Hi,
I have an SP-SPSB-8 battery box with the 8 switches for bass roll off from sound professionals. Could someone who also has this explain what exactly the "open" position is for the switches. It's a little unclear on the box. There's an "Off" at one end but this has an arrow pointing to the other end where it says "Rocker Down". According to sound prof "Off" = "Open" but is the switch Off/open when it is down at the end where the switch numbers and the "Off" are or when it is down at the end that says "rocker Down"
If anyone can make any sense of the above and can clarify it would be greatly appreciated as I'm totally confused
Thanks
Welcome to TS.
You can download the Sound Pros "instruction" manual for the bass rolloff settings for their battery boxes from
here. Check out page 2 of that .DOC file... it says:
Your desired Roll-off Frequency These switches set to the “open” position
16Hz (no roll-off) 2,3,4
69Hz 1,4
95Hz 1,3
107Hz 1,3,4
160Hz 1,2
195Hz 1,2,4
888Hz 1,2,3
That said, on an older Sound Pros battery box I have, it has the bass rolloff switches (the little red blocks with white switches) as follows: "Open" is at one end, and the numbers (1,2,3,4) are at the other end. Flipping the switch down at the Open end = "Open"... so e.g. if I flip switches 1,3,4 "down" (at the side where it says
Open) then that would basically*
set the bass rolloff to 107 Hz, as stated from the aforemention manual.
* "Basically" = as in, the Sound Pro battery box is set for an input impedence on the recorder of 10 kOhm, if I recall correctly. Obviously, the actual rolloff value would differ per recorder with the input impedence being a variable in the following bass rolloff equation: 1 / (2*pi*R*C)
where pi = ~3.14, R = Farad of the capacitor, and C = Ohm of the recorder's input.