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Old 20th March 2017, 07:09 AM   #31
VaNarn is offline VaNarn  Australia
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Take the bass/midrange out of the enclosure and inspect it to see if the suspension, especially the spider is supplying a restoring force. Use a 1.5 V dry cell battery across the speaker terminals and observe if the cone shifts forward and back, when the battery is connected and disconnected. Do this test with the battery reversed and again observe the cone motion. If the cone appears to be moving freely and returning to the same position, do an impedance run with this speaker held vertically and do re-runs to verify the consistency of the measurements.
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Old 20th March 2017, 10:20 AM   #32
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Quote:
Originally Posted by Tweet View Post
Here in a free loudspeaker impedance testing program which I occasionally use, I find it quite useful for quick impedance checks. Making up a simple jig easily makes testing that easy, not like that with SpeakerWorkshop.

It would require a full duplex soundcard though, I use a SoundBlaster Audigy Rx soundcard which is readily available. As I say the program is free but donations are appreciated.
I do have both internal (PCI + 5-1/4" bay) and external (USB) Audigy hardware, though none is currently in-use. That stuff is over 10+ years old, though I'm not sure that matters in this case - so long as its functional.

But does the software run on Linux? I use Mint / Ubuntu.
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Old 20th March 2017, 10:25 AM   #33
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Quote:
Originally Posted by VaNarn View Post
Take the bass/midrange out of the enclosure and (...)
Not sure that's possible.. these are pretty cheap, I didn't even notice if there are screws in the cabinets (or on the drivers). But I get what you're asking about.

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(...) do an impedance run with this speaker held vertically and do re-runs to verify the consistency of the measurements.
Can you clarify? Most all boxed speakers have the drivers - cones that is - in a vertical orientation. Do you mean the driver should face down towards the table surface, or outward, as in a normal listening situation?
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Old 20th March 2017, 12:21 PM   #34
Tweet is offline Tweet  Australia
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I do have both internal (PCI + 5-1/4" bay) and external (USB) Audigy hardware, though none is currently in-use. That stuff is over 10+ years old, though I'm not sure that matters in this case - so long as its functional.

But does the software run on Linux? I use Mint / Ubuntu.

I'm running Windows 7 and it works perfectly, as to Mint/Ubunta ?..... there is no mention of what operating system is applicable ....on the site, so it is a matter of try and see I guess. It is only a 4.6 MByte download.

C.M

Last edited by Tweet; 20th March 2017 at 12:24 PM.
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Old 20th March 2017, 08:02 PM   #35
VaNarn is offline VaNarn  Australia
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legendre, everyone is giving you advice on how to proceed to overcome the apparent fault that your impedance test is showing. Removing a speaker is necessary in order to confirm if it is in working order. If the speaker is fitted via the inside of the box and there isn't a removable panel, then it all becomes a futile exercise. Testing in the vertical plane ,means that the speaker is operating in its normal position, definitely not face down or up.
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Old 20th March 2017, 11:26 PM   #36
Ron E is offline Ron E  United States
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Simplest would be to try Room Equalization Wizard if you have a java client. You can also do these impedance measurements with a linux program called baudline using the same type of jig you use for other programs, but you will probably have to postprocess using something else...like libre office calc.

You could also try running some of the older programs like speaker workshop or ARTA in Wine.
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Old 21st March 2017, 03:16 AM   #37
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Quote:
Originally Posted by VaNarn View Post
legendre, everyone is giving you advice on how to proceed to overcome the apparent fault that your impedance test is showing. Removing a speaker is necessary in order to confirm if it is in working order. If the speaker is fitted via the inside of the box and there isn't a removable panel, then it all becomes a futile exercise.
Hey now.. I'm nothing, if not genuinely appreciative of all the assistance I am receiving here. Very nice forum you've made for yourselves, glad I found my way in.

As for further tests on this specific KLH, this exercise isn't about analyizing or repairing a defective LS, more about working out possible sources of error in my testing methods.. As a pair, the KLH play as expected and serve their intended purpose as "audible test loads" for works in progress rather than risk damaging a finer pair of speaks.

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Testing in the vertical plane ,means that the speaker is operating in its normal position, definitely not face down or up.
Thanks, that's what I was assuming - but being that vertical is unquestionably the default orientation for an LS, I was confused that you specified it.. (did he mean "horizontal"?). You know, Internet.
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Old 21st March 2017, 03:21 AM   #38
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Quote:
Originally Posted by Ron E View Post
Simplest would be to try Room Equalization Wizard if you have a java client. You can also do these impedance measurements with a linux program called baudline using the same type of jig you use for other programs, but you will probably have to postprocess using something else...like libre office calc.

You could also try running some of the older programs like speaker workshop or ARTA in Wine.
Thanks for that. I do have a JVM and will certainly check out that Room Eq software. Not familiar with baudline either, another one to look at.

In case it isn't totally obvious, I don't do much work in software.

@All

ETA: I need to clear up one point. These KLH 9900 have both a removable rear panel and both drivers can be removed from the front of the cab. Sorry about that, if I gave the wrong impression - mostly just that I'd never noticed.

Last edited by legendre; 21st March 2017 at 03:51 AM.
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Old 22nd March 2017, 03:00 AM   #39
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So what I've gathered from this exercise is that, as in many cases, measurements aren't nearly as simple & straightforward as one might expect (or 'hope' might be a better term). Like most complex physical systems, an LS or even a bare driver doesn't always behave in a predictable way.. some experience and finesse is required to obtain good data.

As for these particular KLH models, my sense is that they never really had any break-in, or if they did, they have spent so much time sitting around that the suspensions have become stiff again. They are only used infrequently, here - maybe a day per month, averaged over a year. I suspect that if they were put through a break-in regimen, they would be much more repeatable, at least over the short-term.
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