Speaker Fusing
 

I have an ancient but still very effective passive Janis W1 15" Subwoofer. Came with a 60W amp, later Janis upgraded to a 120W version I believe. I now run 200 (2 channels of my MC 2107) into it and sometimes the 1.5A (fast blo) fuse trips, typically on a loud movie passage of course. I am wondering if I could go a tad higher and/or to a slo blo on this unit without fear of doing real damage. Anyone got any experience here?

Steve.......Is the fuse you are speaking of installed in the interphase crossover amp that is part of the Janis W1 subwoofer system? There is no crossover inside the W1 cabinet so an external crossover of some type needs to be between the preamp and the amplifier that is driving the W1. Is the fuse internal in the woofer cabinet?

Fuse input
 

My Vandersteen 5's have an internal crossover in each..... fused. They come from the factory with slo-blo. In light of my experiences with the Synergistic Research BLACK fuses I went with those. It was a good move audibly and soundstage. As to the question of increasing amperage value, the slo-blo will have a slight allowance for a mini-surge. I do not know what value is in there now but if you go on-line @ the SR site all the fuse values are listed.

The fuse is on a post under the speaker cabinet itself. I have no more Interphase amp, but rather use 2 channels of the MC 7104 and set the crossover in the MX151. Works fine, but as noted, occasional big, boomy hollywood film passages will pop the fuse. Not a big deal to replace, but tiresome. ideal would be to have a small circuit breaker upstream with a pilot light on it I could glace at to be sure the circuit is made.

Steve.......Since the fuse is not protecting a power supply or other circuits, only protecting the voice coil in the woofer, I think you would be safe using a slow-blow fuse or even going up from a 1.5 amp to a 2 amp fuse. The woofer voice coil can take momentary peaks that exceed its rating, just not sustained over driving. You will hear the woofer distort or even make a rattling type noise if the cone excursion exceeds its limits. If that happens, turn it down a bit. The other option is to bypass the fuse.

Thanks, Dan. Your thinking parallels mine, peaks not the issue as long as not sustained. To be safest, I think I will work in stages to see what happens. Stage one will be 1.5 as slo blo and see how that works. Much appreciate the time you took to respond!

Hmmmmmm....just found this. Looks like other folks suffer the same issue I do. Wonder if 5 seconds is too long, though. Since the 1.5A was originally intended for the 60W Interphase, I guess 2.5 makes sense for 200, though these are so inexpensive it might make sense to start with the 1.5 version Heck, it resets itself so why should I worry about more cutouts vs. feweras long as they are reasonably rare as is the case now....

https://www.parts-express.com/speake...-200w--260-830

Steve,
Your Janis W-1 predates modern home theater systems and really isn't designed to handle the big LF effects found in modern movies.
While very effective for augmenting the low end for 2 channel music systems, it doesn't have the power handling capacity needed to make home theater effects bass come alive. It is trying to tell you something when it blows fuses. :)
Tom

I am sure you are right. Makes good sense, but I have to keep it as it is our coffee table and there is no good space available for another sub. The fuse blowing is maybe once every couple of years so not something I can't live with, just would be nice to have a circuit breaker that would re-set itself as the one in the link apparently does. I also need to try to remember to kick the sub gain down a few db when viewing those big LF effects films.

Beautiful
 

The W-1 has a real nice looking cabinet. I understand why you'd want to keep it. I like the idea of a resettable fuse - it would make life a lot easier.
Enjoy!
Tom