Heat dissipation?

Message Topic Search Topic Options Post Reply Create New Topic Printable Version Translate Topic

   With the driver's magnet sealed inside a little box how come the heat doesn't just build up until the driver burns out?

Author	Message Topic Search Topic Options Post Reply Create New Topic Printable Version Translate Topic
RoadRanger Members Profile Send Private Message Find Members Posts Add to Buddy List New Member Joined: 11 December 2009 Location: NE CT USA Status: Offline Points: 9	Post Options Post Reply Quote RoadRanger Report Post Thanks(0) Quote Reply Topic: Heat dissipation? Posted: 11 December 2009 at 6:50pm
	With the driver's magnet sealed inside a little box how come the heat doesn't just build up until the driver burns out?

biotec Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 07 June 2004 Location: United Kingdom Status: Offline Points: 2932	Post Options Post Reply Quote biotec Report Post Thanks(0) Quote Reply Posted: 14 December 2009 at 10:28am
	It may be sealed pneumatically but it isn't sealed thermally! Heat can be lost through the wood, through the hatch screws, through the paper cone, and through every other material which connects the inside of the box to the outside. It is certainly true that this rear chamber is fairly well insulated as none of the materials are particulalry good thermal conductors but in my years of running 1850 horns I never had a driver die from cooking so it must follow that the chamber is able to loose the heat as fast as it is generated once it has heated up to a certain point. Otherwise the chamber would just get hotter and hotter until the drivers failed. If you re looking to extract every ounce of spl out of each cab and feel that the driver would fail thermally (burnt voicecoil) before it failed mechanically (xmax) then you could improve the thermal conductivity between the inside of the chamber and the outside of the box by heatsinking the hatch. The efficiency of the heatsink would be connecting the heatsink as close as possible to the voicecoil; I guess you could shape a piece of metal to penetrate the vent but it starts getting complicated and expensive to solve a problem which was never really a problem! Edited by biotec - 14 December 2009 at 10:28am
	me so horny, me love you long throw.

darkmatter Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 26 February 2005 Location: LDN Status: Offline Points: 2419	Post Options Post Reply Quote darkmatter Report Post Thanks(0) Quote Reply Posted: 14 December 2009 at 1:35pm
	From what I've understood, heat generated by a driver is not transferred from the voice coil/pole piece to the surrounding air very effectively, irrespective of design. A reflex design would suffer thermal effects in a pretty similar way - slightly less pronounced due to increased air flow but not by a huge margin. In either case, the most effective solution is to increase heat transfer directly away from the pole piece. Trying to couple a heatsink to the air/magnet isn't so effective. This is going purely off what I've read, not any first hand tests.

Jake_Fielder Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 08 October 2007 Status: Offline Points: 4236	Post Options Post Reply Quote Jake_Fielder Report Post Thanks(0) Quote Reply Posted: 15 December 2009 at 10:24am
	I think it was JaKe that said, that a friend of his did a test with vibrating air getting rid of heat vs a fan, and the vibrating air did a pretty good job i recall... I have an old thread in the new project forum with a few details...

RoadRanger Members Profile Send Private Message Find Members Posts Add to Buddy List New Member Joined: 11 December 2009 Location: NE CT USA Status: Offline Points: 9	Post Options Post Reply Quote RoadRanger Report Post Thanks(0) Quote Reply Posted: 19 December 2009 at 9:04pm
	I just picked these up. I'm told they put insulation on the inside of the hatch cover - should I remove it?

rich_gale Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 18 February 2008 Status: Offline Points: 2697	Post Options Post Reply Quote rich_gale Report Post Thanks(0) Quote Reply Posted: 19 December 2009 at 9:59pm
	you dont need wadding in the chamber. about vc cooling, i opened up a tweeter once and it had an oily fluid in the vc gap. must be to transfer heat. any bass drivers employ this technique?
	REFLEX ALL THE WAY.... (however, im playing with horns again...) That ok Mister Valiant? :)

adambomb Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 10 April 2006 Location: United Kingdom Status: Offline Points: 3220	Post Options Post Reply Quote adambomb Report Post Thanks(0) Quote Reply Posted: 20 December 2009 at 2:23pm
	Ferofluid.. And nope, don't think it is used outside of hf drivers (would cause problems with a relitivily large coil moving a relitivily long way.
	www.freespeakerplans.com