Taperssection.com
Gear / Technical Help => Battery Boxes, Preamps, Mixers, ADCs, and Processors => Topic started by: robertmode on January 16, 2012, 04:31:00 PM
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Hello
I´ve a question to the soundprof spsb1 owners!
I desired Roll-off Frequency 69Hz
May i obtain a picture with switches 1,4 set to the “open” position, please.
Yours sincerely.
Robert
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I've attached a pic of mine set to 69Hz
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Be careful. Sound Pro's (and most other) battery boxes with roll offs are calibrated for 10 K Ohm input impedance (Sony MiniDisc mic in). If your recorder's impedance is not 10 K Ohms, you will not get the roll off that Sound Pros lists. If your impedance is more than that (and it probably is), you will get less roll off than expected (possibly much less). In the rare case that your impedance is less than 10 K Ohms (Sony DAT mic in) you will get more roll off than expected.
As far as I know, among the inexpensive battery boxes & preamps that we use (SP, Microphone Madness, Church Audio) only Chris Church's Preamps have a roll off that doesn't depend on your recorder's impedance (although you can't adjust the amount of roll off you get with Church gear).
Most of us, I think, recommend not using an roll off when making a recording because doing it this way is not reversible. You can do it is post if desired.
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Hello,
Firstly, thanks very much!
As i own edirol r09 HR with Line input: 15 k ohms, and as Sound Pro's battery boxes with roll offs are are calibrated for 10 K Ohm input impedance, how i can get the bass roll-off frequencies 69hz or 107hz?
Yours sincerely.
Robert
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My understanding is that with 15 k ohm impedance instead of 10 k ohm you will get 10/15 of the roll off listed by Sound Pros. Hopefully someone can chime in on this to confirm or correct but I'm pretty sure this is correct from my notes from an old post.
Assuming I am correct in this the 1,2 open setting would give you 160 x (10/15) = 107
and the 1,3 open setting would give you 95 x (10/15) = 63
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I resume this old topic because I'd like to know how to set my SP-SPSB-1 bass roll-off according to my new Roland R-26.
The recorder specifications are:
Input Impedance: Analog Input 1/L, 2/R 5 k ohms, Plug-in powered mic Input MID/HIGH 3 k ohms and LOW 2 k ohms
Recommended Load Impedance: 16 ohms or Greater
Since I'm not skilled, which number should I watch at (I use analog input or Plug-in with LOW sens)?
Should I avoid using the battery box roll-off using instead the recorder one or neither?
Thanks in advance for any answer...
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Most of us here would recommend not using bass roll off (either set by the battery box or the recorder). What is lost can never recovered and you will often find that too much as been cut. It is better done in post.
In addition, using the battery box roll off with your recorder would be especially bad because your recorder's input impedances are 5/3/2 k ohms (depending on line in, mic in & mic in sensativity) instead of 10 k ohms that the battery box is calibrated for. That means the actual roll off you would get would be 10/5=2, 10/3=3.33, or 10/2=5 times the roll offs listed by S.P.'s. This is a big fault with SP's bass roll off filter that they never tell you about (as opposed to Chris Church's high pass filter on many of his preamps which rolls off the same amount of bass no matter what the recorder's impedance is).
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Most of us here would recommend not using bass roll off (either set by the battery box or the recorder). What is lost can never recovered and you will often find that too much as been cut. It is better done in post.
In addition, using the battery box roll off with your recorder would be especially bad because your recorder's input impedances are 5/3/2 k ohms (depending on line in, mic in & mic in sensativity) instead of 10 k ohms that the battery box is calibrated for. That means the actual roll off you would get would be 10/5=2, 10/3=3.33, or 10/2=5 times the roll offs listed by S.P.'s. This is a big fault with SP's bass roll off filter that they never tell you about (as opposed to Chris Church's high pass filter on many of his preamps which rolls off the same amount of bass no matter what the recorder's impedance is).
Ok, thanks!