why no in line fuses for SDA ?

leftwinger57

We know that the infamous polyswitch on the SDA x-over board is there to 'protect' the tweeters from frying. So why didn't Polk go the way of other companies and install an in-line fuse for total speaker protection ? When I had my now long gone Bose 601s I copied a PDF manual and they suggested to install a certain value fuse in-line w/ one of the speaker leads.

ambiophonics

I think they did have fuses in the older models. Not sure what sounds better, my polyswitches are long gone as I've read they degrade the sound.

boston1450

Wonder if cost was part of the reason. Seems like if it was-that would be the way to go

F1nut

I wouldn't call the polyswitch infamous. It does what it's suppose to do rather well and it even resets unlike a fuse. That said, if you are running good electronics, you don't need no stinkin' fuse or polyswitch.

tonyb

F1nut wrote: »

I wouldn't call the polyswitch infamous. It does what it's suppose to do rather well and it even resets unlike a fuse. That said, if you are running good electronics, you don't need no stinkin' fuse or polyswitch.

True.....but he may need a cast iron bar glued to a certain point on the volume dial. lol

westmassguy

tonyb wrote: »

F1nut wrote: »

I wouldn't call the polyswitch infamous. It does what it's suppose to do rather well and it even resets unlike a fuse. That said, if you are running good electronics, you don't need no stinkin' fuse or polyswitch.

True.....but he may need a cast iron bar glued to a certain point on the volume dial. lol

I have at least one customer who needs a Taser attached to the volume control.

boston1450

Do it. I wanna watch

westmassguy

It won't be pretty

leftwinger57

Goof all you want but truth be told just about all other monitor series speakers had out board fuses. So again why not the SDAs. Jesse I thought you were the biggest proponent of pulling those polys and putting in the Mills resistors to sh$t can the polyswitches. What happened to that rap.

[Deleted User]

Hello,
Back in the CS days, when I was working with a customer who had difficulty detecting when he was overdriving his receiver or amplifier and resulting in damaged speakers, we would make up a pair of in-line fuse holders and a selection of fuse values to offer a way of protecting the speakers. Take the available undistorted power he was working with, divide by the speaker's nominal impedance and find the square root. This would give us a value for the fast blow fuse to use. We would send some fuses that were 0.5A below the calculated value and some that were at the rated value. The customer would start at the lower rating and see if those would suffice, if not go up to the higher value.
What it got the customer to begin doing was understanding the relationship between apparent playing volume and what was happening to the fuse. For some people they would never acknowledge that the sound was "loud". There's the instance where the Monitor 10 owner who kept blowing tweeters and drivers used his speakers, placed on the front porch, playing while he mowed his lawn and wanted to hear music over the sound of his gas-powered lawn mower.
Ah, the stories!
Cheers, Ken

F1nut

Jesse I thought you were the biggest proponent of pulling those polys and putting in the Mills resistors to sh$t can the polyswitches. What happened to that rap.

You must have missed my comment, "That said, if you are running good electronics, you don't need no stinkin' fuse or polyswitch."

gimpod

Jesse, I don't know how much more of this I can take. I mean doesn't anybody know to read anymore. ?

PolkieMan

The only good thing the poly switches should be good for is accidents and party speakers

leftwinger57

Ken that was a great story. Yes you should know your limitations but for the few morons who don't wouldn't a couple dollar fuse be the way to go to protect a pair of $500 speakers and up ? The same thing was offered as a package by Bose for their series 1 601s but not as part of the original purchase. Yeah I think I know to READ.. Oh the humanity " I don't know how much more of this I can take". KISHMEIRINTUCAS......

[Deleted User]

Now that I think back, it was a chainsaw he was using not lawnmower. I had another guy call me up just to tell me poured gasoline on his Monitor 7 speakers and set them on fire because he kept blowing out tweeters and drivers. He wanted to let me know how much he hated them.

Schurkey

First Guess: A fuse, fuse holder, leads, and screws to hold the fuse holder to the structure plus the labor to assemble it all costs more than a polyswitch soldered to the circuit board.

With either the fuse or the polyswitch, one wonders how much you're listening to the protection device vs. listening to the drivers.

boston1450

boston1450 wrote: »

Wonder if cost was part of the reason. Seems like if it was-that would be the way to go

thats why i wondered this. Everyone is trying to save a little