tcpip said:
Why are you using so many drivers? Are you fitting your design to the drivers at hand...But then I wonder, isn't it better to use one JX92S or JX53 instead? The two alternatives would cost the same anyway, I guess.Tarun
you have valid points.
I am making do with drivers and XO components at hand. i am trying to build this now. as we speak. my friend has already built a 27" wide x 6" tall bax. the drivers came out of 2 MTMs.
Wow this is a long thread, I've pretty much skimmed it so forgive me if someone already mentioned this.
What I use for my speaker protection is polyswitches. Sorry if this is a taboo subject I'm a newbe
Basically they sit in series with the driver and if the current gets too high they melt and their resistance goes through the roof. After they cool down again, they resolidify and everythings hunky dory.
I used to drag my amp and speakers to parties all the time (by request), but my amp (at 100W RMS/channel) was much more than the speakers could handle, There is still a thin piece of blue tack signifiying "DONT TURN UP THE VLOUME PAST THIS POINT" which used to work Until someone had too many drinks and cranked it up a notch. I don't know how many drivers got blown. For I while I put in piezo tweeters to get around the problem, but then I blew the mids. Anyway The reason the blue line stayed was because it was really good fun to tell people if they turned it up past that line the speakers would blow, they would do it, the sound would stop and they'ed freak, give it a minute or so and Off we would go again.
There has been a lot of concern in this thread about relays and fuses degrading the quality, and to be honest I haven't done any "critical" listening tests with and without the polywitches, but I suspect that my speakers aren't "yet" up to the standard where the polyswitch would make a detectable difference.
Wintermute.
PS my amp has built in speaker protection using relays, supposed to be a good design, although I suspect I can't post it as it's probably copyright by Electronics Australia. Its a Playmaster Series 200. (but as you can tell from the above, Relay based Speaker protectors won't help you if your drivers can't handle the power of your amp).
What I use for my speaker protection is polyswitches. Sorry if this is a taboo subject I'm a newbe
Basically they sit in series with the driver and if the current gets too high they melt and their resistance goes through the roof. After they cool down again, they resolidify and everythings hunky dory.
I used to drag my amp and speakers to parties all the time (by request), but my amp (at 100W RMS/channel) was much more than the speakers could handle, There is still a thin piece of blue tack signifiying "DONT TURN UP THE VLOUME PAST THIS POINT" which used to work Until someone had too many drinks and cranked it up a notch. I don't know how many drivers got blown. For I while I put in piezo tweeters to get around the problem, but then I blew the mids. Anyway The reason the blue line stayed was because it was really good fun to tell people if they turned it up past that line the speakers would blow, they would do it, the sound would stop and they'ed freak, give it a minute or so and Off we would go again.
There has been a lot of concern in this thread about relays and fuses degrading the quality, and to be honest I haven't done any "critical" listening tests with and without the polywitches, but I suspect that my speakers aren't "yet" up to the standard where the polyswitch would make a detectable difference.
Wintermute.
PS my amp has built in speaker protection using relays, supposed to be a good design, although I suspect I can't post it as it's probably copyright by Electronics Australia. Its a Playmaster Series 200. (but as you can tell from the above, Relay based Speaker protectors won't help you if your drivers can't handle the power of your amp).
wintermute said:What I use for my speaker protection is polyswitches. Sorry if this is a taboo subject I'm a newbe
Anyway The reason the blue line stayed was because it was really good fun to tell people if they turned it up past that line the speakers would blow, they would do it, the sound would stop and they'ed freak, give it a minute or so and Off we would go again.
Wintermute.
polyswitches are really fine for parties. i have seen them used in PA/party equipment but i have not heard them in a critical test so i i cant tell if they would be heard in a test or under more critical listening enviroments. Bose used to use small bulbs that used to glow. no one has yet complained about these either.
If you have a look at http://www.jaycar.com.au and search on polyswitch they have quite a few with suggested power ratings/current.
From memory its a bit of a black art, but helps a lot if you know the RMS power rating of your drivers (rather than system power rating). You have two options, put ONE big one in before the crossover, or put one in series with each driver (matched to the power handling of that driver). I chose the second option.
I think the jaycar catalog may have a bit of a write up on choosing the right device, I'll check it out.
I don't know about availability in India, but since they are small (and cheap) If you need to order from O/S the postage will be next to nothing.
They mention that they won't protect against mechanical overload, but by that I assume they mean something like pumping low freq though a driver that causes it to either resonate and destroy itself, or overextend due to two low a freq etc. They certainly worked for me in the context turning the volume up too far (no clipping just more watts than the speakers could handle). They also should work for current faults etc.
Wintermute.
PS Have you ever had a champane glass shatter due to your speakers? I have. Parties are tough on speakers!!!!!
From memory its a bit of a black art, but helps a lot if you know the RMS power rating of your drivers (rather than system power rating). You have two options, put ONE big one in before the crossover, or put one in series with each driver (matched to the power handling of that driver). I chose the second option.
I think the jaycar catalog may have a bit of a write up on choosing the right device, I'll check it out.
I don't know about availability in India, but since they are small (and cheap) If you need to order from O/S the postage will be next to nothing.
They mention that they won't protect against mechanical overload, but by that I assume they mean something like pumping low freq though a driver that causes it to either resonate and destroy itself, or overextend due to two low a freq etc. They certainly worked for me in the context turning the volume up too far (no clipping just more watts than the speakers could handle). They also should work for current faults etc.
Wintermute.
PS Have you ever had a champane glass shatter due to your speakers? I have. Parties are tough on speakers!!!!!
OK catalog was copyrighted but they have it on their website which is better anyway.
http://www1.jaycar.com.au/images_uploaded/polyswit.pdf I think you can safely ignore the page on MOV's.
also if you want more info there is heaps at: http://www.polyswitch.com/faqs.stm You can also do a distributor search on that site, and check data sheets, they did have a distributor in India.
Interesting that the don't mention speaker protection as one of the uses but, a number of auido sites turned up on a search so it must be reasonably common.
http://www1.jaycar.com.au/images_uploaded/polyswit.pdf I think you can safely ignore the page on MOV's.
also if you want more info there is heaps at: http://www.polyswitch.com/faqs.stm You can also do a distributor search on that site, and check data sheets, they did have a distributor in India.
Interesting that the don't mention speaker protection as one of the uses but, a number of auido sites turned up on a search so it must be reasonably common.
Vivek said:
From my experience they have been reliable, but I've only had them trip a few times (I found out about them towards the end of my party career
) Could have saved a lot of $'s in blown up drivers, but then I guess I wouldn't have experimented as much!I think if you look at the polyswitch site faq It'll probably answer some questions.
I haven't had any probs with the relays in my amp (It's been going since 1987), but maybe if I replaced them I would see that there was a problem????? Slow degradation is hard to pick, I tend to only notice when something major changes (like the distortion I noticed coming from my mids the other day, which prompted me into action, and hence joining this forum).
Hope that helps, I know I was a bit uncertain when I first put the polyswitches in, main problem was I didn't know the RMS ratings of ANY of my drivers, had to take a bit of a guess! But it worked well, no more smelly tweeters
Wintermute.
See what I found at http://www.circuitprotection.com/02Databook/multimedia/03.C12_loud_(118-121).pdf
fantastic vivek. nice article. thanks. my BIL keeps blowing his tweeters make this will help. yes he plays party music and his tweeters are Morel MDT33s. fortunately they are more recent ones where the voice coil can be removed. the earlier versions (pre 1991) did not have this. I have had to replace the orignal hexatech voicecoils with one using round wire. sens dropped 1db but he did not mind.
Glad to be of help.
<grin> I haven't been to one of those parties for going on close to 10 years now, I think all my friends have mellowed out a bit now, and worry more about what the neighbors think!
I think the last one was a 24hour Pink Floyd party, we were supposed to play all their albums, but they sneakily missed one so that we would have to do it all again sometime
<grin> I haven't been to one of those parties for going on close to 10 years now, I think all my friends have mellowed out a bit now, and worry more about what the neighbors think!
I think the last one was a 24hour Pink Floyd party, we were supposed to play all their albums, but they sneakily missed one so that we would have to do it all again sometime
wintermute said:
nope his amp went DC twice. he uses a Harmon Kardon integrated PM665 with a CD63. i built the system out of parts i had lying around. the bass is 2x Focal 8N515 and the mid is a Audax 170Z0 (think watt-puppy). when teh amp went DC it fried the tweeter and bass but left teh mid untouched. go figure.
Vivek said:
angshudas said:
Ok Guys maybe you didn't find this
Raychem Circuit Protection Distributor Search
Search Results Within Asia > IN > All States
INDIA
Representative(s)
Raychem/CP Sales Contact: Vasanth Kini
2C Jubilee Building 45 Museum Road Bagalore 560025 India
(Phone) 91 80 5591485
(Mobile) 91 98 440 10259
(Fax) 91 80 5586039
Email: vkini@tycoelectronics.com
http://www.circuitprotection.com
The cost in Aus is about $2 to $5 (about $1 - $2.50 US) each depending on the rating, and you can buy singles, so I don't think they will break the bank
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