Looking for information on my Perspective speakers


Hi all.  I have a pair of Perspective speakers purchased in Switzerland in 1988.  They have been in storage for 30 years or so and just getting them back into use.  But I would like to find some data on them - originals lost.  They are true studio monitors using 2 back-to-back Davis 12 inch woofers, a Davis midrange and Scan-Speak tweeters.  They are intended for tri-wiring with nine input ports for banana plugs at the rear.  Made by Image et Sons but this firm seems to have migrated away from speakers to studio work.  Can anyone out there help me with any info and especially how to manage the tri-wire setup?  Fingers crossed here!

dean75

It is almost certainly the + is on the right hand side.
the DMM should read ~8 ohms from the left or middle to the right side.
If one of those left or middle shows 0 ohms to something like each other, or any metal, then those would be a ground..

or maybe it is possible that they are some servo type of signal? 
You basically have 3 combos on each row. From left to right you have bananas A, B, C. And from top down you have rows 1, 2 and 3.  fill out the table with ohms.:

  • A1/B1
  • A1/C1
  • B1/C1
  • A1/A2
  • B1/B2
  • C1/C2

we should be able work out the rest from there.

 

Here are the test results...

Have added some to your list on the left.  

 

A1/B1  6             A1/B1   6        B1/C1   0            A1/C1   0             
A1/C1   0            A2/B2   4.5        B2/C2   0            B2/C2   0
B1/C1   0            A3/B3   3.7        B3/C3   4.1        A3/C3   6
A1/A2   0            All vertical combos are zero (eg. A1/B1).
B1/B2   0            Tested with all drivers connected, all nom 8

C1/C2   0            2 x 12" Bass (back to back on cab. sides), 1 Mid, 1 Tw.

What you make of that?  For info A is White, B Black and C Red labelled.

I'm thinking maybe vert row B needs to be bridged if C used.

Cheers

Sorry - I missed this from last week.

Look like it is a/b should be tried.
Do you have a tone generator app on a phone or iPad? and an small amp?
If so, then maybe do a low level sweep, and I would start with the row 3 (woofer?) and work up.

Probably best to do the MR using 200-500Hz.

And the tweeter using 1500-20k.

 

We sort of want to know whether there is a crossover (protection) to keep the drivers from playing out of their frequency range.

The row 3 is likely the woofer.
Row 1 and 2 probably have a capacitor inline which blocks DC, and will make the rows 1&2 B/C and A/C seem off.

No idea on the colours.