Monitor 7C question
3rdrockblue
Posts: 8
First post here, though I have been browsing information for some time.
Background: Have had a pair of Monitor 7Cs with the SL2000 tweeters for about 4 years. Recently upgraded my amp and dac and these have become even sweeter to listen to.
To get the best of my system, I am in the process of upgrading crossover caps and replacing the resistor+polyswitch with a combined 2.5 Ohm resistor. Will also go to RDO194 tweeters.
The crossover is marked 1986 and the tweeter was also made in that year. The insides look clean like it was made yesterday. I believe I am the 3rd owner.
Question: The space behind one of the tweeters (I only checked one) is packed with polyfill. Was this standard, or is this a later mod? If it is a mod, is it recommended?
Background: Have had a pair of Monitor 7Cs with the SL2000 tweeters for about 4 years. Recently upgraded my amp and dac and these have become even sweeter to listen to.
To get the best of my system, I am in the process of upgrading crossover caps and replacing the resistor+polyswitch with a combined 2.5 Ohm resistor. Will also go to RDO194 tweeters.
The crossover is marked 1986 and the tweeter was also made in that year. The insides look clean like it was made yesterday. I believe I am the 3rd owner.
Question: The space behind one of the tweeters (I only checked one) is packed with polyfill. Was this standard, or is this a later mod? If it is a mod, is it recommended?
Comments
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Standard.Political Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk -
In my 7Bs the polyfill is in a horizontal roll and extends down from the top of the enclosure to behind the magnet assembly of the midwoofers. This was how they came from the factory.George / NJ
Polk 7B main speakers, std. mods+ (1979, orig owner)
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Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
Custom Vibration Isolation Speaker Stands and Sub Platform -
Thank you, both.
When I took out the crossover cap I didn't see any polyfill near the bottom, covering the passive radiator, but there may very well be some behind the midwoofers. It was hard to see from a quick look. I'll find out more when I remove the crossover to solder in the new components.
Waiting for the caps and resistors to arrive.
I was going to jumper the polyswitch. Would you recommend adding a fuse for safety? The cap does have a spot where I can easily add a fuse. I've read so many posts where folks haven't bothered. -
Thank you, both.
Can't tell how far down the polyfill extends from the quick look I had. Certainly does not cover the passive radiators.
I was going to jumper the polyswitch. Do you recommend adding a fuse? There's certainly a spot inn the back of the XO cup to add one. In many posts I have seen folks haven't bothered. Is that the common wisdom? -
None should be behind the passive. Replace the polyswitch with a .5 ohm 10 or 12 watt Mills-Vishay resistor. Jumping the polyswitch increases the treble output resulting in an unbalanced sound. Of course, if you are half deaf that may be a benefit.Political Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk -
Copy that.
Here's the full picture, though. My crossover has a 2.0 Ohm resistor + polyswitch in series. I am replacing both of them with a 2.5 Ohm Mills 12 Watt resistor to save board space and cost. In this case jumping the polyswitch keeps the overall resistance the same in that leg of the circuit.
Once that is done to fuse, or not to fuse was the question. I think I will add one for my own peace of mind.
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NO FUSEPolitical Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk -
Thanks.
