Theory: chilling powered amps before competition ?

Chase lapsed

Pondering today the efficiency of electronics, in general the hotter they get the less efficient they are and therefore the less power they can output with a constant, unchanging supply current.

For a cheap solution for SPL competitions, would there perhaps be a noticeable dB difference if the amps were chilled before hand for an hour or two by placing ice-packs over the heatsink ? Even in the tenths of a dB, because it makes a difference in the competition.

I would be interested in trying a practical experiment.

exalted512

I would say chilling the subs would do more than the amps...usually colder subs have a lower ohm load...try it! Put some dry ice in a sub box...lol
-Cody

MacLeod

I kinda doubt it. The top SPL competitors have come up with pretty much every trick in the book and obsessively go over box calculations, computer simulations and countless trials and error yet Ive never seen one spraying liquid nitrogen on their amps. I would think if there was something to this, at least one of them wouldve tried it by now.

treitz3

If it were two channel competition? You would be left in the dust.

TouchOfEvil

Might help if you sit there like a idiot playing your system beforehand and get the setup very hot.
Maybe you could hope for some rain as it is your turn as the rain causes you to hit higher spls.

mmadden28

Speaking strictly from an electronics perspective - I personally wouldn't do anything like that - Considering as it warms up condensation will likely form possibly causing a short and what-not.

If anything, some form of liquid cooling like that which is done to keep overclocked CPUs and GPU's in gaming PC's cool.

exalted512

MacLeod wrote: »

I kinda doubt it. The top SPL competitors have come up with pretty much every trick in the book and obsessively go over box calculations, computer simulations and countless trials and error yet Ive never seen one spraying liquid nitrogen on their amps. I would think if there was something to this, at least one of them wouldve tried it by now.

But there are teams that do their 'world record runs' inside their bays with the AC's cranked. Also, it seems like you get higher numbers in colder weather, something gets an edge in colder weather, I'm not sure if its the subs or the amps or both.
-Cody

MacLeod

Maybe it has something to do with the cold makes the sheet metal more rigid and less likely to flex. Thats worth a db or 2 right there.

Jstas

Geez, guys, really? It's simple physics.

You get an edge in colder weather or more humid weather because of air density. Cold air is more dense so you can build pressure faster and easier because the air pressure is higher to begin with.

You get an edge in humid weather because there is more moisture in the air which is more dense and has a higher mass than air. Therefore, it also increases the pressure of the air which makes it easier to pressurize the air and get the SPL up.

As far as the whole "raining makes you hit harder" thing, I dunno about the rain being the culprit as much as the humidity. Rain is water. Water is a liquid. Liquid cannot be compressed. Hence the reason water in your combustion chambers is so bad.


As far as cooling stuff, heat syncs don't work the same way that a radiator does. They are heat exchangers. They draw heat away. If they are cold, they don't do anything to keep the electronic parts cooler. They just create condensation as moisture collects on the heat sync because it's pulling heat out of the air around it and causing the water vapor in the air to condense.

People at the race track put ice on engine parts because it makes the physical part colder so that the air inside the part, like an intake manifold, is colder and therefore more dense. When the air is more dense, you can increase the power output of your engine by as much as 10 HP by just reducing the intake temps.


If you want to cool stuff while competing, cool the sub magnets. I've seen people using an intercooler or washer fluid pump and flexible copper tubing wrapped around the sub magnets and then covered in thermal tape and/or foam. They run ice water through the tubing or some other kind of refrigerant to keep the magnets cool. The problem is that the magnets are very dense so they have to have them being cooled for a looooong time before the SPL attempt for it to be effective. Otherwise it's just something cool to look at.

But, in ported enclosures, the cooling system can affect the backwave coming off the back of the speaker as well as air flow in the box. It can cause high-pressure turbulence which can cause uneven air flow, high pressure eddys inside the box and port cavitation which can cause port noise like whistling and chatter.

But a burp only lasts a few seconds and SQ competitions usually aren't run long enough at high enough levels to be a concern. If you have heat problems in a daily use stereo then you are likely playing it way too loud and you should consider your hearing and/or you need to find a better mounting spot with more air space around the electronics so they can breathe.

Oh and typically, vented enclosures move way more than enough air to keep the subs cool.

Installer4life

Many years ago I knew a couple of competitors that would surround their Punch 45's with dry ice and run them at 1 ohm loads bridged each powering a couple of punch 15" subwoofers. It worked for the short time they needed it to. Its definately something I would never do.

Chase lapsed

Jstas wrote: »

Geez, guys, really? It's simple physics.

You get an edge in colder weather or more humid weather because of air density. Cold air is more dense so you can build pressure faster and easier because the air pressure is higher to begin with.

You get an edge in humid weather because there is more moisture in the air which is more dense and has a higher mass than air. Therefore, it also increases the pressure of the air which makes it easier to pressurize the air and get the SPL up.

As far as the whole "raining makes you hit harder" thing, I dunno about the rain being the culprit as much as the humidity. Rain is water. Water is a liquid. Liquid cannot be compressed. Hence the reason water in your combustion chambers is so bad.


As far as cooling stuff, heat syncs don't work the same way that a radiator does. They are heat exchangers. They draw heat away. If they are cold, they don't do anything to keep the electronic parts cooler. They just create condensation as moisture collects on the heat sync because it's pulling heat out of the air around it and causing the water vapor in the air to condense.

People at the race track put ice on engine parts because it makes the physical part colder so that the air inside the part, like an intake manifold, is colder and therefore more dense. When the air is more dense, you can increase the power output of your engine by as much as 10 HP by just reducing the intake temps.


If you want to cool stuff while competing, cool the sub magnets. I've seen people using an intercooler or washer fluid pump and flexible copper tubing wrapped around the sub magnets and then covered in thermal tape and/or foam. They run ice water through the tubing or some other kind of refrigerant to keep the magnets cool. The problem is that the magnets are very dense so they have to have them being cooled for a looooong time before the SPL attempt for it to be effective. Otherwise it's just something cool to look at.

But, in ported enclosures, the cooling system can affect the backwave coming off the back of the speaker as well as air flow in the box. It can cause high-pressure turbulence which can cause uneven air flow, high pressure eddys inside the box and port cavitation which can cause port noise like whistling and chatter.

But a burp only lasts a few seconds and SQ competitions usually aren't run long enough at high enough levels to be a concern. If you have heat problems in a daily use stereo then you are likely playing it way too loud and you should consider your hearing and/or you need to find a better mounting spot with more air space around the electronics so they can breathe.

Oh and typically, vented enclosures move way more than enough air to keep the subs cool.

Brilliant !

Face

I like to practice abstinence for a few days before a competition.

MacLeod

Installer4life wrote: »

Many years ago I knew a couple of competitors that would surround their Punch 45's with dry ice and run them at 1 ohm loads bridged each powering a couple of punch 15" subwoofers. It worked for the short time they needed it to. Its definately something I would never do.

I remember those Punch amps. Those things were stable down to flat out insane loads like around 1/4 ohm! Those and the Orion HCCA's. I remember those Phoenix Gold cheater amps too. "25x2" was the rating but the amp was 4 feet long! LOL!

Installer4life

The Orion were stable to 1/2 ohm mono as were the PPI Pro Mos series. I think ratings were 25 and 50 watts per channel at 4ohms depending on amp model for both Orion and PPI. But much more when bridged into 1/2 ohm. The manufacture listed these ratings. Rockford listed the Punch 45 as well as the 75 and 150 to be stable only to 2ohms stereo and 4 ohms mono. A funny thing about rating is the was you state them. If you take a amp and bridge it to 4 ohms each channel sees a 2 ohm load so you could say that that amp was stable to 2 ohms when in fact it's not. I had rockford reps use that line on me several times...