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Posted: **Sun Jul 12, 2020 7:33 pm**

Hello, I'm sorry if this is a stupid question.
I have the normal 6 speaker system in my car as standard, but recently I have installed a Focal 165-AS3 system in my car. To drive it, I have fitted a Pioneer 4 channel in-line amp with a 100W output. Currently I am driving all speakers through this amp, but that means I have the two front channels (Focal system) being fed (via the supplied crossover) as well as the rears (100mm units in the rear bulkhead).
The rear speakers are standard.
So, what I have done is by-pass the rear speakers so that the amp only feeds the high powered 3 way system at the front, so as to remove the risk of blowing up the rears, seeing as their maximum input is only 50W.
Anyway…. Where I’m getting to on this is that I saw on the amp there is a switch to select 2-way or 4-way input. In the instructions there is no explanation, just ‘select what you want’. Can someone explain this to me? If I select 2-way does that mean that all the power will be transferred through the fronts?
TIA!

Posted: **Sun Jul 12, 2020 9:27 pm**

What model code is the Pioneer amp?

Posted: **Mon Jul 13, 2020 12:18 am**

Pbondar wrote: ↑Sun Jul 12, 2020 9:27 pm What model code is the Pioneer amp?

Hi, it's the GM-D1004. Thanks.

Posted: **Mon Jul 13, 2020 10:01 am**

It’s not very clear from the manual.. https://catalogs.pioneer-car.eu/Manuals ... etPDF.ashx

It seems to be..

2 channel equals 2 front speaker inputs drives 2 front speaker outputs in auto bridge mode which is typical Class D amp behaviour..

4 channel is each input drives corresponding output ..albeit with less power..

Posted: **Mon Jul 13, 2020 10:11 am**

Pbondar wrote: ↑Mon Jul 13, 2020 10:01 am It’s not very clear from the manual.. https://catalogs.pioneer-car.eu/Manuals ... etPDF.ashx

It seems to be..

2 channel equals 2 front speaker inputs drives 2 front speaker outputs in auto bridge mode which is typical Class D amp behaviour..

4 channel is each input drives corresponding output ..albeit with less power..

I agree. Yes, I have the manual up on my screen and keep thinking I'm missing something? And google search doesn't really help either. What you say makes complete sense; it'd be nice to get it in a concrete form. Maybe I should contact Pioneer directly?

Posted: **Mon Jul 13, 2020 11:33 am**

Z4C_er wrote: ↑Mon Jul 13, 2020 10:11 am
Pbondar wrote: ↑Mon Jul 13, 2020 10:01 am It’s not very clear from the manual.. https://catalogs.pioneer-car.eu/Manuals ... etPDF.ashx

It seems to be..

2 channel equals 2 front speaker inputs drives 2 front speaker outputs in auto bridge mode which is typical Class D amp behaviour..

4 channel is each input drives corresponding output ..albeit with less power..
I agree. Yes, I have the manual up on my screen and keep thinking I'm missing something? And google search doesn't really help either. What you say makes complete sense; it'd be nice to get it in a concrete form. Maybe I should contact Pioneer directly?

If you can speak to a human being that would be best..these new digital amps are very clever but..anyway FWIW its my nest guess..the amp itself is not that powerful but you can squeeze a lot more in a small box compared to the old Class AB amps of old..

Posted: **Mon Jul 13, 2020 11:55 am**

Pbondar wrote: ↑Mon Jul 13, 2020 11:33 am
Z4C_er wrote: ↑Mon Jul 13, 2020 10:11 am
Pbondar wrote: ↑Mon Jul 13, 2020 10:01 am It’s not very clear from the manual.. https://catalogs.pioneer-car.eu/Manuals ... etPDF.ashx

It seems to be..

2 channel equals 2 front speaker inputs drives 2 front speaker outputs in auto bridge mode which is typical Class D amp behaviour..

4 channel is each input drives corresponding output ..albeit with less power..
I agree. Yes, I have the manual up on my screen and keep thinking I'm missing something? And google search doesn't really help either. What you say makes complete sense; it'd be nice to get it in a concrete form. Maybe I should contact Pioneer directly?
If you can speak to a human being that would be best..these new digital amps are very clever but..anyway FWIW its my nest guess..the amp itself is not that powerful but you can squeeze a lot more in a small box compared to the old Class AB amps of old..

So I contacted Pioneer, and this is the reply:

: 2CH 4CH explanation.JPG (94.23 KiB) Viewed 3020 times

Thanks for your help.
But this looks like I will lose my rear speakers? What I have done as of now is by-pass the amp and go straight to the rear speakers. I may as well leave it as is.

Posted: **Mon Jul 13, 2020 12:22 pm**

Well you can drive your AS3 mega complex off the two front channels and the rear speakers off the two rear channels..doesn't give you a lot of power to shift those woofers though..

Or you can drive the AS3s of a bridged pair of channels and direct drive the rear speakers off the existiing orginal head unit direct (which i I think what you are saying you have done)

The rear speakers provide only a modicum of sound as an infill..not at the same level as the fronts...the OE head unit heavily filters the rear speaker output anyway..compared to your AS3s the OE rear speakers are poor performers..

It depends how much extra effort you want to go to...maybe an additional baby amp and better apir fo rear speakers and then play with the balance..I'd drive them off the front channels and then use the (new) amps controls to tweak it..

All IMHO..

Posted: **Mon Jul 13, 2020 2:42 pm**

Thanks again. OK, this is where I need educating. Going by the image, how can I power the rear speakers if I've used them to bridge the front? Do I split them off before they go to the amp?
Currently I have completely taken them out of the loop and gone straight from the head unit to the rears. The amp is only receiving a signal from the front speakers.
Would this work?

: RR SPK WIRING.JPG (53.37 KiB) Viewed 2992 times

Posted: **Mon Jul 13, 2020 3:35 pm**

Hmmh its slightly tricky..

I think readiing both docs that what you should do is:

Connect the front outputs from the head unit to the front inputs on the amp, as per amp pdf, and, slide the switch to 2 channel, and, then wire the AS3 speaker feed as in 2 channel stereo in the drawing..

Then run the rear speaker outputs from the head unit DIRECT to the speakers..

That should work, I think, then use the fader control to balance old rear speakers with front mega complex..

With less power being drawn on the head unit to power speakers (fromt speaker feed power is neglible) you may get more woomph available to rear speakers,albeit with agressive frequency tailoring..

Conventional wisdom on car acoustics suggests only a modest amount of volume from rear speakers since the 'sound stage' should appear in front of you at the 11 o clock position if you close your eyes..

Part of the issue is the cheapo six speaker head unit has inbuilt frequency tailoring that may not rest well with your speakers n amp..but you have to suck it and see..

a super whizz with NCS could re-program the head unit for a flat response output..but that's beyond my pay grade..

Posted: **Mon Jul 13, 2020 5:18 pm**

Pbondar wrote: ↑Mon Jul 13, 2020 3:35 pm Hmmh its slightly tricky..

I think readiing both docs that what you should do is:

Connect the front outputs from the head unit to the front inputs on the amp, as per amp pdf, and, slide the switch to 2 channel, and, then wire the AS3 speaker feed as in 2 channel stereo in the drawing..

Then run the rear speaker outputs from the head unit DIRECT to the speakers..

That should work, I think, then use the fader control to balance old rear speakers with front mega complex..

With less power being drawn on the head unit to power speakers (fromt speaker feed power is neglible) you may get more woomph available to rear speakers,albeit with agressive frequency tailoring..

Conventional wisdom on car acoustics suggests only a modest amount of volume from rear speakers since the 'sound stage' should appear in front of you at the 11 o clock position if you close your eyes..

Part of the issue is the cheapo six speaker head unit has inbuilt frequency tailoring that may not rest well with your speakers n amp..but you have to suck it and see..

a super whizz with NCS could re-program the head unit for a flat response output..but that's beyond my pay grade..

Thanks so much for the detailed reply! The only thing I find a bit puzzling is that the amp pdf shows using RL- and RR+ to supply the bridge. I have had to connect them to the amp to perform the bridge.

Posted: **Mon Jul 13, 2020 6:08 pm**

Z4C_er wrote: ↑Mon Jul 13, 2020 5:18 pm
Pbondar wrote: ↑Mon Jul 13, 2020 3:35 pm Hmmh its slightly tricky..

I think readiing both docs that what you should do is:

Connect the front outputs from the head unit to the front inputs on the amp, as per amp pdf, and, slide the switch to 2 channel, and, then wire the AS3 speaker feed as in 2 channel stereo in the drawing..

Then run the rear speaker outputs from the head unit DIRECT to the speakers..

That should work, I think, then use the fader control to balance old rear speakers with front mega complex..

With less power being drawn on the head unit to power speakers (fromt speaker feed power is neglible) you may get more woomph available to rear speakers,albeit with agressive frequency tailoring..

Conventional wisdom on car acoustics suggests only a modest amount of volume from rear speakers since the 'sound stage' should appear in front of you at the 11 o clock position if you close your eyes..

Part of the issue is the cheapo six speaker head unit has inbuilt frequency tailoring that may not rest well with your speakers n amp..but you have to suck it and see..

a super whizz with NCS could re-program the head unit for a flat response output..but that's beyond my pay grade..
Thanks so much for the detailed reply! The only thing I find a bit puzzling is that the amp pdf shows using RL- and RR+ to supply the bridge. I have had to connect them to the amp to perform the bridge.

Depends on how the amp is configured internally...when it was analogue it was oh so simple..these digital critters can do things in s/w or h/w so you can’t assume anything..

If they say that’s the way then that’s the way..all IMHO..

Let us know how you get on..

Have you seen my two relevant articles on sound systems and E89 audio upgrades?

You can find the under my non de plume..

Posted: **Mon Jul 13, 2020 6:35 pm**

Pbondar wrote: ↑Mon Jul 13, 2020 6:08 pm If they say that’s the way then that’s the way..all IMHO..

So in conclusion, do you think this will work, or at least be worth trying (ie nothing's going to blow up....)?

: RR SPK WIRING.JPG (53.37 KiB) Viewed 2964 times

And, I'd love to read your articles. I shall have a look for them now.
Kind regards, and thanks for your time today!

Posted: **Mon Jul 13, 2020 8:04 pm**

Z4C_er wrote: ↑Mon Jul 13, 2020 6:35 pm
Pbondar wrote: ↑Mon Jul 13, 2020 6:08 pm If they say that’s the way then that’s the way..all IMHO..
So in conclusion, do you think this will work, or at least be worth trying (ie nothing's going to blow up....)?
RR SPK WIRING.JPG
And, I'd love to read your articles. I shall have a look for them now.
Kind regards, and thanks for your time today!

That’s not the best option but if you want to do it I don’t think it will blow up..

Posted: **Mon Jul 13, 2020 8:33 pm**

Pbondar wrote: ↑Mon Jul 13, 2020 3:35 pm Connect the front outputs from the head unit to the front inputs on the amp, as per amp pdf, and, slide the switch to 2 channel, and, then wire the AS3 speaker feed as in 2 channel stereo in the drawing..

In the drawing, this uses the amplified rear speaker RL- and RR+ . Do you concur, or are you suggesting to ignore the pdf and just use the front speakers as-is and hope the software in the amp will sort it out?

Pbondar wrote: ↑Mon Jul 13, 2020 3:35 pm Then run the rear speaker outputs from the head unit DIRECT to the speakers..

If the above, do you mean the remaining unamplified speaker wires RL+ and RR-? where does the feed for RL- and RR+ come from?

I think I'm coming across as an annoyance, and if so, I'm sorry, but it's not making sense to me. Pioneer's instruction was to use an amplified RR speaker output. This is where I'm confuzzed.

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