Speakerplans.com Homepage
Forum Home Forum Home > General > Advanced Discussion
  New Posts New Posts RSS Feed - *Driver Heat Dissipation Thread*
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

*Driver Heat Dissipation Thread*

 Post Reply Post Reply Page  <1 345
Author
Message
neilpoints View Drop Down
Young Croc
Young Croc


Joined: 03 March 2010
Location: Cornwall
Status: Offline
Points: 976
Post Options Post Options   Thanks (0) Thanks(0)   Quote neilpoints Quote  Post ReplyReply Direct Link To This Post Posted: 29 July 2010 at 3:20am
Originally posted by nineleaves nineleaves wrote:


On aluminum/alloy cones.. even if they are sufficently rigid to withstand the stress of being used in a horn, the alloys used in general are highly prone to stress fractures & will eventualy crack and tear themselfs to pieces. Past experience with these things has been less than favourable at times.


Please can you tell me about other alloy drivers from the past?



< id="gwProxy" ="">< ="jsCall;" id="jsProxy" ="">
former Eurovision contestant
Back to Top
S DeXter View Drop Down
Young Croc
Young Croc
Avatar

Joined: 12 May 2008
Location: Moon
Status: Offline
Points: 1268
Post Options Post Options   Thanks (0) Thanks(0)   Quote S DeXter Quote  Post ReplyReply Direct Link To This Post Posted: 29 July 2010 at 12:03pm
Originally posted by nineleaves nineleaves wrote:

People are still neglecting here that the biggest limiting factor is not the ammount of power you can hammer into a coil without it wasting some of it as heat; but how far the cone can be thrown reliably without running into segnificant mechanical issues of the driver suspension (the main limiting factor for the bottom end output of all drivers), the cones ability to handle physical stress & the design of the permanent magnet circuit.


That is true for certain enclosures, it really depends on what type.... I have seen a few small sealed rear chamber drivers suffer from extreme effects of heat with no cone stress / failure. I remember opening an F218 up and the whole coil had unwound off the former into a big bundle of tumbleweed in the back of the chamber..... but the cone was fine....

Yes if you keep increasing coil cooling eventually the next thing to break will be the suspension/cone.


Enjoy your self...... It's later than you think.......
Back to Top
Meat View Drop Down
Old Croc
Old Croc


Joined: 05 June 2009
Location: Manc
Status: Offline
Points: 1514
Post Options Post Options   Thanks (0) Thanks(0)   Quote Meat Quote  Post ReplyReply Direct Link To This Post Posted: 29 July 2010 at 12:43pm
Anyone got any links to moving magnet transducer designs? Someone must have done it, probably back in the days when everything was untested and new probably.

In terms of phono carts the moving coil is the less sensitive of the two designs...

Anyone ever done multiple concentric coils or coil arrays in the motor?


Back to Top
rich_gale View Drop Down
Old Croc
Old Croc
Avatar

Joined: 18 February 2008
Status: Offline
Points: 2697
Post Options Post Options   Thanks (0) Thanks(0)   Quote rich_gale Quote  Post ReplyReply Direct Link To This Post Posted: 29 July 2010 at 2:02pm
Originally posted by S DeXter S DeXter wrote:



Yes if you keep increasing coil cooling eventually the next thing to break will be the suspension/cone.




i see heatsinking as a way of limiting the electrical power required by lowering the power compression.   and less of an attempt to increase power handling.

lets assume a pd1850 loaded scoop is kicking out 130db at its 800w rated power.  imagine you could gain 0.5db or 1.0db on top of that, per cabinet, using exactly the same power input.  id imagine it would make a huge difference to the listener once cabinets are in multiples.

that would be like the difference between giving the driver 800w and giving it 1000w.  or with 5 cabinets you are looking at a difference of it sounding 1kw worth of amps louder.
REFLEX ALL THE WAY.... (however, im playing with horns again...) That ok Mister Valiant? :)
Back to Top
S DeXter View Drop Down
Young Croc
Young Croc
Avatar

Joined: 12 May 2008
Location: Moon
Status: Offline
Points: 1268
Post Options Post Options   Thanks (0) Thanks(0)   Quote S DeXter Quote  Post ReplyReply Direct Link To This Post Posted: 29 July 2010 at 3:43pm
Originally posted by Meat Meat wrote:

Anyone got any links to moving magnet transducer designs? Someone must have done it, probably back in the days when everything was untested and new probably.

In terms of phono carts the moving coil is the less sensitive of the two designs...

Anyone ever done multiple concentric coils or coil arrays in the motor?




Moving magnets would add large weight to the diaphragm and reduce efficiency somewhat.

Radial coiled electromagnets have been talked of before instead of permanent magnets (to increase BL), there is a patent somewhere. I think cone strength vs weight will always be a major issue...


Enjoy your self...... It's later than you think.......
Back to Top
S DeXter View Drop Down
Young Croc
Young Croc
Avatar

Joined: 12 May 2008
Location: Moon
Status: Offline
Points: 1268
Post Options Post Options   Thanks (0) Thanks(0)   Quote S DeXter Quote  Post ReplyReply Direct Link To This Post Posted: 29 July 2010 at 3:46pm
Originally posted by rich_gale rich_gale wrote:

Originally posted by S DeXter S DeXter wrote:



Yes if you keep increasing coil cooling eventually the next thing to break will be the suspension/cone.




i see heatsinking as a way of limiting the electrical power required by lowering the power compression.   and less of an attempt to increase power handling.



Yes chamber heatsinking most certainly is.
Enjoy your self...... It's later than you think.......
Back to Top
madboffin View Drop Down
Old Croc
Old Croc


Joined: 03 July 2009
Location: Milton Keynes
Status: Offline
Points: 1537
Post Options Post Options   Thanks (0) Thanks(0)   Quote madboffin Quote  Post ReplyReply Direct Link To This Post Posted: 29 July 2010 at 6:32pm
Originally posted by Meat Meat wrote:

Anyone got any links to moving magnet transducer designs? Someone must have done it, probably back in the days when everything was untested and new probably.



I'm sure I have seen some Throne Shakers which used fixed coils and moving magnets.

For really high powered low frequency drivers, take a look at the designs used in shakers for vibration testing. Big moving coils and specialised suspensions. There must be some inspiration, and perhaps technology transfer, to be had there.
Back to Top
nineleaves View Drop Down
Young Croc
Young Croc


Joined: 31 August 2007
Status: Offline
Points: 1327
Post Options Post Options   Thanks (0) Thanks(0)   Quote nineleaves Quote  Post ReplyReply Direct Link To This Post Posted: 31 July 2010 at 9:39am
Grooans.. im staying out of this.. so much facepalm :/
Back to Top
 Post Reply Post Reply Page  <1 345

Forum Jump Forum Permissions View Drop Down

Forum Software by Web Wiz Forums® version 12.06
Copyright ©2001-2023 Web Wiz Ltd.

This page was generated in 0.066 seconds.