Sensitivity of each Khorn section

[artto]

Which driver/horn section of the Klipschorn has the highest sensitivity, the bass, mid or treble? In other words, which part requires the most attenuation in the crossover network?

[Coytee]

My guess is squawker... be interesting to see what the answer is.

[Guest " "]

The sqawker or mid driver, hands down. While there are variation amoung the ceramic vs alinco, the t-35 (k-77 ceramic version) has an spl of 105db at 1w from 3000hz to 15000hz. The PD5HV (k-55-v alinco) has an spl of 110.7db at 1w from 110hz to 4100 +-5db.

The woofer is not even in the race.

[D-MAN]

Concur. The midrange driver is the most sensitive. It is also 16 Ohms.

The woofer/bass horn (+9db) and tweeter are not attenuated.

DM

[Duke Spinner]

mids....

have to be attenuated to match the bass bin ....

[Deang]

The woofer is not even in the race.

Actually, the Klipschorn's bottom is more sensitive than the tweeter.

[D-MAN]

The raw sensitivity of the K33E is approx . 96db (average across a frequency band) but when in the horn AND in the corner, that adds +9 db (or more) to its sensitivity. That is at least a 3-fold increase (ha, pun intended!). That means approx. 105db overall.

DM

[Deang]

!

[artto]

The reason I asked is because I read a paper by Bruce Edgar that Gil posted a while back & I thought I read something where he (Edgar) said his bass horns, or the Khorn bass horn, had the higher sensitivity of the all the speaker frequency sections. At first I thought that was weird, but then after thinking about it I thought it might be because of the trihedral corner loading. Maybe someone from Klipsch could ring in this one since we've gotten so many different answers? Or is this "TOP SECRET"? hehehe []

[D-MAN]

If that's what Edgar said, he was wrong - the midrange is the most "sensitive" component in the Khorn.

Perhaps he was alluding to the fact that the output of the bass horn sets the overall efficiency for the speaker system, the other components being attenuated as needed to match it.

DM

[JohnA]

Yes, the K-55-V/X (PD5-VH) is the most sensitive at 107 dB/w/m mounted

on a horn. The 110+ rating is on a plane wave tube. You

might even be able to call the K-55-V 108 db/w/m if you wanted

to. The K-77s are 105 db/w/m and 104 or 105 is probably right for

the bass horn.

[Deang]

I was going to say that if you used the peaks in FR of the lower section you could actually call the lower section 107dB.

[ZAKO]

Like I said on another forum site.....I dont know why any one listens to Bruce Edger about The Khorn design.....He knows less about the Klipschorn than I do....

[ZAKO]

DeanG........You need to take the peaks & trophs into consideration and not just the Fs.

[Deang]

I understand that Maron, but that's not how we always see it being done!

[WMcD]

Gee, my name got dragged into this. I don't know what article that may be. I posted quite a few.

Generally, the bass horn and the tweeter of the K-Horn have the same rating of 104 dB at one watt, at one meter.

We see that looking at the A crossover. There is no attenuation except for the midrange. It (midrange) is knocked down 3 dB by the autotransformer. Therefore its un-attenuated rating should be 107 dB. At least that is the fair reverse engineering interpretation.

The Belle and LaScala use similar crossovers and therefore, basically, PWK was using the same rating for those smaller bass horns.

It is interesting that the crossovers for the CW and Heresy basically use the same scheme where the bass units have progressively lower efficency or sensitivity. (Technically, the terms are different, but not to go into that subject.) The midrange is always on an autotransformer tap 3 dB lower than the tweeter. In these systems, both the tweeter and mid have to be knocked down to match the bass unit which is less efficent.

= ==

For the record, PWK commented that he use to run the bass horn without even the single inductor in the A, and said "its worth a couple of dB." That is probably from the Edgar (!)interview. Where the few dB were in frequency response, is not reported. However, overall, 104 seems to be a good number for the bass horn, in my view.

= = =

If I may comment on John A's comment regarding plane wave specs of the Atlas midrange, of 110 dB or whatever.

I must admit I thought I saw a 110 dB or so on a plane wave tube on the Atlas spec at 1 milliwatt, not 1 watt. But looked at the Atlas site spec tonight and the drive level does not appear, that I can find. It must have been some other source of information, perhaps for another manufacturer.

In any case. We know the plane wave tube is pure resistive load. But also, the driver is looking into a tube the same size as the driver exit, about 1 inch in diameter. So the entire pressure is fed into that small area. It is the same size as the throat (small end) of a horn.

The measurement microphone is situated at the side of the tube near the driver in making the plane wave tube measurement.

One way of thinking of this is that the microphone is not 1 meter away from the mouth of the horn, and out in the room. Rather it is at the throat.

The sound pressure there is as high as it can get. Any measurement microphone would be blown out. Therefore the electrical drive level has to be very low. Maybe 30 dB down, which would be a milliwatt.

The bottom line is that any dB level of the measuring microphone on a plane wave tube is not being done at one watt. The response curve can have interesting information. But we have to be careful about translating that to what we see 1 meter out in a room on a given horn.

Best,

Gil

[JohnA]

Gil,

I have a .pdf of the PD5-VH spec sheet from 2003. It does show

110.7 dB at 1 mW. I didn't check it, but I remembered the spec

was for a plane wave tube. I erroneously assumed it was at one

watt.

[WMcD]

Thanks. Sometimes all of us have the "I read somewhere." This was my turn.

Gil

[Nklipsch]

Great PWT pic !

http://www.leesound.com/bw_photos/photo15.jpg

:-)