Comments for Chad Huard

Comment on Seas 27TBFC/G H1212 mod by Kent Jensen

Kent Jensen — Mon, 13 Jun 2011 12:29:08 +0000

Hey, nice article, especially including distortion measurements.

However, to me this looks like a big difference! I guess that the FR plots are various degrees off axis, and at first glance they look pretty much the same. However the response without the grid droops off evenly from 5k if the light-brown line is 0 degrees (lowest line in FR without grid, and highest line in FR with). Its almost inverse of the FR with grid, as here the light-brown is almost flat. So it seems that without the grid you will have drooping on-axis response, while off-axis is flat? Might work well in a waveguide? Does the DXT tweeter have a phase-shield?

Comment on Accelerometer Testing by Chad

Chad — Fri, 16 Jul 2010 12:03:11 +0000

I have looked at the Kalman filter and it does look like the tool for the job. I am very new to this though, and implementing the Kalman looks significantly more difficult than the others I have been investigating. Do you know where I might find an example implementation in C?

Comment on Accelerometer Testing by Roger

Roger — Fri, 16 Jul 2010 08:17:35 +0000

Looks like a fun project. Have you thought about using a Kalman filter?

Comment on Introducing Scopezilla: HP 54720A by Chad

Chad — Thu, 10 Jun 2010 13:15:19 +0000

Sorry Siavash, I do not have the programmers manual either. I did find a users manual which details some of the protocol used. I didn’t read that section closely because I don’t have any need to automate, but it didn’t seem to give details on commands or accessible functions, just the protocol itself. If you don’t have a copy of the users manual I can send it to you, but it probably isn’t exactly what you are looking for.

Comment on Introducing Scopezilla: HP 54720A by Siavash

Siavash — Thu, 10 Jun 2010 06:12:47 +0000

Hello,

Do you have programmers manual for the 54720. I just bought a 2nd hand 54720 but I couldn’t find any programmers manual in the web. Thanks a lot,

Best Regards,
Siavash

Comment on Seas 27TBFC/G H1212 mod by Armand

Armand — Fri, 14 May 2010 12:48:38 +0000

You might be right Chad as this tweeter usualy measures pretty flat in this range.

I’m going to try a comparison tonight. What positive differences did you hear without the plate? More detail I presume? You didn’t hear any premature roll-off off axis without the phase plate?

Thanks.

Armand

Comment on Seas 27TBFC/G H1212 mod by Chad

Chad — Thu, 13 May 2010 21:30:45 +0000

@Armand

I think that dip is diffraction. The reason it does not fill in off-axis like the other diffraction effects is because the response is already falling off off-axis at the higher frequencies.

Comment on Seas 27TBFC/G H1212 mod by Armand

Armand — Thu, 13 May 2010 19:54:03 +0000

Hi and thanks for the great post. What do you make of the droop from 5 to 8K in the graph without the phase grid? It would appear that this would be fairly audible.

Comment on Introducing Scopezilla: HP 54720A by Switch Bounce

Switch Bounce — Tue, 13 Apr 2010 00:35:27 +0000

[...] getting extra button press readings when I was releasing the button. This was obviously a job for scopezilla. What I found was [...]

Comment on Distortion Testing by Chad

Chad — Sat, 27 Mar 2010 19:53:39 +0000

I have seen the PE mic and I must say it is tempting. The mic I am currently using is a DIY job, with a DIY mic-pre as well. I must admit that from these tests it doesn’t look to be a very great mic. I may look at a new mic in the future, but it will probably be a step up from the ECM or parts express, perhaps and Earthworks.

In its defense, even at 16″ the level produced by this driver is pretty high. And when you go down to only 4″ there is no reason to think that a little capsule mic like this could hold up without significant distortion. This experiment was to get an idea of how much. Maybe I could try a linkwitz mod on the capsule, but it is harder than it sounds (I wasted a few when I was building the mic before giving up and just wiring it in)!