Sorry I know there are a few geeks on here into their audio..

I’ve just got a replacement speaker for my dm602 s2 which was crackling and all is good now.

However on the back on the pm6005 there are 4 inputs for 2 sets of speakers.. I’m not bi wiring but read somewhere that if you leave 1 set unused for too long then they can oxidise or similar.

Can I wire the positive and negative across both? Ie go into the +ive on the left and -ive on the right to bridge them with no ill effects? I can’t see that in the manual just 4 speakers or bi wiring.. but I’m assuming it’s the same as when you bridge and amp in the car so should be ok?

Any thoughts! thanks

read somewhere that if you leave 1 set unused for too long then they can oxidise or similar.

Never heard that, sounds like guff.

A quick google tells me it’s so you can have up to 2 sets of speakers (or you can join them up for certain speaker impedances).

Just select one set (A or B) and wire them up making sure you get red/black correct for left and right.

Ignore the other set. And the oxidisation thing is guff.

Cool that’ll do for me!

My speakers say 8ohm on the back which is why I thought bridging maybe better? but I literally have no clue

IIRC, 8 Ohm is typical for a regular HiFi speaker. Dedicated surround speakers were all 16 Ohm when I bought my previous amp circa 2000, but that was in Dolby Pro Logic days and went out with Dolby Digital which really wants identical speakers.

Even if there was truth to terminals “oxidising,” what do you care, you’re not using those terminals anyway.

TL;DR, wire them up normally and you’ll be reet, sticking a lump of wire between terminals to make it do something it wasn’t designed to do sounds like a convenient way of blowing up the amp.

My speakers say 8ohm on the back which is why I thought bridging maybe better? but I literally have no clue

They’ll be a nominal 8 ohm, but in reality will vary by frequency (above and below 8 ohms). Best guess is that the normal binding will be fine.

Enjoy your music…!

Thanks guys!

Isn’t a bridge plate usually used if your not bi/amping?

Isn’t a bridge plate usually used if your not bi/amping?

I don’t know a lot about bi-wiring (it struck me as an excuse to sell cable) so could be wrong, but AFAIK you’d bridge a speaker that would be expecting a bi-wired connection. The amp has outputs for two discrete sets of speakers, which is nothing to do with bi-wiring.

My understanding is speakers with two sets of terminals, are for bi amping, you’d have 2 sterio amps or four mono power amps, one powering the stereo tweeter pair and one powering mid driver pair.

or one amp for each tweeter and one amp for each mid.

If using just one stereo amp, you’d bridge the relevant terminals on the speaker cab?

Disclaimer, I might be talking crap, but what’s the point bi wiring if your not bi amping? May as well just run standard stereo amp?

We may be at angry dolphins here.

I was talking about bi-wiring, not bi-amping. I know even less about that.

With bi-wiring there’s a crossover in the amp, and high/low frequencies are sent independently down two pairs of wires to drive the respective drivers within the speaker cab rather than leaving it for the speaker to decide.

My old AV amp had two sets of speaker outputs. They were for two sets of speakers and there was a couple of buttons on the front panel labelled “A” and “B” which could switch either or both on and off. It’s for having a second set of speakers in a different room. This is what I’m assuming the OP has; nothing to do with biwiring, biamping, bicycling, bisexuals or bicarbonate of soda.

Ahh ok. That’d be a ‘normal’ amp with outputs for speakers A and speakers B, for a multi room set up.

A speaker cab with 4 inputs, 2x+ and 2x- is for a bi-amp scenario, and they’d usually come with a bridge plate for the terminals for use with a regular stereo amp set up.

This would be a basic bi amp set up, but the purists would use 4 mono amps rather than 2 stereo amps

Surely the terminals on the amp are gold plated? They’re not going to oxidize any time soon.

Looks like it. (Click for larger view)

It looks like you *can* bridge them, too, and the speaker impedance rating in either configuration is helpfully printed next to the connections.

I did have them bridged as I thought that was the right way to do it based on the diagram I just got scared that I couldnt find that information anywhere and also that the “balance” left / right was then no use which made me think I’d done it wrong… however if my speakers are 8ohm and I can bridge.. should I?

Ignore all that stuff about bi-amping.

To do that you need to have pre-amp outs on the back of your amp, which according to Cougars pic you don’t have.
Bi-amping sends the pre-amp signal to 2 (or more) power amps, which then drive the speakers.
Your amp is a combined pre/power combo with no way to split them. You cannot bi-amp using speaker terminals because the speaker output has already been through a power amp. On the back of my Nad 3020i there is a set of jumpers that if you remove allows you to connect a separate power amp.

The speaker terminals you have allow you to run two pairs of speakers. If you are only,using one pair, then just connect A or B and be done with it. The oxidation thing is nonsense.

Bi-wiring made a noticeable difference with my TDL RTL II’s. Even my mega cynical Dad noticed the difference…

mattyfez – Member
Disclaimer, I might be talking crap, but what’s the point bi wiring if your not bi amping? May as well just run standard stereo amp?

It sends a cleaner signal to the speakers by cutting out the crossover circuitry 🙂

Erm…The signal still goes through the crossover…

Cougar you are confusing no smoking with active systems