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Amplifier heat?


Jduncan15

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Is it normal for a class AB amplifier to get rather hot when playing on 2 subwoofers. It barely even warms up when just playing one. I believe it was do to how I had the "bass/gain" knob set now I believe I have corrected the problem but was curious for any background information. Thank you!

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What kind of amp and subs and how many ohms?

91 C350 Centurion conversion ( Four Door One Ton Bronco)

250A Alternator (Second Alternator Coming Soon)

G65 AGM Up Front  / Two G31 AGM in Back

Pioneer 80PRS

CT Sounds AT125.2 / CT Sounds 6.5 Strato Pro component Front Stage

CT Sounds AT125.2 / Lanzar Pro 8" coax w/compression horn tweeter Rear Fill

FSD 5000D 1/2 ohm (SoundQubed 7k Coming Soon)

Two HDS315 Four Qubes Each 34hz (Two HDC3.118 and New Box Coming Soon)

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More subs, more load for it to push. Also same question above^, model of amp and subs, and exactly how you have them wired will help. If it's a 2 channel amp and you're bridging, it'll probably overheat @ 4 ohms depending what wattage the subs need.

No. The number of subs does not change the output of the amp at a given ohm load. And no to "what wattage the subs need". That also does not dictate output or heat.

OP, It's an A/B amplifier, so it's inefficient and will produce more heat than a class D. The heat is wasted energy. What resistance you're wired to, that is important. The lower the nominal resistance, the more inefficient the amplifier will be. Also, you started at step one, which is your bass/gain knob. Do you know which it is? If you're clipping the signal at all (with either that knob or the actual gain potentiometer on the amp) that will also cause the amplifier to be excessively hot compared to how it is under normal conditions on a clean signal at the rated ohm load.

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The bass gain knob is sadly my outline converter on another sad note I had someone install it. Which they did a clean job and it now only serves as a converter. However my amplifier is a Pioneer GM-A5602 and the subwoofer is also Pioneer TS-W3003D4 the woofer reads 5.6 ohms at the ends of the wires where it will connect to the amplifier. I still have not been able to tell what this amp wants as far as ohms. I am almost certain that the main cause of the heat I experienced was do to the improper gain setting and also the difference in wiring lengths etc. between the two subwoofers.

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Is it normal for a class AB amplifier to get rather hot when playing on 2 subwoofers. It barely even warms up when just playing one. I believe it was do to how I had the "bass/gain" knob set now I believe I have corrected the problem but was curious for any background information. Thank you!

A, AB get warm..... run it at proper load, and dont worry about it.

EDIT - what amp?

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Wire length won't cause a high load. Is the amp 2 channel bridged to 1? Are the subs dual voice coil? If you had them in parallel then your impedance was probably too low.

91 C350 Centurion conversion ( Four Door One Ton Bronco)

250A Alternator (Second Alternator Coming Soon)

G65 AGM Up Front  / Two G31 AGM in Back

Pioneer 80PRS

CT Sounds AT125.2 / CT Sounds 6.5 Strato Pro component Front Stage

CT Sounds AT125.2 / Lanzar Pro 8" coax w/compression horn tweeter Rear Fill

FSD 5000D 1/2 ohm (SoundQubed 7k Coming Soon)

Two HDS315 Four Qubes Each 34hz (Two HDC3.118 and New Box Coming Soon)

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More subs, more load for it to push. Also same question above^, model of amp and subs, and exactly how you have them wired will help. If it's a 2 channel amp and you're bridging, it'll probably overheat @ 4 ohms depending what wattage the subs need.

No. The number of subs does not change the output of the amp at a given ohm load. And no to "what wattage the subs need". That also does not dictate output or heat.

OP, It's an A/B amplifier, so it's inefficient and will produce more heat than a class D. The heat is wasted energy. What resistance you're wired to, that is important. The lower the nominal resistance, the more inefficient the amplifier will be. Also, you started at step one, which is your bass/gain knob. Do you know which it is? If you're clipping the signal at all (with either that knob or the actual gain potentiometer on the amp) that will also cause the amplifier to be excessively hot compared to how it is under normal conditions on a clean signal at the rated ohm load.

For example: One 1000 watt sub on a 1000 watt amp, add another 1000 watt sub = amp overload/over heat when turned up. Not sure exactly where you're coming from. I never said the amp would change output anywhere in my comment, so not sure where you got that from. Also yes, knowing what kind of subs/wattage, and amp/wattage DOES matter. You then went on to explaining exactly what I said, just in a different way, contradicting yourself. I've had subs running on a 2 channel a/b amp before with no heat issues, just gotta have more amp than sub.

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Wire length won't cause a high load.

Interesting. I saw otherwise in the 90 cubic foot wall i helped work on :shrug:

On 5/8/2011 at 7:38 PM, Kranny said:
On 5/8/2011 at 7:35 PM, 'Maxim' said:

It hurts me inside when I read stuff like this and remember you're 15

LMFAO so true

:blush:

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2005 Chevy Colorado Ext Cab

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Substage: 6 Fi BTL 18s in a 4th Order Walkthrough on 3 Wolfram 4500s

Electrical: Singer "390" and JY Power

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you know, when i was a kid, mosfet was a new thing, and class d was not even a thing. class a/b 2 channel amps was what people ran subs off of. i mean, i have seen a few amps with switches that would let you select ohm loads. but now a days people are like, "oh i has a portable easy bake oven, is that normal?" and i am like, "grab a 100 watt light bulb" is it hot? so your 3k amp doesnt melt your face? consider yourself lucky."

but i digest

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