I was wondering what anyone here thinks of Marantz ( the old stuff by them)
I've got some SP1200's from 1978 a friend gave me, I replaced the surrounds on them. When I got them they were practically mint...untill I ran an allen wrench through a tweeter cone trying to take it out. I fixed that though.
They boast a responce of 25hz to 20khz,
Sensitivity of 91 db 1w/1m.
crossover points at 800 hz and 2,300 hz.
Reccomended RMS amplifier power 10watts RMS min, 165 watts RMS max. Liquid cooled midrange and tweeter yadda yadda etc.
Whats the actual power handling on these?? It says Max reccomended AMP power 165 w RMS, is that the speakers Max input or will they really handle 330 watts on a peak each?
All in all they are beautiful speakers, I've hears so many new ones with massive power handling capabilitys and they just don't compare. We used to use these in our band.. as mains.. with my fisher studio standard ca857 amp. they are LOUD too.
The only problem is I blew a tweeter one night. We had the amp pretty much maxed out on the power meter and suddenly "pop!" one channel went out. I guess its "overlaod protection" was initiated...ie a 125v 5 amp fuse. Anyways, I guess when it did that it sent a very distorted high freqency signal at high power to that tweeter and it was gone. I opened it up ( loosened the glue and used an exacto to pry the cone away from the edge without damaging it) and BOTH of the leads from the terminals to the coil had fryed. I soldered them back together, only to have the tweeter blow 2 days later when I was running them very loud. Anyone know where I can get a replacment for this, or if theres even anything close to it?
oh, one other problem I'm having. One of them has a resonancy thats really annoying. Up in the 100-300 hz range I think? It's coming from the woofer and it kinda has a buzz to it. I dont get it if its just low notes, just when it goes up there. I havent been able to determine weather or not its the cabinet trim ring or something in the room. Could the voice coil also be bad?
heres a pic of one of them 🙂
I've got some SP1200's from 1978 a friend gave me, I replaced the surrounds on them. When I got them they were practically mint...untill I ran an allen wrench through a tweeter cone trying to take it out. I fixed that though.
They boast a responce of 25hz to 20khz,
Sensitivity of 91 db 1w/1m.
crossover points at 800 hz and 2,300 hz.
Reccomended RMS amplifier power 10watts RMS min, 165 watts RMS max. Liquid cooled midrange and tweeter yadda yadda etc.
Whats the actual power handling on these?? It says Max reccomended AMP power 165 w RMS, is that the speakers Max input or will they really handle 330 watts on a peak each?
All in all they are beautiful speakers, I've hears so many new ones with massive power handling capabilitys and they just don't compare. We used to use these in our band.. as mains.. with my fisher studio standard ca857 amp. they are LOUD too.
The only problem is I blew a tweeter one night. We had the amp pretty much maxed out on the power meter and suddenly "pop!" one channel went out. I guess its "overlaod protection" was initiated...ie a 125v 5 amp fuse. Anyways, I guess when it did that it sent a very distorted high freqency signal at high power to that tweeter and it was gone. I opened it up ( loosened the glue and used an exacto to pry the cone away from the edge without damaging it) and BOTH of the leads from the terminals to the coil had fryed. I soldered them back together, only to have the tweeter blow 2 days later when I was running them very loud. Anyone know where I can get a replacment for this, or if theres even anything close to it?
oh, one other problem I'm having. One of them has a resonancy thats really annoying. Up in the 100-300 hz range I think? It's coming from the woofer and it kinda has a buzz to it. I dont get it if its just low notes, just when it goes up there. I havent been able to determine weather or not its the cabinet trim ring or something in the room. Could the voice coil also be bad?
heres a pic of one of them 🙂
An externally hosted image should be here but it was not working when we last tested it.
ThSpeakerDude88 said:
Yes, it can be bad.
Seems like your amp made some damage there...
With the amp disconnected, touch each woofer with your hands, press it down and release (gently).
Do they move the same way?
Does one make more force, does it have more resistance to movement, does it make a noise?
If it does, it's bad.
It may have gone off-center and the coil is touching the magnet.
Tighten all the screws.
Old speakers tend to have loose screws, don't be surprized if you have to give 2 or 3 turns on some screws.😀
Old speakers tend to have loose screws, don't be surprized if you have to give 2 or 3 turns on some screws.😀
Switch the speakers left to right.
If the problem persists on the same channel, it is not the speakers.
Otherwise... dunno. It's too hot in here, can't think...
People on the beach at 10 PM.
If the problem persists on the same channel, it is not the speakers.
Otherwise... dunno. It's too hot in here, can't think...
People on the beach at 10 PM.
haha ok. I just downloaded a tone generator, the resonance starts faintly at about 130 hz, gets the loudest at 136-139 hz, starts to lessen at 140 hz, and gets fainter untill 150 hz when its totally gone, and this is only out of my left channel.
no its the same speaker, it sounds internal, not like its coming out of the voice coil on the woofer.
ok, I took the trim ring off and loosened some of the screws holding the woofer in a little. It went away, maybe I need a gasket betwen the woofer and cab? ( it didnt come with one, why I dont know)
tomtt said:
hmm... maybe. What about a dome tweeter instead for both channels ( sortof an upgrade)
ThSpeakerDude88 said:
There's a special black 'paste' for that, you should use it.
I don't know the name in english.
In portuguese it's 'massa caralhuda'. 😀
A direct translation would give... 'dick paste'.😱
ThSpeakerDude88 said:
Your pic is small, but these look typical of the cheap boxes of the time. Here are some generic tweaks that tend to work wonders.
The box can be dramatically improved with some bracing.
use some weathe stripping to seal the driver
loose the trim rings
ductseal the baskets
replace the wire
XOs are often just cheap bipolar elkos -- replace them.
puzzlecoat the cones.
dave
actually the crossovers are fairly high quality, a lot better than just a few caps. Its got a coil of wire ( and inductor?) for low frequency and mid I believe, and a bipolar cap for mid and a huge metal film or poly cap for the tweeter. Heh, I like the trim rings, besides the tweeter's is built in, and the midrange's is set in in the cabinet, so eliminating the woofer trim rings would make them look a little odd. I think I'll just use sealant on them. What kind of bracing do you mean? Also, I was actually thinking of rebuilding the cabinets out of oak ply, only making them taller ( woofer set higher off the floor)
The wiring is original accept for both leads to the woofers. The original wiring is very heavy gague and I replaced the woofer wiring with 18 gague speaker wire. I think the bass ports could use a little work... their just cardboard tubes stuck in there with hot glue, they seem to work ok I guess.. no noise out of them and since their cardboard you wont get the resonance you'll get with plastic. Whats puzzlecoating? Is that the same as polycoating? I've heard of a polypropolene spray used to treat cones, same stuff?
and finally , what do you mean by "ductsealing the baskets?"
😕
If you're referring to the mid and tweeters their closed back... I'm probably not understanding what you mean, I'm sorry
The wiring is original accept for both leads to the woofers. The original wiring is very heavy gague and I replaced the woofer wiring with 18 gague speaker wire. I think the bass ports could use a little work... their just cardboard tubes stuck in there with hot glue, they seem to work ok I guess.. no noise out of them and since their cardboard you wont get the resonance you'll get with plastic. Whats puzzlecoating? Is that the same as polycoating? I've heard of a polypropolene spray used to treat cones, same stuff?
and finally , what do you mean by "ductsealing the baskets?"
😕
If you're referring to the mid and tweeters their closed back... I'm probably not understanding what you mean, I'm sorry
oh and one other thing, I was thinking about useing some R-9 for damping the cabs, think that will work?
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