Another Polk in the house - Monitor 10A with Peerless. ;)

[TennMan]

Update to what I posted previously (quoted below)

My ears weren't fooling me after all. It turned out that the reason I was thinking the 194s were not bright enough was caused by defective polyswitches, especially in the left speaker. The polyswitch in the left speaker had 21.4 ohms resistance and the right had 4.2 ohms resistance effectively attenuating the tweeters in my recently acquired 2Bs. The slightly brighter sounding (to my ears) sl2000 was helping offset that some. Once jumpers were installed across the polyswitches the 194s sounded the way I thought they should.

I just thought I would pass this on in case someone has the same problem in the future.

Mystery I think you may be experiencing something similar to what I have run into going from 10Bs to 2Bs. I've not had the 2Bs but a few days and I really like them. They came with sl2000s. My 10Bs have 194s installed in them for a year or so. Whenever I put the 194s in the 2Bs I feel like they aren't bright enough. I've swapped them back and forth and always feel the same way even though I like the 194s just fine in the 10s. I know it's not a problem with the 194s.

Here is what I think is going on. I hope I can explain where it will make sense:

I'm use to the balance of the lows and highs with the 194s in the 10s. When I put the 194s in the 2Bs that balance changes because the 2Bs go a little lower and the mid-range is a little fuller in them. So, since I'm so use to the 10s with the 194s it seems the 2Bs with 194s don't have the sparkle to offset (or compensate for) the low end of the 2Bs. I think the problem is more what my brain is expecting to hear than it is a problem with the way the speakers sound. Once the 194s are left in the 2Bs for a week or two I think everything will be back to normal.

[Big Dawg]

Update to what I posted previously (quoted below)

My ears weren't fooling me after all. It turned out that the reason I was thinking the 194s were not bright enough was caused by defective polyswitches, especially in the left speaker. The polyswitch in the left speaker had 21.4 ohms resistance and the right had 4.2 ohms resistance effectively attenuating the tweeters in my recently acquired 2Bs. The slightly brighter sounding (to my ears) sl2000 was helping offset that some. Once jumpers were installed across the polyswitches the 194s sounded the way I thought they should.

I just thought I would pass this on in case someone has the same problem in the future.

We have a bingo!

The truth is, in 30 year old speakers that never had the greatest electronic components, it is impossible to compare without first assessing the condition of the crossovers. My guess is that something is amiss..

The 10s will have fuses rather than poly switches, but I'd wager that more than one cap has crept out of spec. It may also be that one or more drivers are frozen, or a bad wire/connection, partially masked by the parallel design, or perhaps the polyfill has slipped out of position.

Really, any of those might be true. Or, just maybe, you prefer the 12s.

The only thing we know for sure, as CNH pointed out, is that Peerless tweeters are refined and smooth, and hold their own even against the RDO series.

If you open them up and look inside, I'm sure the truth will reveal itself.

On a different note, and aside from a collector's desire, why do you keep so many somewhat similar receivers? You might wish to rethink, and instead sell a few to reinvest in a couple higher quality pieces with minimal additional investment.

[StantonZ]

That's good to know about the (mis-match) in the Polyswitches, because I've really like the 194's after replacing my SL2000's in my 10B's. I'm still thinking about re-building my cross-overs, so I may check the resistance as another motivation.

[Mystery]

Polyswitch can be replaced with a .5 ohm resistor right?
That may be a quicker way to eliminate polyswitch issue.

[TennMan]

Polyswitch can be replaced with a .5 ohm resistor right?
That may be a quicker way to eliminate polyswitch issue.

I didn't remove my polyswitches. For troubleshooting purposes I just put a jumper wire across the polyswitchs on the back side of the board which in effect eliminates them from the tweeter circuit. That way I could easily remove the jumper if needed at a later time.

I don't think replacing the polyswitches with resisters would be quicker than installing a jumper. The quickest way to take the polyswitches out of the tweeter circuit would be to tack a jumper wire across the leads coming out of the polyswitch on the front side of the circuit board. It would work but it wouldn't look too good.

I have read here on the forum that some people replace the polyswitch with a resistor as you say. I might try that when I get some extra time to see if I like the way it sounds. I don't see using a resistor as a necessity. I think if polyswitch resistance was intended to be part of the tweeter circuit it would have been noted in the schematics but it's not.