I agree with the impedance tests. I cannot get a reconciliation between the 403 loudspeaker tests and systems that I have used for over a decade. The Smith&Larson Speaker Tester Pro is a solid accepted standard by those that know it and use it. I gave up trying to get the same driver tested on both systems to get the same Thiele Small parameter numbers. A few 10ths of the measurement difference is normal. But Inductance is way out, and Q is also way off. Maybe there is a cure for this. The OEM testing market for loudspeakers needs something that is accurate and solidly dependable. I used to recommend Smith&Larson to OEM manufacturers, but they stopped production almost 10 years ago.
I am very heartened by your software upgrades. This is not a little improvement. It is a huge improvement of a very worthy piece of test equipment.
A friend of mine Claus Futtrup has a website called Speakerbench You need three impedance measurements. Free air, Mass, and 2 x mass 1 and they do the Thiele Small number crunching. Also the advanced driver functioning characteristics. I don’t have your driver here. But I have a few Faital pro drivers. I have used a 6FE100 as a base line for a while because it always tested out pretty close to factory specs. Faital’s manufacturing line is very automated, so adhesive mass is very controlled. That is one of the parameters that gets all over the place in hand assembled drivers where there is no attention to the details. Voice coil height in the gap is another. You see a lot of coil vertical offset in measurements. I’ll give your software a spin. I like the interface in the pictures. Also looked up your speaker work. Almost like you know what you are doing
Is it possible to create such a AC sweep analysis graph and if so how to accomplish with the QA-403? I believe that the issue is the need for a step motor to turn the pots to the different positions as the analysis is being conducted. In addition to the need to change the frequency turn over switch positions.
well, it’s more an example of what can be done with the QA403 and software. The driver was sitting on my desk so not really free-air but here’s the factory spec: SIG150-4 Specification Sheet
You’d have to do a little custom code to send instruction to the motor you’re describing and then do a sweep. It’s possible and not hard if you can write C#. I did this on a preamp recently but by manually turning the dial : )
I ran the frequency response test at all ten positions on the Loudness Control with manual adjustment to the pot to observe the results. Each position resulted in it’ own graph as shown. I thought adding each test result to a common graph may provide the result that I displayed earlier, but no luck.
Haha so I thought, this is easy to show and went and used a Bose receiver I’m working on and had passed as complete. I did three frequency response runs, exported as FRD, imported to REW → Here’s the graph showing tone controls full up, flat, and full down. Uhoh.
