Subwoofer amp over-heating

[audio amateur]

hello fellow members,
I finished a sub project about two months ago. The amp is a rythmik audio 350 plate amp, A/B class amplification (350W @4ohms). It has huge heat sinks.
However, when played loud during prolonged plays (subwoofer at the limit of distortion, no clipping from the amp I don't think), it tends to get very hot, so hot in fact (when I touch it my fingers burn) that the thermal protection circuitry switches on which turns off the amp:( . Didn't think this could happen but it does. It really heats up very fast, dispite the sinks. Does the product have a deffect or is my hunger for bass pushing me to get a class D amp (which would run much cooler)? Is there any way (cheap) to solve this (I used a house fan to cool it down during a couple parties I have hosted, but it's really a hastle)? Will the warranty do anything do you think?
Thanks.

[kexodusc]

So it is a plate amp - Class A/B's run hot, but I can't imagine a Rythmik amp running so hot the circuitry kicks - how loud are you playing your music? You only have 1 woofer hooked up?
Might want to call the vendor and check with them - any class A/B plate amps I've used don't run that hot, and I generally prefer them to the Class D or G amps.

[audio amateur]

So it is a plate amp - Class A/B's run hot, but I can't imagine a Rythmik amp running so hot the circuitry kicks - how loud are you playing your music? You only have 1 woofer hooked up?
Might want to call the vendor and check with them - any class A/B plate amps I've used don't run that hot, and I generally prefer them to the Class D or G amps.

Crap this sucks kex... I've got to stop ordering my stuff from the states. What am I gonna do?? I guess I'll have to get one of my siblings to get it back to the states and ship it from there.
How loud... well pretty loud, I mean the woofer ain't necessarily distorting, just pretty loud, gets hot very quick... I dont have an spl meter so I cant tell you. What a hassle. and even then what if it's actually normal that it does this?? I would be VERY dissapointed. I'm tired of waisting my money on audio. I hope it IS a defect. I bought it from acoustic visons, I guess i should contact Kyle, the owner. It's funny, my 70 watt jamo sub amp doesn't even have any heat sinks and hardly EVER get's hot. It maybe gets warm but that's it...

[Fergymunster]

Crap this sucks kex... I've got to stop ordering my stuff from the states. What am I gonna do?? I guess I'll have to get one of my siblings to get it back to the states and ship it from there.
How loud... well pretty loud, I mean the woofer ain't necessarily distorting, just pretty loud, gets hot very quick... I dont have an spl meter so I cant tell you. What a hassle. and even then what if it's actually normal that it does this?? I would be VERY dissapointed. I'm tired of waisting my money on audio. I hope it IS a defect. I bought it from acoustic visons, I guess i should contact Kyle, the owner. It's funny, my 70 watt jamo sub amp doesn't even have any heat sinks and hardly EVER get's hot. It maybe gets warm but that's it...
Though it in a garbage can before you set the whole house on fire.Look at the Mirage omni series of subs,thier a canadan manufacturer.

[superpanavision70mm]

You might also want to try and 'throw' it in the garbage can too.

[crippledchicken]

hello to all! i'm new here but, i have the rythmik 250 basic driving a Dayton Audio dvc 15" sub which i mounted a fan on so heat sink stays cool but, the darn thing still! shuts down? could this be a sensor for tranny windings causing this any thoughts? Thanks! :confused5:

[audio amateur]

hello to all! i'm new here but, i have the rythmik 250 basic driving a Dayton Audio dvc 15" sub which i mounted a fan on so heat sink stays cool but, the darn thing still! shuts down? could this be a sensor for tranny windings causing this any thoughts? Thanks! :confused5:

I think their subs are flawed. They absolutely suck. I can't even listen to mine anymore, and it's not even 3 months old... Never going to get an AB class amp for my sub ever again. Unless it doesn't have any protection circuitry whatsoever. That was 200$ down the drain. I probably won't find a buyer.

[kexodusc]

I think their subs are flawed. They absolutely suck. I can't even listen to mine anymore, and it's not even 3 months old... Never going to get an AB class amp for my sub ever again. Unless it doesn't have any protection circuitry whatsoever. That was 200$ down the drain. I probably won't find a buyer.

There's nothing wrong with the AB class of amps, I much prefer them to the Class D's...they have real current and can deliver the power sustained over time.

That doesn't mean there aren't a few bad Class AB's though. I'd be bothering the place you bought this amp from. Tell them it keeps tripping the the protection circuitry and cuts out.

Just curious - what exactly do you have this connected to? Are you using the proper wall socket (I believe Rythmik is US based, and your name implies you're in Switzerland)....higher or lower voltage might be the culprit here too...

[BRANDONH]

hello fellow members,
I finished a sub project about two months ago. The amp is a rythmik audio 350 plate amp, A/B class amplification (350W @4ohms). It has huge heat sinks.
However, when played loud during prolonged plays (subwoofer at the limit of distortion, no clipping from the amp I don't think), it tends to get very hot, so hot in fact (when I touch it my fingers burn) that the thermal protection circuitry switches on which turns off the amp:( . Didn't think this could happen but it does. It really heats up very fast, dispite the sinks. Does the product have a deffect or is my hunger for bass pushing me to get a class D amp (which would run much cooler)? Is there any way (cheap) to solve this (I used a house fan to cool it down during a couple parties I have hosted, but it's really a hastle)? Will the warranty do anything do you think?
Thanks.

Do you have the box insulated?
Mine was getting hot too and I took all that insulation stuff out and it helped a lot.
I could not hear any cabinet vibration after removing the insulation either.

[audio amateur]

It is connected to a 230 V plug. The thing that pushed me to buy this thing is the fact that it CAN do this, is has an in built transformer, which means I can choose what voltage I want. It's actually the only reason I got it over an other sub amp in that price range. I talked to kyle, the owner of acoustic visions and b**ched around, saying I didn't think it was normal at all that it kept on switching off at "high" volumes etc.. he said I could send it in if I wanted to, but that it would probably be a waste of time and money because it probably is not a defect, in which case I can definitely back up what I said in my previous post. You see Im living in Geneva which means shipping to the states is a problem. ALready bringing it here was a problem in the first place. It's hooked up to a 4ohm SVC Sony car sub (XS-L122P5S) in a 1.2CF inclosure (Kex, we PM'd quite a bit in the past about this project, bit I never posted the pics I promised, sorry. I'm too ashamed too do so now that it's not working right).
Yes the box is insulated, I have glass wool in it. Maybe that's not helping the heat factor.
Im pretty sad to hear (and I have several times) that you don't agree with class D amps Kexodusc. That would of been my future option. But there's no way im getting another AB if it's going to do this every time. Maybe if I go ported it'll raise efficency and I can turn down the gain. But making a whole new box just to realise it's not going to do anything puts me off. And I don't have the cash to get a new amp either. I mot not very agreed either on its low end response. Can't hear a whole lot under 30Hz. Which means Ill surely go ported on a future design, making a big box, possibly up to 3CF with a 4 inch diameter tube so that it can breath, tuning it to 24Hz. It gave good results on paper.
Anyway perhaps doing this will give it more air to breath and perhaps decrease its chances of over heating.
Another note: The plug adapter is one I got with a shaver, and doesn't allow grounding. Perhaps this comes in as well (limit on current draw?)?
Tell me what u think.

[Rythmik]

It's hooked up to a 4ohm SVC Sony car sub (XS-L122P5S) in a 1.2CF inclosure (Kex, we PM'd quite a bit in the past about this project, bit I never posted the pics I promised, sorry. I'm too ashamed too do so now that it's not working right).

This is Brian from Rythmik Audio. I am sorry to hear about the problem that you ran into. We have sold quite a few of these 350WRMS amps (over 700 just from us) and another 700 from Apex Jr (it is basically the same design). As for the 250WRMS amp that we have, it is the same design as Part Express 250WRMS amp (which may have sold over 2000 units) except we have minor modification to the circuit. The design have been proven in the field so it is not fair to say class A/B always generates heat or our design is flawed. It is possible that the unit you have is defective (our failure rate is less than 2%). If that is the case, I would like to apologize for that and please just send it back and we will examine that. On the other hand, a car subwoofer in a small enclosure will not be very efficient. The required power is inversely proportionally to the square of enclosure volume. That means, a box of 1 cu ft will require 4*350WRMS=1200WRMS as compared with a 2 cu ft with 350WRMS amp. Not to mentioned the roll-off will Even though this is the extreme case, in reality we can easily see 2x to 3x power penalty by going to half the enclosure size. Car subs relies on chamber boost to give you enough output. Using car subwoofer at home without the chamber boost can also easily drive the amp into clipping and you still feel you don't have enough output. Eventually this leads to overheat. It is a very possible scenario.

Another poster mentioned problem of 250WRMS driving a 15" driver. It is almost the opposite of your case, a 15" driver will require more power. Using an underpowered amp can easily drive the amp into clipping and eventually causing it to overheat. That is why you don't see 350WRMS amp drives an 8" driver.

Hope this helps.

Brian

Rythmik Audio

[paulspencer]

I have two of the Rythmik kits with the 370w amp. I have had them shut down twice in the last 2 years I've had them. Both times it was when listening to rock music with constant heavy bass for an extended period turned up loud. I felt the heatsink and it was very hot. The amp needs to shut down at this point to avoid damage.

Previously I ran a pair of 12" subs with a pro power amp - Behringer EP2500 with 650w into 4 ohms. It never ran out of steam.

If you are finding this is a problem all the time, then you are asking something out of the plate amps they aren't designed for. You have 3 options:

1. accept the limits of what you have (no, I didn't think you'd like that one)
2. use multiple subs
3. use an entry level pro amp - they are the cheapest way to get lots of power and they are designed for sustained high levels, but you will have fans to contend with

Plate amps are better for home theatre where the bass isn't constant. They are easily hidden in the sub box, have no noise and are an easy solution. But if you are a young single batchelor without WAF issues then a pro amp is the most fun you can have.

You can get plate amps with more power, but their cost is high. A 500w plate amp can cost you more than a pro amp which can easily give you 2.4kw bridged.

Now I run two Rythmik kits and find that if I want more steam, I'm going to need to turn my home theatre into a bomb shelter to keep the neighbours happy.

[hydroman]

Check my sig for what i consider a excellent sub amp.

[Brainstorm]

Hmm, is it also possible that a standing wave/null is present and you’re unaware of it, so therefore you push the amp harder slightly over its limit to where some portions of the frequency starts to generate excusive heat build up.

[audio amateur]

I think you'll notice this was written 3 years ago.. Indeed the problem wasn't so much with the amp but with the driver and the box. Thanks for the advise though

[Brainstorm]

I think you'll notice this was written 3 years ago.. Indeed the problem wasn't so much with the amp but with the driver and the box. Thanks for the advise though

Right gotcha, so it was the driver VS enclosure wasn’t it suited for the box. No matter the issue has been resolved.http://forums.audioreview.com/images/icons/icon7.gif