Power to sub cutting out with red light on amp

[kizza]

Hey guys,

I heard there were some geniuses on here, so hopefully someone can help

I have a Phoenix gold qx900.1d powering a Jl Audio w6v3 12"

When I turn it up and the bass kicks in the power to the sub cuts off, a red light on the amp will come on, then if I turn the volume down by one or two the amp will power the sub again. I looked at the voltage of the battery when the sub cuts out and it was at about 13.2v sometimes it can go lower than that but still be ok, sometimes it will cut out

I also have a audison sx4 amp powering the components and coaxial speakers & a 1 Farad PG power cap

I'm going to atattach a couple of picture, one showing the levels of the amp, the other of the light that turns red (it's the bottom light of the two)

Thanks in advance

[Blad09]

Try turning bass boost down.


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[kizza]

That won't solve the problem though, the amp isn't even half way up. In theory the amp should be able to put more power into the sub than what I am now

[ttocs]

Pull the speaker and check the wire inside to make sure it is not shorting out.

[trickyricky]

That won't solve the problem though, the amp isn't even half way up. In theory the amp should be able to put more power into the sub than what I am now

Problem is we don't know what or where is "amp should put more power into the sub than what I am now"....know what I mean?

The gain has absolutely nothing to do with bass boost control. If your head unit has a high volt output signal than that would mean your gain would be lower than half (this is just an example). That does not mean you now have ROOM for the bass boost get turned up. PLEASE understand that.

Another example, if I was to add a line driver, then that would make my gain control get turned all the way counterclockwise...does that mean you now can turn the bass boost gain all the way up???? NOOOOO!



Also you have your subsonic filter a bit too low, I would try getting it around 30-32hz (anything below is not audible/hear).


After you check your subwoofer wire, try lowering the bass boost and rising the subsonic filter a bit and that should help...if your bass is lower than expected than your gain may not be set properly or you may have your bass cut down at the source/head unit.

[Blad09]

I always thought adding 3db of bass boost required the amp to double its output power essentially leading to clipping/overload. Dont quote me, just feel like I read something like that on bcae.com or 12volt.com. I'm no expert by any means, but I never use bass boost and I've never had problems with overload or anything. Also agree about ssf, amp could be strained trying to produce frequencies not heard


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[vwdude]

What gauge power wire do you have run in the car? I would remove the cap, it's just a strain on the cars electrical system. What does your voltage drop to when your bass hits? What might be happening is the voltage drops below 11 or 10 volts, causing your amp to not have enough voltage to run.

My theory is supported by you saying that at lower volumes it plays fine...so at higher volumes you are drawing more current, so either wire too thin or a weak electrical system could be causing the amp to go into protect mode. Keep in mind, some power supplies can be damaged from trying to run them at the wrong voltage, so protect mode is actually protecting your amp.

The other advise given is excellent as well. I never use bass boost, if anything, use an EQ to make up missing frequencies. I've found bass boost to mostly just add distortion. On the other hand, setting the xover up properly is key to getting the right sound and not overworking your amp un-necessarily.

Btw, I see nothing wrong with having the subsonic filter at 20hz. If the sub plays down that low then why not? Maybe you can't hear it but you can feel it and your brains interprets that as low bass (like the bass shakers). I'd maybe raise the xover frequency to so ething like 65-75 Hz though...

[kizza]

I've turned the bass level down a bit and turned up the sonic filter earlier see how it sounds, adjust more if I need to and see if it still cuts out. I'll look at getting a bass control knob as well. So is it definitely an overloading problem?

@vwdude as stated in the original post when I was listening to it earlier it cut out at 13.2v sometimes the voltage can drop lower than that and be fine. I believe I'm running 4 gauge, will need to double check though as I've had the power cable for a while now

I'll turn the xover up a bit and see what difference that makes. Having the bass boost up has never caused me distortion, I just feel that if I turn that all the way down that I won't get the bass levels I want

[trickyricky]

Btw, I see nothing wrong with having the subsonic filter at 20hz. If the sub plays down that low then why not? Maybe you can't hear it but you can feel it and your brains interprets that as low bass (like the bass shakers). I'd maybe raise the xover frequency to so ething like 65-75 Hz though...

Well even if you could hear a 20hz, your subwoofer sure as hell cannot produce it. For many reasons that I won't even mention because many should already know. So why waste power trying to produce something that your subwoofer cannot produce and your ears cannot hear?

Not to mention the risk of damaging your subwoofers.

[vwdude]

Good point Ricky.

[Drock]

I had the same problem with a couple amps. It did turned out to be that I was using too small of ga power wire. I went from 4 ga to 0/1 ga. And my problem has been gone since.


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[trickyricky]

Judging by the pic provided it looks like 4g wire. I would imagine 4g would be plenty for his 900watt amplifier (unless its long and has other amplifiers tied to it).

[kizza]

Would it be worth me upgrading the battery to one that has a higher AH rating? Also maybe a better alternator? Second amp has a different power cable

[Drock]

Your stock batt and alt should be fine. But I would do the big three upgrade. And a bigger main power wire from the batt to a distro


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[Drock]

That's assuming your only running the one amp.


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[kizza]

I'll do the 'big three' first, then if that makes no difference I'll look at a better battery. I'm running two amps, 1 for the sub, 1 for the speakers. I would of thought 4 gauge cable would be good enough for my setup? The power cable for the sub amp already goes through a distribution block, I'll replace the power cable when I do the big 3 to see if this helps at all

[ttocs]

I would seriously take the speaker out of the box and double check all your connections inside of it before adding any additional power. Start simple.

[vwdude]

I thought I read earlier that you had a separate wire for the other amp but now you say you are running a distribution block. If it's 1 wire then I'd suggest 1/0 gauge, if it's 2 separate wires from the battery then 4 gauge for each should be fine.

If a 12w6v3 with 900 watts isn't enough then I would consider a more efficient box or a different setup. You might just be maxing out the capabilities of the setup.

Edit: is this amp actually 900 watts at the ohm load that this sub is? I'm assuming d4, run in parallel for a 2 ohm load. I'm not familiar with this series amp. Maybe more power is needed.

[Drock]

Both my 500.1 and 900.1 did this. I had one run of 4g split with a 500.5. After I upgraded my wireing the problem did go away for me.

These were entry level amps, but worked and sounded great. I was very happy with them.


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