RTA-12b crossover upgrade?

bobman7
bobman7 Posts: 55
edited October 2009 in Vintage Speakers
I've been enjoying the hell out of my rta-12s lately, and feel like in the future I'd like to enjoy them even more...can anybody tell me what all I need to change out, and with what, in the crossovers to make them sound their best? They're all original right now.
2 Ch Rig
RTA12B
Audio Research D-90
Nikko Beta III
Harman/Kardon FL8450
Computer Rig
Monitor 5
Yamaha RX-500u
Post edited by bobman7 on
· Share on FacebookShare on Twitter

Comments

  • Face
    Face Posts: 14,340
    edited October 2009
    Replace the capacitors and resistors. I'm a fan of Claritycap ESA's.
    "He who fights with monsters should look to it that he himself does not become a monster. And when you gaze long into an abyss the abyss also gazes into you." Friedrich Nietzsche
    · Share on FacebookShare on Twitter
  • NJPOLKER
    NJPOLKER Posts: 3,474
    edited October 2009
    I am a big fan of Sonic Caps and Obbligato's caps. I'll tell you as others here will that whatever you choose will be far better than whats in them right now. Sonic Craft also supplies Mills resistors many enjoy.

    http://soniccraft.com/products.htm

    http://www.diyhifisupply.com/catalog/22
    · Share on FacebookShare on Twitter
  • bobman7
    bobman7 Posts: 55
    edited October 2009
    I'm pretty illiterate when it comes to electronics...could anybody tell me what caps/resistors i need to buy, and how many of each? I can solder fine, but the technical aspect is a little above my head.
    2 Ch Rig
    RTA12B
    Audio Research D-90
    Nikko Beta III
    Harman/Kardon FL8450
    Computer Rig
    Monitor 5
    Yamaha RX-500u
    · Share on FacebookShare on Twitter
  • NJPOLKER
    NJPOLKER Posts: 3,474
    edited October 2009
    I think the first thing you need to do is to find out exactly what components are currently used in the x-overs. That way you will not have an issue later with non-matching components. The reason for checking the existing x-overs is because Polk did some funky thing back in the day with components, thats what I've been told anyway. Next you need to compare costs of caps with the same value to narrow down your search. It is important to use caps with value that closely match current values. Clarity Caps or SonicCaps are the two I'd look at if I were you. Also picture always are welcome and may help others assist you with this upgrade. You'll be extremely happy with the results!

    Maybe one of the guys who really know how to read the two schematics posted on this site will chime in. The two look very similar to me who is a novice when reading schematics.
    · Share on FacebookShare on Twitter
  • bobman7
    bobman7 Posts: 55
    edited October 2009
    NJPOLKER wrote: »
    I think the first thing you need to do is to find out exactly what components are currently used in the x-overs. That way you will not have an issue later with non-matching components. The reason for checking the existing x-overs is because Polk did some funky thing back in the day with components, thats what I've been told anyway. Next you need to compare costs of caps with the same value to narrow down your search. It is important to use caps with value that closely match current values. Clarity Caps or SonicCaps are the two I'd look at if I were you. Also picture always are welcome and may help others assist you with this upgrade. You'll be extremely happy with the results!

    Maybe one of the guys who really know how to read the two schematics posted on this site will chime in. The two look very similar to me who is a novice when reading schematics.
    I looked at those schematics too...looked like a whole different language! I'll try to get some pics shortly as I don't know what to look for on the crossovers.
    2 Ch Rig
    RTA12B
    Audio Research D-90
    Nikko Beta III
    Harman/Kardon FL8450
    Computer Rig
    Monitor 5
    Yamaha RX-500u
    · Share on FacebookShare on Twitter
  • heiney9
    heiney9 Posts: 25,216
    edited October 2009
    You need to set a budget. The Clarity ESA, Sonicaps and Obbligato's are all upper end caps and are very pricey. They are incredible caps but, if your on a beer budget (nothing wrong with that) they have suggested the champagne of the cap market.

    Just wanted to point that out to you.

    A budget alternative would be the Clarity Cap PX line.

    GL

    H9
    "Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul!
    · Share on FacebookShare on Twitter
  • Bubinga99
    Bubinga99 Posts: 283
    edited October 2009
    The only difference I see between the original and revised 12b schematics is the revised version replaces a fuse with a polyswitch.
    · Share on FacebookShare on Twitter
  • bobman7
    bobman7 Posts: 55
    edited October 2009
    Heres a pic of the crossover, is there another inside the speaker? I haven't bothered to take these guys apart yet...also included a pic of one of em naked just for fun. The top mount crossover would should make it a bit easier to do this mod I think.
    002.jpg 173.1K
    006.jpg 189.7K
    2 Ch Rig
    RTA12B
    Audio Research D-90
    Nikko Beta III
    Harman/Kardon FL8450
    Computer Rig
    Monitor 5
    Yamaha RX-500u
    · Share on FacebookShare on Twitter
  • ben62670
    ben62670 Posts: 15,969
    edited October 2009
    That's it. Read the values off the caps and R's. Let us know and we will desipher it for you.
    Ben
    Please. Please contact me a ben62670 @ yahoo.com. Make sure to include who you are, and you are from Polk so I don't delete your email. Also I am now physically unable to work on any projects. If you need help let these guys know. There are many people who will help if you let them know where you are.
    Thanks
    Ben
    · Share on FacebookShare on Twitter
  • bobman7
    bobman7 Posts: 55
    edited October 2009
    can't see any of the writing...or its worn off
    2 Ch Rig
    RTA12B
    Audio Research D-90
    Nikko Beta III
    Harman/Kardon FL8450
    Computer Rig
    Monitor 5
    Yamaha RX-500u
    · Share on FacebookShare on Twitter
  • geppy1
    geppy1 Posts: 3,075
    edited October 2009
    The diagrams may be wrong. The polyswitch did not get used until the later version of the 12C with the SL 2000. it would be late 85 to 87. keith
    · Share on FacebookShare on Twitter
  • MNmike
    MNmike Posts: 41
    edited October 2009
    bobman7 wrote: »
    can't see any of the writing...or its worn off

    the values are under them.

    I had to remove them from the board to read them.
    · Share on FacebookShare on Twitter
  • jon s
    jon s Posts: 905
    edited October 2009
    I upgraded my Polk RTA-12Cs crossovers with Soniccaps... you can read about it here. To be frank, it was very expensive as the RTA-12C has one of the most complex crossovers of any Polk speakers made. I think there were 9 caps/speaker and some values are expensive.
    · Share on FacebookShare on Twitter