Thanks for the vote of confidence. I am attempting to demonstrate that the WAY better can be quantified.
And in the spirit if DIY I am showing how to make a speaker emulator that any user can construct to check the accuracy of their own T/S parameter measurement system.
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I will say I vote for the WT2.
I had purchased mine from PE when PE was selling them.I believe it was purchased in 2007.
Ok I never used it or even opened the box.Well just a few months ago I had to test several hundred tweeter for CSS and wanted another way to confirm measurements I was getting.
Well a few hours of trying to get the WT2 working I contacted Keith Larson threw the woofertester.com site with in 1 day of my email being sent I was sent a contact info.
No promise was made from Keith as it was purchased years ago. Keith said please send it back.I sent the WT2 back and I was issued another one FREE of charge.And that was over 6years after I purchased the WT2 from PE.(mine was a defective unit)
NOW THAT is service...
Get the ORIGINAL WT2 not a copy or clone. With that you get a great product and service.
woofertester.com
Now I use the WT2 at least 3 times a day for testing products.Next will be a WT PRO to add to my Praxis, Sound Easy and LSP Cad PRO tools.
Thanks Keith again great product and sevice
I had purchased mine from PE when PE was selling them.I believe it was purchased in 2007.
Ok I never used it or even opened the box.Well just a few months ago I had to test several hundred tweeter for CSS and wanted another way to confirm measurements I was getting.
Well a few hours of trying to get the WT2 working I contacted Keith Larson threw the woofertester.com site with in 1 day of my email being sent I was sent a contact info.
No promise was made from Keith as it was purchased years ago. Keith said please send it back.I sent the WT2 back and I was issued another one FREE of charge.And that was over 6years after I purchased the WT2 from PE.(mine was a defective unit)
NOW THAT is service...
Get the ORIGINAL WT2 not a copy or clone. With that you get a great product and service.
woofertester.com
Now I use the WT2 at least 3 times a day for testing products.Next will be a WT PRO to add to my Praxis, Sound Easy and LSP Cad PRO tools.
Thanks Keith again great product and sevice
Yes the circuit is just a cap and an inductor in parallel. The inductor has a resistance in series that is very helpful to make a great Qt emulator. The L and C make the Fs component.
By the way, the Fs measurement of the WT3 is discrete steps. You can see the steps if you start with 15000 uf and add small amounts (10 uf) in parallel in steps and test each step. You will see no change in Fs for a while until there is a jump.
It has been my experience that the Qt is way off for the WT3. That is kind of the whole point of me participating in this thread.
I am willing to send you a WT2 so that you can measure your various emulator configurations and see how accurate the WT is. The only requirement is that you will post your results in this thread and show the entire community an unbiased comparison.
I'm a bit confused here... I'd like to run the test with REW and Speaker Workshop which are the two programs I have always used for testing T/S params, however you need to take a second measurement with either added mass or in a known volume before you can calculate the T/S params. Does the WT2 and WT3 display the Qms/Qes/Qts without the second measurement (which is required for VAS)?
Do you just do two measurements one with a bigger cap to simulate dropping the freq with added mass? and take a guess as to what the added mass would actually be?
Tony.
Do you just do two measurements one with a bigger cap to simulate dropping the freq with added mass? and take a guess as to what the added mass would actually be?
Tony.
The purpose of the emulator is to test the accuracy and precision of your tester.
Testing emulator Fs reveals the frequency resolution/precision/accuracy.
Testing emulator Qt reveals the complex impedance resolution/precision/accuracy.
As you indicated, if you wanted to simulate/emulate the Vas test you would add/subtract capacitance to simulate/emulate the new Fs of adding mass. That test would be redundant. If the tester can resolve Fs extremely well, then it will be good with the mass-added Vas measurement.
Testing emulator Fs reveals the frequency resolution/precision/accuracy.
Testing emulator Qt reveals the complex impedance resolution/precision/accuracy.
As you indicated, if you wanted to simulate/emulate the Vas test you would add/subtract capacitance to simulate/emulate the new Fs of adding mass. That test would be redundant. If the tester can resolve Fs extremely well, then it will be good with the mass-added Vas measurement.
Bump for WT3 test lead resistance calibration problem solved by following these steps. I also set the "USB Audio Codec" mic input to default just to be sure. Also, Windows 7 sets the input level to 100 by default and this must be changed to 1, per below and per the instructions provided with the WT3. Thanks!
Have you tried checking the Qts accuracy with my earlier posted Fs/Qt emulator? It is dirt simple to construct and use. Everyone should verify the accuracy of their test rig.
My test results are also showing big Qts inaccuracies using my WT3. Here is what I measured:
Fs calculated: 59.7
Fs measured: 62.6
Qts calculated: 0.198
Qts measured: 0.226
Yikes. I'll take you up on a comparison with the WT2 and post the results. Send me a PM if you are interested.
Brian
Caveat: I am using an inexpensive multimeter to measure capacitance and inductance. I don't have a standard to verify its accuracy.
Fs calculated: 59.7
Fs measured: 62.6
Qts calculated: 0.198
Qts measured: 0.226
Yikes. I'll take you up on a comparison with the WT2 and post the results. Send me a PM if you are interested.
Brian
Caveat: I am using an inexpensive multimeter to measure capacitance and inductance. I don't have a standard to verify its accuracy.
That's my problem, too. Will be building a test rig this weekend for accurate (I hope) L & C measurements.
Let's see what Pano comes up with for a DIY test rig to measure L and C. At this point you don't know if the inaccuracy is the emulator parts or the WT3.
If Pano's rig does not pan out, I am willing to test your emulator parts individually and as a circuit for exactness of Fs and Qt and send it back to you.
I have thought of offering such a thing as a product. It is unnecessary with a WT2 since the Fs and Qt error is less than 1%.
The issue comes about because PX claims that the WT3 is faster and more accurate than a WT2; that the WT3 is an upgrade of the WT2. All of these are not true. The WT2 can perform "Snap TS" which is a fast TS function using a chirp or a pulse. We don't advertise it since there are accuracy issues with the methodology. The WT2 is much more accurate than a WT3. The WT3 is not an upgrade. It is missing L and C measurement. It is missing box tuning alignment. It is missing the box simulator.
You spend $100s or $1000s on your speaker parts. You save $60 by buying a Chinese built knockoff of the WT2. The WT2 is built in the USA and supported by EEs in the USA.
For those wanting to trade in their WT3, I will accept shipment of your WT3 and give you a $60 trade-in allowance. You will have to email me to get permission individually.
If Pano's rig does not pan out, I am willing to test your emulator parts individually and as a circuit for exactness of Fs and Qt and send it back to you.
I have thought of offering such a thing as a product. It is unnecessary with a WT2 since the Fs and Qt error is less than 1%.
The issue comes about because PX claims that the WT3 is faster and more accurate than a WT2; that the WT3 is an upgrade of the WT2. All of these are not true. The WT2 can perform "Snap TS" which is a fast TS function using a chirp or a pulse. We don't advertise it since there are accuracy issues with the methodology. The WT2 is much more accurate than a WT3. The WT3 is not an upgrade. It is missing L and C measurement. It is missing box tuning alignment. It is missing the box simulator.
You spend $100s or $1000s on your speaker parts. You save $60 by buying a Chinese built knockoff of the WT2. The WT2 is built in the USA and supported by EEs in the USA.
For those wanting to trade in their WT3, I will accept shipment of your WT3 and give you a $60 trade-in allowance. You will have to email me to get permission individually.
For those on the fence or not even on the fence with the WT3 which is a copy of the WT2 get the original if you can. Product and support is GREAT...
That is correct
Most of the public rather think they ARE getting a new improved WT2 when they purchase a WT3.But not the case
The WT2 is a product that was copied and named in sequence to refer to the public they would be getting the same produce (WT2) but a newer version.WHICH IS NOT FACT.Does WT2 work with Win7 and 8 and is it going to be guaranteed to work with future versions of Windows? The woofertester.com site only lists Vista, XP, 2000, ME and 98.
I'd like to buy a WT2 (and get rid of all my desktop computers and t/s measuring jigs) but if it won't work on newer operating systems there isn't much point.
I'm almost getting ready to buy something, I'd prefer the WT2 over the WT3.
Also, if the WT2 can work with Win7 and 8 and will be guaranteed to work on newer operating systems, please update the website. I suspect a lot of business is being lost over an outdated website.
I'd like to buy a WT2 (and get rid of all my desktop computers and t/s measuring jigs) but if it won't work on newer operating systems there isn't much point.
I'm almost getting ready to buy something, I'd prefer the WT2 over the WT3.
Also, if the WT2 can work with Win7 and 8 and will be guaranteed to work on newer operating systems, please update the website. I suspect a lot of business is being lost over an outdated website.
Yes Win 7 and Win 8. Every time MS comes out with a new OS the WT2 s/w is updated.
The latest version auto-detects the OS and sets up the s/w to run correctly. Earlier versions required some tweaking of audio mixer settings based on OS.
s/w downloads are free. Last I checked, WT3 charges for software updates.
The latest version auto-detects the OS and sets up the s/w to run correctly. Earlier versions required some tweaking of audio mixer settings based on OS.
s/w downloads are free. Last I checked, WT3 charges for software updates.
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