Topic: SP BB bass rollover settings?

[deadhoarse]

Right. So you open the batterybox and replace the capacitors within with new ones suitable for your application!

That's right. Works like a charm

[George]

If i understand this correctly, you're wondering whether or not you can apply bass rolloff during transferring a show...you cannot do that.  Also, my understanding is that the bass rolloff is inactive when you record via line in, right?  If that's the case, bass rolloff is useless for folks taping line in and only for people who record mic in.  At least this is what i have gathered from various opinions on ts.   Am i right?

The bass roll off is not disabled when going line input. The analog bass rolloff feature of the passive SP battery box will work into *any* downstream device (line or mic in) but the frequencies stated (the -3dB knee of the filter) will be valid for one input resistance only! The one specified is that of a generic mic input (10 kOhms?).

When going line-in (47 kOhms on many Sony consumer units) the filter knees are shiftet drastically downward in frequency. A "100 Hz" high pass suddenly passes everything above 20 Hz ..   I.e. barely any bass roll off at all.

Excellent, thanks for this quality post  +T

[fandelive]

The bass roll off is not disabled when going line input. The analog bass rolloff feature of the passive SP battery box will work into *any* downstream device (line or mic in) but the frequencies stated (the -3dB knee of the filter) will be valid for one input resistance only! The one specified is that of a generic mic input (10 kOhms?).

When going line-in (47 kOhms on many Sony consumer units) the filter knees are shiftet drastically downward in frequency. A "100 Hz" high pass suddenly passes everything above 20 Hz ..   I.e. barely any bass roll off at all.

So... the only "valid" roll-off frequency when recording loud concerts at boomy venues using line-in will be 888Hz, right?

Mic-in frequencies :
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   

Line-in frequencies (5 times less) :
(16Hz) > 3,2Hz    2,3,4   
(69Hz) > 13,8Hz  1,4   
(95Hz) > 19Hz  1,3   
(107Hz) > 21,4Hz  1,3,4   
(160Hz) > 32Hz  1,2   
(195Hz) > 39Hz  1,2,4   
(888Hz) > 177,6Hz  1,2,3   

[Sean Gallemore]

lol, just do phantom

I swear

[jk labs]

The bass roll off is not disabled when going line input. The analog bass rolloff feature of the passive SP battery box will work into *any* downstream device (line or mic in) but the frequencies stated (the -3dB knee of the filter) will be valid for one input resistance only! The one specified is that of a generic mic input (10 kOhms?).

When going line-in (47 kOhms on many Sony consumer units) the filter knees are shiftet drastically downward in frequency. A "100 Hz" high pass suddenly passes everything above 20 Hz ..   I.e. barely any bass roll off at all.

So... the only "valid" roll-off frequency when recording loud concerts at boomy venues using line-in will be 888Hz, right?

Mic-in frequencies :
195Hz   1,2,4   
888Hz   1,2,3   

Line-in frequencies (5 times less) :
(195Hz) > 39Hz  1,2,4   
(888Hz) > 177,6Hz  1,2,3   

The 39 Hz is too low for anything but very special problems. So yes, you're left with the 177 Hz high-pass.

Pretty severe alright but at 6 dB/octave you are only 6 dB down at 88 Hz. I.e, plenty enough bass on the recording to allow you to EQ it just to your liking in the aftermath.

OBS: If you have the SP batterybox with output level control the frequency will depend on the setting of the level.

[fandelive]

OBS: If you have the SP batterybox with output level control the frequency will depend on the setting of the level.

Thank you all for your answers
I only have the bass roll-off option on my SP battery box.
I'm not able to replace the capacitors on this one, cos' It's the SP-SPSB-6524 model (everything is covered with a kind of "solid" glue).
I think it's not available anymore on the SP website.

So I plan to build my own battery-box with bass roll-of filters that will fit my needs.
Can someone lead me to a DIY website?

Thanks in advance

[Humbug]

Never tried any DIY (ahem, of this kind), but try here:

http://groups.yahoo.com/group/MicDIYers/

[jk labs]

Some months back dklein posted an Excel file that allowed you to calculate the size of the capacitor needed to obtain a certain roll off frequency.  See if you can obtain a copy.

Others here on taperssection are experimenting with homemade switchable filters and are testing out using various makes of parts. See if you can hook up with them.

[dklein]

here it is

[Weazel]

http://burak.relyon.ca/live/battbox.html

i want to make a new batery box too, i have d7 now and sp-cmc-8 mics. if anyone know wich parts to use for the bassoff. anyone know the  input impedance of a d7?

[jk labs]

http://burak.relyon.ca/live/battbox.html

i want to make a new batery box too, i have d7 now and sp-cmc-8 mics. if anyone know wich parts to use for the bassoff. anyone know the  input impedance of a d7?

If you set the d7 line-in to 47 kOhms you're within safe range of the actual value. I need to check with the schematic but I think the actual
value is closer to 50 kOhms. That will not make any practical difference.