Starting to mod KLF-20 cabinet & crossover

[moray james]

KLF 20 Rebuild pictures...

not sure if these two pictures are going to attach. The pictures show the internal braces and how I flipped the vents from the rear of the cabinet to the front. Will post this and see if the pics have attached. Best regards Moray James.

 

[moray james]

found a third picture...

This picture shows both cabinets more or less finished with the vents swapped around and the braces in position. Best regards Moray James.

 

[moray james]

I just recently helped my brother to rebuild the insides of his Quartet speakers. The job was more robust than what I just did on the KLF20 but was a lot more effort as both baffles were secure in place so all the work was done through the driver openings. The Quartet's are like a rock now well worth the effort and time. The Quartet project stretched out over about three weeks of slow going waiting for braces to set up in place with glue and minimum clamps. Best regards Moray James.

 

[LAB3]

not sure if these two pictures are going to attach. The pictures show the internal braces and how I flipped the vents from the rear of the cabinet to the front. Will post this and see if the pics have attached. Best regards Moray James.

Moray
Good Job, I like the braces:thmbsp: Mike will wish he had done this.
His are solid with the braces we added but this is outstanding.
Did the porting chage help the bass?

Louis

 

[moray james]

Thanks Louis: you know if Mike wanted to he could always add some additional braces. When doing the work through the speaker cutouts the trick is to first install the side cleats which the cross braces will sit on. Then the cross braces are cut just a little short so they can be easily placed on the cleats with glue and then set up. Do the side to side braces then the front to back and where possible tie the two together for additional strength.
I am installing parts into the crossovers at the moment. I got some of these incredible German C-Core auto transformers that Set12 used in his Forte rebuild. The main reason for switching the vents is practical for placement. With the vents on the front the speakers can be placed closer to the front wall in a smaller room. Vents really ought to be on the same side of the cabinet as the woofer(s). These speakers are a gift to my daughter and she will be away at school for a few more years living in smaller quarters so the front firing vents will make life easier and the speaker will take up less floor space. Since the vent action is only happening in the low to mid 30 Hz range I don't think that the sound will change much (front Vs back). I have another set of KLF20 for myself and unless I am blown away by the difference I don't think I will switch those vents around. Will post as soon as I have the crossovers done and have had a chance to listen to the speakers. Best regards Moray James.

 

[SET12]

I got some of these incredible German C-Core auto transformers that Set12 used in his Forte rebuild.

Nice work Moray :thmbsp:

BTW people those C-Core Autotransformers that I and Moray have, truly are incredible. In contrast to the ALK and Crites they are smoother and more spacious sounding with lots of body. IMO there is just something to be said about large cores whether for Inductors, Autotransformers or even the 28lb output transformers I use for my 10 watt mono SET amplifiers.

In the case of my output transformers. I had the opportunity to compare my Hammond 28lb tranny's to some popular 6lb James. Subjectively both trannys seem to have the same top end bandwidth that I could hear and both exhibited the same sense of size and space.

But thats were there likeness stopped. From there the sheer sense of low bass foundation along with upper bass and lower midrange body clearly over whelmed the James.

As with large Air Core Inductors body and authority rule making tiny inductors sound wimpy in contrast in my experience. The same is true for the high frequency Inductors I found.

Cheers

SET12

 

[idadude]

Hey Moray James....

I haven't been able to get to mine for a while since the day I took them apart. I've been working seven days a week with many of them being 12-14 hour days. I haven't checked this thread for a while and I was impressed to see the progress you've made with your 20's. I don't think I can take off the front & rear boards of mine since Klipsch really poured on the glue (excessively), but after checking, they seem to be on quite well and probably don't need removal.
Your 20's will be sooooo much better compared to the stock ones you started with and it looks as if we will be getting a report of the audible transformation from you before you get one from me. I may get some free time next week, so I'll see if I can make some headway on mine then. That's some nice work you've done on your cabinets!

Larry

 

[LAB3]

Larry one of Mike's front motor borad was still stuck but we got it out.And the other one was SOLID so we did not remove, we just added 1x2 for extra bracing............ Moray used a rubber mallet and if you use a sharp tool to cut into the seams to cut into the glue then try Morays way with the mallet.

Moray removed his front and back board Much quicker then we did. And his extra brace he built was a great idea and very well done.:thmbsp: I am watching this with great intrest as I really like the KLF20 and 30.

 

[moray james]

Regarding before and after...

with my brothers Quartets we really went to town with 3/4" ply braces and stiffeners and 3/4" strapping. We dropped in a set of KLF20 woofers in place of the stock woofers so we had to open up the rebate to make the new woofers fit. The finished cabinet rocks harder than my Forte ll do stock. We have the stock speaker risers removed and the speakers are up on 12" four post Skylan stands custom made to fit the Quartets. I expect that when the crossovers for the Quartets get the full treatment with new c-core auto transformers the improvement will be bigger than the combined cabinet braces and new woofers. Best regards Moray James.

So much for the pictures which were supposed to attach to this. Hmmm.

 

[moray james]

lets try the pictures again...

perhaps they will attach now.

 

[moray james]

Last try for today...

not sure why I am having trouble post these pictures but if they fail to attach I will try another day. Best regards Moray James.

Modifier Klipsch Quartet fitted with KLF20 woofers.

 

[moray james]

one of the things I did with the kLF20 was to replace the stock washers under the feet with washers almost three times as thick and quite a bit larger in diametre. I also installed 0.5 mm thick lead washers fitted in place with a layer of Weldbond on each side. So the order is foot insert new steel washer adhesive lead washer adhesive cabinet. The stock washers had deformed under the load of the cabinet weight. The new ones will not bend and the lead washer will provide wide band damping. Best regards Moray James.

 

[idadude]

Moray - You have an ideal situation......

Moray James,
I got thinking about it and you have a great set-up there with two pairs of KLF-20s. Once you get one pair rebuilt you can do a live side-by-side comparison between the modded 20s and a stock pair. You won't have to try and remember what the stock pair sounded like since you have an actual pair there. Make sure you give us your impressions when you give them a good listening to. It would be nice to hear your initial impressions and then your later opinion once everything gets settled/ burnt-in. You could also tell us what is lacking soundwise in the stock pair. It looks as if you will get yours done long before I get mine finished. Later........

Larry

 

[SET12]

Yep! exactly what I did with Fortes, its really telling of course. At one point I got so far into mods that it became absolutely shocking to people.

 

[moray james]

Neither of these sets of speakers are the first I have rebuilt like this. As would be expected reinforcing the cabinets results in a cleaner tighter sound. There is just about an elimination of box talk so the speakers do a much better job of going away. What I have not yet had a chance to correct is to reinforce the mid horn walls which are thin and will flex under hard drive. After that I guess that getting the drivers time aligned would be the next big improvement which is something that can be done with the KLF20.
Bracing the cabinets this way makes the kind of difference which is very easy to hear and you would not want to go backwards. Best regards Moray James.

 

[LAB3]

Yep! exactly what I did with Fortes, its really telling of course. At one point I got so far into mods that it became absolutely shocking to people.

I AM Shocked "Every" time I see them, and what Moray has done with his cabinet wood working skills. Next week I will pay the kids down the street to bring in the DIY cabinets my Late Dad made back in the 1960's . one looks like a Big Cornwall/Belle with University Classic Big Folded Horns and a larger Gold Jenson tweerter that kind of looks like a Cornwall tweeter but a little bigger. 15" woofer ( I am selling my old Corvette and thought I would throw some bucks at Pop's old speakers.) It's like SET told me you have $$ one day and wonder if going to have a job the next year. Trying at 61 to stay retired, younger wife has job for insurance and 401K. :thmbsp:

The second box looks like a LacSala/Khorn as the woofer is installed backwards and back and top are meant to be a corner of a wall odd looking KHorn/Lacala is best way to explain from memery, They were in late Mom's Lake House (always in A/C until last year. I had Lowes build me a 12X14 metal Barn and water tight and they are in there. I know they need to be in house..... anyway I want to restore and refinsh them. The big Cornwall was in the middle of a 10foot
cabinet and the other was on the other side of a big living room and it was laid down (NOT desiged to be up in corner,) it bounces bass off walls. Back tall ports.) Dad retworks had two knobs to adjust the horn and tweeter. Dad was like Moray and hand built them in his wood working shop. Expensive 1" thick real wood.screwed and glued together. You two will see where Pop was at back then. Paul Klipsch was his Hero Pop drove a new pick up and trailer to bring home his first Khorns new from Hope ,Arkansas to Fort Worth, Texas in 1966.He had a new McIntosh seperates then. I was 16 and chasing girls in older brothers 409 Impala.Dad Always had the Best tunes when I was growing up.....Lets Party at Lou's hose:yes: when parents seperated and Mom was gone over seeing the Lake House being built. :thmbsp: Dad was 90 when he passed 2 years ago and never got to see the his DIY until Mom passed and I got them and showed them to him 40 years later. Change women and lose 1/2 of you r equipment.:tears:

Louis

 

[moray james]

Louis: it would be great to see some pictures of your Dad's DIY work if you have a camera please post some so we can take a look. I am not that far behind you and am trying to make a living off of audio but it gets tougher every year it seems.
Thanks for your kind comments but I am not really a very good wood worker, fair but not good. While I do have training (wood products manufacturing) for me diy has always been a means to an end, to get something I could not otherwise afford. I have never done the DIY stuff because I loved doing it. For me DIY is an effort which requires much energy to see to its end. I do take satisfaction but I could never make a living rebuilding stuff. I guess the point is that with a little help most reasonably handy guys can make significant improvement to their gear with some effort. If you were looking to buy a new set of speakers which were as solid as the Quartets or the KLF's I posted pictures of you would be well into the 10K range. I think that Dan (SET 12) has the right idea in that the networks will be the easiest to upgrade and have a significant impact on the sound. If you can combine the networks and the cabinet you have a super combination and you can do it over time.
Speakers have always been the weakest link in the audio chain so any significant upgrades at the speaker can make a vast improvement in your system.
If you bought a used set of Forte ll or KLF20 for say $500.00 and spent $1500.00 on top quality crossover parts and diaphragms then if you bought a used ASL AQ1003DHT integrated amp for $500.00 you would have a superb basic system for $2500.00. By audiophile standards that is next to nothing. For most guys I know that's not chump change but think what most guys spend over say ten years attempting to upgrade their systems. It is money well spent in my mind. A good friend who has had a set of Harbeth HL5's for a couple of years now was shocked when he heard my brothers Quartets with only minimal work on the crossovers. His Harbeth's set him back $5200.00 plus another $600.00 for the stands. Used Klipsch and some DIY effort can bring a lot of audio satisfaction for a very reasonable outlay. Best regards Moray James.

 

[LAB3]

Louis: it would be great to see some pictures of your Dad's DIY work if you have a camera please post some so we can take a look. I am not that far behind you and am trying to make a living off of audio but it gets tougher every year it seems.
Thanks for your kind comments but I am not really a very good wood worker, fair but not good. While I do have training (wood products manufacturing) for me diy has always been a means to an end, to get something I could not otherwise afford. I have never done the DIY stuff because I loved doing it. For me DIY is an effort which requires much energy to see to its end. I do take satisfaction but I could never make a living rebuilding stuff. I guess the point is that with a little help most reasonably handy guys can make significant improvement to their gear with some effort. If you were looking to buy a new set of speakers which were as solid as the Quartets or the KLF's I posted pictures of you would be well into the 10K range. I think that Dan (SET 12) has the right idea in that the networks will be the easiest to upgrade and have a significant impact on the sound. If you can combine the networks and the cabinet you have a super combination and you can do it over time.
Speakers have always been the weakest link in the audio chain so any significant upgrades at the speaker can make a vast improvement in your system.
If you bought a used set of Forte ll or KLF20 for say $500.00 and spent $1500.00 on top quality crossover parts and diaphragms then if you bought a used ASL AQ1003DHT integrated amp for $500.00 you would have a superb basic system for $2500.00. By audiophile standards that is next to nothing. For most guys I know that's not chump change but think what most guys spend over say ten years attempting to upgrade their systems. It is money well spent in my mind. A good friend who has had a set of Harbeth HL5's for a couple of years now was shocked when he heard my brothers Quartets with only minimal work on the crossovers. His Harbeth's set him back $5200.00 plus another $600.00 for the stands. Used Klipsch and some DIY effort can bring a lot of audio satisfaction for a very reasonable outlay. Best regards Moray James.

Hey Moray........... wife is into Canon like we are Klipsch. I will have her take some pictures. I hate what Flicker has done changing the way to move jpegs from there to forums...grrrr. I will get them posted up on new thread.
I really just want to recap what Pop had built and see how "He Liked" a speaker to sound. Problem is my little 3/2/2 brick house is super small.
No room for a Khorn and these don't match as Pop was going make a second one that was like the Khorn looking cabinet but never did. I can cut a board:scratch2:......retired

Tool&Die Maker....Air Craft tooling for a landing complay that made the F-16 gear back in the day. :yes: if they Blow Me away I will open the back wall to the den and double the size of that room. 30X30 then.I will need expensive subs then for HD Bluray movies. It never ends. :thmbsp: next project.

Louis

 

[moray james]

Am going to be off line for at least two to three weeks. Will check in when I can. Just did not want my friends here to think I had suddenly lost interest. Will look forward to seeing the hard work of others when I get back. My daughter is getting married on the east coast shortly. Best regards Moray James.

 

[battradio]

Just curious how much internal volume was lost with that much bracing and if it wouldnt have been beter to start from scratch so the internal cabinet volume would end up correct and not changed so drasticly ,so it it would be easyer to tell if the volume change ( cubic foot) was also changing the sonic charictoristics .