21749
From: freddyi, [port-1-20-56k.huntington.zoomnet.net]
Subject: For comparative distortion - how 'bout mic and TrueRTA scope on sine?
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Hey guys - it its a bitch to get useful in-room numbers of distortion - how about using a mic with high spl capibilities in quasi nearfield of woof and look at 'cleanliness' of the sine wave frequency of interest on TrueRTA's scope? Yea or Nea? years ago sure could see JBL 2220H go awry in Khorn below horn's cutoff using EV PL-9 mic and scope - cheap K33E with more Xmax and lower fs did atleast 8db more output around 45Hz than JBL before sine got funky Freddy |
21792
From: freddyi, [port-1-38-56k.huntington.zoomnet.net]
Subject: how 'bout mic and RTA .Thanks for good input Brian and Jason !
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hey guys - sure appreciate your time and thoughts Freddy |
Responses:
None
21771
From: Brian, [gnd210-115.caribsurf.com]
Subject: Re: For comparative distortion - how 'bout mic and TrueRTA scope...
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Use TrueRTA in RTA mode, and feed a pure tone to the subwoofer. Distortion will show up on the RTA as any response other than the response at the tone's frequency. However, CoolEdit might be better for this - use it to record the subwoofer's response, THEN run it through the analyzer. You can also do interesting things with CoolEdit, like ramp up the input signal, record the driver's response, then use CoolEdit to determine at what point distortion becomes noticeable. |
Responses:
[21774]
21774
From: Jason U., [ip68-3-156-181.ph.ph.cox.net]
Subject: Re: For comparative distortion - how 'bout mic and TrueRTA scope...
URL: Electro's Realm
| Microphones will hurt the distortion measurements. Look into accellerometers. However, as the cone diameter decreases, it will be hard to place the accellerometer. |
Responses:
None
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