Well, I got a quote from them this morning. As expected, however, it’s not cheap. Regardless, I’m moving forward and will be sending payment shortly. But I would really appreciate any donations from the community that I can get to help me offset those costs and, namely, to help fund some of the other things I would like to purchase to help me make my testing more efficient and accurate.
If you don’t mind helping out, you can use the link below to contribute to via PayPal (they take 3%, I’m OK with that):
https://www.erinsaudiocorner.com/contribute/
Some of the things I'll be able to provide are:
- Frequency Response on/off-axis (and from that I can calculate power response, early reflection windows, etc)
- Harmonic Distortion
- IMD
- Max SPL (using the Tone-Burst Module)
- Thiele-Small Parameters
- Large signal parameters
- Linear Xmax using a laser for maximum accuracy
- Various other items
If you don’t care about the rest of the details then there’s no need to read any further. However, if you’re interested in what your donations would be going toward, keep on reading…
I want to provide as much accurate information as I can about drive units, speakers and whatever miscellaneous ‘tasks’ I take on. IMHO, Klippel products will provide far more depth of knowledge than anything else and that’s why I’ve chosen their product(s). But I also want to keep my hobby/family balance. Testing takes up a good deal of time; but it's not so much the "test" as it is the setup/takedown time: cutting baffles, setting up the measurement rigs, getting the cabling out and running all the wires, fixing the driver/speaker to the test stand, and then writing up the report. In the time it takes to get prepped for a test I can complete another test cycle.
To help with accuracy and efficiency, I also hope to build a dedicated "test" space in my attic. I have about 11x17 feet that I'll need to floor, wall, and insulate to make it a test room. The reasons this is important to me are:
1) Scientifically speaking, the space would be large enough to push the first reflection out another 1 or 2 milliseconds which may not sound like much but is another 200hz or so of accuracy in my measurements. 200hz is a lot when you're expanding that over multiple octaves.
2) It gives me a fully repeatable environment to work within whereas my garage is a state of constant flux with temperature, humidity and ... stuff. Having a dedicated area means that the ambient conditions are within reason throughout the year but also it means that I won't have to spend hours setting up gear and taking it down to complete a couple tests which would help me complete more tests over time.
3) If I were to go this route I could also build an ‘infinite’ baffle to help with drive-unit testing.
Another thing that would help immensely is a small, tabletop, CNC. For raw driver testing I use a large baffle which has a cut-out for inserting smaller baffles. These smaller baffles are the pieces that the raw drivers are attached to. In my previous years of testing I didn't have the ability to surface mount complex drivers or oversized flange drivers. This was a detriment to my results (I always noted when that was the case). Surface mounting is the proper way to test drivers. I do own a router but the time it takes to cut flush-mount surfaces for some drivers … well, it adds up over time. Therefore, I would also like to purchase a small, table-top CNC router so I can cut my baffles to the exact dimensions needed for a driver cut-out. I've got my eye on an item that is just large enough to cut the baffle templates I need.
The third thing is having an automated turntable for polar measurements (on/off-axis frequency response). Now, I can build one from wood … I’ve done it before. But it’s a manual turning system which consists of: measure speaker, go turn speaker, measure speaker, go turn speaker… doing that in 5 to 10 degree increments over 90 to 180 degrees takes time. So, it would be really nice to use one that’s automated and works with the Klippel where I could click the run button and let it measure and rotate automatically. Again, this helps with repeatability and accuracy. But these are not cheap, either. I’ve gotten a couple quotes back > $3k. So, this is probably more of a pipedream at this point.
Obviously I wouldn’t be doing this if I didn’t enjoy it and feel like I’m learning from it as well so I’m not about to cry “woe, is me” here. But presenting data to the masses requires an extra level of accuracy and robustness that throwing together a simple test setup in my spare bedroom and caveating to the nth degree cannot provide; I know this from experience. So anything you can donate to help me with that would really and truly be appreciated.
Thanks again,
- Erin