Amplifier installation question

[JBOO]

I have read several posts from those that have installed amplifiers in the rear of their Mini's and it seems a lot have had trouble with induced noise. Is this common for everyone or only unique to a few?

For those that have had problems, have you been able to correct it?

For those that haven't, what do you think you did to prevent it?

I'm getting ready to start my install soon and would like to deal with this problem beforehand, if it is even a real problem at all.

Thanks!
J

[minhi]

it can be a problem, you won't know until you install it. do a search, there are a lot of things you can try to fix it. really there hasn't been a consistency among the installs.

to be honest, i wasn't too surprised when i found my noise, i just went through the normal debugging procedures and figure it out. come back when you have things roughly installed, you might not have any problems.

[Andy_D]

Just my 2p worth.

Over 90% of the amp installs I have come accross with interferance is due to the RCA leads running next to a power cabes or power supply. Best method when installing an amp is to totaly strip the interor of the vehicle and run power one side and audio the other. And a final note the quality of the cable is the most important factor in ICE installs, you should buy the best you can afford.

Just my 1p worth.

Andy

[scooterboy]

Don't know if this may help you but when my car arrives I plan on installing an amp in one of the cavities that are found under the carpet beneath each front seat.

I've yet to understand why someone would choose to run cables all the way to the rear cargo area only to run speaker wires all the way back up to the front.

Using one of those cavities, the power and feed cables will run to one of the seats, then speaker wires can run directly to each speaker (avoiding the power cable of course). The amp will be centrally located - more efficient use of cables.

That's my plan anyway.

[JBOO]

I guess I should have clarified most of the cars that I have seen affected by noise have been Cooper S's. I assume since the amplifiers are mounted over the battery?

I haven't seen anything definitive on how much room is available under the seats. That would be the preferred location for me, but I don't want to plan for that only to find out it wont fit once I get started.

Any help?

[ToreB]

I have placed my amp under the passenger seat (on the right side), a styrofoam insert was placed there as I have no sat.nav.
Regards, Tore

[minhi]

Quote:

Originally posted by scooterboy


I've yet to understand why someone would choose to run cables all the way to the rear cargo area only to run speaker wires all the way back up to the front.

Using one of those cavities, the power and feed cables will run to one of the seats, then speaker wires can run directly to each speaker (avoiding the power cable of course). The amp will be centrally located - more efficient use of cables.

That's my plan anyway.

as you can see by toreb's diagram, there's not that much room under the passenger seat (the larger cavity), so you're choice of amps is limited, especially if you want a 4 channel amp. the smaller amps also seem to top off at around 50watts per channel. the only amp i can think of that mightl fit in that space is the blaupunkt PA series--but i didn't base my shopping on that single physical dimension so there should be a few others.



forget it if you also need a sub amp

[ToreB]

I forgot to tell, the carpet can be cut to give more height, there's almost 4 cm. from the carpet up to the seat mechanism. On the other hand, there is absolutely no more space "sideways".
Regards,
Tore

[scooterboy]

Quote:

Originally posted by minhi
the smaller amps also seem to top off at around 50watts per channel. the only amp i can think of that mightl fit in that space is the blaupunkt PA series--but i didn't base my shopping on that single physical dimension so there should be a few others.

forget it if you also need a sub amp

There are actually a few 5-channel amps that will fit that space (just barely), though you are correct that they don't exceed 50 watts/channel. Two such amps I'm looking at are the Clarion APX600.5 and the Alpine MRP-F320.

I had seen ToreB's dimension pic before (thanks!), and I've tried to find out the dimensions of the cavity under the other seat, but so far nobody has been able to tell me that. Is the other one really smaller? I was hoping it was bigger...

[minhi]

Quote:

Originally posted by scooterboy
There are actually a few 5-channel amps that will fit that space (just barely), though you are correct that they don't exceed 50 watts/channel. Two such amps I'm looking at are the Clarion APX600.5 and the Alpine MRP-F320.

yep, depending on how you want to listen, that may not be enough power. i had a 50 watt amp and switched to 100. the 50 watt amp actually got loud enough--but the clarity and bass response was not as good as the higher powered amp. i'm not really listening to it at a higher volume, the quality has just gone up. my aftermarket speakers just sounded better with the higher power. i can't believe you found a 5 channel that will fit in there!

on a related note, how are you going to adjust the amplifier? or replace a fuse? not much access with it under the seat?

[scooterboy]

Quote:

Originally posted by minhi
yep, depending on how you want to listen, that may not be enough power.

Well one of the things I'm trying to figure out is whether I should get a 5 channel amp and a subwoofer or just go with a more powerful 4 channel amp. I have Alpine 6000cs 6.5's ready to install in the front doors and am planning to buy Alpine 693.5 6x9 3-ways for the rear. What I don't know is whether that will be enough bass. Any advice? I don't crank the volume ridiculously loud (not a teenager by any means), but I like it healthy when I'm in the mood.

Quote:

on a related note, how are you going to adjust the amplifier? or replace a fuse? not much access with it under the seat?

Yup, adjusting to the right settings is definitely gonna take some trial and error. I know that after amp installation I don't want to turn the key without the seats re-connected or the airbag light will go on and stay on. So I'm thinking I'll leave it out of the cavity temporarily until it's adjusted to my satisfaction, then tuck it underneath and hope I never blow an amp fuse...

[minhi]

Quote:

Originally posted by scooterboy
Well one of the things I'm trying to figure out is whether I should get a 5 channel amp and a subwoofer or just go with a more powerful 4 channel amp. I have Alpine 6000cs 6.5's ready to install in the front doors and am planning to buy Alpine 693.5 6x9 3-ways for the rear. What I don't know is whether that will be enough bass. Any advice? I don't crank the volume ridiculously loud (not a teenager by any means), but I like it healthy when I'm in the mood.

i would get the strong 4 channel over a 5, the 5's tend to top off at around 40-50 watts per channel, if you can get into the 60-70 i think you'd be happier.
I don't know those speakers so i can't tell you if it will be enough but generally most aftermarket speakers seem to sound best when you give them power near their rated amounts (so if they're rated for 80RMS/160MAX, get at least an 80 watt amp)


i was a bit surprised at the bass response of 50 vs 90. Even though I'm now crossing the fronts at 80, the response is still better. it's hard to explain but the speakers sound fuller, the clarity is much improved. but some of that is a function of the speakers i chose.


about the rears--this is really personal opinion... i went through the hassle of putting in rears, and to be honest, i don;t think it's worth it. the bass response from 6x9s is a little boomy/dirty (it doesn't help that the rear panels are not sealed). the highs are ok, but i think it screws up the sound if there is too much volume coming from the rear. so i tend to turn my fader biased front. it's nice but i could live without it.

a good shortcut would be to run the rears off head power--then you could stuff a bigger two channel for the fronts.

[scooterboy]

You're definitely giving me some great info and ideas - thanks.

It never occured to me to use the head power to feed the rears only. That's a very interesting thought. Question: if there aren't speakers attached to the front speaker cables, does that mean all the power of the head unit will go to the rears, or will they only get the power they would have gotten anyway?

As far as the rear speaker muddiness - I was going to attempt "creating" an enclosure for them within the sidewalls of the car to increase clarity and reduce muddiness. If I succeed, I'll go into the details then.

Years ago, the convention was that front speakers should be "felt but not heard". That seems to have been reversed in a lot of today's systems. I personally have always liked a fairly equal balance between front and rear speaker volume but as you say, that's a preference thing.

Thanks again for the input.

[minhi]

Quote:

Originally posted by scooterboy
You're definitely giving me some great info and ideas - thanks.

It never occured to me to use the head power to feed the rears only. That's a very interesting thought. Question: if there aren't speakers attached to the front speaker cables, does that mean all the power of the head unit will go to the rears, or will they only get the power they would have gotten anyway?

rears would get the same power regardless if fronts are hooked up.

because of the positioning of the rear speakers you can't really hear that much unless you sit in the rear of the car. if you're only going to use them for rear fill, they don't need that much power. my head only does about 20watts rms to the rear speakers and i think it's fine. even though my fronts get almost 100.

good luck sealing up the well, it's possible if you're brave with the exandable foam (be careful with that stuff), but in the end i still don't think it's worth it. I've got some 6x9 "sub-woofers" in the rear of the car right now and they get pretty low, but the bass is too sloppy--boomy. i think that's just a physical limitation of the 6x9s.

I've moved on to building a box for a dedicated sub.

[scooterboy]

Quote:

Originally posted by minhi
I've moved on to building a box for a dedicated sub.

Out of curiosity, where do you plan to put it?

I hesitate to put one in the cargo area since it will be behind the seats and under the rear shelf (and will take up premium space), but there's not many other options.