KLF-30 Rebuild Questions

[SnorkelfaceSS]

Thanks for the replies Moray. I saw in another thread you saying the best ratio for the wood pieces being 1:2.5 mounted on the small edge when placed on the front baffle to add structure. For the front-to-back braces, does it make a difference what which way I mount them (assuming they fit between the drivers both ways)? Also, what wood are y'all using?

 

 

[OO1]

11 minutes ago, SnorkelfaceSS said:

what wood are y'all using?

 

 

MDF or BALTIC BIRCH

[Alexander]

I copied what SWL did with bracing both front and back - one between the two woofers and the top woofer & mid-range.

 

[OO1]

17 minutes ago, Alexander said:

I copied what SWL did with bracing both front and back - one between the two woofers and the top woofer & mid-range.

 

so that's what it looks life , a Cross shape pattern ----

[moray james]

plywoood 3/4" thick cut 1 1/4" wide is all you need for your braces and for the stringers to tie yur braces together. typically you are only pushing the first resonant mode up one octave that takes it out of the range which the woofer can excite. 3/4" square along all your panel to panel seams adds tremdous strength but you only really need a 45 degree pieces at the seams but if you cannot cut 45's a square length is just fine, soft wood or plywood are equally fine for this job. This also insures your cabinet is air tight (use white or yellow wood glue).

[Alexander]

 

 

Keep in mind that the klf-30 cabinets are already known to be too small for the k31 woofers used. So we do not want to get too carried away with stuffing a bunch of unneeded wood inside them.

 

 

[PrestonTom]

If you use the right stuffing it can actually make the cabinets "seem 10% larger".

I would follow the Klipsch recommendations. 

[Alexander]

15 minutes ago, PrestonTom said:

If you use the right stuffing it can actually make the cabinets "seem 10% larger".

I would follow the Klipsch recommendations. 

 

Do you know of or where to access those Klipsch recommendations? I am sure there are others that would also like to know about this.

 

 

[PrestonTom]

Did the KLF30's have material inside them to begin with?

 

The 10% rule of thumb, comes as a general statement form JBL engineers. This was for vented cabinets (as the KLF is) using about 1 inch thick material on the 5 sides (nothing on the baffle side). The material can be pressed fiberglass (eg, heating duct insulation boards or insulation blankets, about 3 lbs /cu ft) this is NOT fluffy fiberglass or closed cell foam rubber), or you might substitute Roxul (safe n sound) which is affordable and readily available at Home Depot etc. There are other materials also, along with over-priced stuff that comes with a great deal of folklore about its supposed benefits.

 

My own general comments are some of the guys are going overboard on the bracing. The braces do not need to be massive 2x4s. Lighter stock will work fine if it is well placed and well attached. Additionally, The venting geometry (cross sectional area and length is dependent on the tuning and cabinet volume, and the desired alignment along with the electro-mechanical properties of the driver). That should be what determines whether the cabinet needs to be "larger" or not. 

[SnorkelfaceSS]

Hey all, finally finishing these up. Back to part of my original questions list, is anyone adding a gasket to the woofers mounting surface. I was noticed a slight vibration there on one of the woofers, and the underside gasket on the woofer from the factory is paper-thin. 

[Iteachstem]

I created new gaskets when I replaced the woofers on several klipsch speakers.  It's on the thicker side, so you might want to be careful.  Klipsch cheaps out and only uses 4 screws to mount their metal frame woofers...so there will be slight bending of the woofer frame with this thicker gasket.  (If it was an aluminum frame, this wouldn't even be an issue.)

 

This is what I used:

 

https://www.parts-express.com/parts-express-speaker-gasketing-tape-1-8-x-3-8-x-50-ft-roll--260-540

 

Good luck.

[SnorkelfaceSS]

Awesome, thank you. That's what's I'm using as well. 😁

[Alexander]

 

A fellow member suggested rope caulk and it works quit well I think. It does not harden so it is fairly easy to remove at time of clean up either during install or down the road. It is cheap and easy to come by at Lowes, Home Depot and even Amazon.

 

I used two “strings or beads” pulled off the roll together and lay it down to either the driver or cabinet side, what ever side you prefer.

 

 

 

[Bigfootexpert]

On 10/11/2020 at 7:39 AM, SWL said:

I have two pairs of 30's and over the years I experimented with I think most, if not all of the cheap tweaks that were easily reversible and found zero benefit from any of them. Mortite/Rope caulk on the back of the horns, lining a portion of the inside of the cabinet with acoustical felt, placing weight on top of the speaker for better bass response, adjusting different port lengths etc. etc.

 

The biggest problem with mine (and many others) was the loose baffles on the cabinet and the crossovers taking a dump at approximately 17 years old. If your crossovers are working properly and your cabs are solid, that will solve most of your problems right there and you can be done with it.

 

I went a few steps further and upgraded the tweeters/horn lenses and midrange drivers. Because I had two pairs I was able to compare side by side and my preference definitely favored the upgraded components. Without a doubt.

 

I also took a chance on on some Italian 12" woofers instead of the K-31's and K-31E. Reason is because the original woofers are very difficult and almost impossible to find.....and also to mention their build quality isn't the greatest to put it lightly.

 

I bought my first pair of 30's used about 11 years ago for $500 bucks. I've put about $1400.00 into them (under 2K total) and I was shocked how similar they sound to the new Cornwall IV's ($6000.00 new) I demoed about 10 months ago. Smoothness and lack of forward midrange come to mind as well as a richer sounding bass vs that boxie, cheap cabinet sounding bass I remember previously hearing.

 

If you do nothing else, at the minimum put Crites crossovers in there.....seal the cabs and put in some front to back bracing (a minimal amount). If these speakers are at least functioning properly, they're impressive. I've heard 30's sound bad many more times than I've heard them sound good because they're usually screwed up one way or another. Also, make sure the mid range drivers are not hooked up out of phase. Another common issue.

 

Good Luck!

 

Sent from my SM-G950U using Tapatalk

 

 

 

 

When you upgraded your KLF30's did you notice the ohms for the Ciare HW321? I just received my new CIARE HW321 and checked with the OHM meter and it reads 5.7 even though they are listed at 8Ohm drivers. So depending how I wire them up I will either get a final Ohm load of 3 or 11. Not sure how this will effect everything.

[Iteachstem]

That's not all that uncommon.  Most "8 ohm" woofers aren't 8 ohms on the dot.  I think my KLF-20 woofers measured around 6.7 ohms.

 

[Alexander]

52 minutes ago, Bigfootexpert said:

When you upgraded your KLF30's did you notice the ohms for the Ciare HW321? I just received my new CIARE HW321 and checked with the OHM meter and it reads 5.7 even though they are listed at 8Ohm drivers. So depending how I wire them up I will either get a final Ohm load of 3 or 11. Not sure how this will effect everything.

 

The “8 ohms” is not meant as a DC resistance (via an ohm meter) but rather an AC impedance.  If you look at your OEM klf-30 crossover you will find that the two woofers are wired in parallel netting ~4 ohms impedance that the crossover will “see”.