Model 5's Yellow wire from crossover mystery

[Sumner]

I picked up a pair of 5's yesterday from a friend. Neither tweeter was operational. I opened one up and noticed a the bare end of a yellow wire wrapped around the small black wire nuts of the woofer. I removed the stuffing to view the crossover. The yellow wire is connected to a terminal block on the crossover right next to a resistor. I opened the second speaker up and sure enough there's the bare end of a yellow wire with the other end connected to the crossover in this speaker also. It doesn't appear these speakers have ever been opened up. Any idea what's going on here?

 

Thanks

[JKent]

Weird. The yellow is the tweeter + and it should be connected to the tweeter lead with a wire nut. The wire nuts don't normally fall off. I dunno. Suggest you pull the tweets and find the connection point, re-connect them. Then see if they work.

There are threads here on restoring the Fives. Re-capping is a must, so is sealing the woofer surrounds with Roy's goo. I'd also suggest refinishing the cabinets--they tend to get dull and orange over time.

-Kent

[Sumner]

I did pull a tweeter on one and it had red and black wires. The strange part is the positive was tied into the woofer positive with the small black wire nut. I ran out of time at that point but will open them back up this weekend.

And yes, I've been reading up on recapping/restoring these. They appear to worth the effort.

[JKent]

That's totally screwed up. Sorry to say, if the tweeters were wired to the woofer circuit they may be fried. Look at the scematics and diagrams here: http://www.classicspeakerpages.net/library/klh/klh_5_klh_model_five/klh_5_schematicsservice/

On all drivers, the black wire is negative. Positive wires are: Red--woofer. White--mid. Yellow--tweeter

So.... Remove the woofers, the crinoline cloth and all of the fiberglass stuffing from each speaker. FG can be itchy so you may want gloves and a mask. Put the FG for each speaker in a plastic bag to save for re-use. Now carefully examine the crossovers (pictures would help) and trace the red, white and yellow wires. There should be one of each color and at the far end each will be connected, using wire nuts, to the appropriate drivers. Except yours are not. So wire them correctly and see if that works. You don't have to put the stuffing back in or even fasten the woofer securely. It will sound crummy but you are just checking to see that all 4 drivers work.

Good luck.

Kent

[Sumner]

It appears to me the positive tweeter is the only one mis-wired. 

Heres some numbers all recorded with all disconnected from one another. Of course the crossover wires were still connected to the board  

1.6 Ohms on pos & neg wires from crossover to tweeter

21.7 Ohms on white (pos) and black (neg) wires from crossover to mids. 

No activity on red (pos) and black (neg) wires from crossover to woofer

16.7 Ohms on white and black from Mids

4.2 Ohms on woofer

pic of that xover

 

2nd speaker measures the same everywhere except the pos & neg from crossover to tweeter I get no activity.

So for sure both tweeters are fried. And something fried on the second xover. Here's a pic of the second. 

 

[JKent]

Try measuring each tweeter, removed from the circuit. You could also try playing music through just the tweeter, at low volume.

[Sumner]

13 minutes ago, JKent said:

Try measuring each tweeter, removed from the circuit. You could also try playing music through just the tweeter, at low volume.

Yeah I did that and must have forgot to include it. I get nothing zero notta. They're cooked. 

[JKent]

So the bad news is you need 2 new tweets. The good news is they're pretty common. I think virtually any KLH tweeter that looks right will be a good replacement. 

I'd rebuild the crossovers. Those old caps are dicey. I also replaced the resistors when I did them because the stock ones are only 5 watts and I've seen burned resistors in Fives and Twelves. 

This is not a difficult rebuild. There are threads here that describe how to. The only confusing part is those #*@% double capacitors but somewhere there's a parts list.

-Kent

[Sumner]

Appreciate the replies Kent. I will eventually rebuild these as soon as time and funds permit.  

Thanks

[Sumner]

Kent you mentioned that any KLH tweeter that looks the same should work. The Model 5's are 6 Ohm tweeters correct?

 

Thanks
Darin

[couldbfishin]

Ok, I will ask the proverbial stupid question. I am rebuilding some 5's right now and it is my first speaker rebuild. I like a challenge.

Why are the woofers and tweeters 4 ohm on average, and the mids 8 ohm on average? I have seen the same in the drivers being pulled from this set of 5's as well as seperates I bought used on line, claimed to be from model 5's. I didn't realize that different ohm rated drivers were used in the same speaker. What is the reason for using both 4 ohm and 8 ohm drivers in the same speaker?

Thanks,

Learning as I go along.

PS: I might also add that in order to make this rebuild project more fun, I seem to have an old model (7000's serial number) and newer model (serial number in the 34,000's) with different cross overs.

And, why are the woofer magnets round in the first/older speaker, and square in the second, more recent woofer/speaker? Does it mean anything at all or are they totally interchangeable, just different suppliers?

So many mysteries.

Thanks

[Sumner]

An update to a 2 year old thread. ?

So these Model 5’s have been sitting for 2 years. Pulled them out last week. Crossovers rebuilt, all drivers functioning, replacement grill cloth and cleaned up the cabinets. Driving them with a Techcnics SU-V7X integrated. I keep asking myself why in the hell I waited 2 years on this project. Fantastic speakers. Unbelievable soundstage. These are going to be hard to knock out lineup. I had no idea these were this good. Wow

 

[JKent]

10 hours ago, Sumner said:

I had no idea these were this good. Wow

Told ya so ?

Nice work. Congrats and enjoy!

-Kent

[JKent]

On 8/18/2017 at 11:03 PM, couldbfishin said:

. . . . Why are the woofers and tweeters 4 ohm on average, and the mids 8 ohm on average?

. . . . I seem to have an old model (7000's serial number) and newer model (serial number in the 34,000's) with different cross overs.

And, why are the woofer magnets round in the first/older speaker, and square in the second, more recent woofer/speaker? Does it mean anything at all or are they totally interchangeable, just different suppliers?

Sorry I missed this back in August

You may confusing DCR with impedance. The Fives are nominal 8 Ohms impedance but the resistance of the different drivers will not read 8 Ohms. And the tweeters may be 4 Ohms. I know that when comparing the Twenty and Seventeen, they are absolutely identical except the 20 has 4 Ohm woofers while the 17 has 8 Ohm woofers. Many 8 Ohm speaker systems use 4 Ohm tweets.

Your crossovers, as you probably know, are identical electrically, it's just that one has point-to-point wiring while the other uses a pcb.

As for the woofers--I could be wrong but I believe all Fives had round magnets. When I bought mine one had an original round magnet and the other had a KLH cloth-surround woofer but it was not from a Five--that one had a square magnet.

All of this may be useless to you because of the delay in responding. Sorry.

-Kent

[DonT]

Yes they are GREAT speakers. After rebuilding mine I will never get rid of them.