zobsky contemplates a variation on the belle klipsch

[zobsky]

FWIW, here's a post detailing DJK's logic in choosing the rear chamber size / tuning frequency for the ported mod. Note his recommendation for a bit of EQ boost and his comments on the use of low Qts woofers . https://community.klipsch.com/index.php?/topic/108425-la-scala-bass-reflex-mod/?p=1202059

If the bass is overdamped, I can employ my old (restored) mcintosh MC2100 that has a damping factor of about 10

 

[zobsky]

I'm in the process of preparing a cut list for the major parts. I didn't component-ize my initial rendering (and therefor cannot easily explode the enclosure) so had to erase a few surfaces to view the internals.
Here's a shot of the rear.

 

[zobsky]

Here's the computer generated cutlist for the basshorns using 3 sheets of ply. I also decided to double up on the rear face (the sides are already doubled).
Now, I need to figure out how to get the rough cut pieces into my car

 

[zobsky]

... And an alternative cutlist using crosscuts first (might be easier to fit into a car)

 

[zobsky]

On further introspection, it seems more efficient to add a center brace to the throat area (large unbraced area), rather than double up on the rear.

My personal rule of thumb is to leave no panel width of greater than 8-12" unbraced. I'm stretching the rule a bit but there should be enough scrap to add further bracing if needed. The important thing to note here is that this is a horn, so the orientation of the brace is as important as the position. Also, excessive bracing can affect the flow of sound waves through the horn

 

[zobsky]

The kappa15c drivers have arrived - brand new and unused, except for battered shipping cartons

 

[zobsky]

Plywood (3/4" baltic birch) has been been cut (about 2.5 sheets worth + some offcuts) . I had a local lumber yard ( Hardwood Lumber Company of Dallas ) make precision cuts for me this time so I don't have to hack at the ply for days in my cramped garage. I've attached the cut list I used to this post. Amazing what will fit in a compact hatchback. I'll soon post a (slightly) corrected sketchup rendering that matches up with the cutlist

 

[zobsky]

Almost done with the pair of midbass horns. Need to glue up the rear chamber, add braces and seal the top. The pic is of a test fit.

 

[weltersys]

Zobsky,

You will either need to rout a surround relief slot or use a "donut" gasket to keep the driver surround from hitting the baffle on excursion peaks.

Art

 

[zobsky]

Zobsky,

You will either need to rout a surround relief slot or use a "donut" gasket to keep the driver surround from hitting the baffle on excursion peaks.

Art

Forgot about that , I'll deal with that then . Will 1/4" MDF be okay ?

 

[zobsky]

Zobsky,

You will either need to rout a surround relief slot or use a "donut" gasket to keep the driver surround from hitting the baffle on excursion peaks.

Art

I'm guessing that doubling up on the gaskets should work. any thoughts ?
Official Speaker Repair Site - Orange County Speaker - Home of GLS Audio Speaker Gasket - 1 Solid Piece (for 1 speaker)

 

[djk]

An externally hosted image should be here but it was not working when we last tested it.

 

[zobsky]

Thanks. Unfortunately, one of the doghouses has already been glued up. Ill see what's possible wrt routing

 

[zobsky]

How deep is that recess? The kappa15c only has 2.4 mm linear xmax

 

[djk]

Looks like 6mm or so, but could probably not be done if all glued up.

 

[weltersys]

I'm guessing that doubling up on the gaskets should work. any thoughts ?

With only 2.4 mm Xmax, an extra gasket (or 1/4" MDF) should provide plenty of clearance, but increases front chamber volume more than the surround recess I suggested that DJK showed.
Increasing the front chamber volume should slightly reduce the HP frequency.

 

[zobsky]

With only 2.4 mm Xmax, an extra gasket (or 1/4" MDF) should provide plenty of clearance, but increases front chamber volume more than the surround recess I suggested that DJK showed.
Increasing the front chamber volume should slightly reduce the HP frequency.

I bought a 1/4" x 2" x 4" piece of MDF,.. mostly because it's cheaper , incompressible , easily available and more customizable than an off the shelf pair of gaskets . I can always add SOME of the internal offcut circle to the front chamber to reduce its volume . More info after i butcher the wood

 

[moray james]

just wondered if you have seen this thread might be of some interest.

https://community.klipsch.com/index.php?/topic/154589-port-location-for-belles-with-bass-reflex/


I just noticed that you have responded there. Others might find the thread of interest.

 

[zobsky]

just wondered if you have seen this thread might be of some interest.

https://community.klipsch.com/index.php?/topic/154589-port-location-for-belles-with-bass-reflex/


I just noticed that you have responded there. Others might find the thread of interest.

From his sketch, I like the way his reflex ports straddles the mid-treble horn. Yet another variation to ponder ....

In a week or so when I'm done with the bass bins (I'm taking this build slow and easy, for a change), I'll start tackling the mid-treble section. Do you have any suggestions for the top half? I'd like this to be a 2 way design. I'm not even sure how much a K501 costs but I don't care to pay any more than needed just for a klipsch badge. That said, I came across this post

http://www.diyaudio.com/forums/full...-trynergy-full-range-tractrix-synergy-51.html

and found the horn cheaper at
Official Speaker Repair Site - Orange County Speaker - Home of GLS Audio PH2380 17.5" x 11" Horn

 

[GM]

From his sketch, I like the way his reflex ports straddles the mid-treble horn.

More work, but better overall to put them next to the HF horn; otherwise make a foam horn extension to cover its perimeter out to the vents similar to the one used on the Altec M19.

GM