30 quid sub boxes in halfords!

[ZippyVR6 0]

Anyone else seen these? just an unported, carpeted box with conectors in 10" 12" and 15" sizes. Just wondering how good they can be.

 

am i right in thinking that an unported box would make a 12" sub feel tighter than ported?

 

last question. Where have people routed the cables to the boot foe their amps and subs?

[Andi 2,147,483,647]

Got a 30 quid sub box in mine from when they did this last year running my 10inch Xplod sub. Tis good quality :)

 

Porting - depends on the driver and cubic capacity its meant to run.

 

Routing - was already in my car, sorry! :)

[_Monkey 0]

Right, when wiring you want to keep the main power feed as far from your rca leads as possible so ideally you want to run the power (4 gauge minimum) down the passenger side of the car and the speaker/rca down the drivers side, otherwise you'll encounter all kinds of interference. Everything unscrews nicely and if you take your time at it you can completely hide all unsigtly carpet bulges.

 

As far as boxes go, you'll get a much better frequency response with a non ported box.

A ported box will sound much louder at certain frequencies but pants at others.

Porting successfully is a black art and you should stick to non ported as they sound nicer and tend to drop a lot lower.

[chrishill 0]

i've got a halfords one too, cant fault it!

 

routing...

 

Power cable.

run from + on battery (make sure fuse is close to battery) through bulkhead via a grommet that comes out top center of the passenger footwell under the carpet, run it under the carpet to the plastic trim at the end of the door opening, under that, then lift the thin plastic trim at the bottom of the door opening and tuck it under there, run it under that all the way to the rear door cards, then tuck it half way along the base of these, then let it run down the side of the seats and into the boot.

 

RCA leads. (remove driver side undertrays first)

from the back of the headunit, run the cables under the steering column making sure you keep them clear of anything that might move, down into the plastic trim by the door opening then along the car as per the power cables and out into the boot.

 

remote power. (remove passenger side undertray)

from the back of the head unit, under the glovebox and down to the trim at the door opening where the main power cable runs, then follow its route to the boot.

 

earth.

theres a bolt in the 'split' of the rear seats, which holds the hinge onto the body of the car. make sure you rub any paint away to provide a good contact and put the earth on there.

 

I've used this setup on 2 corrados now with no issues, although you have to be careful when putting the rear seats up/down so as not to trap any cables.

 

I've also run speaker cable from the other 2 outputs on my amp down the center tunnel, up through the dash then left/right to the door speakers.

 

HTH!

[bix 0]

Ported boxes are louder and more boomy, good for a lower power sub, where as a sealed box are better at lower frequencies, but you need more power really. I always have sealed boxes, and the box needs to be bigger if its ported. I have a 15" sub in a box thats just over 1 cubic foot on a 1.1kw rms amp, fcuk its loud!

[_Monkey 0]

Ported boxes are louder and more boomy, good for a lower power sub, where as a sealed box are better at lower frequencies, but you need more power really. I always have sealed boxes, and the box needs to be bigger if its ported. I have a 15" sub in a box thats just over 1 cubic foot on a 1.1kw rms amp, fcuk its loud!

 

Bl@@dy hell! what sub you running?

[GIXXERUK 0]

over the shelf , down the kick panel, along the inner sill up and under the rear seats

as chris says , ran my amp and sub that way , no issues :-)

 

i'm running a 12" vibe ported sub , saves me hearing the rattles on the c :-)

[Andi 2,147,483,647]

15" in a cubic foot sub?

Ouch!

My 10" needs just under a cubic foot...

[bix 0]

Yup its an audiobahn aw1500q "Rec. Sealed Box Dims: 1.00 - 3.50 cu.ft." I think its just becoz its more powerful it only needs a similar sized box, I had it in a similar sized box before but only on a 400w rms odd amp and it sounded pants!

[saysomestuff 0]

When routing cables It is paramount that you separate power and signal wires. Ideally route them down different sides of the car. Most people mount the amp in the boot so there's minimal signal loss between it and the speaker, but there's no reason that you can't put it anywhere you want as long as you avoid any sources of power.

[saysomestuff 0]

lol I type far too slowly, just spotted all the posts up there!! there was only two when i started typing :oops:

[GIXXERUK 0]

saysomestuff, good point ;-) i routed the audio cables the way i described above and the power cable is routed through the center of the car under the center console

[Neil VR6 0]

Gonna stick my neck out here. If you've got good quality well insulated RCA's and well insulated power cable the interference can be minimal to nothing. I completely agree that it's best to separate them and should be considered best practice though. My old Polo system was running two modest sized amps (700w RMS between them) and the RCA's and power cables were routed next to eachother (Avoid Road Radio ;)) but there was no buzzing or interference.

[Kevin Bacon 5]

All good advice so far.... although don't run anything on the driver's side due to the fuel pump wiring and the relay/fuse board, which can both cause an inductance loop unless you're using expensive RCAs.

 

I personally ran RCAs alongside a power run in other cars without problem. It also depends on the quality of your HU and Amp's ground loop circuitry. In the C I had to run the RCAs down the centre as I couldn't squeeze everything down a single run....the carpet wouldn't go down again!

 

Porting v sealed....always a good one that! Sealed does indeed have the flatter frequency response but it's not necessarily the loudest at the extremes of low end. With sealed, the lower you drop, then the power requirement increases exponentially....so as Bix says, you need schitt loads of power to get the same output in dbs at frequency X than ported and likewise ported has a narrower frequency band but with some clever port loading, you can make the frequencies seemless. Only poorly designed and made ported boxes sound peaky.

 

I'm running a phase linear aliante 10si in a 19 litre ported box (tiny) and it sounds sublime, to my ears.

 

Those Halfords boxes are generic, they may or may not flatter your chosen sub. Just depends how critical you are and for me sound quality is everything, otherwise it's a waste of time....for me.

[bix 0]

Heres my professional :oops: looking install, I also have the (cheap) rca cables running alongside the power cables, and there is no interference, I think it depends on the design of the amp as to whether you get that alternator whine on the output, and also maybe as its a sub amp the low pass filter helps.

 

And yes it does sound a little better than it looks!

[Kevin Bacon 5]

Gonna stick my neck out here. If you've got good quality well insulated RCA's and well insulated power cable the interference can be minimal to nothing..

 

Spot on that man.....

 

Inductance loops is a legacy of the olden days and cheapy leads. Head unit and amp isolation circuits have improved markedly too.

[Kevin Bacon 5]

And yes it does sound a little better than it looks!

 

Which is surely the point? Sound quality, although highly subjective, is the goal! So what if it looks a bit sort of MDFy, so long as it tingles your ear buds, then it's all good..... you can tidy it up afterwards if required ;-)

[_Monkey 0]

Just depends how critical you are and for me sound quality is everything, otherwise it's a waste of time....for me.

 

Totally agree, but unless professionally done it is stupidly difficult to cover all the frequencies in a ported box, you usually need much more cubic space behind the sub too. I managed 142dB in a comp once using 2 120watt rockford amps and a 15' dd sub in a box that resembled a coffin, it was bl@@dy massive!

[bix 0]

Amp's ground loop circuitry.

 

Exactly, an amp has a smps to step-up the 12v to say +/- 100v, and you need to isolate the 0v on the smps output from the cars ground, which makes it difficult to regulate the smps output, so many older/cheaper amp dont, hence the whine!

[bix 0]

And yes it does sound a little better than it looks!

 

Which is surely the point? Sound quality, although highly subjective, is the goal! So what if it looks a bit sort of MDFy, so long as it tingles your ear buds, then it's all good..... you can tidy it up afterwards if required ;-)

 

Yeah I'm only bothered it sounds good and the sub sounds great! Shakes your eyeballs! Just need to get a decent set of 6x9s on an amp and something in the front now!

[_Monkey 0]

My last install used to get shop windows rattling as i drove by, however, when underestimating a bend on a wet night, they decided to leave the car after hitting me in the head!

 

Morale of the story? ALWAYS bolt your sub boxes down as the back seats offer as much protection as tissue paper!!

[ZippyVR6 0]

Thanks very much for all the advice. Having just got back from Halfords, (Yeah Plumbers do finish early on a friday)

 

Unfortunatly there is no way i will fit that box in under my 6x9s, the box is 36cm high and i only have clearance for 32cm, so it looks like im fitting my big, old, low but wide ported box that the sub (12" kenwood something or other) was designed for. I just didn't want to loose all my boot space again.

 

Now time to route that cable. From the Battery where have people entered the bulkhead? and grounding points for the amp? there looks like a good screw and nut under the rear lights.

[_Monkey 0]

There is a nice grommet in the bulkhead, just down from the water pipes, as for earthing, use the biggest bolt you can find for minimal resistance(i find seat belt bolts work well).

[ZippyVR6 0]

Magic. Thats tonights job sorted then. Cheers all.

[_Monkey 0]

Just don't forget to put a fuse between the battery and the bulkhead, i've seen cars catch fire like that before!