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Deang

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Guest David H

There was (is) a guy selling those wooden horns on Ebay that looked similar to these. Are they similar?

These are similar, though I try not to make to many assumptions about the sellers design.

What I can tell about the design is that it is a CNC cut Elliptical stacked wood design. I seem to recall seeing this technique used in the past.

Dave

Edited by GotHover
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Guest David H

Here is the frequency response, looks like the DE-120 is going to be the better choice drop in replacement for the K77

The DE-10 would be ideal, but won't fit in the Khorn, Belle, or Lascala.

drivers3.gif

Edited by GotHover
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The 38 and the 120 both have Mylar diaphragms, so from that perspective they will have a similar sonic signature, but the 38 dips down pretty low in an area that's kind of critical. It's almost at a point where it doesn't look like it has enough sensitivity to make for a good match -- the 120 is much better from end to end.

Unrelated but related, John Warren once posted about the relationship between bandwidth and transients -- if I can find it I'll post a link to it.

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Dave et al,

I do not mean to offend and I applaud you for your hard work. But are the graphs for the different drivers accurate and repeatable? From the driver data on the B and C website your results are surprising to me. Were they surprising to you? I am a humble amateur.

Eric

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Manufactures apply smoothing to their curves. Also, and this is the important part: the driver is mated to a horn of the manufacturer's choice. If you change the horn (like has been done here) - it changes everything (distortion figures, on-axis and off axis frequency response, etc).

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The following just sent to me by Al:

Dean,

To the guy who questioned my plots, here's a plot that Lee Clinton did. He may be referring to the Log scale, which spread out the low frequency. Mine are on a linear scale to best show the high frequency.

post-1106-0-49760000-1383862486_thumb.gi

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Dean et al,

OK linear and log plots can be hard to compare, my bad. But still B and C claims approx 107dB sensitivity at say 10KHz and Lee measures 90? And I am only questioning to hopefully learn and understand more. So the different horn lenses are making that much difference?

Eric

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Guest David H

Eric, the sensitivity of the driver is 107db at 1 watt.

Lee did the response testing approximately 90db at considerably less than 1 watt .

If you go to the B&C graph, I think you will find the frequency response results are very similar.

Dave

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Manufactures apply smoothing to their curves. Also, and this is the important part: the driver is mated to a horn of the manufacturer's choice. If you change the horn (like has been done here) - it changes everything (distortion figures, on-axis and off axis frequency response, etc).

There is so much truth to that. I have personal experience with that very situation.

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The measurements I made weren't at any particular input level such as the industry "standard" of 1 watt @ 1 meter or 2.83V @ 1 meter.

As an old RF engineer, I am used to seeing the linear spectrum scale that Al uses. While the ARTA acoustic software program I use can display either a linear or logarithmic frequency scale, I prefer log for audio use as it reveals more readable low frequency information. I suspect the use of a logarithmic frequency scale on the X-axis came into use for the same reason as the decibel scale on the Y-axis; both are logarithmic quantities and as a result, are able to display a wide range of values (voltage and frequency) in a compressed display.

Lee

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Thank you Lee. Al has been sending me updated info for this thread, I just haven't had time to post it.

From Al,

To Eric on the forum:

Look at the same frequency on both plots. They are nearly the same below 10 Khz where it really counts. At 4500 Hz for example. both plots show about 103 dB SPL. Above 10Khz they show a difference. I would tend to believe Lee's plot. He did the tests in a better environment using software that emulates anechoic conditions. Mine were done in my office. Tweeters are difficult to measure anyhow! All of the three drivers were measured under the same conditions and are good for comparison. Lee will soon be doing testing on the DE120 driver.

Also:

I am worried by the difference between Lee's plots and my plots above 10 KHz on the DE38 driver. I was very careful when I did the comparison of the three driver and I trust Lee. I can't figure why the difference. I think B&C made an error in the scale marking on the published curves. It shows 5 dB / division. I think it should be 10.

Me: I suggest from this point on that only the DE120 be discussed. It will avoid further confusion and it is after all the primary driver of interest. Again, just a suggestion.

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