Post Boot(audio) Installs?

[antil33t 90]

Need some ideas on how to go about making another sub box. Made this box for another car, doesn't work so well with this car hah.

ew.

Kgo

[_ethrty-Andy_ 2122]

The repco ones fit well, there is adequate room to clear the torsion springs, and you can fit two side by side too if you want Doof doof

(Dont have a photo of after tidying the wiring, its the last photo in the album so assume i broke the camera the next day or something)

[Mike 1]

setup I had in my e30

http://www.bimmersport.co.nz/forums/index....ic=8920&hl=

I had the same soundstream sub in my e39 too but that was just in an off the shelf box. thread around somewhere if you search

Edited March 15, 2011 by Mike

[antil33t 90]

will be making a custom box.. imo they are just better.

That looks really nice Mike. pity I have two amps strapped to the back of the seat... trying to retain as much boot as possible.

[kerry 10]

im going to be running 2 amps on either inner side of the guards e.g one above the battery pocket and one above the jack pocket, then mounting my 10" and cap in the center rear of my boot by the parcel tray, will get pics when i get a chance as it currently in my mates workshop.

[MLM 57]

I used to build mine from fiberglass. You cant beat the fit and finish of a glass install with mdf cubes. Glass allows you to take advantage of any psace available ie jack pockets for volume in is often more ridgid.

Its easy to do just takes longer and costs more. But you soon forget the extra time and money when you have a boot with lots of usable space and a unique install.

[kerry 10]

prototype but this will be built with glass also as i already have far to much weight.

[rogan 1]

will be built with glass also as i already have far to much weight.

Ditch the cap then. It's only of use when you have a crappy amp

[kerry 10]

i thought they helped stop battery drain? thats the only reason i have it.

[_ethrty-Andy_ 2122]

Rogan is incorrect.

They are for when you have a standard battery and a not a gell cell. They smooth out the supply of power from the battery to the amps so instead of 60A-Nothing-60A-nothing... every time the bass hits, it takes a steady 30A. Its far better for your on board electronics too like relays and stuff. Ever seen an old starlet that has headlights that pulse to the bass of the car?

General rule of thumb is 1Farad for every 1000W of amplification, but nothing wrong with more. I have 1950W and a 5F cap. For the average person you dont need one as the amp pulls maybe 30A max which it will supply. When you have all your components and a couple of subs running though, its a good idea.

Some people think they are a waste of money. they are also the people that have faulty electronics in thier car because they still use a stock battery. I say keep it

Edited March 19, 2011 by _Ethrty-Andy_

[westy 614]

Rogan is incorrect. blah blah blah.

You've seen his installs?

I think I'll go with Rogan on this one.

[Greg111 13]

This is mine, simple but effective, spent many an hour swapping amps, subs, wiring etc to get what i want, 600W amp providing power to the four cerwin vega split components and an 800W amp providing power to the 800W sub.

I think bluetooth made my picgture go funny?

[antil33t 90]

They are for when you have a standard battery and a not a gell cell. They smooth out the supply of power from the battery to the amps so instead of 60A-Nothing-60A-nothing... every time the bass hits, it takes a steady 30A. Its far better for your on board electronics too like relays and stuff. Ever seen an old starlet that has headlights that pulse to the bass of the car?

Some people think they are a waste of money. they are also the people that have faulty electronics in thier car because they still use a stock battery. I say keep it

lies and hearsay, I have some electrical qualifications so I say u rong boi.

your wiring scares me, a lot :0

What you need, is a BIGGER ALTERNATOR! you can't just buy a bigger battery.. doesn't work like that. can't make power out of nothing.

and having a capacitor that big in the back of my car scares the sh*t out of me. Ever discharged a large capacitor?

and I really do doubt you having 1950w RMS. those Sony amps are all PMPO rated. "Peak Marketing Power Output"

Also, OT, nice installs, keep em coming I'm just acquiring a 1" MDF sheet to start building another box.

Edited March 20, 2011 by antil33t

[kerry 10]

ok so now im confused. my amps used to cut out before i instaled the cap. they didnt get enough constant power as far as i can tell so if i were to take the cap out what would i do, my alt is 120 amp, sub, amps and heady are pioneer prs series.

can get mdf cover sheets for like $20 at placemakers usualy

Edited March 20, 2011 by kerry

[3 SERIES 92]

Here is my install.

Sub box with customwood panel cut nicely to shape, carpeted and bracketed together at the rear.

Space on left was going to be for amp to power front components. Still havnt got there yet, along with

feeding the earth wire back thru the s/s surround.

Cheers

[dubman 39]

^ very nice, clean and professional.

[_ethrty-Andy_ 2122]

You've seen his installs?

I think I'll go with Rogan on this one.

Nope I haven't, I'm going off research I did before buying including talking to my electronics teacher back when i was at school who used to do electronics research. Everyone has different opinions on them I guess. I shouldn't have gone off topic ha

lies and hearsay, I have some electrical qualifications so I say u rong boi.

your wiring scares me, a lot :0

What you need, is a BIGGER ALTERNATOR! you can't just buy a bigger battery.. doesn't work like that. can't make power out of nothing.

and having a capacitor that big in the back of my car scares the sh*t out of me. Ever discharged a large capacitor?

and I really do doubt you having 1950w RMS. those Sony amps are all PMPO rated. "Peak Marketing Power Output"

Also, OT, nice installs, keep em coming I'm just acquiring a 1" MDF sheet to start building another box.

Me too ha

That's correct, and I didn't say you were wrong. I'm talking about the willingness of the battery to give bursts of current, and the long term effects of a battery doing that.

My capacitor discharges itself when I need it to. Charging it is always fun though ha

I doubt it too, I think it's max rated.

My bad ha sorry

ok so now im confused. my amps used to cut out before i instaled the cap. they didnt get enough constant power as far as i can tell so if i were to take the cap out what would i do, my alt is 120 amp, sub, amps and heady are pioneer prs series.

can get mdf cover sheets for like $20 at placemakers usualy

As I said above, a capacitor smooths delivery from the battery to the amps. The battery may have been unable to provide that much current to the amps. Since the install of a capacitor, it provides a smaller more contiuous flow of current

Wikipedia a capacitor if you are still confused

Checking your alternator is up to scratch is always the firs thing you should upgrade if necessary

[polley 916]

ok so now im confused. my amps used to cut out before i instaled the cap. they didnt get enough constant power as far as i can tell so if i were to take the cap out what would i do, my alt is 120 amp, sub, amps and heady are pioneer prs series.

can get mdf cover sheets for like $20 at placemakers usualy

Kerry, from what I understand, a capacitor can deliver current faster than what a battery can if your alternator can't keep up. I.e when big bass hits, and your alternator and battery can't keep up with the current demand, the amp can get a short burst of extra power from the capacitor, the capacitor then recharges from the battery / alternator for when it is next needed.

Without the capacitor the amp is likely to be drawing more than the alternator / battery can deliver and the voltage drops too low and the amp turns off / goes into protection mode. Especially at low RPM when the alternator may not be at full output.

Maybe I am wrong, but that was my understanding of it.

[huff3r 347]

The main issue here is that car batterys are not designed to provide large, constant voltage. They are designed for large, short bursts (starting). So if the alternator is not responsive enough, as stated above, then the battery cannot help out either, so a capacitor will provide a solution. Another solution is to run the audio off a seperate deep cycle battery, also charged off the alternator. However thatd be far heavier.

[j.ingledew 0]

And eventually, your amp will just quit. As mine did, awesome :/

[rogan 1]

Whoops, started a cap debate, apologies to the OP.

Firstly, I am no electronics expert so don't take what I say as gospel; but I do think I'm right based on years of experience amd learning.

I referred to crappy amps, probably should rephrase that as budget amps. A way of achieving cost reduction in manufacture is to minimise the power supply section of the amplifier, and this can be done by reducing the onboard capacitance. A quick look into a high end amplifier (Alpine MRV-F900) shows the caps. 4 x 10,000uF or in easy terms 0.04 Farads; this is for an amp that does about 800rms with the gas pedal all the way down.

If this amp needed any more capacitance then you can bet Alpine would make a capacitor and would be able to sell it for moonbeams. The people who buy this amp brand new wouldn't blink at $500 extra for a cap to match. But Alpine don't, and they don't have a cap in their product range whatsoever. Neither do Pioneer or other brand heavyweights. Most capacitor brands are no namers (with exception of Soundstream and McIntosh - although pretty sure MacIntosh don't do a cap any more). So if you've got a budget amp, there may be deficiencies in the power supply and a 1F cap should band-aid this so you don't notice. I reckon you could head down to Jaycar, pick up a 10,000uF or more capacitor and achieve the same result for less than $10 but I haven't done that so won't guarantee it'll work. Probably worth a $10 punt though. have a look at Focal amps, they've just released a capacitor of sorts: looks to me like they've taken the power supply section outboard, packaged it up nicely and are trying to make a tidy profit on it.

13200uF ( = 0.0132 Farads) according to the specs. So that'sunder $10 worth of electronic components packaged into a US$149 product. To me this is marketing at its best. Cheaper for the consumer just to buy an amp with this on-board, but it does look pretty.

One thing to consider is when then engine is running, the battery is not a power source; it's a power drain (or reserve). It only comes into play once the power generated by the alternator is being fully used at which stage the system voltage drops from the 14.4v generated by the alternator to the 12.6v held in the battery. So is dimming headlights from the 14.4 to 12.6v drop, or from the battery not being able to supply sufficient power and dropping below 12.6v? I'm thinking it's from the 14.4 to 12.6v drop.

There was a myth that you needed a 1F cap for every 500rms of amp power. The JL audio website used to have this as a guideline but it was removed ages back. I've spoken to one guy who have designed car amps and he reckoned that as long as there was a robust power supply section in the amp, no external capacitance is needed. The only amp I know that has massive capacitance is the Rockford Fosgate mega watt beast (don't know model number off hand but it does about 15,000rms. The capacitance used there (an entire amplifier board) is for a different purpose; the amplifier runs on a 16v (or is it 18v) basis so the amp transforms the alternator 14.4v to a higher voltage and the caps are used to store this higher voltage. Note- this isn't a technically perfect description of how it works, but an attempt to put it into layman speak for all of us to be able to understand.

Kerry, your problem sounds like an issue in wiring. Amps will shut down (generally) if they go into a protection mode or there is insufficent power supply. Since installing a cap fixes the problem then lets rule out protection for anything but power supply. What I'm guessing is happening is there is an issue in your amplifier earth or power wiring that is hindering supply. A cap gets around this because it supplies a power reseve and a quasi-earthing. Check your power and earth wiring, making sure your amp to chassis connections are strong and your battery -ve to chassis connection is also good. Earth wire needs to go to bare metal chassis, then cover with something like vaseline to prevent corrrosion. If you've got a poor connection somewhere then you'll reduce the power available to the amp and you'll get it shutting down in the manner you've descibed.

And finally to get the thread back on topic, some boot pics ( 140a factory alternator and no cap ). Power supply would have been an issue if I'd run this anywhere over about 50% full power; I would have upgraded to a h/o alternator to get around this but the factory alternator was sufficient for my listening needs.

There's this myth that your subs will hit harder with external capacitance. To dispel theis, take a look at SPL competitiors. Next to none use caps, and considering every 0.1db is vital to success, surely they'd be in there if they made any difference to the amount of 'hit'.

Edited March 20, 2011 by rogan

[antil33t 90]

That install is pure bad ass Rogan.

Debates are fine, just no bitch fights.

[kerry 10]

i understand.

thanks for all the info chaps and michael how have you decided are you going to build your box to utilize boot space.

[antil33t 90]

i understand.

thanks for all the info chaps and michael how have you decided are you going to build your box to utilize boot space.

I'm definitely going to utilize space, Need to make a few measurements and start designing a few things. Probably make a wedge type box needs to be around 40L