Polk 7A crossovers seem odd

tjw141

Anyone seen crossovers like these in 7As? I'm thinking about recapping them, but not sure yet because they sound pretty darn good as is. Just wondering if there's anything odd with these because I've not seen any pics similar to these anywhere. Thanks

K_M

Those appear Home made. If they are not, Yikes!

pitdogg2

we really need to see more pictures to determine whether or not they are home made. Maybe some VERY early Polk monitor 7's did in fact have this set up. What does the binding cup look like? What are the drivers numbers?
We all know there was some strange stuff in the early days at Polk Audio.

FestYboy

If need be, I could crack open one of my MODEL 7s to compare (very early production).

dkfreebird

This is a pic of some early 10 boards I had so anything is possible.

Viking64

Why do I suddenly have a craving for graham crackers?

pitdogg2

dkfreebird wrote: »

This is a pic of some early 10 boards I had so anything is possible.

Then they are legit! Same cap and bobbin spool inductor.

tjw141

I've already recapped them, just used Dayton capacitors since parts express is right down the road. Once I took the old ones out, the 33 read around 40 on my capacitor meter, and the 12 read around 14.

No cup in the back, have to remove the passive to get to it. Appears to look a lot like dkFreebird's, with the little piece of plywood under the board. These are 7As with serial numbers of 03093 and 03049 so I'm guessing pretty low. One of the midwoofers rubber surround split, so I found a good deal on 2 6500s and put those in, keeping the original 2 for backups, but I'd have to refoam one of them.

uncropped pic below, you can see where the connectors come in from the posts on the back. Some mortite around the wires. Things are sealed tight, too.

tjw141

Here's the back:

K_M

wow, literally a scrap of particle board stapled to the back.
You might have almost pre-production speakers!

pitdogg2

K_M wrote: »

wow, literally a scrap of particle board stapled to the back.
You might have almost pre-production speakers!

Doubt it they had a hole size for something. pre-production I would think would have holes drilled through the back just for the binding post and fuse.

At least that is my take on it...

heiney9

Many of the early Model Polk's were DIY, so to speak. Sandy and Matt probably did most of the x-overs by hand in the early days. A) pc x-over boards weren't that popular in the 1970's B.) They were expensive for a start-up like Polk. Much cheaper to grab a piece of particle board and do point to point. Plus it allowed them to experiment more easily.

Also Polk had a history of "going with what's on hand". So you will see some variation is parts/values used across generations of speakers sometimes.

H9

txcoastal1

Those crossovers are probably worth more since Matt and Sandy’s hands actually touch them