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Need help with Khorn clones!!!


Herc

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Hello all,

Im finishing off some Khorn clones using the following parts:

Beyma Cp-25 tweeters

EV 1824M midrange (on wood tractix horn)

JBL2225H (if I recall correctly) 8 ohms.

I have done the 6" throat mod to the horns also.

I am tri-amping them,as I do not have the passive crossovers yet and the items were on hand.

To drive them Im using:

Nikko 450 amp for lows

Teac 700LP amp for mids ( to be replaced with a Dynaco ST70)

Sonic Impact amp for highs ( to be replaced by Teac amp later)

I am using a DBX 234 crossover ( I know.. not so good).

My question is, the lows seem to be lacking punch? They dont seem tight and the volume is not what I expected, Being an 8ohm woofer does that matter in a active crossover setup?

Any help would be appreciated.

Thank you

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Check the phasing on the bass bins.....you may need to reverse the polarity of the connections.

The woofer issue....check the JBL225H spec's against the spec's of a klipsch k-33.

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Hey speakerfritz, can I simply change the phase with the invert button (low) on the crossover or is that different all together?

And the woofer issue.... are the specs that far off for me to be using the JBL compared to the Klipsch version? Cant check at this time myself.

Thanks in advance

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" can I simply change the phase with the invert botton (low) on the crossover or is that different all together?"

You can, as long as it covers the entire woofer scope, and not just a sub woofer line out.

post-22082-13819314883936_thumb.jpg

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There could be several things that are causing it...

First, check for air leaks, are you POSITIVE that everything is sealed effectively?

2) wiring polarity is an issue, of course, if out of phase, you cancel. Start by ensuring all of the wiring is connected with polarity in mind.

If in phase, suprizingly some cancellation depends on the room and its proportions. Changing ONE woofer polarity can give an indication of whether the room is providing some cancellation of low frequencies based on distances and reflections. If it gets louder with one woofer out-of-phase, then the room is a problem.

4) cabinets form an effective seal with the corner? This will increase the LF response.

5) the woofer may not be optimum for horn loading. I'm unfamiliar with the driver you mention. First, get and post the T/S specs for that driver and we'll go from there...

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Sorry to say but it appears that your woofer is a poor match for the khorn cabinet. Using Hornresp (an excellent horn modeling program) and your woofer specs (http://www.pispeakers.com/JBL_2226.pdf) I get a response of:

original.aspxoriginal.aspx

Compare this with the model of the K33 with a 3 x 13" slot, shown above.

I would suggest you download the program then contact me for the khorn parameters. I would then play with stuffing, slot size, etc. to see if you can get the woofer to behave better.

As a side note the 8 ohm is generally not a problem. I have used 8 ohm speakers very successfully in the khorn cabinet.

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Would "imitation" khorn speakers make you happy colterphoto1? Why would I try to make an exact copy if Id rather have the original but dont? I have an 1966 Ford Mustang coupe that is not worth restoring to original so why not make it what I want? Thanks for the help.

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Yes, I mean stuffing the rear chamber. Unfortunatley the woofer in question is so far off that it does not change anything. However the K33 does respond. The light grey line is with loose fiberglass. It is why you should'nt do it with this driver. Note the high end rolloff.

original.aspx

As a side note I don't see anything wrong with using different drivers. You just need to be carefull with your selection. Matching, not more power, is the key.

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How can you possibly call them Khorn clones with that complement of drivers?

A Klone is the enclosure, not the drivers! The so-called "Klipsch" drivers are Atlas, EV, Eminence (and/or whatever is the cheapest for Klipsch to buy)... who cares about cheap drivers?! Michael, you've got to quit "worshipping" the wrong things...

DM

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Dylani,

Waves, what waves? If a tree falls in the forest does it make a sound? You do not hear the back chamber. The stuffing changes the characteristics of the backchamber thereby changing the operating characteristics of the woofer, thereby changing what you hear from the horn. Stuffing will change different woofers/speakers differently. My AR speakers need it, my khorns do not.

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Dylani,

Waves, what waves? If a tree falls in the forest does it make a sound? You do not hear the back chamber. The stuffing changes the characteristics of the backchamber thereby changing the operating characteristics of the woofer, thereby changing what you hear from the horn. Stuffing will change different woofers/speakers differently. My AR speakers need it, my khorns do not.

Oh, yes you do! I beg to differ! The reflections come back through the cone out of phase. This creates what I can only call "muddiness".

Only Klipsch doesn't use any absorptive material in the horn's back chamber, even when there are parallel walls like the LS, Belle and Jub.

I would agree, however, that due to the Khorn having no parallel surfaces in the back chamber, that it suffers from less reflectivity problems than the others, but I also think that it can have less "muddiness" if reflections are suppressed, but that is my opinion only.

Not really a good thing IMO. This does not mean that you need to add so much material that it alters the response of the driver, only to supress the interference from internal back chamber reflections and standing waves.

DM

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Great quote but not really fitting here. LOL. Reflections play a part in any speaker and the doghouse on a Khorn has to reflect some waves back through the woofer which will cause cancelation. Lets not be quick to write this off. I am willing to move on this point but please give me some supportive evidence other than Tree's in the Forest. However I did like the reference.[:D]

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