roughly, what are the dB losses using electrolytic caps in this position with 8 ohm nominal impedance drivers? 450uF seems a typical value. There are motor run caps available fairly cheap but even that cost a bit at 450uF. (I do realize motor run could prove cheaper over a long period of time)
also, I'm not sure how the cap interacts with a lowpass inductor
also, I'm not sure how the cap interacts with a lowpass inductor
I don’t know about losses but i don’t like to use electrolytics in any speaker. You may be able to find poly motor run caps that large… the Solen 330 uF caps seems to be the largest they have and are near the size of a beer can. You’d have to add a 120 uF cap or use 2 220 uF.
dave
dave
hi Planet10 - here's something so small and cheap that its hard to believe - when they say "plastic" - might that mean the outer wrap rather than the dielectric ? 
AC Motor Plastic Capacitor CD60 450VAC Machine Starting Running Capacitor | eBay
AC Motor Plastic Capacitor CD60 450VAC Machine Starting Running Capacitor | eBay
Hi Freddi!
Why don't you grab XSim and play with some designs? You can play with the LM-1 design files if you'd like, sources here:
A Speaker Maker's Journey: The LM-1 Bookshelf Version
The LM-1 uses a second order HP and LP filter. More discussions about filters on my site, perfect for the absolute beginner.
Best,
E
Why don't you grab XSim and play with some designs? You can play with the LM-1 design files if you'd like, sources here:
A Speaker Maker's Journey: The LM-1 Bookshelf Version
The LM-1 uses a second order HP and LP filter. More discussions about filters on my site, perfect for the absolute beginner.
Best,
E
small size motor start caps are usually electrolytic. Those blue caps in question must be electrolytic as one reviewer says they blew in less than 5 minutes on run application.
". CD60 Motor Start Capacitor are made of by the aluminium foil bar as the poles, alumina as dielectric, mushy state electrolyte and all of devices in one compact unit which can be sealed separately in aluminium case."
100uF 450V AC CD60 2 Black Wire Lead Motor Start Run Capacitor LW SZUS | eBay
a good plastic cap around 450uF would be bigger than a beer can. I have 600uF/600vdc caps and they're pretty large (and expensive)
in home use a decent non-polar connected electrolytic should last for years - whether suited subjectively ...
". CD60 Motor Start Capacitor are made of by the aluminium foil bar as the poles, alumina as dielectric, mushy state electrolyte and all of devices in one compact unit which can be sealed separately in aluminium case."
100uF 450V AC CD60 2 Black Wire Lead Motor Start Run Capacitor LW SZUS | eBay
a good plastic cap around 450uF would be bigger than a beer can. I have 600uF/600vdc caps and they're pretty large (and expensive)
in home use a decent non-polar connected electrolytic should last for years - whether suited subjectively ...
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One thing I found on the HVAC forums is that 70 uf is the dividing line between run caps (lower) and start caps (higher) and that in motor applications start caps are only in the circuit for a second or two, then switched out. Polypropylene seems the norm in run caps.
I believe KEF has used big value caps in some of their sealed enclosures, among others. Those were electrolytics as I recall. Gonna have to try it out. I won't be throwing hundreds of volts at them...
I believe KEF has used big value caps in some of their sealed enclosures, among others. Those were electrolytics as I recall. Gonna have to try it out. I won't be throwing hundreds of volts at them...
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