M10 upgrade xover

sevenbutt

I am new to the polk forum and this is my first posting but have been reading with interest on this forum as I have a M10B own since 1987 with SL 2000 Tweeter and the 5jr+ for 2 years with SL 2500 and I wish to upgrade the xover on both speaker with sonic cap.The 5jr+ is rather straight with only 13.5uf and 1 ohm resistor but as for the 10B I have the following questions

In my Xover I have the

1. 12uf
1. 34uf
1. Polyswtich
1. 2ohms 5 w resistor
1. 2.7 ohm 5 w resistor
1.Yellow or orange cap do not know what is it

Question

1.Polyswitch is be taken out, does it need to replace anything there
2.The yellow or orange cap must it be replace when upgrading the xover
3.In the systematic shows 2 12uf can advise where is the other 12uf as I am unable to locate the other 12uf
4.In this forum advise also to replace with 2 12 uf cap please verify

I need your expert guidance

Thank you

Wilson

NJPOLKER

One of our fine members here stated once upon a time that you will be best served by replacing it with a resistor and I can't remember but maybe .5ohm
Polk Audio customer service will send you a couple new ones at no charge.
Replace all capacitors with same value caps. 12uF's are easy to come by.
Hope that helps.

NJPOLKER

Have you taken the x-over out and looked at the values and number of caps and resistors? If not do that and take some pictures. Pictures are always a great thing to do.

NJPOLKER

Welcome to the Club by the way.

sevenbutt

[/ATTACH]NJ Thanks for your welcome note
My Xover is the same in the picture attach and this picture also show only 1x12uf cap same as mine. Need expert advise as in this forum is to use 2 x12uf cap so when I am upgarding my xover do i used only 1x12uf cap as shown in the picture it have only 1 x12uf cap

Thank you
Wilson

Ricardo

That yellow cap is the other 12 uf cap. Polk used different caps for the highs and lows. (you can use the same brand for both).

For the polyswitch, just replace it with a jumper made of solid wire.

kcoc321

Confirm on the yellow Cap being a 12uF.
The value is under the sticker.
I have the same Cap in my 7b's

sevenbutt

Ricardo you mean the very small cap on top of the 12uf cap is the other new 12uf cap to place.Kindly confirm as I am an idiot when come to electronics

Thank you

NJPOLKER

The yellow cap with the sticker on it is a 12uF capacitor. Under the other (blue) 12uF cap and hot melt glue are the two resistors.

NJPOLKER

Your crossovers look to be in good shape. Be careful when you go to remove the board from the four standoff's. Use a pair of needle nose pliers to gently squeeze the little barbs in and then gently work the board off them. You really don't want to compromise them since they can be hard to find and making something else may work but it will be a nicer job when you retain the original parts. As I remember some of the guys around here have added a drop of hot melt glue to them to be sure they have good strength. That should not be needed if you are careful. Just some friendly advice.

sevenbutt

NJ thank you for your advice will definitely be more cautious when handling the Xover
So where is the polyswitch can confirm is it the very small brown cap is the poly swtich??

When I am going to upgrade all the caps especially the 34uf Soniccap do not have 34uf and I need to use 2x17uf can I hot glue both of them as I am not sure whether the cap can stand the heat from the hot glue gun

Thank you
Wilson

kcoc321

the polyswitch should a orange small 'lollypop' lookin resistor first in line from the terminals.

I am lookin at doing my xovers, and from what I have read/ researched, you don't really need to use the Sonicap's ($40) on the LP circuit, the 34uF. I am going with the Dayton's ($10ea) or maybe the lower cost Clarity Caps-Px ($18).
Dayton (33uF) is ok, btw, as the old ones are +/- 10%
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=027-441


As far as SoniCaps not having specific values, if you go that way, they will make you some for whatever value you want. Just cost the price of the next higher Cap.

And, yeh, ppl do do the hot glue thing, or else just use zip ties or dbl stick tape.

ben62670

The caps can handle the hot glue no problem. Don't hot glue the resistors. Do one XO at a time so you have a model. Also never cut the cap and resistor leads til everthing is mounted. Parts Express has the 33uf made by Dayton.
I have used many different caps over the years, and the shunt cap(34uf) doesn't actually have the signal passing through it to the driver. I certainly amnot saying that using a bottom of the shelf electrolytic is good, but a decent Poly cap is all that is necessary. If you ordered the 17uf caps that is perfectly fine. The Sonicaps are very nice, and I used them pretty much exclusively for the high frequency circuits.
Have fun, and keep the solder hot!
Ben

Edit: I had to add a link for the Dayton I missed.
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=027-441
Thanks kcoc321

sevenbutt

Guys thank you for all the feedback and instruction

Once again thank you

Wilson

Face

I agree with Ben. I doubt you'll notice a difference between Sonic Caps and Dayton for the 34uf, definitely stay away from electrolytic caps though.