New Altec lover

[GM]

The 'easy' way to learn/understand is to use a 'ladder' diagram, so convert a schematic to one and usually it becomes obvious 'what does what' and makes it super simple to troubleshoot.

Then again, some folks start out like I did with 'brain freeze' because it reeks of black magic like I thought horn or anything else electro-acoustical-mechanical design was till I got motivated to learn otherwise, which you are, so you're already halfway there :

drawing ladder diagrams - Google Search

“Ladder” Diagrams : Ladder Logic - Electronics Textbook

Electrical Ladder Drawing Basics

GM

[Petro]

I like that thanks. When I open up a xover I draw it up but my drawing don't look anything like ones I see.

So, more problems!!!!!!! woofer rebuilt, came out beautiful. Horn is testing just under 8 ohms. New caps, and now that speaker works but its at very very low volume compared to the other one. I switched tubes, I switched cables on amp and phonostage. But it's same side everytime.
Any ideas? Anyone? What would cause that?
I'm at wits end here with this. Getting ready to list all the parts on ebay. And bust up the cabinets.

- - - Updated - - -

Oh btw this was the xover that worked fine before I put new caps in.

[GM]

No clue, not even sure which speaker system you're referring to anymore, so need a 'recap' of the components and list of any mods, replacement parts done plus signal chain and how and with what you're using to do testing.

How low is low WRT the other speaker? How was this determined? Any other 'light' you can shed?

For instance, I once had a situation where a tape recording I'd done played fine in my system, but was barely audible in the left channel on others, though these systems otherwise played fine in FM, phono and with other tapes.

Turned out my recorder, preamp and early digital parametric EQ cum 1/3 octave EQ had some sort weird symbiotic relationship in the left channel that no one could figure out, so replaced the cable to no effect, then the recorder and all was right.

Like I said, it's black magic.

GM

[BillWojo]

Can you post some pictures of your recapped crossovers? Any chance that you over heated a cap when soldering it in? Sounds like a bad connection some where in the crossover or a damaged component.
PS I sent you a reply to your PM, did you get it?

BillWojo

[Petro]

My setup is a pair of 808-8a and a pair of jbl d130's. Xovers are 801-8a. My cabinets I just made from taking the a7 I got these parts out of and making them smaller. They are made of 3/4" MDF and are 23 1/2" wide inside space 22", 18"deep and 34" high. But I put 3" feet on them so inside measurement is about 29" high. The port I used an online calculator and came out with 13"x 2.5" it said to make it 4.5" deep but I'm still making something to slide into them so they are just open right now. I'm using a viva 8w 300b integrated with only turntable as source and a yaquin cheap phonostage. I have a decent tube collection and added Telefunken's in phono, jj's for 300b, rca for 6sn7 and national Union rectifiers. Not sure what other info I have. Oh my friend makes cables so i use his avant's.

I'm pulling out xover to check all the connections first. But figure I'll switch speakers first and see what happens. I think it's a poor wiring job. Because I'm no pro. Or a fault cap as bill mentioned as that's the only thing I changed in that xover.

[GM]

Whole speaker low volume or just horn? Whole speaker means in the signal chain, so speaker wiring would be the first to check. A bad cap just takes out the tweeter in a two way.

The main thing is to do systematic testing and not a bad plan to document each test even if just for future reference in case you have problems 'down the road' with this or some other system.

GM

[Petro]

Thanks, it's the whole speaker and i see a wire off one cap was touching the post that jumps the coil to the LF+. So I'm hoping it's that because everything else looks fine, except my crappy solders from wires in the back. And speaking with BillWojo, I now know the solders keep cracking because I'm using wrong type of flux.
As I said I'm a woodworker and this electronic stuff is new to me but I'll get it .... Eventually
Thanks GM you are a huge help!!!!

[GM]

In that case, get some solder wick and remove all solder and begin anew. This is a driver short [or worse] waiting to happen, especially with [horn] tweeters.

GM

[Petro]

Yes I agree the horn works fine now but the LF is still very low volume. I'm going to pull everything off and start from scratch. Thx

Still no luck, I switched xovers and it's the woofer. Just reconed, not sure why. Please don't tell me it has to be remagnetized. That would be worst case scenario so I'm sure that's gotta be it. Damn!!! It reads 1.6ohm

[GM]

Your amp would 'feel' an unbalanced load and if it doesn't have enough drive voltage [not rated for > a nominal 8 ohms], then it might go into protection mode if it has one.

As typical of so many tube amps available today though, there's not squat for tech info on their website or even a 300B amp, so no clue what your integrated can handle and why I asked for specifics.

Anyway, put an ohmmeter across the coil and if it has a reading in the 3, 6, or 12 ohm range to determine if it's a 4, 8, or 16 ohm VC.

For future reference, when using SET or low damping factor [DF] PP amps one normally wants a low current draw, so ideally use 16 or higher ohm components, and for matching impedance amps, then of course match up to whatever it's designed for otherwise you may only get to use a fraction of its power capability and be very weak in the bass, treble.

Also, in these cases the speakers should always be tuned to Fs, which means having equal amplitude impedance peaks regardless of whether it's actually at the published or even measured, Fs.

GM

edit: just saw your edit.

1.6 ohm?! This is a 2 ohm coil measurement! No clue what's going on, but has nothing to do with the magnet. Don't know if [JBL] Lansing ever did D130 in 2 ohm unless for an early dual driver guitar amp or similar.

If the magnet's 'flat', then its Qes, Qts specs will be very high compared to stock, causing a 'bloated' bass response, not barely heard.