Are the crossovers exact same on model 7 and 7a speakers

brcarman

Bb code

Gardenstater

I don't have the decoder key. I answered you in the other thread

Gardenstater

You are correct. lol

Gardenstater

OK as I promised you......

Zoinks! Inflation outa control shockeroo (I paid $181 for the caps and $16 for resistors 3 yrs ago)

2 #506936 Gen I Sonicap 34uF 200 VDC 2 x $100.22 = $200.44 (was $124.02)
2 #506767 Gen I Sonicap 12uF 200 VDC 2 x $55.60 = $111.20 (was $56.92)

The resistors you need are no longer in inventory at Sonic Craft apparently. partsconnexion.com has them)

2 #MILLS-79106 2.7 Ohm Vishay Mills MRA-12 2 x $11.95 = $23.90 (was $8.26 from Sonic Craft)
2 #MILLS-79109 4.7 Ohm Vishay Mills MRA-12 2 x $11.95 = $23.90 (was $7.90 for the 4.5 Ohm from
Sonic Craft)

Looks like 60% more for caps and 188% more for resistors! Total cost $435.54 and without doing wiring and binding posts 😜

If that is a deal breaker for you I would look at ClarityCap CSA from partsconnexion.com

You can get the 12uF but they only make a 33uF which most members here have not worried about the slight difference from 34uF. Brings total cost for caps down to around $110 (vs $311)

brcarman

I'm sorry this is my first online forum, I barely made it this far, I don't even know what the other thread means lol, someone goes by 1nut or something said that polk 7 is 7a, I find that hard to believe, my understanding is monitor is the series, and they produced model 7 model 7a model 7b and maybe even a c

F1nut

brcarman wrote: »

I'm sorry this is my first online forum, I barely made it this far, I don't even know what the other thread means lol, someone goes by 1nut or something said that polk 7 is 7a, I find that hard to believe, my understanding is monitor is the series, and they produced model 7 model 7a model 7b and maybe even a c

There is NO model 7, It's MONITOR.

The 7 and 7A crossovers are the same.

Gardenstater

They actually were calling it Model 7 in the most early days just as a fun factoid. Also in 1977 it was definitely Monitor 5,7,10 and in 1978 Monitor 5, 7A, 10. 1979 was Monitor 5A, 7B, 10A.

F1nut

Give it up dude, everyone knows they are the Monitor.

slow_polk7

Gardenstater wrote: »

They actually were calling it Model 7 in the most early days just as a fun factoid. Also in 1977 it was definitely Monitor 5,7,10 and in 1978 Monitor 5, 7A, 10. 1979 was Monitor 5A, 7B, 10A.

Actually, as "late" as 1978, the "5"s were called "Model 5", not "Monitor 5"

I present, as evidence, the original boxes for the Model 5s I bought new in '78.

xschop

A history lesson for 1nut...anything goes with vintage Polks.

Crack open the crossovers and see what surprise/s await.

F1nut

Got news for you chopstick, anything doesn't go.

Gardenstater

F1nut wrote: »

Give it up dude, everyone knows they are the Monitor.

No. When you've proven something beyond a reasonable doubt it is "I rest my case"

@slow_polk7 I thought that looked familiar so I just checked my M7B boxes and they also say "Model 7" 👌

And regarding the statement that the 7 crossover is the same as the 7A, that is a definite * Not always *

Here's part of the crossover when they were using the Audax tweeter prior to the Peerless:

xschop

^^^Not only does anything go, it gets stranger as more is revealed^^^

brcarman

brcarman

Had trouble getting to my gallery

brcarman

Oops gardenstater is correct, I had contemplated purchase eighther that pair, or the single one, but can't help but thinking there as old an out of specs as what I already have?

Gardenstater

They probably are but buying one would allow you to get the speakers back up and running and get a week or two of listening time in to familiarize yourself with the baseline of how they sound. Then you can fix/upgrade the damaged crossover at your leisure. Then you can swap that one in and compare how the one speaker sounds modded vs the stock one while you work on the crossover you just pulled out during the swap.

I often enjoyed doing a mod that way to just see the stark difference in the modded vs unmodded speaker. You can't of course appreciate the true value of the mod until you have done both and burned them in for maybe 200 hours or so of listening.

brcarman

Would consider just going ahead with the mod if had all the part numbers needed etc and if not too much harder than just fixing the ones I have, I have a tight budget, so going to do one or the other, I do have some sweeet pioneer hpm60s that I'm currently rocking with, but have been anxious to see how the polls compare at lower volume, the hpms rock with some watts, but I'm not happy with them at lower volume, I'll make a move on the polks by this weekend, and let ya all know what what I ended up with, thanyou again for your info and time, thinking I'm now satisfied and convinced I have 1978 monitor series model 7a, you folks I hope all have a Great! Day

Gardenstater

Here's a page from the brochure I was given by salesman when I bought mine in 1979. I also attached the brochure file for you below:

brcarman

Gardenstater, You are awesome!!! So I have decided too deffinantly purchase the #mills resistors, and the ClarityCap , caps from parts connection.com, and will go ahead refreshing both crossovers, those prices are affordable to me. I Never would have been able to find the right parts without your help!! And would have been stuck with used stuff. It will take me a few weeks to a month to get the parts and complete the repairs, I will definantly post when I've got them up and running! Thank you again!! I have always respected that people's time is valuable, and quite frankly astonished at the effort put in by both you, and f1nut to assist a stranger. Sincerely Bill

slow_polk7

@Gardenstater

Thanks for that post.

Not to beat the "naming-convention-thing" to death, but your posted image should clear things up once and for all.
The line of speakers is the "Monitor Series", within which individual models are named "Model 5" etc.

Gardenstater

Ha ha don't bet on it

brcarman

So I'm glad f1nut had me check the fuses and posts, they were clean, but my working pair has two 30amps and the other one 3 amp, and 1 30amp, thinking 30amp not going to protect anything?

Gardenstater

OMG. Even the 3 amp might allow damage if the amp malfunctioned. I thought those filaments looked a bit large, especially the wavy one. 1 amp for the tweeter (top fuse) and 1.6 amp for the midwoofer (bottom fuse). Pretty sure they are supposed to be fast blow types.

brcarman

Thanks again! Will purchase those rated fuses, I'm new at vintage stereo as a hobby, but my employment starting at age 16 as a detailer, ending in 2011was in the automotive industries, with two decades selling the full general motors line, I've restored and have Always driven nothing but muscle cars, currently working on a 71 mustang. What I'm getting at is if anyone has any questions about cars, I would be more! Than happy to try to help, also owned and operated a small body and paint shop, doing all aspects from start to finish, except subbing out any required framework. Have a great evening everyone!