Subs Cutting Out

[Cartzo]

So I have a Kenwood 1800 watt max. I believe I have it hooked up at 4ohms which is 500 watt RMS x 1. The subs are Rockford P3's. I think the RMS is 500 watts and 1000 watt peak each. So technically I should be able to run one of the subs with this amp but I have two. You can see all the specs in my build.

When I have it turned up with hard hitting songs the subs will cut out after a sec. I'm wondering if it is the way I have it hooked up or maybe a power problem. I had the same problem when they were hooked up in my 87 Camry.

 

[Randyman...]

So I have a Kenwood 1800 watt max. I believe I have it hooked up at 4ohms which is 500 watt RMS x 1. The subs are Rockford P3's. I think the RMS is 500 watts and 1000 watt peak each. So technically I should be able to run one of the subs with this amp but I have two. You can see all the specs in my build.

When I have it turned up with hard hitting songs the subs will cut out after a sec. I'm wondering if it is the way I have it hooked up or maybe a power problem. I had the same problem when they were hooked up in my 87 Camry.

Looks like you are running (2) of the 4 Ohm Subs (likely wired in parallel) so you are actually presenting the amp with a 2 Ohm net load. The amp appears to be rated for 2 Ohm and even 1 Ohm operation (has to be current-limited to 900Watts to avoid burning itself up) , but TBH, that amp is not exactly a high-quality amp IMO.

The amp when pushed hard (into clipping, very likely IMO) @ 2 Ohms probably tripping the internal protection to prevent itself from melting

Do you have a DMM Multimeter? Can you see what resistance (or Impedance if you have a high-end DMM) your speakers report when disconnected from the amp? I'm guessing 1.5 Ohms DC Resistance or so. If it's much lower, you might have a bad speaker, too...

I'm betting it's just the lower quality amp. Look into something like a Rockford P500.1BD or a JL XD600/1 or something more in that range - it should be a night and day difference as these amps can actually produce rated power for extended durations w/o entering "Protect" mode.

Or, you could back the Kenwood's gain and bass-boost down, and try to keep it well under it's 900W output capacity (use some restraint )...

 

[Cartzo]

That makes sense. The bass boost is almost all the way down last time I messed with it. I will snap some pics of my connections in a bit.

 

[Skidmarcx]

It would help to know the ohm load... If you have access to an ohm meter measure resistance of the woofer circuit at the amp... That'll tell us how the woofers are wired... Also quality of the power/ground connections will have an influence... At least a 4ga power wire should be used

I also have to agree with Randy in regards to the equipment itself

 

[Randyman...]

It would help to know the ohm load... If you have access to an ohm meter measure resistance of the woofer circuit at the amp... That'll tell us how the woofers are wired... Also quality of the power/ground connections will have an influence... At least a 4ga power wire should be used

I also have to agree with Randy in regards to the equipment itself

Indeed - I generally forget about the power wiring because I know mine is always done right :trophy:

With that Kenwood amp 8Ga OFC is probably sufficient (60Amp fuse is kosher with 8ga OFC), but I would also recommend 4Ga for future expansion and some cushion.

Ditto - What about your ground?

What voltage do you measure AT THE AMP's +12v and Ground terminals when 'slamming so hard that the amp shuts off? What voltage do you rear at the BATTERY when the amp shuts off?

 

[Cartzo]

It would help to know the ohm load... If you have access to an ohm meter measure resistance of the woofer circuit at the amp... That'll tell us how the woofers are wired... Also quality of the power/ground connections will have an influence... At least a 4ga power wire should be used

I also have to agree with Randy in regards to the equipment itself

I don't have an ohm meter. The wiring is true 4 guage. I traded my Xbox for the subs and got the cheapest name brand amp that could power them... There are other things I'd rather spend my money on than my system

Thanks for the input

 

[Randyman...]

Can you measure the voltage at the amp and at the battery when it shuts off?

If the voltage at the amp is within 1Volt of the voltage you read at the battery, it's probably NOT power wiring related unless you are sagging below 10V at either end.

Could still be a bad speaker, or just an amp that can't cope with a 2 Ohm load at "full-tilt" (my personal suspicion).

You could ponder wiring your subs in series to present the amp with an 8 Ohm net load, but your amp will put out less power (and run cooler, and won't shut off no matter how hard you hammer it)...

 

[Cartzo]

Here are the connections.

 

[Randyman...]

Pics are nice, but we need to know a few specifics:

Quick observation: Since you are running a ported box, I'd engage the amp's Subsonic Filter to 25Hz (labeled as "ISF" with the 3-position switch on your amp). This might help as-is...

What voltage are you reading at the amp's +12/Ground terminals when the amp shuts off? Then, what voltage do you read at the battery when the amp shuts off (enters protection mode)? If both get close to 10V, then it's likely your battery and Alternator just can't cope with the ~60-80Amp constant draw of a sine wave (rap bass / 808 ). You could also check the battery ground to make sure it's solid and of acceptable gauge (I'd say battery ground should be no smaller than 6Ga).

If the Battery reads around +12V but the amp drops close to +10V, then the connections from Battery to Amp, and Amp to Ground need to be inspected as they are likely terminated improperly (high resistance terminations = Voltage Drop). Inadequate wire gauge is also a culprit in this scenario - but your 4Ga should be sufficient.

I doubt this is an alternator issue as my stock 150Amp gladly handles my 3600 Watt RMS system with a larger 31M battery under the hood (and that's a "True" 3600 Watts, not "Peak Power" :bolt: ).

I honestly believe the amp is just not up to snuff for your expectations and desired listening habits @ 2 Ohms.

You can also try running one sub at a time (try both, but separately). If one of the subs is flaking out (shorted coil, etc), it will likely still trip the amp's protection even if running by itself.

Lastly - If you want to try another test - connect the two subs in series, and see if the amp still has problems. Since you have both sub's wires ran to the amp, it is simple:

Disconnect one sub's "+" and the other sub's "-" from the amp's terminals, and connect them together (leaving the remaining wires connected to the amp). This is a quick way to run the subs in series and end up with an 8 Ohm load to the amp. The amp will put out less power at 8 Ohms, but is not likely to hit it's protection circuit and will run more efficiently and stay cooler.

If it runs w/o shutting off with the subs wired in series - I'd suspect the Amp just can't cope @ 2 Ohms and a heavy hand (assuming the voltage drop was not the initial issue)...

 

[Skidmarcx]

I'm willing to bet its the amp not being able to handle the demand... Looks correct, but like Randy said you should activate the isf switch

 

[Bucket81]

Whats the other end of your ground wire look like?

I agree with the previous posts, and think you got a blown or on its way out speaker from lack of power and to much volume.

 

[Cartzo]

Thanks you guys! I will turn the ISF to 25 if it isn't all ready. I will see if I can find something to read the voltage. All of the grounds should be fine I will check them out today.

 

[BrianSD_42]

is that actually 4G wire? It looks like 8G.

Even if it is labeled as 4G, are you sure it is true 4AWG and true copper?

#relevant
:frog:

 

[Randyman...]

is that actually 4G wire? It looks like 8G.

Even if it is labeled as 4G, are you sure it is true 4AWG and true copper?

#relevant
:frog:

I'd say even 8Ga can squeak by with this amp (assuming it's still fused safely). "Fudged" 4Ga CCA is more than adequate for this amp IMNSHO. True 4Ga OFC would cost a good deal more, and is not required here IMO (would be a nice cushion for future upgrades, but not needed in current form)...

 

[BrianSD_42]

I have to disagree.

Whether he is running 500W RMS or 1000W RMS (which I doubt) then 8G wire, especially cheapo wire will likely not be good enough.

My 300W RMS Alpine 4-channel was clipping out when connected to 8G wire, finally I just upgraded to proper 4-G and the amp started working fine.

Also based on the picture, the wire used is non-copper 8G wire which is NOT the same thing as Copper 8AWG wire. I believe it is about 40% less conductive than real spec-rated copper 8AWG wire.

Copper isn't doesn't look silver. That is not copper.

Just get a descent 4G kit and you will have wiring that is somewhere between true 4G and true 8G copper. The RF amplifier's power requirements are based on quality copper wiring.


OP here is a link to a decent AMP kit on Amazon. I haven't owned it personally but from the reviews it seems decent.

http://www.amazon.com/Scosche-Revopak4-4-Gauge-Series-Kit-Silver/dp/B001U636NQ/

:rtfm:

 

[Randyman...]

I have to disagree.

Whether he is running 500W RMS or 1000W RMS (which I doubt) then 8G wire, especially cheapo wire will likely not be good enough.

My 300W RMS Alpine 4-channel was clipping out when connected to 8G wire, finally I just upgraded to proper 4-G and the amp started working fine.

Also based on the picture, the wire used is non-copper 8G wire which is NOT the same thing as Copper 8AWG wire. I believe it is about 40% less conductive than real spec-rated copper 8AWG wire.

Copper isn't doesn't look silver. That is not copper.

Just get a descent 4G kit and you will have wiring that is somewhere between true 4G and true 8G copper. The RF amplifier's power requirements are based on quality copper wiring.


OP here is a link to a decent AMP kit on Amazon. I haven't owned it personally but from the reviews it seems decent.

Amazon.com: Scosche Revopak4 4-Gauge Revo Series Single Amp Power and Audio Kit-Silver/Black: Car Electronics

:rtfm:

I'd say the OP's pic shows 4Ga - granted it's probably 4Ga CCA (Copper Clad Aluminum) - but that is plenty for the amp in question (as I mentioned above). OFC 8Ga is good for 60 or so amps, and even though this amp has (3) 30-Amp car fuses, I doubt it pulls much more than a true 60 Amps. But again, the OP's pic appears to show 4Ga CCA going by proportions (look at the remote turn-on wire for comparison - unless that's 24-22ga, then I believe the pic is showing 4Ga)...


FWIW - Measuring the voltage drop across the wire (as I also suggested) would also show if the wire itself was inadequate - and was part of the reason I suggested this measurement (this measurement can also weed out the terminations as a weak point). If he's getting more than a volt or two drop from Battery to Amp Terminals; then the terminations, grounds (amp and battery), and wire need to be inspected further to find out where the extra resistance (manifests itself as voltage drop) is located...

I truly believe the amp just can't handle a "Balls to the wall" max output at 2 Ohms (which is already current limited to 900 Watts per the spec sheet), and the amp is likely shutting itself off to prevent thermal meltdown or worse at full output.

Testing the subs one-at-a-time (to make sure both are good and don't have shorted coils) plus running them in series (8 Ohms) will also go a long way with this troubleshooting IMNSHO (as I also mentioned)...

As you were

 

[ddnww]

those alpine amps put out no where near what theyre rated at.

 

[Cartzo]

The wiring I have is Scosche and everything I have read says it's true 4 gauge. I don't care enough to buy completely different wire for it. I'm going to try wiring it to 8 ohm like Randyman said.

 

[ddnww]

to make a educated comment to advise, one would need to verify the actual model of amp, as well as the number and exact model of subwoofers you have, not just "i think" , after that, one would need to verify the exact way you have it wired up including at the amp and at the sub(s), also include the exact connection example. positive on left terminal connected to 1st subs 1st voicecoil negative etc etc. . otherwise its all just shots in the dark. so that is step one.

most likely thermaled or near thermaled voicecoils

 

[Randyman...]

The wiring I have is Scosche and everything I have read says it's true 4 gauge. I don't care enough to buy completely different wire for it. I'm going to try wiring it to 8 ohm like Randyman said.

That wire is more than sufficient w/o a doubt. You will want to make sure all terminations are tight and clean - including the grounds from Battery to Chassis and Amp to Chassis...

to make a educated comment to advise, one would need to verify the actual model of amp, as well as the number and exact model of subwoofers you have, not just "i think" , after that, one would need to verify the exact way you have it wired up including at the amp and at the sub(s), also include the exact connection example. positive on left terminal connected to 1st subs 1st voicecoil negative etc etc. . otherwise its all just shots in the dark. so that is step one.

most likely thermaled or near thermaled voicecoils

See the the pics the OP posted on the first page of the thread - He also has his build log linked in his sig that contains model numbers and such. Been there done that :brushteeth: Also reference my previous troubleshooting suggestions based on the aforementioned build log and pics...