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Quartet Question: Woofer specs and cross-over point???

Discussion in 'The Klipsch Korner' started by Wharfcreek, Dec 3, 2018 at 9:29 AM.

  1. Wharfcreek

    Wharfcreek AK Subscriber Subscriber

    Messages:
    3,502
    Location:
    Baltimore, MD
    Does anyone have any experience with changing the Woofers on Klipsch Quartet speakers? If so, I'm curious about what kind of frequency response numbers were used as a reference for chosing a suitable replacement? Also, does anyone know the basic crossover point used on the Woofer on the 'stock' factory speaker? Finally, in replacing the 'stock' woofers, is it advisable to stick with the same style 'stamped' frame type woofers, or is going to something perhaps more 'capable' in a 'cast' frame unit a good decision? Any help / thoughts / suggestions is appreciated. Many thanks, WC
     

     

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  2. moray james

    moray james Super Member

    Messages:
    3,087
    Location:
    Calgary on the Bow
    iirc 750 Hz xover point. Bob Crites can give you specific data on the xover and perhaps the driver he may even have a replacement. without a sweep of a stock woofer you will not be able to see what the roll off characteristics are and you need to know that as the network will have been designed to compensate for this. Without knowing what the roll off looks like you could end up with either a drop or a hump in the response as the mid horn rolls into action. in either of those cases you would then need to re work the network. Best to find a driver that matches as closely in this range. you might also look into having your old drivers re coned.
    I found some data you can look at the bass response and follow the natural roll off of the woofer to get a rough idea.
     

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  3. Wharfcreek

    Wharfcreek AK Subscriber Subscriber

    Messages:
    3,502
    Location:
    Baltimore, MD
    Hey MJ,

    Interesting charts....though I have to laugh a bit. At first I thought there was a bunch of good info on each speaker....... until I realized it was the same 5 specs listed in 5 different languages!......lol Clearly the Chorus IIs beat out the Fortes and Quartets in sensitivity. But, from what I see, they all seem to travel in about the same Frequency range........so doesn't appear that one has any great advantage over the other. With 100 watt capability, I'm probably OK using just about any amp I own.....as all are 'tube' units, most with only about 15 to 35 WPC. The amp I build most frequently is the revised Magnavox 8600 unit done by Dave Gillespie and with a LOT of info here on AK. I affectionately dubbed it the DG-SE1....which has kind of stuck! I've built the circuit about 2 dozen times now in various iterations. But, in any form, they're all about 4 watts / channel....so needless to say, the higher the efficiency of the speakers, the better these little amps sound. On Cornwalls you'd think you were listening to far more substantial. On Forte IIs.....still excellent. I've yet to try my Quartets on anything other than my little home-made revised Dynaco ST-35 using Shannon Park's revision circuitry.....or parts there of. I rather did my own version using Dynaco's 'stock' output section and Shannon's driver stage. Worked out well....and no 7247s to have to go buy!

    I'll get a hold of Mr. Crites! He's an old friend....though I've not spoken with him in the past few years. He may not even remember me at this point. But, I'd guess after some conversation he will. And, you're right about him being the resource to go to on this kind of thing. I know of no other 'Klipsch' expert on the vintage stuff with any better knowledge the Bob.....except perhaps someone still at the factory. And, I don't know a soul there!!

    By the way, I should mention that your package arrived yesterday. I've not yet opened it...... and upon doing so I may just go ahead and do all the dampening you referenced and then just put them both in my cabinets. I did 'repair' my original woofer....... used it for about 2 days without any real detrimental affect from either the damage or repair. I then found 1 'original' for sale on ebay and bought it....installed it......and in reality nothing sounded any different. In short, I think they sound great!! And, like I said, I'm only using about 15 WPC to drive them. I have a project slated for this winter, a complete re-build of a Citation 5 power amp with all the bells and whistles available. I forget the name now of the chap I purchased it all from, but it's complete power supply revisions, coupling cap replacement, meter repl, a some other odd-ball stuff. I think it even adds a choke where there was none before. When done, we'll see how that amp drives the Quartets.....as that will become my new 'living room' amp where the Quartets now reside.

    Anyway........ thanks again for all your help with this. I'll let you know once I get in touch with Bob....which may not be until after the first of the year. Until then, stay warm up there in the cold country. BTW, just exactly what part of Canada are you in? I had attempted to take a motorcycle trip into Canada this past summer. I was going to enter Canada up at the Niagara Falls bridge, make a run up to Toronto, then up through Sudbury and on back into the US at Michigan's Upper Peninsula at Sault Ste Marie. Having grown up in Michigan, we used to run up to Canada all the time, particularly in my youth. I even had a girlfriend in London Ontario for a while. I don't remember them even looking at my driver's license back in those days. Anyway, now I guess it takes an actual Passport.....of which I did not have. So I ended up leaving Niagara Falls on the US side, headed through Erie, PA, up through Detroit, on up to the Mackinaw area where my younger son now own's 10 acres of property. He's built himself a tree-house up there that rivals some luxury apartments!! A frickin' tree house!!! Anyway, I finished my ride by heading down Michigan's western shore, then on back to Baltimore. About 3000 miles in 10 days. A good ride! Hopefully next summer I can do this as I'd originally planned....only the next time I'll have my passport. I was just wonder how far off my path you are? I always like to stop and meet people I've gotten to know on this and other web sites. Nice to put a face to a name......not to mention mooch a cup of coffee....(or even a beer.......lol).

    OK......I'm out!! Thanks again, Tom D.
     
  4. Searing75

    Searing75 AK Subscriber Subscriber

    Messages:
    385
    You can always visit your old Cornwalls in Olean for a quick cup of joe!
     
    moray james likes this.
  5. Wharfcreek

    Wharfcreek AK Subscriber Subscriber

    Messages:
    3,502
    Location:
    Baltimore, MD
    I miss those guys!! Don't think I haven't regretted that deal! BUT....that said.....couldn't have gone to a better home!!

    Thanks for the offer Chris! I may take you up on it. I'm planning on doing some pretty intense cycle riding this coming season.... and your area is on my list of places to go. I've found that a riding companion is virtually impossible to locate, so I'll be taking most of these travels solo, which is what I did with the trip to Northern Michigan last summer. I did make another run 'nearly' to NY in the fall..... had a buddy with me then. We went through the Sproule State Forest in northern Pennsylvania....which leads to yet another state forest, a bunch of mountains, and to the border of NY State. We got about 6 miles or so from NY and realized we needed to turn around and go southwest. It was already getting dark then. We ended up in some kind of 'Elk' country....where apparently they'd 'imported' a heard of Elk some 30 years ago thinking it would be a clever thing to do. Now they've multiplied to the point of becoming hazardous in the area. Apparently they just jump off cliffs at night an into the road. Supposedly there's at least one 'Elk Collision' nightly in this area....which for the life of me I don't recall the name of now. All I remember is that every stop along the way all we heard from gas station attendants, restaurant people, and passer's by: BE CAREFUL OF THE ELK!!! There's always something different!! While in Michigan I almost hit a Black Bear that decided he needed to cross the road in front of me and as I was on an all black motorcycle....I guess he thought I was 'kin'!!.....lol

    Anyway....nice to hear from you. Hope all is well in Olean and you're feeling well! Catch you again ..... maybe for the cup of java!!


    Tom
     
  6. moray james

    moray james Super Member

    Messages:
    3,087
    Location:
    Calgary on the Bow
    chorus has the same response as the Cornwall at minus 3db at 39Hz (Chorus is much less efficient than a CW though). Quartet is lower and the Forte lower again so in a good room you can dig a little deeper with the Quartet and Forte and Forte ll.
    I am out west in Calgary. You can re tune the Quartet by adding 2.5 oz of dead weight in the form of large flat steel washers. You can do the same on a Forte or a Chrous ll and with a chorus or a forte just lengthen the vents to seven inches long.
     

     

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  7. Wharfcreek

    Wharfcreek AK Subscriber Subscriber

    Messages:
    3,502
    Location:
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    Jim, just where do you put these flat washers? And, is any other type of weight suitable? I ask because I have virtually unlimited access to 'used' auto wheel weights. We've got BUCKETS of old lead weights sitting around the dealership where I work up next to the wheel balance machines, of which we have 3. As to 're-tuning' the other speakers, I presume these are the 'ported' versions....of which I have none. My Forte versions are the II types, so loaded with passive radiators in the rear. I'm not sure how you'd re-tune those. In any event...... I'm OK with the frequency response patterns I have in both my listening areas. My problems have been 'mechanical' in nature....where I either get 'buzzing' or rattling from failed diaphragms or speaker cones. Honestly, I've had amazingly good luck with most my sets of Klipsch speakers.....and have yet to feel a need to rebuild cross-overs or perform a lot of 'mods'. But....'repairs'......yea, I've had more than my share of blown mids and tweeters, as well as torn or failed woofers. I've even had cabinet failure where joints have come un-glued. So, your discussion about 'bracing' hit home pretty well!! Not always necessary, but certainly helpful!!

    Calgary has been on my 'bucket list' since the days of the olympics!! I recall press photos..... particularly of the river front area! Spectacular!! I actually thought about making the trip prior to heading south down into Michigan's UP. I'm guessing you're about 6 hours or so from there? I'd love to see Calgary! Hope I get the chance. My 'other' bucket list area is Great Britain ..... which is probably more un-reachable than Calgary. But, still..... I aint dead yet!!

    Later,

    Tom
     
  8. moray james

    moray james Super Member

    Messages:
    3,087
    Location:
    Calgary on the Bow
    you want to use a flat round weight, lead would be fine, the weight needs to have a low profile so it does not have a cantilever action on the passive cone. fix the weight at the apex of the passive cone which is on the inside of the cabinet. Pull the passive out and you will see where there is already a factory weight there but it is covered in paper. The apex of the cone is truncated and that is the spot.
    Be glad to have you stop by for a visit and a beer or a whiskey and a listen.
     

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