Question About 4 Channel Amp Installation

[acornbean]

Car: 2003 accord coupe EX

Stock Component and Rear Speakers

Amp: Alpine MRP F300

Sub: 12" Infinity Sub (not sure which model)

Head Unit: Pioneer FH-X721BT

Ultimate Amp Wiring Kit

Ultimate Amplifier Installation Kit (AMP4) : Car Amplifier Kits - Future Shop

Stinger 17Ft 2 Channel Stereo Interconnect RCA cables

Hey there I tried googling my question and couldn't find a direct answer. I did stumble upon this site and saw many helpful responses to other people's questions so I thought I'd throw mine into the mix!

Okay I just bought an Alpine MRP-F300 4 channel amp and I was wondering if I need a crossover for it. I want to hook channels 1 and 2 to my front speakers and bridge channel 3 and 4 to my sub. I read somewhere that this amp has "Variable high-pass/low-pass filters" that "let you adjust the frequency output for either full-range speakers or a sub." Can I use the high filter for the front speakers and the low filters (that possible?!) for the sub or do I not use any filters and get a line out converter for the front speakers?

Also, the factory speakers are component, I believe, as they have tweeters (That makes them component??) Would they be powered by the Amp if I hook up the front speakers via one of the 2 sets of RCA pre-outs on my head unit?

Is there anything else I will require for my installation that's not provided by the ultimate amp wiring kit and extra set of stinger RCA cables?

Was planning on on running front speakers and sub off amp and rear speakers of the head unit... That sound like a good way to go? Any recommendations, tips, and answers are GREATLY appreciated! Thanks!!!

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[LosIsATool 5,000+ posts]

You would need a way to cut off the front mid on the high end and tweeters on the low end. The rear should be full range

 

[Boominburban]

A MRP-F300 is an Alpine amp btw ...

 

[Jepalan]

Your headunit only has one set of RCAs, and you can either use them as full range outputs or sub-only outputs.

You can connect the HU in one of two ways:

1)

Set HU RCA outs to full-range mode.

Connect L/R RCAs to CH1/2 and CH3/4 input using y-splitters.

Use CH1/2 for fronts and bridge Ch3/4 for sub.

Set Ch1/2 filter to highpass at ~80Hz

Set CH3/4 to lowpass at ~80Hz

OR you can connect this way:

2)

Connect HU front speaker outputs to CH1/2 high-level speaker inputs on the amp (you do not need a LOC, amp has speaker level inputs too).

Set HU RCA outputs to SUB mode and connect to CH3/4

Set amp HP and LP filters same as noted above.

I prefer the second method^ because it retains headunit fader and sub control.

You will be fine running rears off HU. You only want a little fill from rears anyway.

I see it is a 2003 Accord EX. The factory tweeters have their own inline crossover cap so you can connect them to the CH1/2 outs with the midbass speakers without needing anything else.

Here is a pic of your tweets - the capacitor is the little round thing at the bottom so you are good to go.

 

[LosIsATool 5,000+ posts]

Your headunit only has one set of RCAs, and you can either use them as full range outputs or sub-only outputs.You can connect the HU in one of two ways:

1)

Set HU RCA outs to full-range mode.

Connect L/R RCAs to CH1/2 and CH3/4 input using y-splitters.

Use CH1/2 for fronts and bridge Ch3/4 for sub.

Set Ch1/2 filter to highpass at ~80Hz

Set CH3/4 to lowpass at ~80Hz

OR you can connect this way:

2)

Connect HU front speaker outputs to CH1/2 high-level speaker inputs on the amp (you do not need a LOC, amp has speaker level inputs too).

Set HU RCA outputs to SUB mode and connect to CH3/4

Set amp HP and LP filters same as noted above.

I prefer the second method^ because it retains headunit fader and sub control.

You will be fine running rears off HU. You only want a little fill from rears anyway.

I see it is a 2003 Accord EX. The factory tweeters have their own inline crossover cap so you can connect them to the CH1/2 outs with the midbass speakers without needing anything else.

Here is a pic of your tweets - the capacitor is the little round thing at the bottom so you are good to go.

You're forgeting one important filter. Cutting off the mid around 4k

 

[acornbean]

Thanks for clearing that up!! Do you know if the tweeters would be seperatly wired? Or are they connected to the front speakers? Just wondering if I can just hook up the front and power both

 

[Jepalan]

You're forgeting one important filter. Cutting off the mid around 4k

He's using factory front/rear speakers. No need to confuse things for him. Natural roll-off of the factory mid will be good enough for now. Once he blows the factory drivers with the new HU & amp he can get a set of components with passive xover and all is good.

 

[Jepalan]

Thanks for clearing that up!! Do you know if the tweeters would be seperatly wired? Or are they connected to the front speakers? Just wondering if I can just hook up the front and power both

By searching online wiring diagrams, it looks like the tweeter is wired to the door speaker (not separately), so you should be able to make one set of connections to the fronts and both will power up.