John Warren Posted January 3, 2010 Share Posted January 3, 2010 Here's the unit the measurements were taken with. Note the removable throat. An o-ring type gasket was machined in the baffle to provide a good seal between the plate and baffle. Also not the v-notches on the opposite side of the baffle that grab the horn outer wall. They stiffen the wall signficantly. Quote Link to comment Share on other sites More sharing options...
John Warren Posted January 3, 2010 Share Posted January 3, 2010 Tucked in corner. Quote Link to comment Share on other sites More sharing options...
DrWho Posted January 3, 2010 Share Posted January 3, 2010 The top of your bin isn't sealed? Quote Link to comment Share on other sites More sharing options...
John Warren Posted January 3, 2010 Share Posted January 3, 2010 The AK-4 LF section is a mod that attempts to tame the peak amplitude response in th 100-200Hz region using a notch. The mod is worth doing but it begs the question-why go to all the trouble of horn loading if you have to throw gain away to obtain a linear amplitude response?(?). Quote Link to comment Share on other sites More sharing options...
ClaudeJ1 Posted January 3, 2010 Share Posted January 3, 2010 The AK-4 LF section is a mod that attempts to tame the peak amplitude response in th 100-200Hz region using a notch. The mod is worth doing but it begs the question-why go to all the trouble of horn loading if you have to throw gain away to obtain a linear amplitude response?(?). Indeed, sir, indeed. Which is why I'm a fan of modern surround sound receivers with the Audyssey EQ. It automatically does that. Better yet, put Grasshopper's measurment rig together and get a Behringer DCS 2496 Xover for Bi or Tri-amping (little T-amps are all you need for mid a tweet) and flatten those suckers out at the sweet spot and get them time aligned in the process. It's all bits anyway on the front ends, eh? Quote Link to comment Share on other sites More sharing options...
John Warren Posted January 3, 2010 Share Posted January 3, 2010 Indeed, sir, indeed. Which is why I'm a fan of modern surround sound receivers with the Audyssey EQ. It automatically does that. Better yet, put Grasshopper's measurment rig together and get a Behringer DCS 2496 Xover for Bi or Tri-amping (little T-amps are all you need for mid a tweet) and flatten those suckers out at the sweet spot and get them time aligned in the process. It's all bits anyway on the front ends, eh? Claude- The 100-200Hz peak is an amplitude domain error, best fixed via a conjugate. Time domain errors are what EQ is all about (room nodes and so on). Quote Link to comment Share on other sites More sharing options...
freddyi Posted January 3, 2010 Share Posted January 3, 2010 Hi John - are the results of AK-4's notch filter perceived to be in general "better" than type A/AA? - are there published LCR values? (or guestimates?) - my 77 Khorn with CTS gives the graph below - I've not tested my 85 set but they seem to sound 'flabbier' (could be old caps) - is the 4mH/100uF lowpass considered to be a better blend to K400 vs type A? (assuming reasonably low drive Z) -- Best, Freddy Quote Link to comment Share on other sites More sharing options...
DrWho Posted January 4, 2010 Share Posted January 4, 2010 The mod is worth doing but it begs the question-why go to all the trouble of horn loading if you have to throw gain away to obtain a linear amplitude response? But you're not really throwing gain away...changing the electrical signal before the driver doesn't affect the acoustic loading on the driver. Depending on how the EQ is implemented, the amplifier might have to work a bit harder, but the amp should never be the bottleneck on system performance. Quote Link to comment Share on other sites More sharing options...
AltmanEars Posted January 6, 2010 Share Posted January 6, 2010 The plot below is interesting. It is the impedance modulii of the K33e (1980s vintage) in free air (hanging from a wire) and the same mounted in the folded unit with the folded unit tucked into a basement corner (all three sides poured concrete). The beneficial effect of a concrete corner is signficant. The radiation resistance provided by the horn is at a maximum when placed in a location like this. The loading provided by 2x4 studs + blueboard + plaster veneer is not as good as shown below. Note that the horn likes to work into the 100-200Hz range(!). The unit that was used in the measurements is one that allows for changes to the throat opening. The slot was a 3" wide one shown in the pics. So the takeway here is that the Klipchorn works best in a concrete corner. That pretty interesting but does it address the user who has the 2x4 studs +++ and concrete which is typical of your average man cave. Quote Link to comment Share on other sites More sharing options...
AltmanEars Posted January 6, 2010 Share Posted January 6, 2010 Greg relative to Khorn improves I had a chance to go to your website which in turn lead me to the Klipsch museum. There is an odd speaker (Khorn) with the tweeter mounted in the throat of the squawker under a sign that says Mahoghany Klipschorn. One really wonders if this is/was an improvement to the Khorn. The second improvement which is not generally thought of as an improvement in the US is to mount the passive crossover in a dead/hardened box outside of the speaker. Living voice, Tannoy and a few other highend folks think this works... Quote Link to comment Share on other sites More sharing options...
John Warren Posted January 6, 2010 Share Posted January 6, 2010 That pretty interesting but does it address the user who has the 2x4 studs +++ and concrete which is typical of your average man cave. It does not address that nor was it meant to. Quote Link to comment Share on other sites More sharing options...
seti Posted January 6, 2010 Share Posted January 6, 2010 Greg relative to Khorn improves I had a chance to go to your website which in turn lead me to the Klipsch museum. There is an odd speaker (Khorn) with the tweeter mounted in the throat of the squawker under a sign that says Mahoghany Klipschorn. One really wonders if this is/was an improvement to the Khorn. The second improvement which is not generally thought of as an improvement in the US is to mount the passive crossover in a dead/hardened box outside of the speaker. Living voice, Tannoy and a few other highend folks think this works... Mounting the crossover in a box is probably a good idea. For example just crack open a Heresy I or Cornwall I and look at the crossover in comparison to a Belle, La Scala, or Klipschorn crossover where it is exposed. The Heresy or Cornwall crossovers are in incredible shape. I did this the other day and the oil caps were shiny and the solder joints looked great. Not sure if there was a difference in performance. I do know not to toss out old klipsch crossovers I posted a pair on ebay with a BIN of $90 but someone bid instead of buying and ran the price to $280. check this late 70's heresy Quote Link to comment Share on other sites More sharing options...
msutton Posted January 7, 2010 Share Posted January 7, 2010 The unit that was used in the measurements is one that allows for changes to the throat opening. The slot was a 3" wide one shown in the pics john, would you happen to have plots for any other throat sizes you might have tested with the K33 you could post? Quote Link to comment Share on other sites More sharing options...
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