After many years the need is absolutely here to update my original Audio 10 cassete player with something. I am considering a Pioneer head unit (SPH-10BT) coupled with a GM-D1004 amplifier and a TS-A250D4 subwoofer. Haven't gotten around to considering the speakers yet but I do have space for 2 tweeters + 4 speakers + 1 subwoofer. However, this head unit only has a 4-channel output. If I add the above mentioned external amplifier, which is also 4 channels, does this mean I will be able to connect 6 speakers (2 from the head unit + 4 from the amplifier)? I don't know much about car audio but I would think the amplifier would connect to 2 channels from the head unit so what I am wondering is if I could connect, for instance, 2 front speakers to head unit, 2 back speakers + 1 subwoofer to the amplifier and eventually 2 tweeters directly to the front speakers. Any help much appreciated. Thanks.

 

Things to be aware of, that may, or may not be relevant with your setup.

If your AMP has DSP (digital signal processing) it can sometimes add a delay into the audio. Not a problem if it drives all speakers, but if some are from a different source, may produce noticeable "echo".

Most POWERED subwoofers work off a stereo input so no need for a separate SUB output from head unit or amp. Does the power Amp you choose not have a SUB output? Maybe look for an alternative amplifier with four channels and a SUB output.

Tweeters will connect directly to the main speakers (you do not normally use separate channels for them) if you use a crossover, which only allows high frequency to them. Crossovers readily available for this application.

 

Hi. Thanks for your input. I am not sure whether this amplifier has DSP like you mention. There is nothing in the spec sheets that indicates it. It is a class-D amplifier although I'm not even sure what that means. If it does NOT have DSP, can I wire the speakers as I had initially mentioned?

I am particularly interested in the head unit I mentioned because it physically articulates with your smartphone. Unfortunately it only has 4 channel-output as I mentioned. Also not really looking for high-end audio system... just something that will sound reasonably good.

 

The Pionner amp you mention has no DSP as such, but it is a Class-D amp, which means it handles the electrical side of things differently from "normal" Class-A ou AB amps, using up far less eletrical power. I do not think that implies delay to the sound, but I have never tried the situation with different speakers powered by a headunit + Class-D amp.

If I were you, I would power the 4 normal channels from the headunit, and use an amplifier only for the sub-woofer. Simpler, easier to wire, and you can always add a 4-channel amp (that Pioneer or something else) for the main channels, if you ever feel the need. The subwoofer amp can be placed on the underside of the rear tray, and all you need is to lay a stereo signal wire to the trunk. Power on the trunk is available from the fuse box there, unless you use a very powerful amp and subwoofer.

There are other possibilities, but this is the simplest, I feel.

I presume you will use the OEM speaker placements, and that is why you're thinking of 4 channels? The OEM setup, on non-premium audio, has two speakers per door, plus one tweeter on the sail pannel by the door mirror. The front door speaker plus the tweeter are connected to the same front channel. The rear door speaker (rear position on front door, to be clear...there are no rear doors, obviously!) is connected to the "rear" channel on the same side. Since the car has no rear doors, that's how MB chose to place the speakers. On my pre-facelift CLK, there is also a 10" subwoofer on the rear tray. Rather weak, but works somewhat. It is powered from the rear channels of the headunit, the same channels that powers the "rear" speakers on the doors.

You could ditch the "rear" speakers entirely, buy a nice pair of components to mount on the front OEM locations, and use the rear channels to power the subwoofer, preferably via a dedicated amplifier that accepts speaker-level inputs.

That Pioneer amp is small and cool enough to be mounted on the glove compartment, which makes things easier. I know of no 5-channel amps that are small enough for that. They may exist, but I do not know of any. All the 5-channels I know are too big and too hot for that.

Mind you, my experience is all referring to OEM, non-premium audio setup on a pre-facelift CLK. I have no direct experience with OEM premium audio setups, or post-facelift models.

Let us know how you get on. Good luck.