General Forum

Re: Surround Sound & Active Speakers

PerroMal — Sat, 15 Nov 2008 07:43:12 GMT

Hi Ralf and Steve,

Thanks very much for your advice. I realised that sticking a power line-out into an active speaker used on a pre-amp line-in signal didn't appear to make sence but when it seemed to work I was like a dog with a bone and looking for a work around with common sense flying out of the window.

I bought my Denon 1909 a few weeks ago and planned a 5.1 system with passive sonance speakers and a sunfire woofer. The side surround speakers was an after thought so tried using my Bolab 6000 I bought a few years ago making it into a 7.1 system.

However, thanks very much for your replies and advice which I really appreciate. What I intend doing now is swopping or putting my 1909 on eBay and buying the Denon 2809 with power line out and pre-amp.

Many thanks Warren (Perro Mal) South Wales

Re: Surround Sound & Active Speakers

Steve at Sounds Heavenly — Sat, 15 Nov 2008 06:20:29 GMT

Hi PerroMal,

Welcome to the forum! The one piece of advice I have is please, please, please don't try to connect your Beolab 6000 speakers to an amplifier with speaker level outputs! Here's why:-

1) You will not get rid of the buzzing

2) The speakers will not work properly

3) The sound quality will be very poor

4) You will very likely damage the amplifiers and/or drive units in the speakers, causing hundreds of pounds worth of repair bills!

Basically, you need to either change your speakers or your amplifier. I would suggest that you look into selling your existing amp and getting a different model with volume-controlled pre-outs, eg. the 2809 model mentioned by Ralf. Other options are the excellent AV processors/pre-amps made by Onkyo or Rotel, any model with pre-outs is suitable.

But please forget any idea of using your existing amp with the Beolab 6000's!

Best regards,

Steve.

Re: Surround Sound & Active Speakers

kallasr — Fri, 14 Nov 2008 14:06:43 GMT

2809 has pre-outs.

Ralf

Re: Surround Sound & Active Speakers

kallasr — Fri, 14 Nov 2008 14:04:12 GMT

You should use pre-outs, but as far as I remember, the 1909 only has amplified outs.

Ralf

Surround Sound & Active Speakers

PerroMal — Fri, 14 Nov 2008 10:40:14 GMT

I am in the process of setting up a theatre surround sound system. My query concerns the audio side.

I have a Denon 1909 AV receiver that only has speaker level outputs. The three front speakers and two surround back speakers are passive and work perfectly. My two side speakers are B&O Beolab 6000s, which are active. My particular query concerns these two speakers.

The cable between the receiver and the speakers is a high quality Ecosse two core cable. However as this cannot be terminated into the speaker I have to make a joint to an RCA phone plug. The little bit of cable connected to this plug (0.5 metres) is single insulated core and an uninsulated stranded copper. Both covered by the overall PVC over sheath. The core is connected to the plug centre pin and the stranded copper to the other phone terminal. This is then connected to the two core speaker cable running from the Denon. The Beolab 6000 is connected via the phono plug and the speaker switch, R L & Line, is switched to line. This is as instructed in the speaker handbook for using it with non B&O equipment.

When the Denon AV receiver is switched on and in standby mode, the Beolabs sit there also in standby mode with a green light showing and a humming noise. When I commence playing a source through the Denon, the speakers works perfectly. When the source stops, playing the speaker sits there with the green light on and then switch to standby after two to three minutes showing the red light exactly as expected.

However, when I switch the Denon AV receiver to standby or off the two Beolabs hum loudly until I switch off the power feeding each speaker. The same applies if I switch them on when the Denon is switched off.

I am a little baffled as both speakers work perfectly (apart from the loud humming as described which I have to solve). This is most odd as I am putting amplified line output into a speaker, which is only suppose to accept line in.

Can anyone give some advice on how to get rid of the hum other than switching the speaker supply off every time it is not in use? I have tried a few things but have been unable to solve the problem. Would a power Line out/to RCA line in converter assist? I feel it could be an earth loop problem but then I think it could be something to do with a speaker level in to a speaker that only, I believe, accepts preamp signals.

Summary of tests. Light condition refer to the light at the base of the Beolab 6000s.

(1) Denon switched off, speakers switched on - Speakers hum green light on.

(2) Denon swithched on to standby, speakers switched on – Speakers hum green light on.

(3) Denon switched to source, speakers switched on – Speakers play perfectly no hum.

(When the source has finished playing the speakers switch to standby about 3 minutes after playing – light red).

(4) Denon switched to standby, speakers switched on – Speakers hum green light on

(5) Denon switched off and power plug removed, speakers switched on – speakers hum green light on.

Above conditions apply to any source used.

I look forward to any responses received.