K33 alternatives for Khorn/Cornwall clones?

[DizRotus]

Im grateful to everyone for the valuable input regarding the relative merits of the T35 vs. the Beyma CP25 in the thread, Beyma CP25 .

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Also in that thread there was some discussion regarding squawker drivers for a wooden Trachorn. That too was useful.

Its now my plan to eventually again make Klipsch type bass bins (I built Speakerlab SKs thirty years ago), unless I can obtain a pair of suitable existing bass bins. I know that Al K. has recommended using the Klipsch bass bins and drivers as they are. Can someone direct me to the specifications of the K33 so that I can consider an Eminence or similar equivalent?

To further complicate the matter, I plan to make <?xml:namespace prefix = st1 ns = "urn:schemas-microsoft-com:office:smarttags" />Cornwall style cabinets as an interim measure until I am able to complete or obtain the folded horn enclosures. I intend to follow the advice of Dean and Al and use the Trachorn driven by the K55 crossed at 300 Hz with the Cornwall-type enclosures and eventually the folded horns.

Again, your insights and advice are welcomed.

Thanks,

[Frzninvt]

Drop in replacements:

K-43

EV 15WK

Stephens TruSonic 15

K-33J (Jensen P15LL)

Any other drivers used would have to be close the T/S parameters of the woofers above.

I think that the gains would be minimal due to the limitations of the horn, or cabinet enclosure. Unless you totally redesign and go with a high quality JBL driver.

[D-MAN]

K33E from Marvel's past post: (keep this handy) -

From Eminence:

=============

SPEC 15162

PART # K-33

RE OHMS 3.39

FS HZ 34.46

LE MH 96

MMS GMS 78.59

QM 7.39 CMS

mm/N .2714

QE .410

RMS NS/M 2.3037

QT .390

VAS LTRS 301.66

XMAX MM 8.20

SD SCM BL TM 11.88

EBP 84.4

EFF % 2.91

SPL dB 96.6

Wattage 150rms

Now, bear a couple of things in mind: The K33E is not going to match the Khorn by T/S specs, it was derived from empirical testing before T/S specs came into existance.

The K33E doesn't follow the rules as we know them. It really does need the narrow 3" wide throat slot. My advice is that for the Khorn, the K33E is probably best. If you want higher power handling capability, then you need to go with an 8 Ohm driver for the widest selection, which means that you may have to alter the crossover to match the impedance for smoothness as well as the throat opening cavity (slot). How much work do you want to do?

The specs on the Khorn are Vb = 4800+ cu.in (about 3 cu. ft) , St=39 sq. in., Fc=40 Hz.

Note that the ACTUAL throat cross-section size is 78 sq. in., it's just a smaller slot opening for the exclusive use of the K33E. All other drivers should use the maximum size (up to 78 sq. in.) allowed for 1:1 efficiency (96.5 db to match the standard Khorn upper frequency drivers). If you go for higher woofer efficiency, then you presumably would also have to move to other high frequency drivers, etc.

For bass-reflex use, there are many other drivers that would fit the bill. Personally, I think the K33E is best used as a bass horn driver rather than a direct radiator, but there are a lot of satisfied CW owners out there! Sort of depends on how much you want to spend.

In general, direct radiators usually use a heavier cone structure than the K33E sports to prevent deformation. Lighter cones work better in horns. The Gms of the K33E is less than 80 grams, towards the light side. Some direct radiators Gms approach 200 grams being quite stiff and having a rapid rolloff in the upper bass frequencies.

DM

[Tom Mobley]

excellent post D-Man. It should also be pointed out once again that the K-33 is heavily optimized for the Klipsch boxes.

It's also a tremendous bargain, new from Klipsch they're about $130 shipped. You'll have a tough time beating that or even come close.

[WMcD]

There are two different application. A box and horn.

Regarding the vented box or CW clone. PWK had said that Don Keele did an analysis of the CW and found it to be very close to a Butterworth design.

This sort of thing is very well understood these days and there are lots of computer programs which will guide you.

If you are going to build a bass horn, I would suggest you go with a Jubilee. It is far easier to cut and has better performance. Also, we all here need more info on this from home builders.

In the area of bass drivers, I think there is a lot of oddball information which has to be sorted out. For example. Classical theory puts driver resonance Fs at Fc of the horn. In the AES paper on the Jubilee, it looks like that is done. Yet in the K-Horn, the Fs is lower.

Best,

Gil

[formica]

For bass-reflex use, there are many other drivers

that would fit the bill. Personally, I think the K33E is best used as a

bass horn driver rather than a direct radiator, but there are a lot of

satisfied CW owners out there!

I would have to agree on that... as well as the fact that the two types

of enclosures would require different x-overs as well.

Something important to keep in mind when building a temporary

enclosure... esp the assc costs.

Rob

[DrWho]

The eminence magnum drivers are pretty close in T/S parameters (though they actually require a smaller cabinet for the same performance).

[DizRotus]

If you are going to build a bass horn, I would suggest you go with a Jubilee. It is far easier to cut and has better performance.

After seeing the photos of D-Mans Jubilee project and after building Khorns, Im not sure if I agree with the easier part. More important, what does D-Man say?

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Irrespective of the relative difficulty, reviewing the Jubilee posts has me seriously considering going that route, unless D-man talks me out of it.

[colterphoto1]

I don't know the specs, but when my original CW's were having the woofers reconed, I slapped a couple of EVM-15L drivers in there. Sounded great and massive power handling capability. Not coincidentally, I had previously designed an all-in-one PA cabinet around those drivers and it was almost exactly CW dimensions ! Had EV 1823 horn and the EV (k77) tweeter as well.

(insert twilight zone music here...)

Michael

[WMcD]

Professor Lidenbrock has contacted me. A very strange fellow.

He points out that most parts of the Jubilee are rectangular and of the same height, which is about 38 inches.

So if you start with a few 4 x 8s of plywood and rip them to 38 inches, you've made almost half the cuts necessary

Maybe he'll tell us more.

Gil

[bigdnfay]

I used 6 sheets of 3/4 plywood. This will allow you to build 2 Jubilee bass bins and have enough left over to construct upper cabinet for the mid and tweeter. The tops and bottoms (bass bin and upper cab) will take almost 2 sheets, depending on how you orient the grain.

Big D