Rode NT1 Kit (the black one) Mods

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Well-known member
Apr 28, 2011
Thanks for the response Kingkorg
I use Line Audio CM4 for cardioid reference. ... I used both of these to make calibration file for CM4. It needs just a tiny bit of correction, it could really be used with no calibration, but i did my best to make measurements as precise as possible.

But that's just my personal trip. I use omni capsules for omni, and ribbons for F8.
Do you have the CM4 calibration handy? I would really like to look at it.

This brings back many memories.

I was a Beta tester for the early B&K TSR machines. I came up with Angelo Farina's method independently circa 1990. I wanted to measure speakers for response & THD in the theoretically shortest possible time. At that time, the computing power, and in particular, the A/Ds were too $$$ for what I wanted which was loadsa sets of Factory Test Eqpt. .. so it was all theoretical.

I think Angelo was shocked when he visited this beach bum in Cooktown and I showed him code that replicated his stuff. :)

I've used all the methods that Steve Temme describes in his video.
Sadly i can't do CK12 F8, as all the mic bodies i use it with are cardioid only. I have this weird trip and don't care about using LDCs in F8 and omni. I feel no matter what i do and what capsule it is i get weird responses, and feel like diaphragms fight each other.
Alas, this is exactly what I'm trying to get a handle on.

I did capsule & microphone design for Calrec but I've never designed a dual-diaphragm capsule for real. I see some of the problems you mention in the LDCs I've tested this Millenium. I'm tempted to see if they can be simply corrected by modifying eg a Chinese K67 capsule.

What size room are you doing your measurements? What's the floor-ceiling height?

BTW, I think yours are the best amatuer mike measurements I've seen on the internet this Millenium though I still have reservations :)


Well-known member
Apr 15, 2017
Thanks a milion. This means a lot coming from you! I basically live and operate in three countries, so sometimes i don't have my room with me, but i do have my mics.

My default measurement setup is in a heavily isolated drum room. 100kg/m³ rock wool covered every inch on the inside. 3m tall room. This is where i get best results, but i've had really similar results almost anywhere i've tried this technique. Low end does vary, but i am not that much interested in low end. It's pretty much flat on any LDC cardioid.

Sometimes i'm in a rented studio which has a cool mic locker, i use their gear and existing setup to measure them for my archive. As long as my mics, laptop, and interface are with me i can get consistent results to compare my builds or other mics. I've also done measurements outdoors when i don't have any treated room available.


Well-known member
Mar 12, 2005
Tampere, Finland
Regarding the polarization voltages (just started reading this thread from the beginning), it doesn't mean much but the polarization voltage is really the output voltage of the DC/DC converter minus the 6.3V bias voltage required for the Vgs of about -1V (on NT-1A at least, so it's capsule has just 66.5V over it).