Valkyrie

Hi guys,

I would have put this in the general electrical section but I'm after some recommendations for equipment that I'd buy here in the uk and not overseas (different product market in some cases, after all).

Recently decided to do something about the stock audio situation, so far I've bought and fitted a Pioneer DEH-8100BT HU and have been donated a set of 5.25" Focal PS130 component speakers. I'm in two minds whether or not to fit these in the doors despite them being a tad smaller than stockers.

Kit I had left over from my last car is an Alpine MRV F345 four channel amp and 4awg wiring kit so I'm intending to run a sub this time that I'm building into the spare wheel recess -

It's real basic as I've never done anything like this before and understand very little about audio -





Fits very snugly, and it'll get carpeted before it's finished. Sealed without a sub it provides 0.56cu ft. Now this is where I need help, regarding amp output too.

The alpine bridged, puts out 300w RMS @4ohms although I've heard these units actually pump out more than the manual stipulates. Sub wise, does this mean I'll be requiring a SVC 4ohm or DVC 2ohm item? And does it have to be rated at 300w RMS? Matching this with the box volume is quite limiting. And being in the S I'm not looking for out and out sound quality because unless I'm parked it'll be wasted on me.

This is my Amp's manual -




Mounting depth is about 125mm and the box will be upside down to allow speaker excursion into the recess below the box.

This is one that I'd been considering but noticed it said warranty voided if wattage exceeds 300.


All help with amp settings and sub selection is very welcome,


Cheers guys

BenRNBP

I came across this on the Alpine site recently http://www.alpine.co.uk/support/ampl...ng-charts.html at least you might find a similar spec to the Alpine recommended and be able to go from there

Tommybuoy

Ideally you want to match the RMS of each.

A sub rated at xxxRMS with run that no problems. Exceeding the RMS for the sub can heat the coils and damage it, running a little lower power causes no problems.

Your going to want a sub with 300W RMS (or near too, not under) at 4ohm as that's the resisitance when bridging.

Ideally you want to make your box to the sub, not the other way round. Also, you'll get a lot of rattle I would have thought placing it under the roof tray.

Also, with regards to the front speakers, Focal make some nice speakers and with your four channel amp I would recommend powering them via this as you'll end up with the sub running away from them. Just make sure the impedance and RMS are OK and fit them well. I've not heard of anyone fitting smaller speakers, but no reason why not I guess.

For sound quality the fit is as important, if not more in these cars, that the quality of the speaker. Sound proofing adds weight, but I'm going back and putting more in mine anyway.

For reference, I run a Hertz 4 channel in the spare wheel space, a 10" in a fibreglass box sunk into the tool / store area in the boot and Focal components up front via the amp. I've left the roll over tweeters are they are.

Good Luck

lovegroova

loftust

Your roof tray - big plastic thing behind the seats will rattle like hell. I believe UncleFester wrote a good thread about sound proofing and damping.

Sent from my GT-I9300 using Tapatalk

Valkyrie

Thanks guys, appreciate all the input. From the alpine link, it recommends a shallow mount sub that would ideally fit my enclosures cubic capacity, and two of their newer amps running 300w RMS - the SWE-1044e

But, we were just discussing that a 300w RMS amp output would require at least a 300w RMS sub (@4ohms etc) otherwise overheat could occur. This recommended alpine sub is only rated at 150w RMS (500w peak), though. Am I missing a trick here? sounds like it'd wreck it.

Tommybuoy - fully intending on soundproofing. I'd intended on using the paint rather than matting having been searching a lot, although it looks hard to source in the UK for some reason.

lovegroova

You are more likely to wreck the sub running an underpowered amp than you are with some power to spare. This is a useful article, if a little technical. http://www.bcae1.com/2ltlpwr.htm

You won't go wrong following the Alpine advice.

Tommybuoy

If you search online for matching subs and amps you'll find argument after argument.

You can run a hugely over powered amp with a low rated sub all day long if you manage the gains etc.

I'm going over to the audio specilists I use tonight to I'll ask the question and let you knwo their opinion.

Valkyrie

Cheers guys, appreciate it

As for increasing box capacity by a small amount, I've read that pillow stuffing works... sounds a bit dodgy with heat involved from the sub but I'm assuming it's something to do with increasing surface area, or is that totally wrong?

Valkyrie

How'd you audio guys feel about this slimline sub, and experience? It's the JBL MS-10SD2 10", runs at 250w RMS and 1000w max. The 300w bridged input at 4ohms should be manageable, I'd have thought.

This is how I've understood a DVC (with 2ohm per coil) to be wired, let me know if I'm wrong -