RTi6 Crossover Rebuild

ALL212
ALL212 Posts: 1,553
edited May 2011 in DIY, Mods & Tweaks
I decided to have some winter fun and rebuild the crossovers on my RTi6's. There is another thread here that goes over this as well but I thought I'd add my 2cents. :rolleyes:

Parts List: (Clarity caps from Madisound, the rest from Parts Express)

2 Clarity Cap 12uf
2 Clarity Cap .47uf
2 Dayton Audio MP 7.5uf Cap
2 2.5 ohm Mills resistors
2 5 ohm Mills resistors
2 .5 ohm Milss resistors

I couldn't find Clarity caps in a 7.5uf - my options were either 6.8 or 8.2 and since I didn't have a schematic I decided not to decide and went with the exact value in another brand. Nor could I find a Mills resistor in 5.7 ohms and I don't like using Mundorf resistors (too long, leads are too short) so I compromised with a 5 ohm in series with a .5 ohm for 5.5 ohms instead of 5.7.

You'll also want to order some type of batting - a pound of Acousta-Stuf (Parts Express) should be fine. I just got done pulling the fiberglass batting out of a Dahlquist DQ-10 so I used a couple handfuls of that. There is one small piece of an excuse for batting in these speakers and I think it should have something more reasonable.

1) Remove the woofer - this requires a hex screw in a 3.5mm size I think. A 1/8" will work but not fit very tight - any other inch type hexs didn't even come close. Insure you mark which connector held which color of wire - I'm usually not shy and just use a big sharpy and write on the magnet.

2) Remove the wires from the tweeter - Mark which connector held which color. You do NOT have to remove the tweeter.

3) Remove the input terminal - four screws and she's outa here! Now we're going to have some fun! :o

4) Remove all of the input terminal cover's and the brass input jumpers.

5) Remove the 4 black screws from the circuit board - it won't come off yet but should be slightly loose.

6) A 5/16" nut driver will take out the 2 nuts under the board holding the circuit board to the input cup - make sure you catch the washers.

7) I used a needle nose plyers to hold the back nuts against the wire connector underneath the board and then used my 1/8" hex key in the terminal hole to remove the nuts from the back two input terminals - this is no fun, please be careful. Hold the nut with the plyers and spin the input terminal with the hex key. This way you won't make a mess of the threads. Once done the circuit board should come free of the input cup.

8) Now for some real fun :mad:. Somebody at the factory has a huge tube of silicon calk and has been told to apply liberally. You'll have to clear the back two wires from the mass of silicon. Eventually I found that a sharp knife will cut through most of it and once you get some of it free it might be possible to just pull it off the board. You don't have to free it from the front terminals - just enough to get two the connections between the wires for the very small cap. You'll also find it handy to completely free these 2 wires - it will make reassembly much easier. Go easy here...;)

10) In your favorite manner remove the three capacitors and two resistors. Mine were held on the board with something sticky - just pull once you have the solder free - they'll come! :eek: Each component is marked on the board so you don't have to get fancy and mark or remember anything. ;)

9) You'll need a drill - a Dremel tool works great - to open up the holes in the circuit board - a 1/16" bit works perfectly. I opened all 10 holes just to make life easier.

10) Bend one lead of the 2.5 ohm resistor all the way down over the body of the resistor - it won't leave much exposed wire but enough to feed both leads through the holes - solder him in.

11) Twist one lead from the 5 and .5 ohm resistors together - don't solder yet. Work the other leads through the holes in the 5.7 ohm place and solder those down - I'd leave a little clearance between the board and resistors so you can move it around later to fit the large cap in. Once soldered to the board - solder the top and cut off any excess.

12) Strip off all of the insulation from the .47uf cap - right to the body and bend the leads all the way back to the body - this cap fits almost exactly into the holes in this state. Solder, cut off the excess and save these two long copper leads.

13) Solder one of the saved copper leads into the hole closest to the resistor on the 7.5uf side leaving almost all of the wire poking up through the hole towards the component side. One issue is that the caps don't have enough lead wire to sit them on the board and reach the holes.

14) Solder the other saved copper lead into the hole furthest from the resistor on the 12uf side leaving almost all of the wire poking up through the hole towards the component side.

If you don't get these right it's not that big a deal but it will make positioning
the caps on the board easier.

15) Pick a cap...any cap. Bend one lead completely over the side and strip the other lead all the way back to the body of the cap (the 7.5uf won't need this striping step :p) and straighten it out completely from the body of the cap. Insert the straight lead into the remaining hole on the appropriate side. You will have to bend that copper lead around so that you can push the cap down as far as possible. Work the cap into position - you can leave a little bit hanging over the board but not much - the hole in the cabinet is almost exactly the same size as the board. :mad:. Once positioned work the copper lead and the remaining lead on the cap together and solder this connection together - solder the other connection to the board.

16) Repeat that step for the other cap.

Should end up with something like this:

DSC_4546.jpg

17) I use hot glue to insure that nothing can vibrate against anything else and am probably guilty as the person in the factory for using as much as I feel is necessary to complete that task! :D

The New and Old:

DSC_4549.jpg

Reassembly:

1) I'm hoping you have two wires that are freed from their adhesive base - remount those two connections back on the input cup - watch your polarity - it is marked on the cup. Black to - and Red to + (for those of you who weren't sure! :p) Use the 1/8" hex key to keep the hole in the terminal facing forward as you tighten them down - I used a bit of Permatex blue to insure they don't come loose - don't forget the washer!!

2) Work the last two wires (still anchored in their adhesive homes) to the input cup and secure those to the terminals - if you are careful you can use a nut drive to get these tight - use the 1/8" hex key to hold the terminal in place as you tighten them down.

3) Now put the screws to the board and secure it to the input cup - I put a dab of hot glue on each of these when done to insure they don't wander out of thier holes.

4) Apply 1/2 pound of Acousta-Stuff to each speaker - don't block the tube inputs.

5) Somewhere along this process the gaskets have fallen on the floor ;) - you should have one for each speaker. Make sure you have these in place before you put the input cup back into the speaker.

6) Mount the input cups back into the speaker - insure you have them rightside up (or down if you have the speaker upside down).

7) Reattach the speaker wires - blue's go to the tweeter, green's to the woofer but you should have marked the polarity and I'm not taking mine back apart when you call and ask what should go where! :D

8) Remount the woofer.

Plug 'er in to your most expensive amp and with the volume all the way up...JK - don't do that...:D:D

Test - low volume - make sure the woofer is vibrating and that when you cover the tweeter with your hand you stop hearing the upper registers.

I'm hoping that when done and after a reasonable amount of time for break in that your RTi's now sound a bit closer to LSi's! :cool:
Aaron
Enabler Extraordinaire
Post edited by ALL212 on
«13

Comments

  • ben62670
    ben62670 Posts: 15,969
    edited January 2010
    So how does it sound? Don't forget it takes around 80hrs to sound close to being burned in.
    Congrats
    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
  • ALL212
    ALL212 Posts: 1,553
    edited January 2010
    Even now with just a couple hours on it - better "tone" definition. Instruments sound like what they should sound like without just sounding like a note. Upper midrange seems to be better defined. I'm wondering if the crossover slope is better handled by upgraded components.
    Aaron
    Enabler Extraordinaire
  • heiney9
    heiney9 Posts: 25,053
    edited January 2010
    Good to see you posting a little bit in the main forum A. This is the guy that has helped me do all of my mods.

    Nice work as usual. Glad to hear there is a marked improvement.

    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!
  • NJPOLKER
    NJPOLKER Posts: 3,474
    edited January 2010
    Beautiful
    What else can one say? It will be cool to read about your listening impressions.
  • Face
    Face Posts: 14,340
    edited January 2010
    Very nice!
    "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
  • Amherst
    Amherst Posts: 695
    edited January 2010
    We obviously are looking at some fine work here. Great job Mr. ALL212!

    The info here will help many to try and tackle their own mods.

    I have a question if I may. Would there be any merit to taking a tie wrap around the board and those giant caps and hot gluing the wrap in with the caps for support? Or not necessary?
    Parasound C1, T3, HCA-3500, HCA-2205A, P/DD1550, Pioneer DV-79avi, Oppo BDP-83, WD Media Server W/HDD,
    Dynaudio Contour 3.3, Dynaudio Contour T2.1, Polk OWM3, Polk DSW micropro 1000 (x2),
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  • ALL212
    ALL212 Posts: 1,553
    edited January 2010
    These particular caps really aren't that big - I've worked with some 80uf stuff from Solen and Clarity and those look like baby cans of pop. I didn't think there was any worry about the hot glue job not holding these down. On the other hand - any support you add certainly won't hurt. Anything that even thinks about vibrating is not a good thing.
    Aaron
    Enabler Extraordinaire
  • ALL212
    ALL212 Posts: 1,553
    edited January 2010
    I've got a pile of caps here for two other speaker crossover rebuilds (JBL L19 and Dahlquist DQ-10). When sizing your caps you've also got to make sure you can physically get them where they have to go and that may make a difference on what you purchase. Those three tiny little guys on the bottom are the caps removed from the RTi6. The blue caps are Clarity PX caps rated at 250v and the red caps are Clarity SA caps rated at 630v.

    From left to right:

    Standard can of Coke
    80mfd 18mfd 6mfd
    15mfd 8.2mfd .33mfd
    .47mfd penny
    12mfd 7.5mfd

    DSC_4551.jpg
    Aaron
    Enabler Extraordinaire
  • Face
    Face Posts: 14,340
    edited January 2010
    Purdy.
    "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
  • ALL212
    ALL212 Posts: 1,553
    edited January 2010
    9/64" hex wrench to remove the front screws.
    Aaron
    Enabler Extraordinaire
  • ben62670
    ben62670 Posts: 15,969
    edited January 2010
    I have some of the baby blues on there way sometime soon.
    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
  • superjunior
    superjunior Posts: 1,632
    edited January 2010
    man I need to hook up with you or Ben, this is really something I want to learn how to do :)
    panasonic th-50pz85u
    pioneer elite vsx-92txh
    pioneer elite bdp-05fd
    emotiva xpa-3
    monster power hdp 2550
    sa 8300 hd dvr
    sda 2b's
    fronts - rti a9's
    center - csi a6
    surrounds - fxi a6's
    sub - polk dsw pro 600
    harmony one
  • ALL212
    ALL212 Posts: 1,553
    edited January 2010
    Gonna be a road trip and a half but you're more than welcome to watch on the next rebuild. I think the hard part is getting to the components and then getting them out. :mad: Putting the new stuff in is the fun part. :)

    It's not hard but it hurts like hell when you grab the wrong end of the iron! :eek: Hot glue is another entertaining component - my kids love to watch me try and pull it off my hand as it cools - while I'm swearing! :p
    Aaron
    Enabler Extraordinaire
  • ALL212
    ALL212 Posts: 1,553
    edited January 2010
    ben62670 wrote: »
    I have some of the baby blues on there way sometime soon.

    Building something fun?
    Aaron
    Enabler Extraordinaire
  • ben62670
    ben62670 Posts: 15,969
    edited January 2010
    I am converting my custom SDA2.3's to passive. I have the active, but the electronic crossover is the weak ling now.
    http://www.polkaudio.com/forums/showthread.php?t=78359
    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
  • superjunior
    superjunior Posts: 1,632
    edited January 2010
    ALL212 wrote: »
    Gonna be a road trip and a half but you're more than welcome to watch on the next rebuild. I think the hard part is getting to the components and then getting them out. :mad: Putting the new stuff in is the fun part. :)

    It's not hard but it hurts like hell when you grab the wrong end of the iron! :eek: Hot glue is another entertaining component - my kids love to watch me try and pull it off my hand as it cools - while I'm swearing! :p

    video tape the important stuff :p
    panasonic th-50pz85u
    pioneer elite vsx-92txh
    pioneer elite bdp-05fd
    emotiva xpa-3
    monster power hdp 2550
    sa 8300 hd dvr
    sda 2b's
    fronts - rti a9's
    center - csi a6
    surrounds - fxi a6's
    sub - polk dsw pro 600
    harmony one
  • ALL212
    ALL212 Posts: 1,553
    edited January 2010
    I read through some of that - That is one AMAZING set of speakers!

    PX's? no SA's or other brand? I'm not using Solens anymore (except for power supplies or non-sound issues) but other than Clarity Caps haven't played with anything else.
    Aaron
    Enabler Extraordinaire
  • ben62670
    ben62670 Posts: 15,969
    edited January 2010
    The cheap ones. I do a lot of XO's for Polkies, and the Clarity cap line up has sparker my interest. People don't realize what they are missing doing an XO upgrade. I have been very pleased with the Dayton's, but if I try the Clarity's and they are better people won't be so turned of from the upgrade. Thanks for the compliment.
    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
  • ALL212
    ALL212 Posts: 1,553
    edited January 2010
    Gotta say it again - not to get in the last word or anything other than absolute appreciation for the work you've done:

    Those are some AMAZING speakers.
    Aaron
    Enabler Extraordinaire
  • sTiLlLeArNiNg
    sTiLlLeArNiNg Posts: 805
    edited January 2010
    AWESOME mod! Thank's for sharing :)

    I'd like to do something similar to my RTi A's but am unsure of what to use exactly? If i simply replaced the factory cap's with higher quality cap's of the same value would there be any noticeable difference?

    Cheer's!
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  • Face
    Face Posts: 14,340
    edited February 2010
    There could be.

    It depends which caps and what you replace them with. The biggest difference would be replacing the tweeter caps with something of higher quality.

    What kind of sound are you looking for?
    "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
  • ALL212
    ALL212 Posts: 1,553
    edited February 2010
    AWESOME mod! Thank's for sharing :)

    I'd like to do something similar to my RTi A's but am unsure of what to use exactly? If i simply replaced the factory cap's with higher quality cap's of the same value would there be any noticeable difference?

    Cheer's!

    If you can find a picture of that crossover it will make the decision easier - I'm not familiar with it at all. Some of these speakers leave almost no physical room for upgrades either so actually pulling the crossover will give you an idea of what to expect.

    As far as picking what caps to use - set your budget - you can spend $10 for caps and up through $1000 for caps. I've found the PX line of ClarityCaps to be better than Solen (I've done A/B testing with these) and also very economical. These caps are usually substantially larger that whatever came stock.

    You'll notice a difference - promise!
    Aaron
    Enabler Extraordinaire
  • ben62670
    ben62670 Posts: 15,969
    edited February 2010
    Thanks for your findings. If you could be a little more descriptive about your findings that would be greatly appreciated.
    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
  • comfortablycurt
    comfortablycurt Posts: 6,745
    edited February 2010
    I can't wait to hear some listening impressions on these. I'm on the fence on selling my RTi6's right now...and seeing this makes me want to keep them a little more.:cool:
    The nirvana inducer-
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  • ALL212
    ALL212 Posts: 1,553
    edited February 2010
    10 days later...

    Much smoother top end - that tweeter doesn't hurt my ears anymore. Soundstage is opened up very nicely. Bass - smoother but less, I've got to adjust some of that baffle material I put in - well, maybe just not so boomy anymore!

    Anyway - well worth the $50 in parts and a couple of hours in time.
    Aaron
    Enabler Extraordinaire
  • ALL212
    ALL212 Posts: 1,553
    edited February 2010
    I was a bit confused on why there was a .47uf cap on this board and then confused again that it was the same cap/value on the RTi4. I've got a schematic for an RTi 70 and low and behold - another .47uf cap!

    Polk is using a technique of putting a nicer but very small cap in parallel with a larger, but cheaper (read electrolytic) cap to get a better sound - or at least hoping to get a better sound.

    An option on this crossover is to use an 8uf cap (caps in parallel are additive) or something close, 8.2uf wouldn't bother me at all, and leave the .47 cap out completely.

    If you like the idea of putting a higher quality cap in here you could still use an 8.2uf cap in place of the 7.5uf cap and then put a .1uf cap of higher quality (ClarityCap SA or ESA series - or pick your favorite) in place of the .47uf.
    Aaron
    Enabler Extraordinaire
  • Face
    Face Posts: 14,340
    edited February 2010
    I've done the same thing, replaced the 7.5uf and .47 with a 8.2uf. A single series cap in the HF circuit will always sound better than two parallel series caps of of unequal size.
    "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
  • Ricardo
    Ricardo Posts: 10,636
    edited February 2010
    Very nice job A2. Very clean.

    22 posts now; what are you selling? ;)
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  • ALL212
    ALL212 Posts: 1,553
    edited February 2010
    Ricardo wrote: »
    Very nice job A2. Very clean.

    22 post now; what are you selling? ;)

    Whatcha lookin' to buy and how much you got to spend?? ;)
    Aaron
    Enabler Extraordinaire
  • Ricardo
    Ricardo Posts: 10,636
    edited February 2010
    All I will say is dibs!!
    _________________________________________________
    ***\\\\\........................... My Audio Journey ............................./////***

    2008 & 2010 Football Pool WINNER
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    Thank God for different opinions. Imagine the world if we all wanted the same woman