Top resistors

@pbnaudio

Fusible and flame-proof resistors are quite common in the electronics industry but usually in an amplifier, not a crossover. :) The idea of the former is just like you would expect. When power is exceeded they are guaranteed to open, instead of potentially shorting or catching on fire, and save the rest of the device from a complete meltdown.

Duelund's are really weird. One of their selling points is that they have a high sensitivity to heat and power so will change values rapidly. The very last thing I want in a power resistor! :)

For speakers I stick with Mills. VERY thermally stable, very quite, very tight specs, and really small for the wattages. Also reasonably priced, all things considered.

I do want to someday work for a speaker company that will let me build with some caddock resistors and heat sink them, but so far I haven't the time / energy / funds to experiment with them.

@erik_squires

I think you must be referring to this type of fuse

http://www.mouser.com/ProductDetail/Littelfuse/0251002MXL/?qs=sGAEpiMZZMsNIlwy3aAdUVxIQvxhy%252bighe...

which is a fuse not a resistor, although to a layman it might look like it. That being said I find your posts enlightened and offering good advise.

I believe that this thread was questioning why one speaker manufacturer use resistors as fuses, which I consider sub par engineering at best and further evident as some report that these change value over time - which of course they will as they heat up - cool down.

Depending on their insertion in a crossover I use different resistor types, if in a zobel network for impedance correction of a woofer or midrange generally I use 25W cement resistors and almost always several in parallel as to get the power handling up where it needs to be. For attenuation of a tweeter, which I generally try to avoid, I’d use either the Caddock MP9100 which I heatsink or several 5W MOX resistors in parallel again to get the power handling up.

I agree Mills non inductance resistors are nice too and use them on occasion too.

http://pbnaudio.com/speakers/speaker-kits/scanspeak-b741

Above is a link to a kit I designed for ScanSpeak a few years back - this will give a good indication on how I propose the use of resistors in a X/O network.


Good Listening


Peter

justubes2 or salectric, do you have any more progress to report on the Path Audio resistors. I presently have Kiwames mixed with Duelunds in the tweeter section. The top end is quite lively (bright) and using all Duelunds was too bright. Mixing Kiwames tamed things down but I would like to get better resolution but without the brightness.  Did you find the Paths mixed well will Duelunds? Also, do the Paths affect the rhythm. Any further input on the Paths will be appreciated.

Sbl, I am afraid I can't help you.  I abandoned my Duelund resistors (regular and CAST) several years ago.  Same thing with my Path Audios.  All of them left too much of a fingerprint on the music.  Therefore I went back to where I started---with Mills 12w---and I have had no interest in trying anything else.  Sorry.

@pbnaudio Nope, here is a better example:

http://www.mouser.com/ProductDetail/Welwyn-Components-TT-Electronics/EMC2-4R7K/?qs=sGAEpiMZZMs%2f2%2...

These are quite common in amplifiers. They come in a variety of useful resistor values, but are also fuses which will permanently open above their rated power.