PZM-185 output level vs. Sound Grabber output level
I used to have a Sound Grabber that I loved for its ability to pick up any sound (seemingly regardless of distance). When it finally failed I replaced it with a PZM-180 which I assumed was the same but with different cabling. I have installed a 6V 28a battery and the sensitivity is particularly weak, even when compared to ordinary mics. Will a different battery make a difference? Is there a difference between this and the Sound Grabber? Could there be something else wrong with the PZM-180?
Reply: A 6V battery is a good choice. A higher-voltage battery will not increase the mic's sensitivity.
The PZM-185 and the discontinued PZM-180 are 8 dB less sensitive than the Sound Grabber, which is about half as loud. That's because the Sound Grabber is high impedance but the PZMs are low impedance. All else being equal, low-impedance mics have lower output than high-impedance mics. To compensate, low-impedance mic inputs generally have more gain than high-impedance mic inputs.
Both the PZM-185 and the PZM-180 have an XLR (3-pin pro audio) connector. Are you plugging that connector directly into your recorder, or are you using some sort of adapter cable (like XLR to mini phone)?
If your recorder has a mini phone jack, there are two ways to increase the output of the PZM-180 or PZM-185. These methods change the PZM from low impedance to high impedance, which increases its output level:
1. Cut the mic cable next to the flex relief of the XLR connector.
2. Strip the cable insulation back 1/2 inch.
3. Solder the white lead to the center tip terminal (the short one) of a mini (1/8") phone plug.
4. Solder the cable shield to the outer sleeve terminal (the long one) of the same mini phone plug.
1. Get a Radio Shack "A3F XLR Jack-to-1/4" Plug Adapter/Transformer", model 274-016, $14.99.
2. Also get a Radio Shack "Gold-Plated Mono-to-Mono Inline Adapter", model 274-885, $4.99.
3. Plug the PZM XLR connector into the Radio Shack A3F adapter.
4. Plug the 1/4" phone plug on the A3F adapter into the mono-to-mono adapter.
5. Plug the 1/8" phone plug on the mono-to-mono adapter into your recorder.