Could i wire a small class d amp into the passenger footwell terminals?

for the CCCU etc i mean. would this cause any problems? would save me alot of time on my tablet install.

thanks, hope youre all having a great day.

define "small class d"? KAC 3004 or something a little more potent?

There is *no fuse* between taht plus point and the battery (well, there is, but it's 150A, so you need to fuse anyway) and I would be very, very careful about shielding and interference issues. You'll also need to run a decent sized earth. Yes, the cable is big enough to deal with some more load, but I'd still not want to put it there, mainly because of the lack of secure mounting points. There's also not that much room, to be honest...

- Bret

cheers for the input.

a little higher specced but not by much. mine is rated at 75wx4 (RMS) at 4 ohm. not a decent brand or anything, doing a proof of concept before i go balls out on expensive gear. yeah i saw that 150a fuse hahaha, made me think twice about poking around down there too much, not that 12v can do much of anything to you unless you try pretty hard.

i refute the fact that interference does anything in car audio (maybe if youre going hard at it, SPL level ****) unless youre really stupid in layout (run rca/speaker parallel to power and ground for the length of the car etc). from my limited understanding of electronics its much more of an issue with AC than DC?

i'll take all the normal precautions such as fusing and careful wire routing of course. i wont be mounting the amp itself down there, that will be hidden behind the tablet in my dash. i will run the wiring down the inside of the centre side footwell panel and into the footwell the same way i did for my sub in the boot, keeping as much space between them as possible.

Interference does an awful lot. The "DC" created by the alternator is extremely dirty and I'll put beer, right now, on you getting an engine rev-related whine that requires the tablet to be on battery before it goes away. Cigarette lighter USB power adapters don't help because they tend to be cheap and cheerful and the varying "ground" voltages cause massive interference. I've tried running laptops in the car before and had nothing but trouble. It's extremely common. Ways round it generally include shielding RCA cables correctly (that would be with the shield connected only at the source end), mutual ground points, and a good connection back to ground. You're also running your source directly above some 90's electronics, otherwise known as the climate control.
I've had enough problems with PAs in the office, so much so that we'll now only ever run from one socket for source and active speakers, or we end up with 50Hz hum everywhere.

It's also not the 12V that will blow things up, it's the direct short between 12V and ground (chassis) with fat cables.

75W x 4 is still actually quite a bit, current wise. Even at 90% efficiency, that's a good 30A at full power. I'd probably fuse at 30A or so and use 6mm2 for the amp on both sides. Remember you're fusing to protect the cable from too much current, not the amp.

- Bret

Well damn. I hope you're wrong. We shall see I'm willing to wager a couple of bottles of Belgium's finest I should correct "refute" to "not had any problems with it personally" I guess. Haha.

I have to say I'm most worried about my fasttech special usb car charger now... Hahaha

Although during testing I haven't noticed any kind of hum or whine. I will take it out for a drive today and find out for sure and do some extra shielding. I've had the sub installed for some time with no hint of extra noise.

Oh yeah I know a 12v battery shorted will wrath you and your electronics like a snubbed mistress. I meant for my health and safety rather than the cars. Done a lot of silly things with 12v in the past and it never shocked me unless I was being an idiot. Skin offers a lot of resistance to low voltage.

Will be using 8 gauge and a 50a fuse.

I myself wired my Amp 1200Watt and stereo Directly from the main power line with the 10mm bolt and 8mm red power cable from the passengers ecu and cccu compartment although feed the power lines with an inline fuse over the center tunnel and placed the amp in the driverside compartment as to the heat it gives off and keep it sepperate from the ecu and cccu , and then run the wiring along and up the drivers side of the center tunnel to the head unit as less wiring that route so less chance of picking up interference on the rca lines, i had no problems with interference although in my other A2 i use my iphone charger in the 12v cigerette socket i do hear it slightly through the speakers ive noticed with the standard synphony headunit.

-Gary

Note ,, The thread where the 10mm power line bolts on is very short, so i used a extra long 10mm nut , which is about an inch long and tightened that down first then a short length of 10mm rod to allow for 2 power terminals for my amp and head unit then the original powerline with the captive nut connected to the red power lead goes back on the top and tightens the hole lot together ... worked a treat

excellent good to know its been done and works well thanks! i may also route the wiring under to the drivers footwell then up to the dash, sounds like the best plan, bar mounting the amp in the footwell, mines tiny so no point.

even more worried about the car charger now though.. thats an integral part of my tablet install.. wired a new cigarette lighter socket below the ashtray with a 2.1a fast charger in it, 2 ports. one for the tablet (wire mostly hidden going up behind dash, and a coiled 1m cable in the indent to charge phones etc.

would a buck converter or something do any better if i get a decent quality one?

thanks
Sam

Edit..

Considering it further it might be better for me to mount the amp in the drivers footwell too. That way I ran run a lot of the rca and speaker cabling over that side. Ill see what play I have in my cabling. Amp should arrive tomorrow

its done. i mounted the amp behind the dash and ran the wiring up the left hand side, it worked out easiest and i found a good earth behind the centre console/passenger footwell trim.

i attached live to the main positive terminal in the passenger footwell, made sure there wasnt enough wire (8 gauge) to meet the chassis before my 60a fuse (what i had laying around, good enough for my means) which was cable tied to the frame of the cccu housing. i ran my live cable up and out the same route that the thick black cable makes it way out at the back right, closest to the centre console. really easy actually.

now im just waiting on a few rca connectors etc and ill have everything done except make it pretty. probably going to be the long/hard part hahaha.

going to order some good quality usb chargers too - had my cheap one plugged in for an hour charging my phone in the 2.1 amp slot and it was too hoooooot after.