[supergoat]

Long story short, my HIFI amp is going. It works, but lots of popping.

I listen to mainly talk radio and podcasts. So a great amp for music isn't really a must for me. I have read and read and THINK I have an understanding but would like some guidance.

What are the minimum requirements for an AMP for the HIFI system?

I have heard about crossover, 2 ohm, 4 ohm, 4 channel, six channel... Just need to know what to look for. If I can buy a cheap amp and be done with it that would be great. I'm not worried about the install as I can handle wiring just fine, especially since there is a great diagram on this site.

Again, just need the system to work, do not care about amazing sound quality. I just need to know what minimum requirements I need and I will then go scour the internet and find my amp.

Thanks in advance.

[cdgatti]

You should get technics harness and an amp that can accept differential balanced inputs. You'll need 6 channels, which break down as the 2 front doors, the 2 under seats and the 2 rears. The Jl XD600/6 is a very popular economical amp that fits the bill.

[davegill]

As stated above, your best bet is a xd600/6. You can probably find a used one for $300, just keep checking craigslist and the classifieds in these forums.You can use other amps as well, but you won't find any others that have more than 5 channels. Two 4-channel amps is an option. Or if you plan on getting a trunk sub at some point, a 5-channel and a 4-channel. Also as cdgatti said above, the amps you use must accept balanced RCA inputs.

I did some research when I was looking for an amp, and found these manufacturers make amps that accept balanced RCA inputs:

JL Audio XD
JL Audio HD
Alpine MRV, PDR, PDX
JBL MS-A
Kicker DX and up
Rockford Fosgate Punch and Power amps
Arc Audio KS
Precision Power (PPI), all current amps
Soundstream, all current amps

These are just based off of my research and what I could find online, I may be wrong on some of them. Probably best to confirm with the manufacturer that the amp you decide to purchase actually has balanced RCA inputs before you order it. I also can't vouch for the quality of all of those amps, I've personally only used the xd600/6 and an Alpine MRV. Just thought the list would help point you in the right direction. Good luck.

[ptpending]

there are plenty used hifi amps on ebay for a reasonable price

[cdgatti]

Originally Posted by ptpending

there are plenty used hifi amps on ebay for a reasonable price

+1 good point for the OP. I sold my oem hifi amp for $150 when I did my upgrade and that seemed like about the going price. That would definitely be the cheapest and easiest way out for you.

[supergoat]

Thanks guys!

[supergoat]

Last question. I'm running an aftermarket head unit, in that case does the whole "balanced input" thing even matter anymore? I keep reading that it only applies to the OEM HIFI head unit.

[cdgatti]

oh that's a different ball game completely! Might have wanted to mention that one!

No you don't need balanced input capability anymore. You may not need an amp, most aftermarket head units have small amps in them already.

[supergoat]

Sorry about that. Thanks for the reply, I really appreciate it.

[bmw325i]

Originally Posted by supergoat

Last question. I'm running an aftermarket head unit, in that case does the whole "balanced input" thing even matter anymore? I keep reading that it only applies to the OEM HIFI head unit.

You can use any amp. Did you use the rca outputs from the headunit? There is a diagram on this thread that shows what I mean by that.
http://www.e90post.com/forums/showthread.php?t=809490

[supergoat]

I did not use RCA outputs. I have them on the unit, but did not use them.

[bmw325i]

Originally Posted by supergoat

I did not use RCA outputs. I have them on the unit, but did not use them.

You have 2 options.

1. Change the wiring in the dash to use the RCA outputs. If you do this changing the amp is no different than if you still had the stock headunit. Other than the fact that you don't need balanced inputs of course.

2. Run RCA cables to the trunk.

Either way you need Technics hifi harness for the speaker and power connections.

[cdgatti]

Originally Posted by bmw325i

You have 2 options.

1. Change the wiring in the dash to use the RCA outputs. If you do this changing the amp is no different than if you still had the stock headunit. Other than the fact that you don't need balanced inputs of course.

2. Run RCA cables to the trunk.

Either way you need Technics hifi harness for the speaker and power connections.

325 the op would have a 3rd option also...

3. Run your speakers off the aftermarket head unit - no amp.

[bmw325i]

Originally Posted by cdgatti

325 the op would have a 3rd option also...

3. Run your speakers off the aftermarket head unit - no amp.

Not really an option IMO. At least not worth doing. You would have to extend the speaker wires to the harness in the trunk or run new ones. If he had base that would be easier to do but any headunit will be underpowered.

[bmw325i]

Originally Posted by supergoat

I did not use RCA outputs. I have them on the unit, but did not use them.

I just thought of something. Your stock amp might not be messed up. The popping might be because you have speaker level outputs going into the hifi amp. If you use the RCA outputs instead maybe the popping will go away. Not sure if this is really your problem but I think its worth a try.

[taibanl]

Originally Posted by supergoat

I did not use RCA outputs. I have them on the unit, but did not use them.

Probably explains why you most likely fried the hifi amp inputs :-/

[supergoat]

Originally Posted by taibanl

Probably explains why you most likely fried the hifi amp inputs :-/

Incorrect, the popping happened with the oem unit as well prior to the install of the new head unit.