allows me to bi-amp the fronts, would I be better switching the amp to bi-amp mode, then leave my fronts as they are, but pass some speaker cable from the amps extra speaker outs to the sub?

My amp is a Yamaha RX-V3800.
 

dzg7pl

Standard Member
Hi

I have just stumbled across this thread - I have exactly the same issue with my 108S :-( Did you ever work out a solution?

Cheers

Tim
 

CandKTurvey

Standard Member
Tried to get it up and working again last night. The sub has inputs and outputs for left and right, via speaker cable. I took the cable currently running into the front left, and plugged it into the sub, and I do get sound :)

Now im thinking of trying a few different connections, but dont want to do anything that could damage my speakers or amp.

I assume I can take the cables currently running into my fronts, and connect them into the sub, and then use the outs on the sub to wire in the fronts. But what will this actually do? Will the subs amp still be used to power it, or will I essentially just have added an extra bass cone to the fronts? Will the signal coming out of the sub be adversly affected? I dont run the amp at anywhere near full volume, so it could drive a lot more than it currently does.

My amp allows me to bi-amp the fronts, would I be better switching the amp to bi-amp mode, then leave my fronts as they are, but pass some speaker cable from the amps extra speaker outs to the sub?

My amp is a Yamaha RX-V3800.

Hiya, Did you manage to find a solution? - I think I have a similar situation and would be good to know what you did! :confused:
 

The latest video from AVForums

Is 8K TV dead? Philips OLED+907, Pioneer LX505 AVR plus B&W 700 S3 Reviews & Visit + AV/HiFi News
Subscribe to our YouTube channel

Full fat HDMI teeshirts

Support AVForums with Patreon

Top Bottom