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McIntosh dipole surrounds are not dipolar

Hi all. I need help with McIntosh HT-3’s. I have two pairs separately purchased and decided to try one pair of them as fronts (knowing that this is not ideal) but with the idea of seeing how “poor” they would sound. What I found was the opposite. There seems to be too much presence for a dipole which is meant to be an invisible speaker offering a very diffuse sound field. Then I tried the other pair at the rear with the null adjacent to the seating position. Again the surrounds were very present and not as diffuse as I expected. So I took a single AA battery to the binding posts and found that both drivers push when polarity is observed correctly. This seems wrong to me. I would expect one to push and one to pull. When reversing polarity both drivers pull. This tells me I have a bipolar configuration. (I am very familiar with bipolar speakers since my stereo setup are Mirage M3si and I also have used Mirage MBS in a HT setups) I don’t expect there to be an oscillator of sorts in the crossover but haven’t opened everything up yet. This could mean that I could “fix” them by reversing polarity on one side of the speaker. I have tried getting help from McIntosh but I get directed to a service tech and that’s all. Does anyone have a schematic for the crossover?
bcwoody

Showing 1 response by oldhvymec

oldhvymec
5,101 posts
 
That is strange the way it is worded. At 350hz and up ONE LF drivers SWITCH polarity.. That is what it's saying.. I'd like to see that myself.
1/2 of the front baffle is polar opposite @ 350hz and up

It may sound fun and look cool, but it can't work.. Dipoles are tough to make work at 180 back to back or OB. I found OB almost impossible for a monitor section. I like dipole but about 18-24" from front to back, two separate drivers, not shared.  20-45 degree baffles just can't work. There is more noise bouncing around than at 1/2 time at a foot ball stadium.

Maybe one side of the driver baffle per enclosure. That would work. Give a good effect I bet, with 4 of them. You have 8 poles, only use 4..

Regards
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