# Request help w/ JL Audio 300/4v1 Amp



## p1co_ (Mar 27, 2012)

I'm fairly new to setting up car audio. I've physically installed all of the components below, wired the amp, and have music playing. The left and right channel seem the same, when I fade towards the left or right, I can still hear some sound coming from the faded side. The tweeters sound like they are distorted, and seem way too loud. The mid-range speakers on the other hand seem too quiet.

I also have dual MTX 12" subs in the back, powered by an infinity reference 1600 mono amp, and they don't seem to be as loud now that I have the components set up (vs having stock set up), I need to turn the head unit volume up higher than I used to to get the same effect.

I have the front speaker outputs bridged, and the wires are going to the right-side crossover. The rear speaker outputs are bridged, and they go to the left-side crossover. The idea behind this was that the left and right signals would get split up in the amp and/or crossovers, but I've learned that isn't the case, so I think this would solve my issue: 









Will this work?

Also, the manual(linked below) says this about bridging:








What is a Y-Adapter? Ive googled around, but I cant find the device that I think pertains to what the manual talks about.

Thank you so much for your time!

List of components:
Alpine SPS-610C
Alpine SPS-610C Type-S 6-3/4" component speaker system — fits in 6-1/2" or 6-3/4" openings at Crutchfield.com

PCZXO - 2-Way Passive Car Audio 12dB/octave Crossovers
Amazon.com: PCZXO - 2-Way Passive Car Audio 12dB/octave Crossovers Compatible with All Car Audio Component Systems. Made by Alphasonik, Sold in Pairs.: Car Electronics

JL Audio 300/4v1
http://mediacdn.shopatron.com/media/mfg/9013/media_document/live_1/300_4_MAN.pdf?1317780879


----------



## RiLoWa (Nov 9, 2011)

p1co_ said:


> [/url]


Not as you have it drawn. You don't use all four output terminals when bridging. The picture and the amp show you how to bridge it by using only the Left + and the Right - below the output terminals.


----------



## cobra93 (Dec 22, 2009)

This is an rca y adapter.
For only $2.44 each when QTY 50+ purchased - 6inch RCA Female to 2-RCA Male Digital Coaxial Splitter Adapter | High Quality RG6 Digital Audio 24K Gold-Plated Cables w/ Fancy Connector

Jl is showing you that you will only be using the outer mosr speaker connections, Left + and right - when bridging the two channels. *The left-, right + are not used when bridging.*

You'll connect the left output form the headunit to a rca y adapter to rear input on the 300/4 and connect the speaker wires to the the same outputs left + and right-. Do the opposite for the other, right in this example, input/output.


*Don't do what you posted in the first image*.

You could use the front outputs to drive the tweeters and the rear outputs to drive the mids, but I wouldn't suggest this until you understand how to run an active crossover system. If you screw up you will trash your speakers, tweeters especially.


----------



## p1co_ (Mar 27, 2012)

cobra93 said:


> This is an rca y adapter.
> For only $2.44 each when QTY 50+ purchased - 6inch RCA Female to 2-RCA Male Digital Coaxial Splitter Adapter | High Quality RG6 Digital Audio 24K Gold-Plated Cables w/ Fancy Connector
> 
> Jl is showing you that you will only be using the outer mosr speaker connections, Left + and right - when bridging the two channels. *The left-, right + are not used when bridging.*
> ...


Alright, I think I understand.










I was having trouble visualizing how the y-adapters were going to work, but makes sense.


----------



## cobra93 (Dec 22, 2009)

You will take the left/right rca outputs, connect your rcas to them on the headunit. 
Run the rcas to the amp.
Take the left rca and connect a y splitter and plug them into the rear amp input (left/right). this will be your left side. 
Connect another y splitter to the right rca (from the headunit) and connect them to the front amp input, this will be your right side.


----------



## p1co_ (Mar 27, 2012)

Thank you!


----------



## cobra93 (Dec 22, 2009)

You will have a left /right rca from the headunit to the amp.
Next connect the splitters between the rcas and the amp. Single female to double male.
The splitters will allow you to have 4 inputs connected to the amp instead of 2.


----------



## cobra93 (Dec 22, 2009)

No problem. :beerchug:


----------



## p1co_ (Mar 27, 2012)

Thanks, your suggestions worked great. I can now hear the proper channels in all the right places.

Have a new question; not too sure if this is a problem or if it is normal; the amp seems to get really warm - not hot enough to force my hand away, but it definitely is hotter than the ambient temp of the car. The following are my settings:










The "input voltage" for both sides was set to "low", which caused the amp to get hot; on low the speakers sounded much better, when set to high, the tweeters get louder and distorted. They also overpower the mid-range speakers and seem to play the range intended for mid/lows.










Appreciate the time!


----------



## RiLoWa (Nov 9, 2011)

When using the RCA's out of the head unit, setting the switch to "low" is the proper setting. This is a class a/b amp so it will warm up even just idling. When playing it bridged and loud it will get much warmer. It has a protection circuit that will engage if it gets too hot.

Didn't your Alpine components come with a crossover? You may be having a problem with the Alphasonik crossovers, if you are using those instead.


----------



## p1co_ (Mar 27, 2012)

RiLoWa said:


> Didn't your Alpine components come with a crossover? You may be having a problem with the Alphasonik crossovers, if you are using those instead.


The alpine components did come with crossovers. The mid-range woofers had them built onto the speaker frame, the tweeters had a separate attachment. I was advised that the alpine speaker crossovers wouldnt do as good of a job as a standalone crossover, and using a separate crossover is what my buddy who put his system together used, so I figured that would work for me.

Would it be counterproductive to use the alpine crossovers as well as my alphasonik crossovers?


----------



## adrenalinejunkie (Oct 17, 2010)

Make sure that your amp/s are grounded to bare metal as this can prevent them from heating up and will have them perform better.
Not sure if you're aware of these methods, but hear ya' go.
Gain Settings
Hope that helps.


----------



## RiLoWa (Nov 9, 2011)

p1co_ said:


> Would it be counterproductive to use the alpine crossovers as well as my alphasonik crossovers?


Yes. The crossover that was supplied with the speakers is probably more appropriate than the Alphasonik's are. Alpine has determined what the high pass should be for the tweeter not Alphasonik.

If your head unit is not sending a high pass signal to the 300/4, you may want to activate both front and rear crossovers, setting the switches to HP and adjusting the frequency to around 70Hz. Pick either 12db or 24 db which ever one sounds better.

I looked up the Alpine components using the link in your first post. I get the impression that using the amp bridged, may not be the best solution on those speakers. The recommended RMS power range is 2-80 Watts and the possibility of sending 150 Watts to them may / will overdrive them. Setting the high pass will help their power handling some.


----------



## p1co_ (Mar 27, 2012)

RiLoWa said:


> Yes. The crossover that was supplied with the speakers is probably more appropriate than the Alphasonik's are. Alpine has determined what the high pass should be for the tweeter not Alphasonik.
> 
> If your head unit is not sending a high pass signal to the 300/4, you may want to activate both front and rear crossovers, setting the switches to HP and adjusting the frequency to around 70Hz. Pick either 12db or 24 db which ever one sounds better.
> 
> I looked up the Alpine components using the link in your first post. I get the impression that using the amp bridged, may not be the best solution on those speakers. The recommended RMS power range is 2-80 Watts and the possibility of sending 150 Watts to them may / will overdrive them. Setting the high pass will help their power handling some.


I read in the 300/4 manual that the filter control settings should be set to 'off' if utilizing an off board crossover. Given that the Alphasonik and Alpine crossovers are off board, do you still recommend changing the setting to HP & adjusting the freq? (not trying to insult to knowledge base here, I'm just trying to learn everything I can from the advice here).


----------



## p1co_ (Mar 27, 2012)

adrenalinejunkie said:


> Make sure that your amp/s are grounded to bare metal as this can prevent them from heating up and will have them perform better.
> Not sure if you're aware of these methods, but hear ya' go.
> Gain Settings
> Hope that helps.


Thanks! Ill check that out after I configure the filter settings.


----------



## RiLoWa (Nov 9, 2011)

p1co_ said:


> I read in the 300/4 manual that the filter control settings should be set to 'off' if utilizing an off board crossover. Given that the Alphasonik and Alpine crossovers are off board, do you still recommend changing the setting to HP & adjusting the freq? (not trying to insult to knowledge base here, I'm just trying to learn everything I can from the advice here).


The intention of that statement in the manual means that IF you use a different _active_ crossover before the amp (such as one in the head unit) then you would not need to activate the one inside of the amp. I see how that could be confusing but it is not meant for outboard _passive_ crossovers after the amp, so yes I still recommend that you turn them on.


----------



## p1co_ (Mar 27, 2012)

RiLoWa said:


> The intention of that statement in the manual means that IF you use a different _active_ crossover before the amp (such as one in the head unit) then you would not need to activate the one inside of the amp. I see how that could be confusing but it is not meant for outboard _passive_ crossovers after the amp, so yes I still recommend that you turn them on.


Thanks for clarifying.

With the off-board crossover, I figured the signal would be split by 2, so the mid-range and tweeter would have ~75w each. I take it that isn't how it works?


----------



## RiLoWa (Nov 9, 2011)

p1co_ said:


> Thanks for clarifying.
> 
> With the off-board crossover, I figured the signal would be split by 2, so the mid-range and tweeter would have ~75w each. I take it that isn't how it works?


Yes, you are correct that if 150W is applied both speakers would dissipate about 75W each, however the power handling they are rated for is 2-80W for *both* tweeter and mid meaning about 1-40W each when run full range.

This isn't aways true, sometimes the woofer handles more power than the tweeter by design, but the sum of both equalling max RMS power handling is generally true.


----------



## p1co_ (Mar 27, 2012)

RiLoWa said:


> Yes, you are correct that if 150W is applied both speakers would dissipate about 75W each, however the power handling they are rated for is 2-80W for *both* tweeter and mid meaning about 1-40W each when run full range.
> 
> This isn't aways true, sometimes the woofer handles more power than the tweeter by design, but the sum of both equalling max RMS power handling is generally true.


Ohh, so would using one channel per crossover be a better idea, both in performance and care for the speakers?

Also, I was playing around with my head unit today, I noticed a "LPF" setting, which allowed me to set for 78Hz, 125Hz, or off. According to what you guys have said, the best setting for this would be 78Hz; that would mean my head unit does HPF too. Having said that, should i turn off the filtering options on the amp (I turned them on as recommended from an above post)?


----------



## RiLoWa (Nov 9, 2011)

I think that one channel per crossover, woofer, and tweeter set would be better for the longevity of the speakers.

If your head unit only has selectable frequencies, I would probably still use the crossover on the amp since it is a bit more variable for finer tuning later on.

Have any of the suggestions made any improvements yet?


----------



## p1co_ (Mar 27, 2012)

RiLoWa said:


> I think that one channel per crossover, woofer, and tweeter set would be better for the longevity of the speakers.
> 
> If your head unit only has selectable frequencies, I would probably still use the crossover on the amp since it is a bit more variable for finer tuning later on.
> 
> Have any of the suggestions made any improvements yet?


The Y-adapter advice certainly helped. I am sure that the bridging advice saved me a lot of money and time re: preventing damage to my equipment as well as increasing the performance of the speakers.

while playing around with the head unit settings, I discovered DSO settings (0-2) which seem to crank up the output levels. Ive been making a lot of adjustments without setting that to 0, which I believe is part of the preamp config (setting everything to 0), and then adjusting the amp levels for optimum performance.

I'm going to remove the bridge and just use two channels and then let you guys know the outcome.

Again, I really do appreciate your help, I've learned a lot!


----------



## cobra93 (Dec 22, 2009)

Good to see you got your wiring figured out.
As stated above the JL 300/4 will get hot.
My 300/2 can get pretty toasty, but has never shutdown.

I'd also use only the x-over that came with the component set, safer/simpler.

The input sensitivity can be high/low depending on the headunits preamp output voltage, there's no simple answer.
The low side is up to 2volts, the high is up to 8volts input if memory is correct.


----------



## p1co_ (Mar 27, 2012)

cobra93 said:


> Good to see you got your wiring figured out.
> As stated above the JL 300/4 will get hot.
> My 300/2 can get pretty toasty, but has never shutdown.
> 
> ...


I connected the left crossover to front CH1 and the right crossover to front CH2. I also set the amp back to 2-channel mode (from 4 channel), and then took the y-adapter off, connecting the RCA to the front input.

My head unit's DSO (dynamic soundstage organizer: creates a more ambien sound field, using virtual speaker synthesis, to enhance the sound of speakers, even if they are installed low in the door) is set to 0, and I turned off the LPF.

The system sounded much better when I did this. The tweeters weren't overpowering, everything just worked. Im going to read up on that gain tutorial, but everything is starting to work well.

Thanks!


----------



## RiLoWa (Nov 9, 2011)

:thumbsup: Awesome, now you are getting somewhere.


----------

