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Old 19th August 2014, 12:44 AM   #1
zacster is offline zacster  United States
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Default Measuring Fs

When measuring the Fs of a driver, using the Measuring Loudspeaker Driver Parameters procedure, how do I suspend the driver? Do I need to clamp it to something away from any surface or do I just hang it loose? I would think that clamping it would impact the measurement due to the clamp surface, but hanging it would just let it vibrate. I guess that's what we want.
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Old 19th August 2014, 08:18 AM   #2
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Quote:
Originally Posted by zacster View Post
When measuring the Fs of a driver, using the Measuring Loudspeaker Driver Parameters procedure, how do I suspend the driver? Do I need to clamp it to something away from any surface or do I just hang it loose? I would think that clamping it would impact the measurement due to the clamp surface, but hanging it would just let it vibrate. I guess that's what we want.
http://www.mh-audio.nl/downloads/Read-Measuring-tsp.pdf

http://www.thielesmall.com/

Last edited by AmadeusMozart; 19th August 2014 at 08:21 AM.
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Old 19th August 2014, 08:26 AM   #3
AndrewT is offline AndrewT  Scotland
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I read and used the "hang it loose" method.

But this Forum suggests rigid fixing to a substantial mounting jig.

That is quite an engineering exercise, so I have not been able to compare the results from the two methods.

But the room/house MUST BE QUIET.
The driver must be far from all reflective surfaces.
Hang/mount in the middle of the biggest room in the house. Send the wife and kids away for the day.
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regards Andrew T.

Last edited by AndrewT; 19th August 2014 at 08:29 AM.
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Old 19th August 2014, 08:30 AM   #4
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From what I can find on the RS driver for which the specifications are sought I would personally not be interested in its use. It has apparently a foam surround and I have a dislike for foam due to the limited life span. (often in the range of 10-12 years). Since there are no details to be found on the web it suggests to be already quite dated so how much life can one expect out of it?

Cabinet costs and work involved outweigh the cost of a decent driver.

http://support.radioshack.com/suppor...oc65/65820.pdf
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Old 19th August 2014, 08:27 PM   #5
zacster is offline zacster  United States
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I understand what you are saying, but I'm trying to keep the cost of this build at 0, both USD and NZD. I've already blown my budget though, I spent .99 on the freqency generator app for my iPad.

I've already had these drivers for a number of years, and the reality is this is just a project to keep me busy. If they don't last forever, so be it.

Interesting too, I see that Fs is stated as 80hz on the pdf. I hadn't seen that mentioned anywhere else before. At least I have something to measure against, even if 80hz is just a rough estimate.

Last edited by zacster; 19th August 2014 at 08:33 PM.
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Old Yesterday, 01:05 AM   #6
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Originally Posted by zacster View Post
I... I've already blown my budget though, I spent .99 on the freqency generator app for my iPad. ...

O boy, you've wasted money. Since you're posting here it is obvious that you've got a computer and WinISD (free) has a signal generator built in.
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Old Yesterday, 03:21 AM   #7
zacster is offline zacster  United States
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I have an old iMac, but I have Audacity which also has a generator built in. The iPad is just more convenient. I paid for the "upgrade" which included more options, the base app is free. It was worth 99.
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Old Today, 01:00 AM   #8
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You can download Room EQ Wizard (REW) for free. It is a very good tool to make impedance measurement and calculate TS parameters. You don't need any new hardware but your existing computer sound card.
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Old Today, 01:17 AM   #9
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Hopefully you saw this post: Jensen coaxials, worth moving 10k miles?

Honestly I feel you are wasting your time with the obsolete RS drivers.
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