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Power Response and the Last Dates of the Magnepan 30.7 Road Tour

TitaniumTroy

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#1

In the video Wendell Diller of Magnepan explains about the importance of power response in trying to reach a more realistic stereo experience.
I might try to make some of these dates to hear the 30.7s in a different room than I did in Chicago. Plus I like talking to Wendell Diller in person, to talk about speakers and the audiophile world.
Aug 19 - Kazoo Audio, Kalamzoo, Michigan
Aug 21 - Ovation, Indianapolis, Indiana
Aug 23 - Sound & Vision, Columbus Ohio
Aug 24 - Hanson Audio, Cincinnati, Ohio

Needless to say, RSVP is required and dates may change.
 

amirm

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#2
Hmmm. Harman's research shows very poor correlation between power response and listening preference. So don't know why he says Dr. Toole's research indicates otherwise.
 

Ilkless

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#3
Hmmm. Harman's research shows very poor correlation between power response and listening preference. So don't know why he says Dr. Toole's research indicates otherwise.
I thought the poor correlation was, specifically, with the Consumer Reports target for flat power response. A smooth power response is still desirable - a sign of off-axis directivity control and matching.
 

Floyd Toole

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#4
The Magnepan description at 2:15 minutes or thereabouts, describing "Toole's" research is totally wrong - an outright lie. The first requirement of a good sounding loudspeaker is its on-axis response, second, it's early reflection response, and at low frequencies, its steady-state in-room response. Sound power by itself is a poor correlate of overall sound quality. It is useful because it is a component in the traditional metric of directivity index, and if it is smooth, it can help confirm the absence of resonances.

BS baffles brains, especially when people don't read and promoters of products are simply either ignorant or deliberately misleading. I suspect both in this case. He is using it only to get my name in there. It pisses me off !!!!
 
Last edited:
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#8
Wendell has himself tangled up with the language quite a bit, but I think he understands what he was trying to get at. Maybe. :)
But, I can certainly understand why Floyd would have a problem with the description.

Even with that, I suspect the eyes were glazing over in the audience for much of that. :)

Dave.
 

Ron Texas

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#9
Your, right I will talk to amazon about getting a copy of your book. In my search for truths, I switched from Magnepan 3.6's to JBL 4367's so that's a start.
JBL 4367's sweet. @Floyd Toole thank you for catching the BS.
 

Floyd Toole

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#11
Below about 500 Hz in normal - smallish - listening rooms bass performance is dominated by resonant standing-waves in the room. The room and the loudspeaker cannot be separated, so in-situ measurements must be made. As explained in great detail in Chapter 8 of the 3rd edition of my book, there are several ways to address this problem.
 
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#12
Agreed. One way to address is using so called room eq. Here is a speaker that has had Audiolense DSP applied from 500 Hz and below. Top curve is the speakers's measured steady state in-room response. Up to 25 dB total variation in the low frequencies. Very audible. Bottom curve is with the DSP applied below 500 Hz, now within +- 3 dB. Bass response sounds much better! The frequency response above 500 Hz is left alone.

500 Hz partial correction.JPG
 
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