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DIY heresy


mungkiman

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Perhaps my search technique is improper, but I am looking for a project, as well as good advice.

Can anyone provide dimensions/details for a Heresy cabinet?

Can anyone tell me if the following components are compatible:

Type E network, large oil caps

K-22-E woofer

PD5-VH (Atlas) mid w/800 Hz EV 8HD lens

T-35 EV tweeter

Any help would be appreciated. Thanks,

Chris

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That combo should be great!

The type E crossover point is 700 Hz, but at 6 dB/octave. I'll bet the E-V horn can cover the 700 Hz crossover point quite well. Six dB/octave is such a mild crossover point and 700 to 800 Hz is only a note or so apart; it should not be audible.

I'd be more concerned with the 8HD's response above 4k Hz. Mr. Paul designed his horns to reduce dispersion as frequency rose to correct for falling response from the PD5-VH at high frequencies (all compression drivers do this).

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Thanks John! What is the upper crossover point? I guess I'm asking how much you think I might miss above 4K Hz. before the tweeter comes into play.

Is there anyone that can help me with the dimensions, ply thickness(es), bracing details? Helpful information or references would be greatly appreciated.

Chris

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Dimensions vary a bit depending on cabinet style and material. My Decorator Heresys (no recess for grill) are approx. 13.25 x 15.5 x 21.375 and made of 3/4" plywood. No internal bracing. Just 3/4" cleats for the back panel to screw into.

Type E network is fine for the components you have listed. Just make sure the T35 is an 8 ohm model and has the phase plug like the K77s. And make sure it is a T35, not a TW35 or any of the smaller magnet OEM versions of the T35.

I am not sure, but IIRC, the 8HD is longer than the K700 horn. You might have to adjust dimensions accordingly to accomodate.

Crossover points are 700 Hz and 6000 Hz.

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Your issue on internal volume is going to be dependent on the mid range horn size and a clear picture of the Xover performance. It seem some folks have enough info on the performance to say ok to the Type E.

The size of the mid horn may be the deciding box issue. Ask Trey Cannon at Klipsch for the woofer T/S measurements and then apply a tried and true box program such as WINISD or BoxPlot to build the box. The caveat is that the Heresy box is really on the edge for the length of the original mid horn and if the new mid lens is a couple of inches longer you will have to adjust the depth accordingly and (if possible) apply the 'golden ratio' to the other dimensions.

Should be no problem with a bit of care.

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Don't have an easy way to post a picture of them right now. The only real difference is that the decorator Heresys have a flat front and no grill. The regular ones have a recess in front in which the grill sits. I think Klipsch's intent was that the decorator version was to be built into something and the regular ones were ready to go furniture. The decorator versions were made right along with the regular ones for many years. Total enclosed volume of all the Heresys is close enough to call the same.

Hmmm... maybe the correct term is designer not decorator. Don't recall for sure anymore. Any way, the front of them looks like the theater version in my icon.

K-22-E was one of the woofers Klipsch used with the Type E crossover.

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Thanks to everyone for your interest and information. The overall length of driver and horn is only 10.25 inches without the dust cap.

If I am thinking clearly, the internal volume would be close to 11.75 x 14 x 19.875. Is the back panel flush with the sides or recessed? In models with grills, are the speakers deeper by the thickness of the grill panel?

I wish I knew of a speaker design program for Macs. I know I would enjoy using BoxPlot or other such tools, but don't know of any for my computer. Any suggestions out there?

Does the shape of the internal volume affect anything? Could I build a corner Heresy or Cornwall with good results, or is this another can of worms entirely? Thanks again,

Chris

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----------------

On 1/10/2004 1:25:21 PM Malcolm wrote:

Don't have an easy way to post a picture of them right now. .... Hmmm... maybe the correct term is designer not decorator.

----------------

Just though I'd post the image... and your were correct in calling them "decorator" versions as they were often sold unfinished (ideal for a decorator who wants a custom finish 2.gif )

IMG_1223-web1.jpg

post-11489-13819251324768_thumb.jpg

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Thanks all.

Malcolm, part of the reason I was asking about box shape has to do with my Shorthorns. By keeping the top intact, but re-building the back chamber of the Shorthorn, I could achieve the same internal volume as the Cornwall. It could also have the same port dimensions available between the "legs", but a different box. Istead of being rectangular, the top and bottom plates of this box would be 6 sided like half a stop sign, if that makes sense. Finished, the Shorthorn would look the same as it does now (the side grills would be dummies) and wouldn't HAVE to be in a corner. Mine would.

I know I would need a different motorboard, crossover, woofer (mine are 16 Ohm), and maybe a different mid lens, but I'm OK with that. The mod would be reversible, the woodworking would be relatively simple, but I don't know if it's a good idea.....

Any thoughts out there??

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16 ohm woofers? The early ones were 16 ohms, alnico, made by EV or CTS, and went with Type C networks. Most of the K-22-Es I have seen were 8 phms, ceramic, made by Eminence (E = Eminence), and went with Type E networks, a few with Type D networks. I have seen an alnico K-22-E and thought it too was 8 ohms. Is there an EIA code you can see on the woofer like 67-xxxx. Might be under the label. The 67 indicates Eminence manufactured it. If they are 16 ohms, it only takes a change in one cap and the autotransformer taps to change a Type E into a Type C.

Increasing the volume to that of a Cornwall may or may not be a good thing. Some of the early woofers, like the one based on the EV SP12B might benefit from more volume and a ported design since there were designed for such use, not sealed cabinets. Don't know how other flavors of the K-22 would do. You would have to measure the T/S parameters of the woofers you have to figure out how well they would work. I measured K-22s manufactured from 1965 through1978 and the parameters were all over the place. Just goes to show you how forgiving a sealed design is relative to some others.

Of course, if you have a Cornwall size cabinet, you could always shoot for the stars. It would just take the appropriate woofer, a K-600 lens, and the appropriate network or modifications to your network. You already have the hard to get piece, the autotransformer.

In any case, it all sounds like fun. I am in the very slow process of building octagonal cabinets with marble tops for some of my Heresys so they look more like furniture than speakers.

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Sorry if I confused you or anyone else along the way. Currently, I have everything I need for project 1 (Heresy), but it led me to thinking about improving my existing Shorthorns too (project 2). I would keep everything for the Heresy project, but would change my woofers (16 Ohm Trusonics), as well as the networks, motorboard, mid horn lens, etc. in the Shorthorn mod. Thanks,

Chris

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