Amplifier help!

[Wolf-Strong]

Alright, so my 93' BMW 525i has this 4 channel amp with built in cross overs that is history, and I need to replace it. Now, I have no problem installing the amp, rather I am a bit confused on the amps themselves. These are the two amps I am looking at:
Alpine F300
Infinity REF475

Now I am leaning more towards the Alpine for the simple fact that it is half the weight and size while being cheaper, however my descision lies in quality. They say they have built in crossovers, which is good, however my car has a 10 speaker system (high/mid/bass on left and right sides up front, and high/bass in the rear), so can either of these amps handle that, or am I just asking too much out of a single amp and should rather start looking into separate crossovers. Mind you, I am trying to do this on a budget of less than $300.

[Wolf-Strong]

Re: Amplifier help!

Thought I would also like to add that I am TRYING to see if I can bypass the amp and use the factory crossovers, but so far, no good. The only tutorial that is written up is for an earlier style one.

[Joe's detailing]

Re: Amplifier help!

I think the Infinity and the Alpine amps are great choice, however the crossovers on amps stink period. I wouldn't bother trying to hook up any amp to the origional crossovers. Here's what I suggest http://www.millionbuy.com/pyrcr74.html here you can customize the sounds you want it has a built in filter which is WAY better then any built in amp crossover ...
As for what brand I prefer Infinity and JBL are both made by Harman.
Alpine makes great decks, speakers and amps either way you can't go wrong both are CEA compliant on power ratings ...

[ken_ja]

Re: Amplifier help!

I think the Infinity and the Alpine amps are great choice, however the crossovers on amps stink period. I wouldn't bother trying to hook up any amp to the origional crossovers. Here's what I suggest http://www.millionbuy.com/pyrcr74.html here you can customize the sounds you want it has a built in filter which is WAY better then any built in amp crossover ...
As for what brand I prefer Infinity and JBL are both made by Harman.
Alpine makes great decks, speakers and amps either way you can't go wrong both are CEA compliant on power ratings ...

I use infinity or JBL in all my installations so you can't go wrong there. And definatly get a separate crossover, the 6ch one that Joe linked to is actually quite reliable, I recently used one in a friends car.

[the other pc]

Re: Amplifier help!

It really depends on how the factory system is set up, if the existing crossovers are passive, mounted after the amplifiers or if they’re internal to the electronics.

Do you have a wiring diagram for the car that includes the factory stereo stuff?

Just taking quick look at Crutchfield’s info on your car, I’m guessing that it’s configured with four amplifier channels and the speakers have passive crossovers. If that is indeed the case, then a four channel amp should be fine. But you’d need to confirm that.

You can also call Crutchfield and talk to an advisor about what they have and how you would go about installing it in your car.


PC.

[Wolf-Strong]

Re: Amplifier help!

First off, it is a 10 speaker system with two tweeters on the door, two mid range speakers on the dash, two mini subs on the kick panel, two more tweeters in the rear deck, and two mid range/sub speakers below them. The factory stereo sends the sound to a factory 4 channel amp with a passive crossover which powers it all.

Now, time for a little update!

I took the amp apart hoping to follow a tutorial on a forum on how to bypass the amp so I can just use the passive crossover, and behind that, I was hoping I could place the amp there. Upon opening the amp up, I quickly realized that it was a different one than in the tutorial. A little depressed, I just looked at all the solder points to make sure everything was solid hoping that perhaps the amp was failing just due to a bad solder. Well, to remove the circuit board, I had to drill out one of the screw heads as it was soldered to the board which after taking out the board, I realized was to provide a ground for the amp. After finding nothing wrong with the connections, I put the thing back together and just soldered the remaining part of the screw (still in the casing) to the previous solder, and screwed it together.

Now honestly, I of course didn't expect anything to fixed so I just set it aside for a few days, and yesterday, I went ahead and thought "Oh what harm can it do". I plug and mount the amp back up, turn on the stereo, and BOOM! SOUND! It seems to be working flawlessly, which leads me to believe that it was probably a bad ground somewhere, and doing whatever I did, it fixed it!

So, I have sound for now assuming it doesn't go bad again, which is good because now I can spend that money elsewhere!

[Joe's detailing]

Re: Amplifier help!

it was probably a bad ground somewhere, and doing whatever I did, it fixed it!

When my system goes quiet thats the first thing I check...Joe

[Tim Lingor]

Re: Amplifier help!

Years ago when I was into sound offs, I used to run Alpine, Soundstream, Audio Control and MB Quart. I did a lot of installing back then...

I used an active Audio Control crossover as well their EQL for leveling the channels. I really like the way I could tailor the crossover and EQ to give what sound I was after. But you can do the same with passive crossovers as well. It all depends on how you want to set up the system.

At sound offs, there are many different divisions, in which case you may use one or 20 amplifiers. As a result, people had to choose what category to be in and then go from there.

I will warn you though, every piece of equipment especially EQs must be star grounded as each ground point has a different ground potential. This ground potential can set up a ground loop causing alternator whine etc. I had one vehicle that no matter what I did, the windshield wiper motor made noise through the speakers. I ended up wiring a capacitor onto the motor to shut it up!

When you say that the factory deck is sending a cross-over signal that confuses me. Normally when a stock system does that, each amp is integrated with each speaker. If that is the case, then we have a huge problem. Many stock decks will not "step-down" to an aftermarket amplifier, in which case you will need a step down converter. This is in itself is not good as that can open the door to noise and a poor noise floor levels.

I am not trying to discourage you, but trying to adapt an aftermarket amplifier to a stock deck (which usually has a high impedance) and to stock speakers which will also have a high impedance most likely, you may have a real headache coming.

One site that is very helpful for these problems is called the:

http://www.the12volt.com/

It is mostly an installers site, but you should be able to register and get into most areas of the Forum. I would check there and see if an installer has dealt with your situation before and how to solve it.

Tim

[guitarman502]

Re: Amplifier help!

(off topic sorry!) Tim, did you compete IASCA or USAC?

[Tim Lingor]

Re: Amplifier help!

I only participated in a couple non sanctioned events. Then went back and just enjoyed my system.

I got tired of people following me home. They wanted to see where you lived so they could rip off your system. We got told, if you like your system do not play it around town so everyone hears it as that too will draw attention from theives. Finally avoid all brand stickers. I love it when I see a car with a big Alpine sticker. Gee...I wonder what they have in their car!??

Now that I am getting older, I only have a deck and speakers.

Tim

[Jeepster04]

Re: Amplifier help!

Thats a little messed up tim. I use to have a MTX sticker on mine but I took it off shortly after putting it on once I got some common sense.

I wouldnt have a use in putting a system in my Jeep if I couldnt listen to it!

[Wolf-Strong]

Re: Amplifier help!

The factory stereo deck sends out a very weak signal that consists of left and right. This is then fed to the amp box. It is then amplified and then sent directly to the passive crossover (which is integrated into the same circuit board) which then splits it from L/R to left (high/mid/low), right (high/mid/low), right rear (high/low), and left rear (high/low).

[Tim Lingor]

Re: Amplifier help!

But is the "amp box" a factory amplifier? I am trying to figure out how and why they placed a passive crossover on a circuit board when the vast majority are usually mounted just before the speaker (perhaps they are trying to save space).

Either way, you are wanting to add an aftermarket amp, you will need to make sure that the signal from your deck is correct impedance or you will need a step down. You will also need a remote turn on lead. Does your stock deck have a remote lead?

I think it best if you checked out the site I linked to as it has wiring diagrams and people that probably have come across your exact question.

Tim

[Tim Lingor]

Re: Amplifier help!

Thats a little messed up tim. I use to have a MTX sticker on mine but I took it off shortly after putting it on once I got some common sense.

I wouldnt have a use in putting a system in my Jeep if I couldnt listen to it!

I had a friend whose Ford Probe was loaded with Precision Power Amps etc. He left an event and sure enough, they thrashed his car about 3-4 days later. But he liked having his stuff all visible for people to see, and believe me they saw it!

The stickers are a dead giveaway that you have a system installed or want a system. Either way, you will get noticed, and usually by the wrong person.

I got so fed up with car audio because of having to deal with thieves that one day, I pulled out all of the components and sold them to a friend of mine. I miss having a cool system, but I do not miss going outside every time my alarm went off!

With your Jeep, you can have a cool system. Just be cognitive of where and when you are playing it....



Tim

[Wolf-Strong]

Re: Amplifier help!

But is the "amp box" a factory amplifier? I am trying to figure out how and why they placed a passive crossover on a circuit board when the vast majority are usually mounted just before the speaker (perhaps they are trying to save space).

Either way, you are wanting to add an aftermarket amp, you will need to make sure that the signal from your deck is correct impedance or you will need a step down. You will also need a remote turn on lead. Does your stock deck have a remote lead?

I think it best if you checked out the site I linked to as it has wiring diagrams and people that probably have come across your exact question.

Tim

Yes.

Either way, it seems to be working now. If it does go out again, I will just save up for a new system with a new deck/amp/crossovers.