Tweeters?

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Well I have a pair of Sansui Sp-1500's that I have restored. I accidentally blew all four 1 inch metal dome tweeters one day while working under my desk. The amp was on and up half way and I accidentlly unplugged the source.. needless to say it fried all four coils.


I can't seem to find a set anywhere, I have checked ebay but without any luck. The tweeter domes themselves are easy to replace or recoil, but I have no idea where I would get replacment diaphragms, or if the domes can actually be recoiled.

They are 16 ohms each, run in paralell to equal 8 ohms.

I was thinking about getting four of these http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=279-082

and wiring two in series in each cabinet to make 8 ohms.


I was wondering what your sugguestions are and what you think of this particular tweeter. Also, is there a way to be able to use 8 ohm tweeters in this? It would make tweeter selection a little easier, as I might be able to get some with replaceable diaphragms.


when I get replacment tweeters, especially if their originals, I am going to put inline fuses with them to prevent further mishaps!! :hot:

any reccomendations on what type of fuse to use also?
 
Combination of two 8ohm drivers will give either 16 or 4 ohms , depends on way you wire them (but I guess you knew that). It is not a problem ,them being a different impendance, but this requires changing some values in crossover. That driver you gave link for seems ok and honestly I don't think these speakers deserve better than that. If the faceplate of driver and baffle cutout fit together I can't see a reason not to go for it. I guess the highpass filter is set high so any proper sounding tweeter would fit in. You only have to take care of sensitivity, don't know what was the sensitivity of original tweeters.
 
Hi,

8 ohm tweeters would be difficult use without modifications to the
crossover. In low efficiency speakers it would be possible to pad
the 8 ohm combo back to an eight ohm pair but in your case I don't
think this a sensible proposition.

Your proposition for the Peerless tweeters appears entirely sensible.
At that price opinions on the sound quality of the tweeter are pointless.
But I'd suggest they probably will be better than the old tweeters.

Fuses on tweeters I haven't seen for a long time.
I suggest you investigate Polyswitches.
If the Peerless units use ferrofluid they will be very robust.

:) /sreten.
 
alright, its only $35 so its not completly breaking the budget. Besides, if I come across an original pair on ebay later on I can grab them. Do you think sensativity will be an issue?

just a thought, but I can't seem to find many 4 ohm tweeters out there. Are there any others you can think of ?
 
Hi,

the two Peerless tweeters in series will pan out at 93dB/W.

in a 3-way speaker a 93dB/W tweeter would be used
with a 93dB/W midrange and a 99dB/W bass unit.
I'm presuming this is where your 99dB/W has come from.

A speaker with flat response and a genuine 99dB/W
midband sensitivity would need a 105dB/W bass unit.
I'm presuming this it not the case for your speakers.

:) /sreten.
 
The woofers are only rated at 20 watts each, so they seem to be very efficient, because it takes very little power (5 watts total into the cabs) to make lots of noticably loud sound. The mids are 15 watts each I believe , and the tweeters were 10-15 watts each (cant remember exactly)

So with the new peerless tweeters, I might be able to EQ out any difference in upper end, right?
 
on the selector switch, they seem to have a 16 ohm resistor between the leads to the tweeters for the "natural" setting. I believe it also choses between two different values on the inductor for soft, natural, and clear is just one value on the inductor and then straight through...

kind of confusing ! :xeye:
 
meh, ok. I'll have to find some time to sit down and trace it out, its pretty complicated ( or so it seems.)

I also noticed they used some capacitors in paralell to make different values, I'm assuming I can replace those with the proper ones?

Like for instance.. 1.5 uf in paralell with .5 uf to get 2 uf... These are all bipolar too, Can't I get most these values today? Another one is 4.7uf with 2.2 uf in paralell, to get 6.9 uf (close enough to 6.8)
 
Hi,

some argue a 0.5uF||1.5uF will sound better than a 2.0uF.

For bipolar electrolytics I certainly would agree with them,
though using a film type for the 0.5uF would be better.

For film types - its more arguable. If the capacitors you are
referring to are film types there is no point in changing them.

:)/sreten.
 
alright heres the deal ( this sucks...) the link I posted for those peerless tweeters- well just when I have the money , they stop producing them. So those aren't available anymore!! :mad:

Alright.. I cannot find any other 4 ohm tweeters that won't break the bank. So I have a few questions..

Will just using two 8 ohm tweeters run in series ( 16 ohms, I suspect I will lose volume there) or in paralell (4 ohms) hurt anything or mess up the responce at all?

I have tried to schem the x-overs out.. its a little confusing, I will give it another go here soon, But I cannot tell you what the values of the inductors are ( not listed on them.. I don't think, anyways like sreten said they could be autotransformers.)

One question though.. this Is my main one, Would running them in 4 ohm hurt anything, change overall impeadance of the speakers, or subtract from sensativity? Because at this point all I can really do is two 8 ohm tweeters in each cab..

thanks for any help,

TSD88~
 
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