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Author Topic: higher output replacement comp drive for EAW KF650e/is (or alt cabinet?)  (Read 4028 times)

James Heyser

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I welcome feedback on why this is unnecessary as well as how it can be accomplished. 
Or even a comparable cabinet that has a little more throw (with no sacrifice in quality, I'm a tone-junkie!).

The specs on the compression driver are 3db less than the 10" midrange, unlike the KF850 where they are spec'd equally.  If I could get 3 more db out of them they would basically be an 850 with poorer pattern control and almost half the weight.

I'm running L16 towers and trying to maximize my throw/coverage without switching over to to an array (too much $$$!).

I can accommodate up to four 250 lb cabinets on the L16's, and the 650's dispersion patter is great at that height (not too loud up front, some shows I even skip the front fills 'cause it sounds clean up to the first few feet).  The sound gets a little blurry at 150'.  This is probably all I should expect from them, but I thought maybe a little more beefy high end (in balance with the capacity of the mids) might give me another 50 feet.  There's a lot of potential ticket holders in that zone!  :-)
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Matthew Knischewsky

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How many 650s are you running now?
In my experience, I have never been looking for the extra 3dB the spec sheet says the HF is missing in the max SPL. Usually I have problems with the 15" keeping up. At 150' I think you're experiencing the end of realistic expectations for any box in that category. For more projection you'd need a lot more trim height and 2 rows of boxes per hang with some shading to get even coverage from front to back.

Are you running at max SPL for your shows? That's really the only time you should notice the HF isn't keeping up, the sensitivity is the same as the MF.

a couple of potential issues with just changing the HF driver-
-the 15" driver is directly behind the HF driver and there isn't much extra space there. any replacement would need to fit there.
-The sensitivity of the HF is more than just the driver, it's also the horn flare it's mounted to.
-any change of driver or horn is going to change the acoustic x-over point.
-if you're thinking of using the 850 HF driver, it's 10 ohm nominal impedance compared to 8 for the 650's. that's going to alter the passive EQ network in the box which won't be correct anyways for any other driver but the OEM.

Have you considered adding delay speakers?



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James Heyser

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How many 650s are you running now?
In my experience, I have never been looking for the extra 3dB the spec sheet says the HF is missing in the max SPL. Usually I have problems with the 15" keeping up. At 150' I think you're experiencing the end of realistic expectations for any box in that category. For more projection you'd need a lot more trim height and 2 rows of boxes per hang with some shading to get even coverage from front to back.

Are you running at max SPL for your shows? That's really the only time you should notice the HF isn't keeping up, the sensitivity is the same as the MF.

a couple of potential issues with just changing the HF driver-
-the 15" driver is directly behind the HF driver and there isn't much extra space there. any replacement would need to fit there.
-The sensitivity of the HF is more than just the driver, it's also the horn flare it's mounted to.
-any change of driver or horn is going to change the acoustic x-over point.
-if you're thinking of using the 850 HF driver, it's 10 ohm nominal impedance compared to 8 for the 650's. that's going to alter the passive EQ network in the box which won't be correct anyways for any other driver but the OEM.

Have you considered adding delay speakers?

I'm running four as two pairs, suspended by 10" chains from 16' towers.  Not sure if I've really topped them out yet, end of the month I likely will, so I'm thinking about it more.  I've heard that the 850 drivers don't fit, as you said it's a tight squeeze.  I've been reluctant to implement delayed repeaters, but I guess it's time I bit the bullet and gave them a try.
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Rich Frembes

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Matthew's list of potential issues is spot on. Another thing to consider: here's a graph of high frequency air loss you typically encounter at 150 ft.  Add, er, subtract this plus whatever bad things are happening where the horns overlap and methinks a 3 dB more sensitive driver may not get you where you need to be.

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James Heyser

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Matthew's list of potential issues is spot on. Another thing to consider: here's a graph of high frequency air loss you typically encounter at 150 ft.  Add, er, subtract this plus whatever bad things are happening where the horns overlap and methinks a 3 dB more sensitive driver may not get you where you need to be.

I understood going into this discussion that it was likely I was at my limit with this rig.  But 2.5db would get me the same result at 200 feet I now have at 150 (except for however that graph might change, I do get that the higher frequencies fall off faster).

Again, I figured I was at my limit (excluding repeaters), just wanted to be sure I wasn't missing something.  I do enjoy how it performs now, just reaching for a little more.
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Peter Morris

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I welcome feedback on why this is unnecessary as well as how it can be accomplished. 
Or even a comparable cabinet that has a little more throw (with no sacrifice in quality, I'm a tone-junkie!).

The specs on the compression driver are 3db less than the 10" midrange, unlike the KF850 where they are spec'd equally.  If I could get 3 more db out of them they would basically be an 850 with poorer pattern control and almost half the weight.

I'm running L16 towers and trying to maximize my throw/coverage without switching over to to an array (too much $$$!).

I can accommodate up to four 250 lb cabinets on the L16's, and the 650's dispersion patter is great at that height (not too loud up front, some shows I even skip the front fills 'cause it sounds clean up to the first few feet).  The sound gets a little blurry at 150'.  This is probably all I should expect from them, but I thought maybe a little more beefy high end (in balance with the capacity of the mids) might give me another 50 feet.  There's a lot of potential ticket holders in that zone!  :-)


The HF drivers in the 650 and 850 are very similar. Its the small horn flare in the 650 that impacts on the output more than anything. Usually the 15 runs out first, but in some situations it can be the HF driver.

I found that the 650z will go noticeably louder than the 650e.  The mid-high section is more efficient  (109-110) .  If you raise crossover frequency between the sub and 15 from 90 to 120hz so you can take advantage of the output capabilities of the mid-high section without the 15 running out you will get about 3 db more output compared to the 650e.... not far off the 850!

Peter

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Matthew Knischewsky

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But 2.5db would get me the same result at 200 feet I now have at 150

Did you take into account that if the HF is louder at the back it's also louder at the front? So the spectral balance will be tilted towards the HF for the first 100 or so feet before flattening out and eventually rolling off. This is why I suggest delay cabinets to pick up where the air losses become too great to overcome. Yes, they are kind of a pain to set up and align but done properly well worth it. Any box from any manufacturer is going to be subjected to the same air loss over distance. Perhaps going to a box like the KF750 might help, but you'd need at least 3 per side to get comparable coverage. and they are heavier than 650s.
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