Author Topic: Crossover Mods  (Read 9833 times)

Offline paden501

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Crossover Mods
« on: January 12, 2010, 09:26:48 AM »
hey just wanted to put this up as an FYI.  I just ordered the parts to do a crossover upgrade on my SDA-1Cs. 

I'll be using Mills 12w resistors and Clarity Cap PX line capacitors.  Hopefully the parts will be in by the end of the week.  :P

I'll update this with some photos as the action kicks up.

~Matt
--- My System ---
Front L/R: Polk Audio SDA-1C w/ Modified xovers
Amp: Carver TFM-24
CD: Jolida JD100a
HTR/Pre: B&K Reference 20
Turntable:Pioneer PL-516 W/ Shure M97xe
Surrounds -Polk Audio Monitor 4As

Offline F1nut

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Re: Crossover Mods
« Reply #1 on: January 12, 2010, 07:45:44 PM »
Why the PX and not the ESA?
« Last Edit: January 12, 2010, 07:49:17 PM by F1nut »
  'Political Correctness'.........defined

"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a turd by the clean end."
 

Offline paden501

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Re: Crossover Mods
« Reply #2 on: January 12, 2010, 08:46:21 PM »
I've got a limited budget.  The ESA's came highly recommended, and I may someday step up to them.  For now though, I can only really afford to go as far as the PX.


~Matt
--- My System ---
Front L/R: Polk Audio SDA-1C w/ Modified xovers
Amp: Carver TFM-24
CD: Jolida JD100a
HTR/Pre: B&K Reference 20
Turntable:Pioneer PL-516 W/ Shure M97xe
Surrounds -Polk Audio Monitor 4As

Offline schwarcw

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Re: Crossover Mods
« Reply #3 on: January 12, 2010, 09:44:47 PM »
Good luck on your project Matt!  I have done several SDA crossover upgrades with ver nice results.  Have you changed the tweeters?
Carl

Offline paden501

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Re: Crossover Mods
« Reply #4 on: January 12, 2010, 09:49:56 PM »
I haven't done the tweets yet.  That's one of the reason that I went with the middle-grade PX caps, so that I could save money for RD0's in the future.

Hopefully this upgrade is as big of an improvement as others have hinted.
~Matt
--- My System ---
Front L/R: Polk Audio SDA-1C w/ Modified xovers
Amp: Carver TFM-24
CD: Jolida JD100a
HTR/Pre: B&K Reference 20
Turntable:Pioneer PL-516 W/ Shure M97xe
Surrounds -Polk Audio Monitor 4As

Offline F1nut

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Re: Crossover Mods
« Reply #5 on: January 13, 2010, 02:07:06 AM »
I've got a limited budget. 

That explains it alright.

Quote
Hopefully this upgrade is as big of an improvement as others have hinted. 

It will be, but remember, they have to burn in for a couple hundred hours, so don't pass judgement until then. Get those new tweeters asap.

  'Political Correctness'.........defined

"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a turd by the clean end."
 

Offline paden501

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Re: Crossover Mods
« Reply #6 on: January 13, 2010, 09:10:50 AM »
Thanks F1.

I've got a 'tweeter fund' going right now.  It'll take me a few months to save up the cash though.  I'm also trying to pay off my car and our new washer/dryer and such at the same time (I hate it when the rest of life interferes w/ my audio obsession).

My long term plan is basically this.  I'm going w/ the PX for now.  I'd imagine that they're a good step better than the stock electrolytic caps on the board right now.  If I fall out of love with them sometime down the line, I'll upgrade again and likely reuse at least the 12uf and 39uf PX caps in my monitor 5bs that I use as surrounds... so it won't completely be money lost.
~Matt
--- My System ---
Front L/R: Polk Audio SDA-1C w/ Modified xovers
Amp: Carver TFM-24
CD: Jolida JD100a
HTR/Pre: B&K Reference 20
Turntable:Pioneer PL-516 W/ Shure M97xe
Surrounds -Polk Audio Monitor 4As

Offline F1nut

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Re: Crossover Mods
« Reply #7 on: January 13, 2010, 02:42:41 PM »
Quote
I hate it when the rest of life interferes w/ my audio obsession 

I can relate.
  'Political Correctness'.........defined

"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a turd by the clean end."
 

Offline paden501

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Re: Crossover Mods
« Reply #8 on: January 14, 2010, 01:44:44 PM »
Caps made it today.  I'll be installing them this weekend.  The resistors are on their way from SonicCraft.  They should be here on Tuesday.

~Matt
--- My System ---
Front L/R: Polk Audio SDA-1C w/ Modified xovers
Amp: Carver TFM-24
CD: Jolida JD100a
HTR/Pre: B&K Reference 20
Turntable:Pioneer PL-516 W/ Shure M97xe
Surrounds -Polk Audio Monitor 4As

Offline F1nut

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Re: Crossover Mods
« Reply #9 on: January 15, 2010, 01:52:16 AM »
I'd suggest you wait for everything to arrive as it can get a bit tricking fitting all the new parts. A dry fit is always a good idea.
« Last Edit: January 16, 2010, 12:29:01 AM by F1nut »
  'Political Correctness'.........defined

"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a turd by the clean end."
 

Offline paden501

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Re: Crossover Mods
« Reply #10 on: January 16, 2010, 12:10:32 AM »
I'd suggest you wait for everything to arrive as it can get a bit tricking fitting all the new parts. I dry fit is always a good idea.

While that's probably a good idea, I decided to dive right into it.  I'll throw some pics up later on.

 8)
~Matt
--- My System ---
Front L/R: Polk Audio SDA-1C w/ Modified xovers
Amp: Carver TFM-24
CD: Jolida JD100a
HTR/Pre: B&K Reference 20
Turntable:Pioneer PL-516 W/ Shure M97xe
Surrounds -Polk Audio Monitor 4As

Offline F1nut

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Re: Crossover Mods
« Reply #11 on: January 16, 2010, 12:32:21 AM »
Well, you can't say you weren't cautioned. Resistors get hot, so make sure you leave plenty of open space for them.
  'Political Correctness'.........defined

"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a turd by the clean end."
 

Offline paden501

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Re: Crossover Mods
« Reply #12 on: January 16, 2010, 01:18:32 AM »
Thanks for the caution F1

The mod went fine.  The caps are all soldered and glued in.  I left a ton of space around the resistors so that I have room to work later.

Unfortunately, I can't seem to find my camera's USB cable right now, so photos will have to wait.  I did run into some 'justification' along the way.

I had previously removed the left speaker's xover to inspect it and get the right values... but I've never been in the right cabinet before tonight.

Well... when I pulled the right xover, I knew right a way that I was in trouble, because somebody had been in there before and labeled the connectors.  It looks like the previous owner had blown a poly-switch and to fix it he simply twisted the switch around until the leads contacted each other and jumped the switch.  Well, the switch was completely burned up, as was part of the 12uf capacitor nearby.  Lots of chalky black stuff was on the PCB and the end of the capacitor, and almost no evidence of the polyswitch remained, other than a little bit of the coating.

So right there, I feel justified in doing this modification.  The system is back together for now, and sound pretty good.  I can't make a judgement on the mod really just yet, as the caps are nowhere near broken in.  I will say that immediately I notice more depth though.


M resistors will be in Tuesday.  When I do them, I also plan on applying dnamat to the baskets of the woofers and PR, as well as appying mortite around the basket rings.
~Matt
--- My System ---
Front L/R: Polk Audio SDA-1C w/ Modified xovers
Amp: Carver TFM-24
CD: Jolida JD100a
HTR/Pre: B&K Reference 20
Turntable:Pioneer PL-516 W/ Shure M97xe
Surrounds -Polk Audio Monitor 4As

Offline F1nut

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Re: Crossover Mods
« Reply #13 on: January 16, 2010, 02:32:05 AM »
Excellent, seems like you're on your way.

Mortite...yeah, I don't know I just can't get behind that one....oh well.
  'Political Correctness'.........defined

"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a turd by the clean end."
 

Offline paden501

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Re: Crossover Mods
« Reply #14 on: January 16, 2010, 09:53:59 AM »
Excellent, seems like you're on your way.

Mortite...yeah, I don't know I just can't get behind that one....oh well.

Well its only a couple bucks so I'm going to try it.  We'll see what happens.   I figure it can always come back off if it's no good.

~Matt
--- My System ---
Front L/R: Polk Audio SDA-1C w/ Modified xovers
Amp: Carver TFM-24
CD: Jolida JD100a
HTR/Pre: B&K Reference 20
Turntable:Pioneer PL-516 W/ Shure M97xe
Surrounds -Polk Audio Monitor 4As