The Power Difference Between Sine Waves, and Musical Bass

[Raven 10+ year member]

Was there a specific wattage that the coil would stabilize at? Were you able to keep 10 watts on the coil indefinitely or would it eventually burn out?

 

[bigbassman Premium Member]

ok.. just finished up testing to cover thermal rise..

still using the same equipment as above... this time I focused on actual wattage, and actual impedence...

volume level kept the same throughout...

coil had a standing temperature of 80 F when testing began..

Graph one shows actual wattage

Graph two shows actual impedence

now keep in mind, this does not take into account any related impedence shift due to the box, and frequency played.. this merely shows how temperature affects impedence.. and as you can see.. it can really have an effect //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

Thanks for the idea Squeak!

Loyd L.

 

[Raven 10+ year member]

Now THAT'S insightful. //content.invisioncic.com/y282845/emoticons/yourock.gif.93d527d504392657a77fa577298070a1.gif

 

[bigbassman Premium Member]

Was there a specific wattage that the coil would stabilize at? Were you able to keep 10 watts on the coil indefinitely or would it eventually burn out?

this coil stablized at 18 watts, where it raised to 350 F, and stayed there without issue..

now the fun part, to demostrate how crucial airflow over the coil is... I waved my hand around the coil... temp dropped all the way down to 185 F until I stopped waving..

while waving my hand around the coil, I was able to increase wattage into the coil, up to 30 watts or so, and maintain 350 F...

so its a duh thing.. but cooling is very important.. keep the coil moving, and make the driver with cooling channels into it, and power handling goes way up..

wee

Loyd L.

 

[Raven 10+ year member]

A 50% gain in power handling with a wave of your hand. That's gotta be the stuff of legend. =p

 

[bigbassman Premium Member]

A 50% gain in power handling with a wave of your hand. That's gotta be the stuff of legend. =p

almost magic.. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

Loyd L.

 

[addisdar 10+ year member]

Good read

 

[NDMstang65 10+ year member]

good info //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif...didnt know you did this...

 

[Wkbdkid 10+ year member]

i doubt if this is right but because of heat your impedence rises?

 

[NDMstang65 10+ year member]

thats exactly right actually

 

[Wkbdkid 10+ year member]

hell yea me a learnin //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

 

[Raven 10+ year member]

The relationship between electrical resistance in wire and heat are well documented. I knew it was there, I just didn't know it there were cases that extreme.

 

[squeak9798 5,000+ posts]

Excellent thread as always Lloyd !

I can't believe just waving your hand by the coil reduced the temp that much //content.invisioncic.com/y282845/emoticons/eek.gif.771b7a90cf45cabdc554ff1121c21c4a.gif

Now, the important question....what frequency were you waving your hand at ? //content.invisioncic.com/y282845/emoticons/up2something.gif.dd110ecf3ae4b76050d87598f2f8de7c.gif//content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

 

[mannyb18b]

This makes me really interested to see how Ryan and Ray's 4 MT18 build is going to do with that SWEET azz cooling system they have going into those things.

 

[bigbassman Premium Member]

The relationship between electrical resistance in wire and heat are well documented. I knew it was there, I just didn't know it there were cases that extreme.

indeed.. and I learned something I didn't know..

throughout all testing last night... voltage into the coil stayed exactly the same

15.18 volts regardless of coil temp.. current was the factor..

Loyd L.