• Please note that there are a few updates and clarifications made in the Audiokarma Rules, mostly relating to advertising and the addition of the new "Paying it Forward" & "Giving back" forums in the AudioKarma Audio Marketplace section.

Cornscala Build Finished

Arrow

Arrow

Member
Hello,

This is my first post here.

I just finished my Cornscala build from Crites website. This is my very first experience with horns. The sound stage is huge.

As I am breaking them in, I can't help but wonder if I the box needs some interior dampening/treatments. As per the instructions it is bare wood inside: no fill, no lining.

The box is stiff (3/4" ply with 1/4" veneer) with a decent brace side to side and thick backing all around.


Is there any point in lining the the interior of the box with NoRez or fibreglass? Any suggestions would be great. I plan on doing some frequency sweeps once I get the room a bit more together.

Thanks for looking
 
Register to hide this ad
take a look at this book if you want to see how to brace and stiffen a cabinet like yours. I don't expect that you have left much volume to account for brace materials so you likely won't be able to do this retro full hog but no reason to to throw in 10-15% worth of materials. Damping will depend upon how much volume you use to brace but traditionally you only need to damp the back a side and a top with a reflex design.
you should be prepared to add a brace to the back sides and top and also horizontal braces to the baffle between the driver and the horn, You will also want to include stringers to tie the braces together at one or more points and if you can contrive it to have the stringers tie to one another. This adds tremendous stiffness to the cabinet walls and will push the panel resonance up an octave or more. for a cabinet the size of a Cornwall I would use baltic bich ply and the wall braces would be 1.5" thick by 3.75" wide stringers would be 3/4" by 1.5". You can also include 45 degree brackets as much as you can fit in and the stiffer and more rigid you make the baffle the better. Hope this is of some interest.
You can see a link to the brace job done on a pair of Heresy 3 this is all solid oak as I wanted the greatest strength and stiffness from the least amount of material . You will see every panel is double braced and all the braces are interconnected at least twice. I have also included a link to sow brace work on a larger cabinet of about 3 cu.ft. volume. Best regards Moray James.

http://www.amazon.com/Build-Speaker-Enclosures-Alexis-Badmaieff/dp/0672205203

http://www.audiokarma.org/forums/showthread.php?t=372783&highlight=klf20
 
thanks for the fast reply.

here are a few cel phone images. You can see there is a large brace for the horn which goes side to side and a shelf brace between woofer and horn. The XO braces the rear baffle somewhat. Horns and woofers are surface mounted. Finish is cherry with oil.

Overall, sound is great. Pretty happy with it and really good value. I'll be doing some nice photos soon.

Realistically, I am hoping for a little more bass control and 'presence' in the room. That said, you can see from the final photo that the room is a little bare at the moment. Curtains, rug, plants, art to come and will calm the sound a bit I'm sure...

I wil have to check my volume again regarding if there is any room left for more bracing. As I mentioned above, the front and back baffle have a 1/4" ply laminated on which really stiffened it up well.

I was mainly hoping to get some info on what dampening will do to the sound and what materials are best...?
 

Attachments

  • IMG_3008.jpg
    IMG_3008.jpg
    52.2 KB · Views: 244
  • IMG_3014.jpg
    IMG_3014.jpg
    68.2 KB · Views: 240
  • IMG_3030.jpg
    IMG_3030.jpg
    75.3 KB · Views: 240
  • IMG_3001.jpg
    IMG_3001.jpg
    63.5 KB · Views: 288
  • IMG_3031.jpg
    IMG_3031.jpg
    61.2 KB · Views: 202
  • IMG_3089.jpg
    IMG_3089.jpg
    52.2 KB · Views: 325
Looks like you did a fine job on the build. You might want to try placing your speakers on the long wall start with an equilateral triangle centre to centre of the cabinets to you head all the same dimension. Best regards Moray James.
 
moray james said:
Looks like you did a fine job on the build. You might want to try placing your speakers on the long wall start with an equilateral triangle centre to centre of the cabinets to you head all the same dimension. Best regards Moray James.
Click to expand...

Thanks. I will be repositioning them on the long wall in the fall, once I get a sofa.

I am still learning a lot about listening to horns. My previous experience with building speakers was all open baffle. These interact with the room and with toe-in much differently than anything else I am used to.

I will add some fibreglass to the inside of the cabinets next time I open them up. Any pointers on material and amount?
 
Great job! Always wanted to hear these! I had Cornwalls and knew the Cornscalas are the best of both worlds. By the way nice rig, what is your setup? Tubes for the horns?
 
Thundermud said:
Great job! Always wanted to hear these! I had Cornwalls and knew the Cornscalas are the best of both worlds. By the way nice rig, what is your setup? Tubes for the horns?
Click to expand...

They seem pretty great right out of the gate. My friends have tweaked LaScala's and I've heard them plenty. But it is always different in your own space.

Currently very happy with my VPI Classic and Leben 600 (tubes). I will be looking to update my cart and phono pre in the coming year.
 
Thanks everybody. I'm still waiting to find decent spikes for them and I buried magnets under the veneer to (eventually) get around to a grill.
 
You don't need much by way of damping as the reflex vent is tuned to do that job (damping the driver box resonance) all you need is 1/2 - 3/4" of that high density yellow fiberglass they make those flexible acoustic ceiling tiles with. This is just enough to catch mid range reflections inside the box (the upper range response of the woofer) and eat them up and keep them from escaping via the vent. You might also try a set of four (per cabinet) of those Teflon glide disks sold for fridges and stoves you will find them at hardware stores. I have had better success with those than with spikes and they make speaker positioning really easily. Best regards Moray James.
 
i put this stuff in the back and on the port shelf:
TYROTEX.gif

because of the thickness and density i doubt it has much impact on lower frequencies. but atleast it was a noticeable improvement. more dynamic midbass and a cleaner lower midrange.
 
Last edited:
Hey there, I built the set on Bob's website bout halfway down the page. I have had them now for about 3 years now and just love them!! About a year ago I decided to line mine ( nothing over the top, just some plain ole polyester white, inch thick stuff from my local parts guy) and wish I had done it earlier, what a difference, everything just seemed to come together so much nicer, more musical, the tiny bit of mid shout I would get from crappy recordings was gone and the bass became much deeper and more importantly more defined!!!!
 
Thanks again for the info and compliments. I would certainly recommend this project for anyone wanting in on the Klipsch sound without having to deal with older gear. Less than $2K for this type of soundstage is unbelievable.

I am getting a bit of an upper mid shout on older and poorly recorded records. At this point I am still chalking that up to my room which is pretty loud right now.

you guys just glue the insulation/poly to the inside, or staples maybe...?

Anyone wrap the horn with that stuff too? ...couldn't hurt...?
 
You must log in or register to reply here.
Back
Top Bottom