John Curl's Blowtorch preamplifier part II - Page 2883 - diyAudio
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Old 2nd November 2012, 02:51 AM   #28821
fas42 is offline fas42  Australia
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Originally Posted by Joshua_G View Post
It depends on whether there is a dynamic amp which reveals deficiencies elsewhere in the system, or whether an amp may be both dynamic and having a harsh sound to it.
Yes, the problem areas can certainly be inside the amp, in fact in earlier years I found most power amps to be problematic, at least on casual listening. The latest breed seem to be considerably improved in key areas, another example that made the right noises for me was the Technical Brain monoblocks, but a system problem can still originate from the power amp, definitely ...

Frank
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Old 2nd November 2012, 01:41 PM   #28822
RNMarsh is offline RNMarsh  United States
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Anyone with experience with the GEDDES speakers?
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Old 2nd November 2012, 02:16 PM   #28823
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Anyone with experience with the GEDDES speakers?
OMHO, high HOMs due to brutal angle, damped by foam ...
You should read IMHO, the threads: "Hornresp"; "horn versus waveguide"; "Geddes on waveguides", "reviving the Onken", "Beyond the Ariel"...
Several BEM simulations done by Bjørn Kolbrek:
http://www.diyaudio.com/forums/showt...postid=1765863
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Last edited by Esperado; 2nd November 2012 at 02:21 PM.
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Old 2nd November 2012, 02:32 PM   #28824
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Originally Posted by Esperado View Post
OMHO, high HOMs due to brutal angle, damped by foam ...
You should read IMHO, the threads: "Hornresp"; "horn versus waveguide"; "Geddes on waveguides", "reviving the Onken", "Beyond the Ariel"...
Several BEM simulations done by Bjørn Kolbrek:
http://www.diyaudio.com/forums/showt...postid=1765863
I have a pair of kits that were supposed to be for my listening room, but the return of my unemployed offspring has put that on hold.

They'll probably end up in CA. I made sure we had at least one room with NO abbutters.
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Old 2nd November 2012, 03:07 PM   #28825
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I have a pair of kits that were supposed to be for my listening room, but the return of my unemployed offspring has put that on hold.
"Never having to finish anything." Applies for kid's education as well as loudspeakers kits.
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Last edited by Esperado; 2nd November 2012 at 03:22 PM.
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Old 2nd November 2012, 03:48 PM   #28826
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Well, I'm back on the measurement track. I hope to have somewhat 'better' test equipment in future. I certainly saw some nice equipment at the AES. The Stanford Research audio distortion analyzer is a dream to wish for. I hope to get one, if I can get enough work to justify it.
Of course, I will only measure AM distortion. I will have to rely on the work of my colleague Ron Quan to help me sort things in that department. Still, I have hope for even better audio products coming in future.
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Old 2nd November 2012, 04:14 PM   #28827
gedlee is offline gedlee  United States
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Originally Posted by Esperado View Post
OMHO, high HOMs due to brutal angle, damped by foam ...
You should read IMHO, the threads: "Hornresp"; "horn versus waveguide"; "Geddes on waveguides", "reviving the Onken", "Beyond the Ariel"...
You have this wrong I am sorry to say. My waveguides can be proven to have the least HOMs not "high HOMs". The foam is not to reduce them because they are high, the foam is to reduce them even further than the design allows because they are so low. The foam does little to nothing in a device with already high HOMs.

For example, lets say that we have a device with HOMs of some arbitray number, 100, and we have another devices with low HOMs of say 20. The foam reduces each by 10. The poor device is now at 90, hardly even a noticable change, while the better device has had its HOMs cut in half, a major audible improvement.

Please, let's not continue to disseminate false ideas.
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Old 2nd November 2012, 04:41 PM   #28828
RNMarsh is offline RNMarsh  United States
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Default horns et al

Quote:
Originally Posted by Esperado View Post
OMHO, high HOMs due to brutal angle, damped by foam ...
You should read IMHO, the threads: "Hornresp"; "horn versus waveguide"; "Geddes on waveguides", "reviving the Onken", "Beyond the Ariel"...
Several BEM simulations done by Bjørn Kolbrek:
http://www.diyaudio.com/forums/showt...postid=1765863
I read them.... same stuff.... only Geddes has something new to offer. A lot of re inventing the many horn issues....short length, fast expansion etal. And, his seems to be done the most thoroughly and completely including new designs and original and more complete theory. I'd try them just for that reason alone..... need the bass extension as I would only be happy with high quality to 30Hz. Thx-RNM

Last edited by RNMarsh; 2nd November 2012 at 04:53 PM.
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Old 2nd November 2012, 04:55 PM   #28829
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The Stanford Research audio distortion analyzer is a dream to wish for.
We have one, a beauty for sure. Guess who inside.
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Old 2nd November 2012, 04:57 PM   #28830
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I use YOUR designs in MY test equipment as well. Just not for audio playback.
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