Klipsch R28F Hyper-Drive Crossover Replacement Project

Discussion in 'The Klipsch Korner' started by SET12, Jan 20, 2016.

  1. SET12

    SET12 Super Member

    Messages:
    1,838
    Location:
    Appleton,WI
    I'm use to being entertained by some very expensive products. Though nowadays I can no longer afford them. So I'm left to DIYing.

    I wish it were that easy for Manufactures to build the performance that I now have but as Moray below has pointed out It's just simple economics. And not a lot of people really care that much. I really thank people like Steen Duelund who spent most of his life devoted to high performance parts. He often had more money tied up into his crossovers than what the actual drivers cost.

    The beauty of these R-28F's is that the networks are relatively simple and the parts values are small. So its very cool when these R-28F's and $500 in parts are competing against $2500 in parts for my Forte's.

    You don't live to far from me so your welcome for a visit, and who knows the experience could change your whole outlook.



    Very well said Moray!

    I think the thing to understand for DIYing is the return value. For every dollar spent DIYing, it can be worth as much as $10 returned. Of course that doesn't always happen IMO and often because people don't go far enough IMO. But in my case with the R-28F's I have had most of this satisfaction. Its been a great return in performance.

    But there is something to be said to comparing hardly $50 in the stock parts to the $500 I spent, I expected some performance returns but these levels are unreal for the money spent.

    I would suggest reading this on capacitors http://www.humblehomemadehifi.com/Cap.html

    This on Inductors, BTW when I first read it I was in complete aw of what was said. Unfortunately the North Creek site is down. What you may want to read is North Creeks FAQ's on Inductors.

    Resistors, for me the Duelunds are the finest I have ever heard. This is mostly because they have a negative temperature coefficient meaning as the heat up their resistance falls instead of rising like most resistors do. This allows effortless power expression with great smoothness.

    Read this excellent report on resistor sound http://duelundaudio.com/wp-content/.../02/Resistors-vol5-no-3-HIFICritic-Hi-Res.pdf

    Hope this will give you a start.

    In the end it all matters, in my system everything is heard, its why I prefer a minimalist system.

    SET12
     
    moray james likes this.
  2. flat4

    flat4 New Member

    Messages:
    8
    SET12 how are the mods sounding? Still happy with them? Have yo tried any cabinet bracing?

    Is it possible to replace the cheap plastic nuts on the binding posts?
     
  3. RuralTom

    RuralTom Active Member

    Messages:
    201
    Looks like North Creek went belly up.... too bad, I was thinking I'd eventually invest in their coils. C'est la vie, it's a tough business for sure.
     
  4. SET12

    SET12 Super Member

    Messages:
    1,838
    Location:
    Appleton,WI
    They were in business for about 25 years. The historical site is up and running. He has retired but there is a lot of good information on his site. http://www.northcreekmusic.com/Retired/Inductors/inductors.html

    I also found this on Mundorf Inductors http://www.hificollective.co.uk/sites/default/files/mundorf_baked.pdf

    I intend to try the Mundorf out in the future They can be purchased here http://www.hificollective.co.uk/inductors/mundorf_L_range.html

    Mundorf does vacuum impregnation which was a real plus for the North Creeks.




    The modifications sound great and have improved with time on them. I am quite happy with the results. I haven't done any cabinet bracing as I am pretty happy as they are.

    I may purchase the RP-280F's come fall and if I do I'll use the Mundorf Vacuum Varnish Inductors.

    The RP-280F has a new horn design.

    As worded from Klipsch

    "90x90 HYBRID TRACTRIX HORN Redesigned Tactrix® Horn utilizes a circular horn throat paired to a square horn mouth to further improve high-frequency response and extension, while enhancing imaging and dynamics. The compressed molded rubber construction adds high frequency damping to reduce harshness and improve detail. This creates the cleanest, most natural sound possible."

    As far as the speaker binding posts, I know what you mean as to their cheesiness. But after talking with the salesman he pointed out that the speaker binding posts have a plastic plug that can be pulled out so that one can use these. I guess they call them BFA Styled Banana Jacks. They work great, and are very secure, no more spades for me.

    [​IMG] You could still replace the speaker post with something better but the posts with their clips worked out very nicely for me as you maybe able to see I use single to dual clips so I could easily run separate CAT5e cables to each of the three drivers. The CAT5e internal cabling BTW sounds great, way better than what I might have expected. I'll never spend big $ on wire again.
    SD531524.JPG
     
    flat4 likes this.
  5. flat4

    flat4 New Member

    Messages:
    8
    Thanks for the reply SET 12. I am using standard bananas on the bass but using bare wire for jumpers. Would like something a bit more solid as the outer plastic on the locking screws are not very solid and fall off.

    The RP's look good but been looking at b-stock RF 7-2's for just a bit more. Been also searching crags for some low cost Lascala to perform some mods.
     
  6. Pavelow

    Pavelow New Member

    Messages:
    6
    So you modded your R28f's. that's pretty cool. I have a question for you SET12. the crossover on one of my R28f's failed. I'm going to take a look at that crossover to see if I can repair it. but my question to you is, what would be a direct replacement for a crossover? I don't want to spend 1000 dollars modding my R28f's. would just like a simple replacement. another question would be, if I can't get the exact stock model, for a crossover. would lets say, a couple 40 dollarish Dayton audio crossovers be acceptable??? what are my options here SET12? any help would be very much appreciated man. Thank you if you've read this far.

    or if anyone can help guide me I'd very very much appreciate it.
     
  7. SET12

    SET12 Super Member

    Messages:
    1,838
    Location:
    Appleton,WI
    Thanks much!

    What makes you think you've blown the crossover? It could very easily be a tweeter and more often then not it is, especially on a two-way these.

    [​IMG]
    As you can see there is not much to the crossover which is why I like it. As far as the cost of building my project I spent $500 for the pair of outboard crossovers. One could easily spend less and get most of the sound improvement that I got.

    I saved the stock network just to demo against the my modded which only takes a couple of minutes. The resultant sound improvement isn't even a contest IMO or others that have heard them both, The speaker was built to a price point of course and I respect that. It is just amazing what can be done to improve on what is one of the weakest links in a sound system IMO. The late Steen Duelund (crossover parts designer) often had more money tied up in his personal crossovers then what the actual drivers were worth. And today you find his parts in many of the worlds finest loudspeakers.

    As far as a Dayton replacement that is not going to work very well. If you think it really is the network or ruled it out by exchanging networks with the other speaker then I would call Klipsch parts it can't be real expensive. You could easily replace the two caps and the resistor. It is highly unlikely the Inductors are bad.

    The cheapest part on the network has to be the non polar 3.6uf cap on the tweeter portion which is barely a couple of dollars if that. The 1.5 ohm resistor is my next bet but not likely is the 43uf cap. If the 43uf cap across the woofers gets shorted that would cut them completely out or even partially shorted effect their volume level.

    Hope this helps!

    SET12
     
  8. Redboy

    Redboy a few good watts Subscriber

    Messages:
    10,994
    Location:
    Twin Cities, MN
  9. SET12

    SET12 Super Member

    Messages:
    1,838
    Location:
    Appleton,WI
    Hey Redboy! Hows it going?

    Well Saturday I'm going to hear a new pair of $3300 speakers that are about 99db efficient called Tekton Double Impacts that are fast becoming a rage. If you read this review you may see why! https://hometheaterreview.com/tekton-design-double-impact-floorstanding-speaker-reviewed/

    I've heard a lot of speakers over the years and one never knows.

    So it should be very interesting especially being a speaker that is rated to go down to 20Hz 10 watts powers them to the moon.
     
  10. Pavelow

    Pavelow New Member

    Messages:
    6
    I found a 50hz sine wave and played it. turned the balance to one side, left speaker worked perfectly. turned balance right side, the speaker on the right wasnt producing the low frequencies at all. I luckily found a "terminal" on ebay which was salvaged from a physically damaged speaker for 60 dollars. it has the crossover attached. so i will replace the entire terminal + crossover assembly now. thank you for reading my post but I'm sure I have it solved. <3

    PS. all woofers and coils are intact, read right on the ohm meter, and push and pull under power. so it is certainly not a speaker, and the tweeters well, both sides are deafening when you put your ear up close to them, so both tweeters are working full strength.

    the lpf on the crossover failed, is what I think. and I'm going to replace the entire crossover assembly in a couple of weeks. I'll update you. thanks again.
     
    Last edited: Jan 11, 2018 at 8:44 PM
  11. moray james

    moray james Super Member

    Messages:
    3,011
    Location:
    Calgary on the Bow
    if you have isolated the problem to the woofer section of the crossover then it is almost certain that the issue is with the 43 uf capacitor and not the inductor. why not replace the cap and see if that sets things right?
     
  12. Pavelow

    Pavelow New Member

    Messages:
    6
    I'm getting a replacement -and- I'm going to repair mine. I am an Electronic-Optronic Systems Technician and I have capacitors at work. 43 micro eh, good to know.
     
  13. Pavelow

    Pavelow New Member

    Messages:
    6
    -----

    so 43 microfarad cap killed confirmed, crossover replacement coming in a weekish, but, if I am going to repair my old crossover, I need to find a 43 microfarad 100v capacitor.... do any of you guys have any idea where I could buy one? I can't find them online anywhere. my boss said I can order caps through work and get a discount, but i kind of doubt the military will have what I need.... .... .... any -more- help would be appreciated. Thanks guys.
     
  14. SET12

    SET12 Super Member

    Messages:
    1,838
    Location:
    Appleton,WI
    Try this https://www.hificollective.co.uk/catalog/components/capacitors.html I believe it maybe reasonably close to you.

    I think the military could very well have what you need. I work with medical equipment and I see caps all the time that I could work with.

    What you want is a 100 volt Polypropylene film cap. Remember when you go higher in voltage the cap will be larger so you kind of want it to fit.

    SET12
     
  15. Pavelow

    Pavelow New Member

    Messages:
    6
    ... I'm in Canada. and yeah my boss found some promising looking caps. i just need the nitty gritty details like ESR that I need now... polypropylene film cap perfect. thank you.

    yeah the caps my boss found are tantalum
     
  16. Pavelow

    Pavelow New Member

    Messages:
    6
     

Share This Page