Determining ML-1C Mid-High and Tweeter Polarity

[mcdmgb]

After watching auctions for a year, I was able to acquire a replacement mid-high and tweeter to replace the non-functioning ones in one of my ML-1C speakers. However, there are no obvious indications as to polarity on either the old or new ones. I know with woofers you can use a battery to determine polarity, but I don't think that trick will work with the mid-high and tweeter. Does anyone know if McIntosh had some convention regarding marking the drivers in some non-obvious way, or otherwise suggest a safe way to determine polarity of these them, short of installing them and listening? I would prefer not to do the install and listen procedure to avoid having to pick up the soldering iron too many times. Also, is the thin gasket on the mounting plate of the mid-high driver essential? I was unable to successfully salvage the one on the old mid-high.

Thanks

 

[c_dk]

I would be very skeptical about any replacement driver bought off ebay.......but without a polarity correct microphone and oscilloscope testing polarity not really doable......maybe with a magnifier you could observe the movement.

The original domes were made by United Audio, tweeters were Peerless. Roger Russel's site goes into the detail of them.

Mac parts did make replacement in house decades ago......they were built in a completely different manner.

Pics might help.

 

[mcdmgb]

The parts have McIntosh part numbers and look like the originals. All I'm trying to do is install them correctly the first time, particularly the tweeter since it requires soldering and I rather just do it once.

 

[c_dk]

If you go to Rogers site under drivers you will see pictures of the original 036-016 as well as the replacement they built a decade later.

Originals had a red washer to show the + for the mid dome.

The DC resistance should be 9.8 ohms if the voice coil is not burnt......

 

[mcdmgb]

Thanks.

 

[Johnny_Law]

Note that on the 036-016 dome midranges, the washer is on the FRONT. And it isn't completely red, they just left a little bit of the red uncovered by the black paint.