Copying content from the original thread main post verbatim. Design by CJD; Original build thread author —k—

CJD: In-Khan-Neatos – In/On Wall or Stand Mounted RS180/RS150/RS28 3-Way.

The In-Khan-Neatos.

NOTICE 11/29/10: Parts Express has discontinued the original RS Shielded drivers these were designed for. CJD has done some limited testing of the new unshielded 8 ohm drivers and believes that they are near drop-in replacements in the Khan designs. No alteration of the crossover is believed to be required in the standard sealed condition. Ported alternatives may require slight changes in the box size and tuning. See the Statements for ideas. Also note, the RS28F fabric dome tweeter can also be substituted without crossover modifications. If you have questions, please start a new thread in the main forum.

CJD has graciously agreed to do one more crossover design for me, so my post must start out with thanks to him. These are going to be a medium size In/On-wall 3-way. The intent is for them to be the final piece in the Khanspire line. The primary design will be a flush mounted in-wall design, however there will likely be an on-wall crossover version developed to give people a little more flexibility.

What we know so far:

Price: ~$130 for the Drivers + ~$80 crossover = $210/ EACH.
Design: In/On-Wall Sealed MTW 3-way
Tweeter: (1) RS28a
Mid: (1) RS150-8
Woofer: (1) RS180-4
Crossover Designer: CJD

Design Goals

  • Overkill Surround! A 2-way MT would probably be sufficient, but who wants sufficient? I want something that all other men can point to and use as a reference point when negotiating with thier wives for something bigger than Bose.
  • Used as a surround speaker in a 5.1, 6.1, or 7.1 system. So, listened to without toe-in (primarily off-axis), with a big wide sweet spot.
  • Intended to be crossed over to a subwoofer in the 60hz – 80hz range.
  • A bit less expensive crossover than the Khans. Because it will be in-wall, the inductors can be smaller and less expensive. Because it is a surround, perfection within the crossover is not at the top of the list (CJD disagreed with this goal ).

While I’m going to be using these as a surround speaker, there is no reason they can’t be used for front left, right and center speakers. They should work very well at all 7 locations.

The completion of this design probably won’t be completed until May, 2009, as I should be doing other things in my life right now. However, I’m trying to take advantage of the economy and winter pricing to get a good deal on the a contractor to refinish my family room to accommodate the in-wall speakers and in-wall bookcases for my wife. So, I need to finalize the size of the speakers.

So, here we go…

EDIT: DONE!!! 5/25/09:
Finished, in wall:

Boxes next to the Khans:

Box layout:

Baffle layout:



MTW Layout:
Total = 24″ High x9″ Wide x 10.5″ Deep (Outside dimension) = ~24.9L
Mid = 6″ High x 7.5″ Wide x 9″ Deep (Inside dimension) = ~ 6.6L
Woofer = ~ 18L

Insides lined with 1″ of PE Sonic Barrier. Empty space at bottom for the mid and woofer crossovers. Tweeter crossover hung upside down behind the tweeter. Stuff woofer chamber with 2-3 handfulls of Acoustic Stuff or to taste – they will be a little bassy without any. No roundovers on the edges, since it is to be an in-wall.

Alternatively, these will fit perfectly in a PE 1 CUFT Box. Building your own is pretty easy, because the sides, front, and back are all the same: 9.5″x24″. Top, bottom, and divider between the mid and the woofer: 8″x9.5″
Optional Box sizes:
Minimum: 37″ Tall x 9″ Wide x 6.5″ Deep = ~21.6L
Ported: 24″ Tall x 9″ Wide x 13″ Deep = 30L, f3 = 34hz.



(Alternate crossover for stand mounting away from the wall:

Crossover photos.

First up, the tweeter:

Then only a mid that CJD and ET could love. A pair of resistors and a cap are hiding left of the Jantzen inductor.:

Finally, the woofer with it’s tiny electrolytic caps. They’re so small, I’m wishing I would have used 4 small ones instead of two, just to make it more respectable size.


Original thread here: http://htguide.com/forum/showthread.php4?t=32111