hartge amp project

[placey]

it's been a while. that doesn't mean i've disappeared or given up with interesting ice installs.

our favourite hartge convertible is up for some serious sounds....



there's been some planning for this. a couple of cheap but very good amps were sourced, mrv-f407 and mrv-t757...



they were in not such good cosmetic condition and the 757 needed some components sourcing and soldering. after some time and love however, they finished up colour coded and minty...

.

now let the strip down begin while the sun stays out... i hope you enjoy the pictures that follow.

[placey]

here's the usual mismatch of spaghetti. note the cheapest speaker cables mankind has ever produced and the (for me unfathomable) cut and non terminated cables. why is there so many people out there that don't do a job properly?

[ImysE30]

Look forward to the updates, fitting a sub too?

[placey]

yes there's a sub, but maybe not at this point in the install. this is a two part effort - amps now and builds for fronts and sub later.

here's the n/s rear speaker. this was professionally installed. i do know who the professional was too, but have been asked not to name.



i think i can improve on this a little. even a second screw would improve it!

[placey]

plan was to mount one amp each side on the inner wings at the rear, having stripped it down however i think on the rear bulkhead is a better idea. they fit better there and the weight is more central - mass centralisation and all that. a 12" sub fits each side where the amps were to go...



i've ummed and arred over whether to lift the carpet out, i think it can stay. the glovebox and quarter panel trims will come out after lunch and some organisation of the spaghetti can start....

the white cabling on the left is domestic 1mm lighting circuit cable powering some permenantly on leds. this will have to be re-done. still waiting clarification om what the data cable is, i propose to re-locate this to under the gear stick gaitor as it was hanging loose before. there's various insulation tape joinery there that will have to be re-visited too.

[toby]

That loose speaker is just shockingly bad.

[miniblob]

Love the attention to details on the amps!!!!!
If you do the rest of the install half as well, this will be quality!!

One day i hope i'll have the time and patience to do an install properly!!

[placey]

there was much progress this afternoon, although as always with prep work it doesn't look much.

there were one or two wires that were considered unnecessary.... now please tell me what the very heavy rear battery tray trim piece is on the right here. it weighs a ton! why would bmw fit such a thing?



the boot floor cleaned and waxoiled in the more vulnerable areas, ready for amp mounting boards tomorrow morning, weather permitting.



and the interior as left overnight. look any cleaner? it may still look like spaghetti but i have identifed every wire and made a plan for them all...

[E30BeemerLad]

that heavy bit of scrap is some sort of harmonic damper and needs to be retained. I don't know where they are supposed to be mounted though

[Rav335uk]

that heavy bit of scrap is some sort of harmonic damper and needs to be retained. I don't know where they are supposed to be mounted though

They are mounted in the rear of the boot, driverside instead of the battery, you can remove them if you're replacing with a battery though.

[placey]

steady but unspectacular progress today. rain stopped play this morning. the existing wiring has all been tidied up and the rca and amp signal cables are run into the boot. the front right speaker is wired too, the other three tomorrow. it was very difficult to unscrew the front speaker (it had 3 screws holding it in - the record so far!) and re-fit without sound proofing and mdf work to make it sound better. i know that's stage 2 but still, it goes against the grain...

[Ziggy]

I'm going to have to come and visit you one day Paul...

[placey]

real progress now. the head unit is in:



and the rest of the wiring is in. i know this as 'first fix', those in the trades will know.

[HartgeH27]

Superb ! Loving the progress !

[mrLEE30]

whats you plan for the subs? where will they be? i had trouble getting 12 inch sub under the roof enclosure, so in the end i made an angled box.

For info there is a 30A fused power supply just behind the rear seat that is desigend for the rear demister. not sure how you plan to power the amps but if they are not too big you can consider taking you 12V from there. let me know if this will work and i can explain more.

[HartgeH27]

Lee, the sub is an angled 12" and the amps have power run to them already.

[spook]

I hope you threw those Coldplay cds away.

[Blitz]

I've got to this on my cabby.

[placey]

ziggy - that would be great.

mrlee - thanks but these amps could conceivably draw 90 amps so i'd rather power them directly from the battery and fuse them each end for peace of mind.

lack of progress pictures due to other events in life requiring attention.

a visit to a couple of breakers saw a pretty good anthracite boot carpet come along. this was shampooed and scrubbed vigourously and was soon pretty decent. it was stripped of wheel well boards and backing and used to trim the amp board thus ensuring a colour match.

here's the amp board mounted with wiring in place....



the metal plates down each side are for the magnets to hold the cover in place. this is 18mm mdf and will be trimmed on the outside with more boot carpet and colour coded on the inside (royal metallic blue), still to be finished, pictures to follow.

here's the amps all wired in and fused:



so very nearly phase 1 complete.

the sub will be fitted to the battery tray area in a moulded enclosure - part 2 of this project when customer funds and my time availability allow.

[pac1982]

looking really nice dude, i doing a fresh install on mine soon, i've just got some quality alpine amps similer to yours but one of thems a mono block and i want them on display, my old set up had some shitty looking amps which i had hidden away under a false floor.

I've also just got myself a type R sub which i have mounted backwards which looks really trick

[jbh]

there must be something I don't know.. don't get me wrong I like my music but I'm happy with 4 good speakers and a good headunit and the sound of my m20 b2.5

it all looks good but sadly wouldnt be in my car I would feel robbed of space in the boot

[ImysE30]

Looking good so far, looks very neat

[mrLEE30]

that looks excellent!! great idea using magnets to hold the cover on....you shoudl be careful about giving trade secrets away!!!

will the amps not run too hot mounted like that i.e. heaksink down? although i assume you have considered this.

really looking forward to seeing the rest

[placey]

jbh - whole install is 110mm thick. that includes the cover when fitted. not very much space loss.

mrlee - it's only a hobby to me, i don't know how people do it for a living. i only take on peoples install work that i like or find interesting. full time professionals must have better backs of legs and backs than mine! i've done hinged doors and fixed covers etc, but with magnets the cover is held securely enough for spirited driving and easily removable for showing. i'd like to find strong enough magnets to place the plates under the carpet to hide them but haven't sourced these yet. old speaker magnets would work but are too big! i wouldn't want them to be strong enough to interfere with the amps at any rate. these v12s don't run very hot even when driven hard. they are fused down and the cover gives them some ventilation so i don't forsee a problem in that way.

the amp cover is in primer and filler right now - some blue should be applied shortly as it's drying from the latest wet 'n' dry session:

[HartgeH27]

The attention to detail has been incredible.

Looking forward to phase 2 once funds permit !



The hard work is much appreciated !

[skyway]

What size power cable you using?......Looks a little puny

[HartgeH27]

I just love constructive posts !

[jbh]

jbh - whole install is 110mm thick. that includes the cover when fitted. not very much space loss.

the amp cover is in primer and filler right now - some blue should be applied shortly as it's drying from the latest wet 'n' dry session:

that type of loss I could live with. its when you see full boots covered in it!!!
it does look to be getting kept on the small scale which I like the look of.. might speak to you and get advice on somthing to improve the sound I get.. but again I wouldnt like to go OTT

[skyway]

I just love constructive posts !

Im only asking because im interested to understand how many amps the amps will pull and what the cable might be?

I just read that the amps may draw 90 Amps

So 4AWG cable should be used as a minimum.....hence my 'Puny' comment!

[placey]

there's 8awg to the amps from the battery. there's a 40 amp fuse at the battery and each amp has a 20 amp fuse to protect it. 4 awg fits under the loom clips alongside the loom on the drivers side sill of the e30 should you wish to use it. it doesn't show and causes no issues with carpet lumps or anything.

experience tells me that these alpine's are quite happy driven hard on half the on-board fuse rating without blowing fuses or heating cables - as an example i am running 3 mrv-t707 amps in my work van on a single 8 awg cable and each with a 20 amp fuse. they are all turned up and regularly driven hard for extended periods and the standard charging system and cables and fuses all take it. (although this is at the limit of what i would ask 8 awg to do) i think the trick is not to drive them so hard as to induce distortion (clipping) and that is pretty easy to tell by ear. who wants to listen to distortion anyway?

the 90 amps mentioned comes from the amplifiers on-board fuse ratings - 50 and 40. those amps will never draw 90 amps in use - can you imagine 90 amps? enough to power a crane! the standard charging system doesn't have 90 amps headroom. maybe momentarily but not for any extanded period. you'd have to get into the realms of uprated alternators, 2 batteries, split charging system and uprated cables everywhere to provide 90 amps for music continuously....

i am a part p qualified electrician and have a good understanding of cables, fuses, ratings and real world safe and practical solutions and what happens under fault conditions. (this is important as i have to sign off domestic installations and it's me in court should it go wrong....) as a (very) general guide - if it works and no copper is visible or accessible and it doesn't get hot it's ok...!

hth skyway. either fuse down or cable up. personally i prefer to fuse down, (hopefuly!) then a smaller fault current trips your device.

[skyway]

Im sure you know exactly what you are doing with your installs and it good that you have an electrical background ( although AC and DC are two different beasts! )

And thanks for your response....its good to see someone thinking about what they are doing.....There is room for some improvement but you are definitely getting there!

Personally I would always go for the heaviest gauge cable possible in any installation from the battery and for the ground.....simply for the fact that the goal is to provide as much current to the amplifier as it could possibly need for optimal performance...Thicker cable=more current....regardless of alternator or battery size.

One question.....does the negative power cable go back to the battery?

Ill let you see one of my installs one day

[placey]

skyway - i also have a work background of several years working in the electronics industry. we tested many cables and components to destruction for products that were often sold to the military so i know these cables will take some fairly hefty currents before degredation. manufacturers claimed current ratings are usually most conservative. 8 awg is fine for this application. if i was in any doubt i'd have run 6 or 4 awg. (it makes no difference at install time) there's not going to be a 3rd or 4th amp added, that would have influenced cable choice too.

there's no point in running 4 awg unless the charging system can push sufficient current down it to warrant the extra. like i said above, you're then into the realms of under bonnet upgrades and this project is not that big.

i disagree with you - thicker cable doesn't mean more current - it means less resistance. if there's sufficiently low resistance already then there's very little to be gained by running anything bigger. more current comes from either the battery or alternator.

amps are earthed just behind the amp mounting board, shortest runs possible to the same point. standard practice. (battery under bonnet, not in boot)

[skyway]

I disagree with you - thicker cable doesn't mean more current - it means less resistance..

and less resistance means more current!

You seem to have taken some offence at my response to your comments.....
I am not trying to force an argument...and I realise you are doing this installation for someone else who is paying you for it.

I just had a couple of legitimate questions about the installation.

Im sorry to cause any offence.

I also have a background in electronics and have been installing high end car and home audio systems since 1987 so have a little experience to fall back on.

once again I apologise if my comments seemed inflammatory!

Good luck with the rest of your installations.

p.s. I hope you grommeted those cables passing through the bulkhead!

[placey]

no worries! no offence taken or meant. i enjoy an informed debate and appreciate your comments. it's nice to know what people think and i like to be questioned - it makes me question myself. i'd like to know where i sounded offended as i didn't want to come across that way.

less resistance does give greater current granted, unless of course there's so little resistance in the first place that a bigger cable gives no difference. in this very case i think that the difference would be so small a larger cable is not warranted. if the owner comes back to me and says that it gets hot or keeps blowing fuses i'll come back to this thread and admit that i got it wrong!

i've been doing installs for 20 years now. i think i know what i am doing. if i don't there's no hope and i'll give up straight away. there's many on the zone that have heard my work - hopefully one day you'll hear it too, i'd certainly like for that to happen.

grommeted? what's that then?

[spook]

Grommeted, sounds like something nasty one would do to a plasticine dog.