MR2 Roadster Owners Club

The Workshop => Audio / Security / Electrical => Topic started by: Mikeymead on April 1, 2014, 19:57

Title: Joining front and rear speaker channels
Post by: Mikeymead on April 1, 2014, 19:57
If you are only running front speakers is there any advantage in joining the front and rear speaker channel outputs from the head unit instead of only using the front feed?

My thinking is that should boost the available power to the front speakers (Of course I could be completely wrong about this)
Title: Re: Joining front and rear speaker channels
Post by: AmeR on April 2, 2014, 00:19
Most modern headunits have the option to adjust the bias from front to rear / left to right. It may be worth checking that first.
Title: Re: Joining front and rear speaker channels
Post by: AndyM on April 2, 2014, 01:15
I agree.

Unless you can properly bridge (them as a setting to make the head unit only output one signal at twice the power) I suspect you will just end up giving the speakers two slightly conflicting signals which may give you more volume but also potentially cause distortion/interference.
Title: Re: Joining front and rear speaker channels
Post by: Mike G on April 2, 2014, 07:50
No, apart from the internal electronics of the head unit not being designed for this , there would only be a 4 ohm value across the combined output
Title: Re: Joining front and rear speaker channels
Post by: Mikeymead on April 2, 2014, 08:51
Many thanks for the answers, I'll leave it as it is then.
Title: Re: Joining front and rear speaker channels
Post by: cptspaulding on April 7, 2014, 12:11
As an afterthought to this, I just fitted a new head unit & amplifier on mine. Rather than getting frustrated trying to feed new speaker cables through to the doors (please, audiophiles, just tut & avoid flaming  s:P :P s:P  ), I spliced the speaker cables at the back of the head unit.

I reckoned I wouldn't then need to even put the speaker block (block B) back into the head unit, so initially I didn't. Result = nothing to the speakers. Now I was certain I'd spliced the front speaker cables on the block (3,4,5 & 6) & then put the block back in the HU. Result = music, thank you.

I did a double check & disconnected one speaker cable at the amp to make sure the sounds weren't coming direct from the head unit. it's not. It's from the amp as I've connected it.

My question is academic really considering I have it all working. But what is connected to the outputs of the rear speakers on the loom & why does the head unit not want to output to the RCA when the speaker block is not connected?

Odd.   s:? :? s:?
Title: Re: Joining front and rear speaker channels
Post by: trickyD on August 11, 2014, 15:59
Sometimes a decent head unit will allow you to bridge (via a setting) the rear channels into the front to "double" the power.
I forget which but an Alpine HU I had would let you do this.
A brilliant option for the '2, but please don't just wire it up without a setting!