13 replies to this topic

[fenghuang]

My head unit has 2 stereo output pairs. One can be configured to drive rear speakers or a sub. There is no dedicated sub output.
All the amps I've found so far only have a dedicated sub output if they also have a sub input.

I'm hoping to have front components, rear coaxials (on the parcel shelf) and a (it looks like I'm getting a pair of subs.

What would be the usual configuration for driving the rears and subs in this scenario?

[mr cooke]

You can get RCA splitters

[fenghuang]

Feed the rear/sub output on the HU into the rear and sub inputs of a 5ch amp?
Or split the full freq rear output of a 4ch amp into the rears and the sub? Or via a LPF?

[Ruckus]

Honestly think very hard about why you want the rear full range at all.

[fenghuang]

Fair point. It's a very small space! Rears and fronts make a big difference in a Focus estate, but if a Mini is SIGNIFICANTLY different that makes life simpler and cheaper.

[vx220]

Fair point. It's a very small space! Rears and fronts make a big difference in a Focus estate, but if a Mini is SIGNIFICANTLY different that makes life simpler and cheaper.

Rear speakers make a difference, but they arent needed (except for people in the back...)

You should get enough "rear fill" from reflections, like in a concert hall/theatre

[Ruckus]

If you see a band play live the only sound comes from the front...
If you care about staging of the sound then rears just created problems.

Plus if you install them on the rear shelf and the subs are in the boot then you got to enclose them as well.

[fenghuang]

I'm not sure I necessarily agree that rears will inherently cause you problems (and that's my professional opinion as a sound engineer ) but the specifics of set up in a small car are not my area of expertise.

 

The subs aren't going to be in the boot, and rear enclosures is something I've been considering. (A sub in the boot has never made sense to me, at least in terms of fag-packet accoustic theory.)

[Ruckus]

 (A sub in the boot has never made sense to me, at least in terms of fag-packet accoustic theory.)

 

Unless of course is been built to be a 4th order bandpass enclosure which mine has, add a bit of Time alignment and the subbass images on the dash.. ;)

[fenghuang]

That's more than I can fit on a fag packet!

The bit that's never made sense to me is effectively putting one of your speaker enclosures in a metal box (the boot of a saloon car) and then adding a layer of sound deadening (the seat squabs) between you and it. Admittedly I've never locked a hostage in the boot of a car, but I would imagine half the point of that is so they can't be heard.

[Ruckus]

So you've missed the point 

 

• What you want to hear is the sound waves being produced by the 'precision' low frequency sound wave generator called 'The Subwoofer'...
   
• What you don't want to hear is the random noise, pops, buzzing and wobble from the large thin bit of cheap steel covered by a bit of foam and leather..

 

The boot and all panels need to be dead BUT the boot MUST have adequate aperture's made in the rear shelf for the air to move freely. The upshot of this effort is you hear the sound from the subwoofer and nothing else. Also the aperture's (holes) need to be big enough NOT to act like ports UNLESS you are building a bandpass type setup.

 

[fenghuang]

If you're going to remove enough of the parcel shelf of a mini to make a difference, does it make any sense at all fitting it in the boot not in the shelf?

(I probably didn't bothered reading that bit as it wasn't relevant to my plans.)

[Ruckus]

You can only get a 8" sub (10" with lots of work and angled) on the rear shelf really. And then you need a bloody great box hanging down.

The right hand corner space is normally pretty wasted space to me its ideal for a small enclosure.

The best place audio wise is rear bin builds, but that's a huge comprise in the cabin and is a lot of work to do right. It also takes the car from 'stock with a nice sound system' to 'a car around a system', if you know what I mean...

[fenghuang]

To me the rear bins are dead space. As is the space under the rear seats, which is my plan.