Hello,
Having some problems installing this amp into my 2013 Mustang. Vehicle has stock ford radio (non shaker) and 4 aftermarket Pioneer speakers in doors/deck) no sub.

Purchased PAC FRD24 unit and just using the wiring harness that came with it. Made all connections from the Alpine 4ch amp (using speaker level signal) to the PAC wiring harness and then connected the 24 pin connector between the factory radio and vehicle harness. There is an additional connection on the back of the radio that goes to the vehicle (16 pin) but I left that connected. The back of the stock radio has one 24 pin plug and one 16 pin plug and the antenna.

Hooked it all up and it seems at first to work fine. I turn up gains on the amp and the sound level increases in the speakers so i know the amp is working. Problem is that either with no amp or with amp connected and set to min gains, the sound level is the same in the car--it's as if this Alpine amp is adding to the factory amplification instead of replacing it.

Am i missing something here? I thought that the Alpine amp was supposed to replace the factory amp? With or without the amp connected, the sound levels are the same.

Does the base model radio have an amplifier built-in that can't be bypassed? I looked all over and don't see an external factory amp anywhere.

thanks for any help.

 

nitpick- all radios which can directly drive speakers have built-in amplifiers.

there is no external amplifier in the non-Shaker system. The radio has a 16 watt x 4 channel amp built in (like almost all OEM and aftermarket radios.) You've added a 45 watt x 4 "booster" amplifier in line. You aren't going to hear much if any difference except at the very top end of the volume scale, and if you don't have your input "gain" levels set correctly on the Alpine, the radio may clip before the Alpine amp runs out of headroom.

 

Thanks for the response! I figured I was losing my mind when I hooked up the amp and it sounded almost the same as when I removed the amp from the system. Everyone kept saying to bypass the factory amp but it makes sense that it can't be done if it's already built into the head unit.

Do you think I'll gain anything by replacing this amplifier with say a regular Alpine 4 channel amplifier instead? thanks.

 

only a bit more headroom. which- again- only comes into play if you're blasting your system.

 

and honestly, don't get too wrapped up in amplifier power. I also have a KTP-445U amplifier and I've put it on my test bench with an Audio Precision APX-586. with 14.4 volt supply it puts out an honest 4x 44 watts clean. Going to one of the bigger Alpine amplifiers which advertise 4x55 watts will get you nothing of value even though the thing is four times the size. aftermarket loves telling people to throw power at their speakers 'cos none of them know how to build a damn system.

 

Thanks for the replies. Sounds like basically there's no point installing additional amplifier. I plan to keep the stock head unit for now. Any other suggestions for getting better sound from the current non-shaker system?

 

add a subwoofer. due to the cabin acoustics and the speaker locations, you can't get much bass out of the 4 speaker system.

 

Tripling the power should increase the sound by about 30%, which you should be able to hear pretty easily. One of the big reasons for adding an amp, is many stock car radios do not have good bass, as the bass frequencies require a lot more power the mids and highs. If you are using the factory speakers that do not have good bass you may not hear much difference. Can you post the model number of the Alpine amp?

 

Hi Chromeshadow. First post of thread had all the details--4 Pioneer aftermarket speakers in doors and rear shelf. Alpine amp is KTP-445U small compact amp. Actually fits inside dash under factory radio. When I connected this amp, I heard maybe a little more bass and more power but nothing significant (in my opinion).

 

it's a (theoretical) 4.5 dB increase; you'll get a bit more loudness before running out of headroom, but it's not going to be that drastic a difference. And that's assuming your speakers can do something useful with the additional power other than making distortion.

that's more a justification for adding a subwoofer with its own amp. Simply boosting the power to the door speakers isn't going to get you more bass. A typical full-range/mid-woofer/co-axial speaker just isn't physically capable of moving enough air to give you good bass. If you try to make them do it by hammering them with more power they'll just reward you with distortion.

the factory 5.5"x7.5" full range speakers aren't that great, but the form factor itself is the limit. You're not going to find a speaker that size which can "do it all." The woofer portion doesn't have the cone area or the excursion capability to really provide decent bass. You can make a reasonable true woofer in a 5"x7" but you're going to sacrifice its midrange frequency response, so you'd really have to make it part of a 3-way setup (woofer-mid-tweeter.)

at any rate if the OP wants more bass, in his case adding a subwoofer is the only realistic option.