Quote:
Originally Posted by gIzzE
I missed the replies on here before my previous reply.
Most head units are not set from 12-14v, but the BMW ones are, so the Alpine has been set to see this, however voltage is variable, as you up the volume the voltage increases.
Many Alpine head units can put out around 18v before they start to clip.
Some Pioneers can put out 20v.
However, just just don't turn it up as loud, you will be fine. But, you are then going Pre amp - amp - pre amp - power amp.
You are far better to use the head unit as a pre amp only to an amp without amplifying it twice. Sound quality wise
The head unit will not be the best sound wise amplified, it doesn't have the current to sound that great, hence why we use power amps and use the head as a pre amp only, for a nice clean signal into the power amp, then match the inputs to get the best sound quality possible, setting your gains between pre ad power and getting it spot on makes a massive difference to overall sound quality.
Set the input too low and you loose dynamics and sound stage, set them too high and it clips and can sound harsh.
Have a look at this......
http://mobile.jlaudio.com/support_pages.php?page_id=143
The Professional head unit is EQ'd to make the basic system sound better, however, it then is too loud at certain frequencies for the Alpine amp, hence why you can code later versions to flatten it all out, it is then right for the amp, and sounds so much better.
Regarding coding etc
Without the OEM head unit in the car the system throws a wobbly and so you can't talk to the car, so you have two choices, either keep the factory head unit so you can plug it back in if needed, or wire it up so it has power and can + and - and hide it in the boot.
The third option is to get someone to delete your radio completely from your vehicle order, so when it gets plugged into BMW or any diagnosis machine it will play ball. |
Thanks for explanation. You mention that the professional system is EQ'd, but mine is the box standard business system is this also EQ'd. Does the business head unit have the same coding issues and so my car won't talk to the diagnostic kits without it?
I've found this thread fascinating as I knew/know nothing about this. I understand about how you have to balance the input to the output, and balance EQ's etc but I'm still confused as to what you mean when you say "leave it at speaker level". Would it possible to explain in complete numpty terms what you mean by this please, and also what outputs/inputs you use to wire it a 'speaker level'?
With regards to the centralisation of the single DIN, why is it single DINs are off centre but Double are central? Is it not possible to replace the whole single DIN housing with a central one? I have seen it centred, see below.
It seems as though there's a lot of negatives against getting an aftermarket head unit in an E9x BMW, without taking into account the problem with the Alpine Amp. There's the question mark against warranty, coding issues, and the centralisation of a single DIN, should I choose to go this route. The iphone station is looking a better and better option. It's such a shame they aren't going to mount it better.