#11
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Those Heathkit look really nice... the only thing I might not like is what looks like an MDF front panel. Don't those have a crossover box that can be opened? I bet if you replaced the stock 2 electrolytic caps with some nice film or oil caps I bet you would be blown away! =)
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Last edited by junker; 09-01-2015 at 02:32 AM. |
#12
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You are correct about the MDF. Fortunately it is only used on the front and rear panels; the rest is solid 1/4" plywood. Very nicely made overall. As far as the crossover goes, there don't seem to be any caps that I can see. What do you think? |
#13
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I left the stock crossover in place and merely disconnected all the wires from the drivers and the little plate (can't remember its technical name) that the speaker cables get connected to.
Then I used Belden hookup wire, recommended by Jabo Labs and also used by Shindo in some of their own applications, to connect these OUTBOARD crossovers to the drivers. I ran the wire through the little opening that remained when I removed the little plate. My Auditorium 23 speaker cables then get connected to the proper places on the crossover. Depending on which connection you choose you can fine tune the attenuation of the high frequencies to suit your room and taste. There is also a dial that can allegedly adjust the crossover point up or down from the normal 800 hertz. I have found it can make a significant difference in the sound. All in all, the crossover cost a little over $500. Truly a bargain relative to the improvements in sound it netted me. |
#14
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Yeah there are two electrolytic caps in the white cardboard box - should be a 10.5 and a 4 uF. So, if you swap them out then you will probably need to go with a 10 and 3.9uF. A lot of good options here depending on what your budget is. At the very least you could grab a multimeter and test that their values are +/-10%.
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#15
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So is the area where you are running the crossover into the cabinet relatively well sealed?! Mine have ~1" oval opening behind the connector plate. :/ You'd be much better off using a small piece of wood drilled with two holes to mount to the stock plate locations and then drilling a tight fitting hole to pass your Belden 9497 through. If I understand correctly... Also I can post a pic of a previous wood plate I used when I ran my crossovers external if that helps.
P.S.: I would REALLY love to hear how the speaker balance changes with x-over point...that would be super interesting!!! Are you at the stock 800Hz position then? Quote:
Last edited by junker; 09-01-2015 at 02:23 PM. |
#16
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Thanks Junker & JayBass. That information is very helpful.
I've often heard the crossover point of 800 Hz too low and change to 1,200 brings dramatic improvement to the 811B's performance. |
#17
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Well some bad news today. I decided to head into Orange County Speaker to have the Alnico magnets re-magnetized today. Supposedly Alnico can de-mag up to about 1% per year and more if subjected to shock. So, OCS took them in the back to "test" while I was there and came back on one and said the voice coil was rubbing. I didn't hear anything when I took them out and compressed, but I have to assume the one was like that. OCS charges for re-mag'ing where Great Plains Audio includes this with a re-cone so I'm just going to send them in and expecting to be without LF drivers for a few weeks. Good news. I bet they'll sound a hell of a lot better when I get them back re-charged.
Last edited by junker; 09-02-2015 at 10:01 PM. |
#18
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Bummer Junker. How will a the new cone help the coil? I thought the cone referred to the paper driver. How hard would it be to find 2 drivers in good shape?
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PS Audio P10, dCS Bartok, McIntosh C1100, Legacy Wavelet, McIntosh 452, Legacy Aeris |
#19
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Hey Rick!
Yeah it's all one assembly - the cone, voice coil, dust cap, spider, wires, and surround. He removes the old assembly, cleans everything, installs the new assembly and applies glue and the tar goo to the surround, and check that the magnetic gap is centered and not rubbing. Bill at Great Plains Audio acquired all of the factory gear when they closed down and still services per factory, as well as sells his new current iterations. He also re-mags the Alnico to factory strength as part of the service. They will be good as they were circa 1967. They should sound killer and have more bass now. The kit should look something like this: Last edited by junker; 09-03-2015 at 07:35 PM. |
#20
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Nice, you will have to break them in again.
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PS Audio P10, dCS Bartok, McIntosh C1100, Legacy Wavelet, McIntosh 452, Legacy Aeris |
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