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Starting to mod KLF-20 cabinet & crossover

looks like the xovers fit nicely in the bottom. I like the dynamat. dumb question here, whats the difference between the stuff that looks like tape with dynamat written on it, and the stuff that looks kinda like a dark grey construction paper?

can't wait to hear your impressions on how these sound
 
nrap said:
looks like the xovers fit nicely in the bottom. I like the dynamat. dumb question here, whats the difference between the stuff that looks like tape with dynamat written on it, and the stuff that looks kinda like a dark grey construction paper?

can't wait to hear your impressions on how these sound
Click to expand...

The dark grey is actually a 1\4" foam, with adhesive on the back. I wasn't sure I needed tape to seal the seams, but since I've never done this before, I did decide to get the tape. Turns out it's looks exactly like the "duct tape" we use at work - it's silver, thin with incredibly sticky adhesive. Not to be confused with the common grey, clothy "duct tape".

So, I just used the tape to cover the seams and edges of the thick foam stuff.
 
Still a few more gussets to get installed

Finished up the last few front baffle gussets. Hopefully, this cabinet will be ready for assembly tomorrow.

Also picked up the Armstrong ceiling tiles, this supposidly has the "good" fiberglass acoustic that costs more when not formed as a ceiling tile.:dunno:
 

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that foam won't do much

Dingman said:
The dark grey is actually a 1\4" foam, with adhesive on the back. I wasn't sure I needed tape to seal the seams, but since I've never done this before, I did decide to get the tape. Turns out it's looks exactly like the "duct tape" we use at work - it's silver, thin with incredibly sticky adhesive. Not to be confused with the common grey, clothy "duct tape".

So, I just used the tape to cover the seams and edges of the thick foam stuff.
Click to expand...

I have found that dynamat is best for damping the horn body to damp it in fact I brace and damp the horn when the walls are as thin as they are on the KLF20 and the CF3 horn. Best regards Moray James.
 
Dingman said:
Sorry for the mess of glue.. it is a bit runny at first and I'm sure not going to err on the side of NOT ENOUGH glue, I'm gonna make sure it's TOO MUCH GLUE. HA HAHSHAHAHAH. :banana::banana:
Click to expand...

Too much is the way to do it. Wet paper towels will clean that right up.
 
Stopped using the Dyna-tape

I decided to stop using the tape I bought for the Dynamat. The tape is nothing special and the Dynamat sticks well enough that I don't think the tape is needed. And the "seams" seem to seal up pretty well, so no tape there either.

I did wrap the magnets, not sure if it's needed, but it's done now.
 

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Loctite and speaker gasket

I put speaker gasketing around the flat and worn out looking original gasket on the speaker connection mounting plate.

Didn't really work well, too thick and so the plate deformed somewhat when mounting.

Also used loctite on the backside\crossover connections in addition to the original locking washers. Can't hurt, right?

I had some small pieces of Dynamat left, they ended up on the plastic ports. Can't hurt, right? LOL.:scratch2:
 

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What's the dimensions of the ports?
Is the inside opening apps 3.2 inch diameter?
And outside apps 4.75?

I still haven't found a pair.

Anybody with klf 10s that can give their dimensions?
 
nrap: the KLF20 vent is 3" internal dia. The unflared length is just over 1.25 inches same for the flared section, mouth of the flared section is 4.25 in dia.. Id. of the hole in the cabinet is 3.25 inches. So why don't you start off with a straight tube of 4 inches in length? I think that after you redamp the cabinet you will find that a tube length somewhere in the 4 - 6 inch length will damp the drivers very well. You can make testing tubes out of rolled up card stock and some tape. If you go with a flare on the outside your vent tubes will be shorter. What ever you decide to do tuning is not hare to do by ear and even easier if you use a cd with a steady state test tone.
Use a test tone no lower than 28 - 30 Hz and adjust the length of the vent tubes for minimum cone motion at the chosen tuning frequency and you are done. I chose a reasonable tuning frequency of 30 Hz for these woofers with my KLF20 speakers. Hope this helps best regards Moray James.
 
Moray,
I hate to bug you about this, but i want to be sure here.
If you measured the outer most diameter of the klf20 plastic port, not the actual opening but the edge of plastic to edge of plastic, is it about 4.75 inch?
i've got a lead on a pair of 20 ports, taht i want to use on my 30's (because mine are missing). I think they are exactly the same but want to be sure.

i haven't been able to play around with adding port length because im missing 2 ports, and they wouldn't be the same diameter and flare if i made my own. Hopefully these are the same. I'd really like to try adding a bit of length to them
 
the rebate in the baffle is just under 4 7/8" dia.
I can't see why you have to wait to find a specific plastic vent to play with your tuning. Four pieces of thin cardboard stock and some tape any you can roll a tube to fit the cutout in the cabinet and make them what ever length you want. A paper tube works as well as a plastic tube or what you have got in hand at the time. An eighth inch larger or smaller makes very little difference and paper is fast and easy to test with, tape and a pair of scissors and you are in business. Don't make this harder than it needs to be. Any difference in vent dia is simply offset by the length it's no big deal it amounts to exactly the same thing in the end, wider tube longer vent, narrower tube shorter vent. If you find a pair of stock vents later you can use them with some paper extenders there is a little flange expressly for a tube extension in the stock flared vent. Hope this helps. Best regards Moray James.
 
awesome. yeah they are the same then. thanks for the measurments.

I had just figured if i could tape some craft paper or whathaveyou to the existing (or non existent in my case) vent it would act as a solid place for the paper to anchor to. And give it a proper shape.

im a bit of a port noob. So longer narrower tube, has same effect as a shorter wider tube? or do i have that backwards?
 
backwards. Just play with some vents and a cd with some test tones. Klipsch state 34Hz. as the 3db down point so tune for 32 Hz flat with the stock damping. If you damp the top section of the cabinet (down to the bottom of the mid horn) with high density fiberglass tune for 30 Hz flat. I tuned my Quartet like this and got grate bass into the upper twenties. Best regards Moray James.
 
Hope you get to feeling better!
can't wait to hear your feedback on the mods.

i got my replacement ports today! been hounding every seller on ebay selling klf parts for 3 months. most blew me off. finally one guy responded asking for specifics and he came through!
 
Yup, thanks, got over my virus and couldn't wait to get these speakers back together.

Cut and slammed in some of the ceiling fiberglass - kinda messy, hard to fit in as it was glued into "blocks".

Did not do the felt on the spider thing. Maybe later.

I did get washers epoxied together for one speaker - LOL, didn't find enough of the right kind of washers in my garage, so one is stock feet. But neither speaker showed signed of "pulling through" or anything, so it's OK for now.

So ultimately, I ended up with a pair of speakers that - aren't the same. The internal bracing is the biggest difference. That means the crossover mounting is slightly different and getting those crossovers in and out can be done - if you're good at puzzles.

One speaker has the washers on the feet, the other doesn't. One speaker I not only crimped the connectors on the spade end, I also flowed a little solder in there. But didn't do that on the other one, thinking about when I want to take the drivers our, for example, for the felt\spider install.

So, I don't think any of the differences will result in a difference in sound - I'm good there.

The speakers have been playing at a moderate volume for about 8 hours, and at low volume for another 16 hours.

I haven't done the A\B testing with the ChorusII's yet. I'm gonna try to take alot of time to decide which speakers I want to keep.

I can tell you this so far - these suckers are "bright". The top end is just that - on top of everything else. I like the bright sound, but this is almost too much for me. I'm sure this is related to the crossovers. Not positive, but I might even have a buzz that *I think* that I *might* have heard from one speaker. I need to go back and play that same track again, thru both the CII and the 20's. But it might be these speakers are now showing all sounds with sometimes painful clarity.

At this point, I can say the ChorusII's are more laid back but they've had the crossovers\ti tweets in them for months now.
 

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I guess one of my last big questions would be this - have I changed the tuning of the cabinet?
  • Does the "tuning" only affect the low frequencies?
  • What's the best way to tune a speaker like this?
  • Do I need an expensive frequency analyzer? Or can I use my phone with that Audio Tools App?
 
if you changed port length or the internal volume of the cabinet then yes. But my guess is the internal volume of cab is now slightly lower, but extra fiberglass should help counter that. and the volume probably wasn't changed significantly. i'd say not a big deal.

I agree they are BRIGHT. On my 30s the bass is def there. thumpier than my chorus. but the klf's just SCREAM at times.

do you have the stock diaphragms in both horns?
 
Midrange is stock, the Tweeters have Crites Ti's in them. The Ti's have been in for over a year, ran them when the speaker was stock.
 
the Ti mids do sound better. But im not sure they are any less bright than the phenolics.
i was so eager to hear your impressions of the crites xover in hopes that it would result in a slightly smoother sounding speaker.

I've read people say their klf's sound a little recessed in the mids. Not mine. Especially the vocals to upper midrange frequencies.

update us on your impressions after you've burned in those new xovers.
 
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