LOC or High Level Input - Powered Sub

Hi all,

I am going to be adding a powered

$280 Rockford Fosgate P300-8P Punch 8" 300-Watt Amplified Subwoofer in Ported Enclosure - Slim Design for Tight Spaces - Black

Rockford Fosgate P300-8P subwoofer to my current system. I have a factory Entune 3.0 non-JBL HU, upgraded tweeters and door speakers that are powered by a 4-channel

$214 Alpine KTA450 Alpine KTA-450 4-Channel Power Pack Amplifier with Dynamic Peak Power 45W RMS x 4, At 2 Or 4 Ohms

Alpine KTA450 amp. It sounds great, but it lacks a little in the low end, for obvious reasons.

My question for ya'll is, should I install a LOC (something like a

$17 Kicker 46KISLOC2 Speaker Wire-to-RCA Line-Out Converter w/LOC+12v Turn on Lead

Kicker 46KISLOC2) between my HU and the powered sub, or would it be fine to just pass the signal via high level input off the front speakers?

As I understand it, the RF P300 will auto sense the high level input and turn on/off the sub's amp. This is a plus. However, the aforementioned Kicker LOC has a remote out that I can tap and run to the sub (presumably it gets this signal from the high level input anyway).
I've got to run the wire (speaker or RCA) anyway, so adding a remote-on wire isn't that big of a deal. Is there really a significant difference between the two? I know the LOC is supposed to flatten the signal and correct bass roll-off, but again, I'm not looking for bumping bass. I listen to everything from metal to jazz, so clarity and fullness matter more than anything to me.

Any and all input is welcome. Thanks

 

I want to clarify something so you go in informed

the particular LOC you linked (and most LOCs in general) do NOT flatten the sound or deal with bass roll off or change the signal in any way.

with that said, the Rockford will do a perfectly fine job accepting the high-level input so no loc is needed.

be sure you get your audio signal from the FRONT speakers, not the rear. And be sure you get the signal BEFORE the alpine amp.

 

Thanks, Destin. That's great insight.

I didn't realize that the LOC I linked didn't alter the signal... which in hindsight I should have guessed given the price point.
When I installed the Alpine amp I used a Red Wolf T-Harness so that I didn't have to cut into the factory harness. While I was in there, I pre-labeled the wires for the right and left front (in front of the amp) so that adding this sub would be that much easier.

Thanks again, you gave me all the info I need to move forward with this.

 

Hey,
I also have the Power pack amp. I was looking for exactly what you described, an interrupt harness so I don't have to cut the Factory wires. What is the model # of the harness you used? I'm thinking of sending the Front channels out to the power pack and using LINE to RCA's because the Power pack can handle 14V input (Stock stereo inputs...)


Thought I was having on increasing the low end...I was wondering if you split the front right and left outputs of the factory radio and send them to both the Front and Rear speaker level inputs of the power pack...and then the Front outputs to the front doors with 6.5's and crossovers with tweeters and then send the "rears" which are split clones of the front to the REAR doors more bass focused speakers (possibly even 6.5 components with 40hz range and just don't connect the tweeters)
Essentially never using the rear signal from the Etune...
Were you at all satisfied with the amp?
Any issues?

 

i'm essentially did just that. the speakers i'm using have an Fs. of 45hz. the reality is the rear doors just aren't setup well acoustically. you would need a lot more voodoo to get any amount of decent bass out of them. there's also issues with magnet size and depths. the rear window comes down just behind the speakers, leaving 2-3/4" depth from the door panel, which is mostly what eliminates the majority of sub sizes that would fit.

 

So did you actually send the front speaker output to both the front and back of the amp? no issues?
Or did you just abandon the rear doors?
I know it's out of stock right now...But this is what I used to make tweeter templates for my 2nd gen...a plastic $2 cutting board, a jig saw and a hole saw...perfect.
https://www.walmart.com/ip/Mainstays-8-5-x-11-Poly-Cutting-Board/14964984?fulfillmentIntent=In-store

 

I love the amp. No issues.
Here's the harness that I used: RED WOLF Add AMP Amplifier...

$14 RED WOLF Add AMP Amplifier Subwoofer Speaker Wiring T-Harness Radio Stereo Plug Connector Compatible with Toyota 2018-2022 Camry RAV4 Tacoma Corolla Non-JBL System

https://www.amazon.com/dp/B09DTY8PMD?ref=ppx_pop_mob_ap_share

I kept my rear signals going to the rear speakers, I just turned the gain up to the highest non-distorted setting at 3/4 volume. I used a 100hz tone to tune it. I didn't touch the gain on the front channel at all. This helped bring the rear channel up a bit and balance the sound. Not great, but better for sure.

 

i did at one point. i had replaced all the door speakers first(peerless hds nomex), found the oem eq to be horrific(like sticking my head in a bazooka bass tube), which made me replace the head unit with an aftermarket model. i ran that in the oem setup for 20 minutes until i learned that it overpowered the oem tweeters, and the rear speakers offered zero advantage to the front soundstage. i attempted to use them, but found any audio from them always pulled the upper dash soundstage down, muddied the vocals, and lacked bass addition, ruining the effect of 'the band rocking out on the hood'. they're far too forward/behind the front seats, and far too low to have any advantage to any typical sound-shaping techniques.

granted, the peerless hds is a very good bass/midbass with a relatively severe high frequency roll-off at around 2k that demands a minimum 2-way tweeter setup, with better support of a 3-way setup, though shines best with a wide-band 800+hz large format 'twiddler' tweeter/midrange setup.

after that 20 minutes of playing, i disconnected the rear speakers, rewired the tweeters and head unit for full-active mode, and have been happy with it ever since--though fair warning, i haven't ran rear speakers in any of my vehicles for the past 20 years now--none of them lended any advantage to the front soundstage, despite one of the vehicles being specifically selected based on it's speaker layout...

i do have some plans to add some planar tweeters off the rear glass in the future, once i ever get to my amp install, as i'll have 2 extra 'bonus' dsp outputs i plan to route to a spare 4-channel amp, which i want to play with some delay effects to increase the presence and depth of the front soundstage. but otherwise, the initial lackluster testing of the specific location of the rear door speaker doesn't give me any promise for any sound techniques that won't pick apart the front soundstage in negative ways. my only current plan for the rear speakers is for a 'party mode' where the doors are open and projecting audio somewhere behind the truck.

 

I completely get it...The Tacoma I just sold Had only Front component speakers on an after market...I had the power pack amp on it but realized that the amp was the SAME power as the radio so It was unnecessary. When I wired straight to the after market head unit it sounded fantastic. It was a set of Polk components that are now almost $300!!!! They filled out an access cab nicely. I disconnected those rear joke speakers as well...

 

Perfect...Rear speakers are not overly expensive so I can experiment...