KLH Model Eight Questions

[mckay3d]

Starting out with a big thanks to Kent for his PDF on the Model Eight, I have a couple of questions. My Model Eight is an earlier one with two 3" speakers, Serial No. 3391. After replacing the power cord and repairing the speaker plug I decided to check out the speakers because the sound just wasn't up to the quality I remembered the first time I heard a Model Eight back in 1962. I didn't want to remove them from the baffle board and they looked all right when I opened the black cloth they were wrapped in. So I decided to see what a different speaker might sound like and made up an MDF box with a Realistic FE-103 wide range 4" speaker that I have had for a while. I put a contour network in it that I made up from an old Popular Electronics article that used the same speaker. I also stuffed it full of "Acoustastuff" I bought from Madisound. Listening to it as I write this it sounds pretty good despite the impedance mismatch but a trifle "boxy". Somewhere I remember reading the the Model Eight amplifier was contoured to match the speaker(s). Is this correct? I am thinking of making another enclosure and using two 3" wide range 8 Ohm speakers. Any comments or suggestions would be greatly appreciated.

Maurice

[JKent]

Hi Maurice

Welcome to the CSP. Glad to be of help. btw--I'm working on the 6th version of that pdf and there are a number of changes.. The 5th version is here: http://www.classicspeakerpages.net/IP.Board/index.php?showtopic=6387

Don't know what the problem is with your 3" drivers but it's possible one is bad. I'd suggest trying them individually and see if there is a difference between the 2.

I'm not familiar with the Realistic speaker but wonder if it's a copy of the Fostex FE-103 (or maybe it IS a Fostex). One thing to try would be to listen without the contour network.

I've tried using 2 modern drivers, such as Tang Band, and it sounds fine but not really like the original.

If one of your 3" drivers is bad you're sort of out of luck as far as finding a replacement but you couls use a single 4" KLH driver. In later Eights KLH used the same 4" driver that's in your 21. That driver was also in the Five and Twelve (as a mid) and in the Eleven, Fourteen, Fifteen, Nineteen, Twenty-One and several others as a full-range. KLH did not use any kind of filter, except in the 708, which had an LCR filter (photos here http://www.classicspeakerpages.net/IP.Board/index.php?showtopic=8194).So they're plentiful. If you do switch to a single 4" in the original cabinet you'll have to relieve that wood frame behind the baffle to accommodate the 4" driver's basket.

I'll be happy to help in whatever way I can.

-Kent

[mckay3d]

Hi Kent,

I have the test speaker hooked up directly without the contour network as you suggested and I think it really sounds better. And yes, it is an FE-103, probably made by Fostex. The ad below is from the 1960's. I paid about $11.00 for mine and have a couple more. It's interesting that one was made in Japan, one in Korea, and the one I'm using now was made in Taiwan.

I checked out the two 3" speakers from the Model Eight and they seem fine now so I'm going to put them back in the enclosure and do more listening tests. Scraping off the old sealant that had really hardened up has been tough so I am thinking about using silicone sealer instead of duct seal.

Thanks for all your help. Foolin' around with this stuff keeps me out of bars and low places!

[JKent]

That's a great buy if those are indeed Fostex FE-103s. Those are very highly regarded.

I think the old sealant was Mortite and yes, it pretty much turns to cement. Duct seal stays pliable and is a good choice. I've never used silicone but I suppose it would work. My only concern is it may act like glue and make it hard to remove the baffle if you need to do so.

Don't know what else to suggest regarding the two 3" drivers. Let us know what progress you make.

-Kent