I'm interested in a DIY crossover upgrade has anyone seen this?

chef-nick

I saw an upgrade kit on ebay. http://cgi.ebay.com/Polk-Audio-Monitor-5-7-RTA-8-Upgrade-Kit_W0QQitemZ260382950705QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item260382950705&_trksid=p3286.c0.m14&_trkparms=72%3A1205%7C66%3A2%7C65%3A12%7C39%3A1%7C240%3A1318%7C301%3A1%7C293%3A1%7C294%3A50 I have a better than novice set of skills, but by no means pretend to be an expert. Can I just order those 4 parts from either parts-express or madisound and be better off? any advice would be nice

DollarDave

The smart folks around here convinced me to purchase the parts separately (I used Parts Express). There are a couple threads on this and a sticky at the top of the vintage page that will give you the schematics and cap and resistor values. Depending on the speakers you are working with, there may be a parts list already compiled.

NJPOLKER

Hey Chef
Like a cheap knife - stay away!
Look to the guys here to lead you to the "right" components and methods for x-over mods.
Which speakers do you have, I can't remember.

chef-nick

RTA 8T they are original and stock, although I am looking to replace a "frozen" mw6510 from a drop that was new puppy related, so I thought I would tackle both at the same time. If you modded your crossover on the same speakers I want to know what you did and where you got your stuff.
you guys are the best

NJPOLKER

Here is what I think you need to order to do BOTH x-overs
2) 34uF caps
2) 12uF caps
2)2 ohm resistors
2) 2.7 ohm resistors
and two polyswitched from Polk CS
You should open up your speakers and double check the existing x-overs to be sure about the components.

NJPOLKER

http://www.polkaudio.com/forums/attachment.php?attachmentid=18704&d=1155781881

Here is the link to the schematic

NJPOLKER

I'd order the 12uF Sonicaps from Sonic Craft and the Mills Resistors from them too!
http://soniccraft.com/sonicaps.htm
For the 34uF's I guess that is your call, Solens or Daytons which are both easy to find and about the same cost.

zingo

I have purchased my parts from Partexpress and Sonicraft, and I have used the Dayton, Jantzen, and Sonicap caps as well as Mills resistors. If you can use a soldering iron, it's an easy mod, and buying the right parts is just as easy. The parts list I have for the RTA 8T is:12uF capacitor, 34uF capacitor, 2.7 ohm resistor, and 2 ohm resistor. Check those against your XO as it may be a little different.

zingo

I double posted! :eek:

NJPOLKER

It can never hurt to double check what I say :rolleyes: and most importantly what I do!

Chef,
I assume you plan on keeping these for awhile so use the best components you "want" to afford.

bcline

This kit is using (Bennic/Dayton caps) for the 12 uF (high pass)... which arguably are probably not too bad for the price ($4.57 at parts express). He is using a cheap bipolar electroytic cap for the low pass shunt cap. It looks like the same electroytic cap that you can get a parts express for about 65 cents. So if you just add those two part together you are looking at about $11.00 in parts for both speakers. It also says he gives you some solder, desolder braid, and instructions. I don't think he is really ripping people off for the price he gives, if you grant him a little profit, but I'm sure many around here will argue that they are not the best caps to use. I expect they will make it sound better than before, just not as good as it could sound. He also does not include any resistors, which everybody here says you should change out with Mills.

chef-nick

thanks guys all really good advice. but being a noob to the crossover stuff what are the watt ratings on those resistors? and if it's not too much to ask can someone explain the differences between the types of caps? they seem to have different materials with different effects?

zingo

Mills resistors are 12w, Mundorf are 10w, and Dayton are 10w.

Types of Capacitors

NJPOLKER

I just ordered some Obbligato Capacitors for the High Pass in my SDA2a's - Thanks to the President - NO NOT HIM - our president - Jesse I'll write it up in another thread but they are going to be great and cost effective.

Face

I've been meaning to try those out also, be sure to post your impressions.

chef-nick

ok one last question. why don't I see a 34uf cap at any of the places people have guided me to? I see 33uf. I would like to order all the stuff from one place at one time.

NJPOLKER

The 33uF will be fine. What are you going to order?

chef-nick

i'm leaning towards Parts-express at the moment since they have some other computer related parts that I also need. I have shopped at madisound and NJPolker pointed me towards sonicraft. any other reccomendations? I love shopping around.

ben62670

Sonicraft has the correct values for the resistors, and PE is the best place for the larger caps. You really should get from both suppliers.
Ben

NJPOLKER

33uF's from Madisound or PE
12uF's and resistors from Sonic Craft
I bet you get the parts from Sonic Craft first
Maybe you should do the binding posts while your at it. Trust me its never ending.