lowering cabin temp for better db

[crunch1 0]

What are the advantages of lowering the temperature in the cabin to gain higher dbs. example: refrigerating the cabin to say 50f before taking a spl reading VIA portable refrigeration unit powered by a generator.

[johnecon2001 82]

Keeping the amps cooler is essential to higher numbers. Also just as important is keeping the subs cooler. If the coils go into thermal compression, you're going to lose a lot of deebeez.

Someone told me once that he'd seen competitors freeze their subs and hook them up right before the burp to gain that extra edge.

[ford302redneck 15]

Alan Dante does it.

[crunch1 0]

Interesting. I was thinking of using cold packs on the amps.

[johnecon2001 82]

I don't see how the cold could hurt them. As long as you slowly dropped the temp and slowly brought it up. If you do it to quick I'd imagine something would crack internally.

[Tirefryr 1,742]

Cold air is denser than warm air. I am sure this will have some effect on sound, but not sure what. Sean would know.

[dopey 0]

It would have the effect of lowering the tuning freq. Not sure how much.

Too cold and stuff gets stiff and brittle.

[audio-neon 34]

The motor trick works very well, freeze the motor/ sub. And you will gain ~ 1db on the first burp, the good news is your average gain will be ~ .6 db's for an hour or so.

[crunch1 0]

Sounds like a big advantage to freeze the motor, but in between runs I wonder if you can refreeze the motors.

[audio-neon 34]

Sounds like a big advantage to freeze the motor, but in between runs I wonder if you can refreeze the motors.

not really, lol. You probably wouldn't have enough time to get them frozen, and pulling them out of your box to chill would be a major pain. Setting the motors in ice between rounds will only chill the motor a little bit whereas letting it sit in a freezer for 24 hours will get it to a nice ~0* temperature.

[crunch1 0]

ya there a couple ways to refreeze the motors in between rounds to achieve 0f. I was just wondering about the radical temp drop in such a short time and what it would do to the mags.

[dopey 0]

Dry ice is pretty inexpensive...you could fill a cooler with crushed dry ice and in-between runs set the motor on that. If you have any doctor friends, you could see about getting some liquid Nitrogen. I bet a bath of compressed CO2 and liquid N would get a motor cold quick.

Both of these options would be better than a freezer due to CO2 and N being "dry".

There is probably a longevity issue will cooling the motor below dew point, and then letting air come in contact with it. Condensation in the gap, can't be beneficial. It can rust the plates, and no telling what it would do to the inside of the gap or former.

[troy_audi0 0]

wow we just talked about that before & after Mark got metered on Saturday.. he had been demoing the subs all day & drove up from PHX 1hr or so drive..

95+ Temps

could get more out of the subs on a optumum day/ prep..

Peace Troy

[vladd 26]

speaking of dry ice, with the right setup you could just put the dry ice in the box, it'd decrease the box volume but would enable you to keep cold air around the subs. Someone need to machine some 1" holes all the way through the motor (vertically from top to bottom plate) so it looks like the cylinder from a revolver and then make a freeze pack that fits right in it. bl would probably go all to hell though.

is it the memphis subs where you can unscrew the motors? would be cool to have a cooler full of spare frozen motors and switch them between burps, especially easy if your subs were inverted.

here's to 3am nonsense

[Sameer 0]

wudnt freezing the sub cause the metal to contract which can cause the coil to burst?

well there is a rumour that a cooler interior will give you a rise in SPL level.

the inside shudnt be too cool though, but jus cool enough.

keep in mind this will put an additional load on ur electrical system unless u have upgraded alternators an batteries.

an tint your car heavily to maximise your A/C.

and dont have your car in the heat before testing as if it is too hot ur amps may trip when its time to test.

[jmzneal 0]

wow..there is a lot of stuff being said ...as far as cool is conserned..yea it helps... the alt needs to be cool to run at max output...the box could be ran with a liquid cooling system like you would see on the inside of a pc just to help when air sucks and blows cooler air in and out of the VC...the amps same thing...build the rack in a manor so that a simple 12 volt fan with a liquid cooling system could blow over/through them and exit through a fan at the other end of the rack blowing air out of the rack. Also if you really want to push your subs to the limit, call the manf and get the thermal breakdown point of the adhesive used to hold the wire around the voice coil and put a thermometer in the box real close to the VC so you know when to back off(~20deg before the breakdown point). ( That's the first failing point on subs due to Heat, when the adhesive fails the coil pack slips off the former and causes destruction...then the former will warp or disform if the coil doesn't get your attention.) Running the A/C in the Cabin before helps(if you haven't taken it off to put another alt on, power steering pump was first to go on my truck then A/C for that few extra horsepower)...i wouldn't recomend the rapid cooling effect because of the bittleness of the magnet and voice coil...i would suggest NOS or CO2 ports in SMALL quanities if any thing radical directly into the box....LOL 75shot at most...GOT BOOST?

[helotaxi 46]

Consistent cabin temp will give you consistent results as far as frequency peak and box tuning. What's the point of trying to perfect your box if you don't run it in the environment in which is actually performs best?

[crunch1 0]

Thanks for all the input. Seems like I have some thinking to do lol. Right now I was tossing around the idea of fitting a evaporator around the sub motors and using the stock ac unit to power the system, but condensation concerns are holding me back.

[galacticmonkey 0]

Ive metered my car in 105 degree weather, and in 65 degree weather. Same setup, same mic position, same exact Termlab, same note, etc. I was over 2dbs louder in the 65 degree weather compared to 100+.

I just figured colder air was denser, and therefore when compressed it puts more pressure on the mic.

There are some shows down here that it gets so hot and it kills peoples numbers. There was a show in a blacktop parking lot and just out in the parking lot it was 120+. People were losing a good 4dbs consitently throughout the day.

[Lord Baccus 1]

i was reading that temp has an effect on the speed that sound travles...

[ANeonRider 3]

Of course it does.... simple physics. Humidity does too.

[Lord Baccus 1]

this would explain why my note changes with hotter temps:

i am still learning...

so i get if i keep the air conditioner on and cool off the truck befor a run i can incress my score

im loving this forum

[subwoofery 0]

Not sure if anyone know about this but hey...

12v Cooler / warmer:

# Cools to 20-25 Degrees C Below Ambient Temperature

# Warms to +65 Degrees C

# Hot/Cold, On/Off Switch

# Red/Green LEDs Indicate Warming

# Power Consumption: 48 Watts

# Non-Wearing Thermo Electric (Peltier System)

# Handle Recess When Not In Use

# Equipped with 1 Pc Long Life Brushless Motors (30,000 Hours) for Heat Dissipation to Outside

# Convenient-Plug Into Any 12 Volt Cigarette Lighter In Car, Boat or Plugs into Safe Adapter Indoors

# 9 ft. Detachable Power Cord

# Full Polyurethane-Foam Lining Without CFC

# Cap. Two 355mi Bottles Can Stand Upright

# Operates On DC 12V, AC-110V or 220V

If you put one or two of those in the boot + the aircon in the cabin = GREAT RESULTS

[helotaxi 46]

If you want consistent results, you have to get a consistent temp. That goes for testing and competing. Since the speed of sound changes with temp, so will the response of the system. Unfortunately humidity makes a difference (though not as much) and you'll have a hard time controlling that.

[crunch1 0]

Not sure if anyone know about this but hey...

12v Cooler / warmer:

# Cools to 20-25 Degrees C Below Ambient Temperature

# Warms to +65 Degrees C

# Hot/Cold, On/Off Switch

# Red/Green LEDs Indicate Warming

# Power Consumption: 48 Watts

# Non-Wearing Thermo Electric (Peltier System)

# Handle Recess When Not In Use

# Equipped with 1 Pc Long Life Brushless Motors (30,000 Hours) for Heat Dissipation to Outside

# Convenient-Plug Into Any 12 Volt Cigarette Lighter In Car, Boat or Plugs into Safe Adapter Indoors

# 9 ft. Detachable Power Cord

# Full Polyurethane-Foam Lining Without CFC

# Cap. Two 355mi Bottles Can Stand Upright

# Operates On DC 12V, AC-110V or 220V

If you put one or two of those in the boot + the aircon in the cabin = GREAT RESULTS

The (Peltier System) is way to inefficient to use, Im still leaning towards using the stock ac pump but I never got low enough temps to go any further with it. I never did use a evaporator connected directly to the motors either because of massive amounts of condensation. Ah well im saving this for next summer, more money and maybe new ideas.