Topic: Help with bass for SP-SPSB-6 - SOUND PROFESSIONALS - MINI BATTERY MODULE

[karmapolice]

Hi,

I recorded my first show with my JB3 AND SP-SPSB-6 - SOUND PROFESSIONALS - MINI BATTERY MODULE and needed some help.

The show came out not as much bass as I'd like.  The battery comes with 7 position bass rolloff.  What position should I put it to gain back bass.

thanks in advance,

Michael

[kfrinkle]

which did you use?  the lower the value, the more bass you get...

[setboy]

what kind of music? what kind of mics?

Raphael

[karmapolice]

kfrinkle,

my bass rolloff positions are switches that are either up or down.

Michael

p.s. I was taping rock and my mic is SOUND PROFESSIONALS MINI STANDARD CARDIOID STEREO MICROPHONES SP-CMC-19

[kfrinkle]

I hope you have more than one switch though homey, i have what, 4 switches for both left and right channels....

[karmapolice]

yes 4 switches for left and right channel.

Michael

[taktheride]

this made me have a question myself...what would the situations be for each of the settings on these battery/bass roll-off boxes?

The freqs. I have listed for mine are
16hz
69hz
107hz
160hz
195hz
888hz

Like which would be LOUD small rock club or which would be arena show...?  Any have any experiences with the different settings?  i got this box about 4 years ago, used it once, going to use it like 5 times this month(proud parent of a new JB3)  Thanks folks.

[kfrinkle]

Well, those settings are purely for bass roll-off. So it doesnt depend on the venue.  If you know the bass isgonan eb brutal, set the bass roll-off higher.  If you are going to see something mostly acoustic, set it very very low.

[soomlos]

https://www.soundprofessionals.com/cgi-bin/gold/category/manuals

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   

[thierryhenry]

Plus it says all of this on the back of the battery pack, so it shouldn't be that hard to figure out..


Good luck.

[jk labs]

https://www.soundprofessionals.com/cgi-bin/gold/category/manuals

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   

If we are talking about the jb3 line input then all frequencies above must be divided by 3.7

Ref: see posting by dklein in one of the jb3 threads

[taktheride]

Plus it says all of this on the back of the battery pack, so it shouldn't be that hard to figure out..


Good luck.

When did you get yours?  I got mine a few years back and mine doesn't say any of that anywhere.  I printed it out and glued it to the inside

[thierryhenry]

https://www.soundprofessionals.com/cgi-bin/gold/category/manuals

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   

If we are talking about the jb3 line input then all frequencies above must be divieded by 3.7

Ref: see posting by dklein in one of the jb3 threads

Whoah, whoah why is that? Because the A/D isn't as powerful as a DAT or something? I'm confused..

Thanks.

[jk labs]

https://www.soundprofessionals.com/cgi-bin/gold/category/manuals

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   

If we are talking about the jb3 line input then all frequencies above must be divided by 3.7

Ref: see posting by dklein in one of the jb3 threads

Whoah, whoah why is that? Because the A/D isn't as powerful as a DAT or something? I'm confused..

Thanks.

 
It has to do with Pi being 3.1415927.. . :-)   and the jb3 having a perfectly circular harddisk ....

Seriously, the EE explanation for the operation of a passive RC filter involve C and R: the filter knee in Hz depends on both C and R.  The SP bbox contains the C (four of them actually) but not the R. The R that enters the formula for the filter knee is the effective _input resistance_ of the downstream device. 

Now, if you buy a car that can accelerate from 0 - 100 mph in 5.9 seconds clearly some assumption is being made about the weight of the driver.  A 9000 pound elephant just wouldn't see that performance.

The same with the SP filter knees. The frequencies stated (the "SP filterknees") are derived by ASSUMING that the downstream Rin is 10 kOhms. We know that the jb3 line input has an Rin of 37 kOhms. So SP underestimate Rin by a factor 3.7... Then EE tells us that the "SP filterknees" are overestimated by the same factor.

[sml42]

The same with the SP filter knees. The frequencies stated (the "SP filterknees") are derived by ASSUMING that the downstream Rin is 10 kOhms. We know that the jb3 line input has an Rin of 37 kOhms. So SP underestimate Rin by a factor 3.7... Then EE tells us that the "SP filterknees" are overestimated by the same factor.

This is kind of academic, because I'm no longer using my SP-SPSB-6, but I'm curious enough that I'll ask anyway...

Where does the 10k figure come from? There is nothing written on my SP batt box (other than contact details and the table of switch position / frequency listed above), there was no documentation came with my SP batt box, and I can find nothing on their website (under SP-SPSB-6 at least) to that effect.

If there is other publically available documentation I've missed, I for one would be curious to see a copy. However I suspect you'll tell me you derived the 10k figure empirically by measuring the frequency response

best regards,
stephen