Topic: SP-SPSB-11 roll off setting help

[AndyLGR]

This is a query for those that use this battery box which I purchased to replace my old one that I broke.

Its virtually the same except this one has the word OFF written next to the bass roll off switches. My old one had the word OPEN.

The instructions say this about bass roll off:

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

Because my new box says the word OFF instead of OPEN I assumed that off was the opposite of open. So I set my switches accordingly for 107Hz roll off.

I've now found out that this is a typo on the part of the manufacturer and the word OFF should read OPEN (just as my old one did).

Therefore when I used my mic yesterday the only switch that was actually set to open was switch 2.

Does that mean I recorded a gig with no bass roll off on my mic? The recording I got is very good, so I'm a bit confused.

[acidjack]

This is a query for those that use this battery box which I purchased to replace my old one that I broke.

Its virtually the same except this one has the word OFF written next to the bass roll off switches. My old one had the word OPEN.

The instructions say this about bass roll off:

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

Because my new box says the word OFF instead of OPEN I assumed that off was the opposite of open. So I set my switches accordingly for 107Hz roll off.

I've now found out that this is a typo on the part of the manufacturer and the word OFF should read OPEN (just as my old one did).

Therefore when I used my mic yesterday the only switch that was actually set to open was switch 2.

Does that mean I recorded a gig with no bass roll off on my mic? The recording I got is very good, so I'm a bit confused.

Haha, Andy, I had the same question.

OFF = OPEN. 

NO ROLLOFF = position 2, 3, 4 "OFF"

Max Rolloff = position 1, 2, 3 OFF

Not sure what only 2 being "OPEN" would get you, but Chris at Sound Professionals can probably take a guess.  Needless to say, yes, you failed to get the 107Hz you wanted.  I made this same mistake when I first started using the SPSB-8 and now have a couple shows with some unintended amounts of rolloff (luckily, they still sound good).

[AndyLGR]

I emailed Chris again and he says he will ask the designer what roll off I will have ended up with.

Unintentioally though I have ended up with some good audio . I cant complain too much

[Ziggz]

Shit, I think I used "Off" as the opposite to "Open" as well.


<edit>, oh yes, I've had 2,3,4 / No Rolloff round the wrong way  So I wonder what the lone "1" switched on was doing  Recordings sound ok and have a good amount of bass.

[soundpro]

Hello:

Yes, the comapny that made the old rec switches (that said "open") stopped making them. The new blue switches say "off" instead. In the electronics world, an "open" circuit is "off", so, they essentially mean the same things in this case.

Basically, you can interchange 'open' and 'off' on these products.

Hope this helps!

Best Regards,

Chris Carfagno
sales@soundprofessionals.com
www.soundprofessionals.com
The Sound Professionals, Inc.
3444 Sylon Blvd
Hainesport NJ, 08036
800-213-3021
609-267-4400
609-267-0054 fax

[fmaderjr]

Another problem with battery boxes is that the roll off you get depends on the impedance of your recorder's input as well as the settings. My 10 year old Sound Pro's box was calibrated for a 10 k Ohm impedance (legacy minidisc mic input).

If I set the roll off to 107 and used it with the minidisc's line in (20 k Ohm), I was actually getting a roll off of only 107 x 10/20 = 53. If I used my DAT's line in (47 k Ohm)at that setting, I was only getting a roll off of 20 (107 x 10/47).

To know the roll off you're getting from any battery box, you need to know the impedance it is calibrated for & the impedance of your recorder's input. Depending on your recorder, you can easily wind up with a roll off that is way higher or lower than you intended.

Just another reason it is almost always better to do your roll off in post.

[Dede2002]

Another problem with battery boxes is that the roll off you get depends on the impedance of your recorder's input as well as the settings. My 10 year old Sound Pro's box was calibrated for a 10 k Ohm impedance (legacy minidisc mic input).

If I set the roll off to 107 and used it with the minidisc's line in (20 k Ohm), I was actually getting a roll off of only 107 x 10/20 = 53. If I used my DAT's line in (4.7 k Ohm)at that setting, I was only getting a roll off of 20 (107 x 4.7/20).

To know the roll off you're getting from any battery box, you need to know the impedance it is calibrated for & the impedance of your recorder's input. Depending on your recorder, you can easily wind up with a roll off that is way higher or lower than you intended.

Just another reason it is almost always better to do your roll off in post.

Couldn't agree more.
I've had the same issues regarding impedance and ended up with no roll off at all.
I gave up using mine, for good or worst.

[Ziggz]

Here's a pic of old and new, now both hopefully set at No Roll-Off    Anyone know what the reverse would have been on the new with just Switch 1 "open"/"off"? Still had a decent amount of bass, so hopefully little, if any, was cut (http://rapidshare.com/files/245701460/PFE_sample.mp3 )

[yawnfactory]

this whole thing just confused me..

i use the same box, and tend to roll@69.

i too have the blue off box. i flip the 1 and 4 switches up while leaving 2 and 3 down.
, or would i have to do the opposite of this for roll off@69

if this is wrong, then what frequency did i get.


typical set up.
sound professionals cmc8w/low sensitivity modification>sp sbs11@69>mic in>r9>2gb memory card

[yawnfactory]

can i please get some clarification on this issue? i dont want to sound too thick. a show is coming up very fast and i dont want to mess
it up.  thanks

[fmaderjr]

According to Chris Carfagno "off" = what they used to mark "open", so you need to have switches 1 & 4 down to have a nominal 69 Hz roll off. I say nominal because the roll off also depends on the impedence your recorder's input. See my previous post:

Another problem with battery boxes is that the roll off you get depends on the impedance of your recorder's input as well as the settings. My 10 year old Sound Pro's box was calibrated for a 10 k Ohm impedance (legacy minidisc mic input).

If I set the roll off to 107 and used it with the minidisc's line in (20 k Ohm), I was actually getting a roll off of only 107 x 10/20 = 53. If I used my DAT's line in (47 k Ohm)at that setting, I was only getting a roll off of 20 (107 x 10/47).

To know the roll off you're getting from any battery box, you need to know the impedance it is calibrated for & the impedance of your recorder's input. Depending on your recorder, you can easily wind up with a roll off that is way higher or lower than you intended.

Just another reason it is almost always better to do your roll off in post.

Your desired Roll-off Frequency These switches set to the “off” 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

[yawnfactory]

thanks for the help.  i did 50 shows w/o knowing i flipped the wrong switches. needless to say, it kind of flipped my swtich!
nevertheless, most of shows turned out real well.  being that i pushed 2 and 3 down, or 2 and 4 down, i wonder what i did?

i wonder if this has anything to do with volume issues on the recordings. several of them were just not too loud.

hate to ask a stupid, noob-like question, but how do i know the switch is on?would i push the switches down to have them on?


btw, i use a R9 with sound pro cmc 8 w/low sensitivity modification w/ the sbs 11 battery box.


i almost feel like running out and testing it tonight so i dont mess up the next show.  ughhhh

[fmaderjr]

nevertheless, most of shows turned out real well.

how do i know the switch is on?would i push the switches down to have them on?

Maybe most turned out well because the way you had the switches set produced little or no roll off. If you got way too much roll off you'd know something was wrong.

To turn a switch off push down the bottom of the rocker switch. You want 1 & 4 off for the 69 Hz setting.

But again, you won't actually get 69 Hz unless the impedance of the recorder's input it the same as the impedance the battery box was calibrated for. If the newer SP boxes are still calibrated for 10 k Ohms, like my 10 year old one, you will only get 10/20 of that roll off going mic in to an R-09 and 10/17 going line in (since the R-09's input impedances are 20 k Ohm for mic in and 17 K Ohm for line in). To get something closer to a 69 K Ohm roll off, you may actually need to set the battery box to the 107 or possibly even the 160 setting.

Again, this is one of the many reasons most of us advocate doing your roll off in post.

[yawnfactory]

so how would i know how the sbs 11 is calibrated? i did order it with the sbs 8 mics at the same time, with sound pros knowing
it was going to be used with the r9. perhaps they specifically calibrated it?  based on what you are saying, it sounds
best not to use and roll off at all. so i might try that next, and see how it goes. but i hate experimenting with abig act

[fmaderjr]

so how would i know how the sbs 11 is calibrated? i did order it with the sbs 8 mics at the same time, with sound pros knowing it was going to be used with the r9. perhaps they specifically calibrated it? 

based on what you are saying, it sounds best not to use and roll off at all.

I'm sure all the SP battery boxes (at least of a given model) are calibrated the same. Send Chris Carfagno of SP an e-mail asking him what impedance a recorder's input must have for the roll off to produce the effects they list. I'm guessing it may still be 10 K Ohm like my 10 year old one.

Most of us feel it's best to do all roll off in post and never with a battery box, partly because of problems like this with different recorder input impedances, but also because the bass you don't record can never be recovered.