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Gear / Technical Help => Ask The Tapers => Topic started by: jeromejello on April 27, 2005, 10:33:55 PM

Title: AT853 & spsb bass roll off
Post by: jeromejello on April 27, 2005, 10:33:55 PM
just trying to get a feel for what most peeps who run AT853's thru a sp battery box set the bass roll off switches for.  i realize that it may have a lot to do with the pa of the room/venue or the type of music, but i was curious if there is a starting point on your rig or a setting that has been consistant with your experience.

the 16Hz is considered to be no-roll as i understand it, which is how it comes set from sp.
i set mine for 69Hz for now, but will entertain other ideas.

thanks for the feedback
Title: Re: AT853 & spsb bass roll off
Post by: som on April 28, 2005, 08:32:24 AM
I leave the bass roll-off off. I haven't had any problems with the bass overloading the mics. I don't tape rap or metal shows, though.
Title: Re: AT853 & spsb bass roll off
Post by: mattb on April 28, 2005, 10:34:48 AM
Keep in mind if you go line in the rolloff settings will have no effect. I also keep mine off (and use line in on the JB3) and it's usually good.
I did have some serious brickwalling for Eric McFadden in a tiny bar a few weeks ago but it was amazingly loud. The same mics (AT933s)  phantom powered for the other set came out nice.
Title: Re: AT853 & spsb bass roll off
Post by: som on April 28, 2005, 12:41:52 PM
I didn't know that going line in would make the bass roll-off irrelevant. How/why is that?

(A purely academic question, since I don't use bass roll-off!)
Title: Re: AT853 & spsb bass roll off
Post by: mattb on April 28, 2005, 03:03:01 PM
I didn't know that going line in would make the bass roll-off irrelevant. How/why is that?

(A purely academic question, since I don't use bass roll-off!)

I'm sure someone else can give you a better answer, but in short they are designed for the mic inputs of consumer gear (DAT and MD). When you have different electronics on the other end (line in) you need to compensate and change the roll off electronics too. A roll off could be made for line input, but all the ones I know of only work on mic inputs.
Title: Re: AT853 & spsb bass roll off
Post by: jeromejello on April 28, 2005, 08:22:20 PM
I didn't know that going line in would make the bass roll-off irrelevant. How/why is that?

(A purely academic question, since I don't use bass roll-off!)

I'm sure someone else can give you a better answer, but in short they are designed for the mic inputs of consumer gear (DAT and MD). When you have different electronics on the other end (line in) you need to compensate and change the roll off electronics too. A roll off could be made for line input, but all the ones I know of only work on mic inputs.

paging someone with that better answer... i am not liking the sound of that.  $20 out the window if be true.  i may have to inquire with chris at sp to get the scoop.  i mean, he knew my gear and that i was recording line in and still was supportive of the roll off... hmm...
Title: Re: AT853 & spsb bass roll off
Post by: dhora on April 29, 2005, 02:37:01 PM
I think the roll off does something with line in on a jb3.  When I got my mics, (AT831's) I recorded the same song from my stereo with a few different roll off options (SP-SPSB-1) and if I remember correctly, I got different results with different roll offs. Do a test and see if you notice any differences.

In answer to your question, I've been using 95Hz the most.
Title: Re: AT853 & spsb bass roll off
Post by: kfrinkle on April 29, 2005, 02:41:04 PM
I agree, you can get different results with bass rolloff on the JB3.  If you search through some other posts, you have to take the value of abss rolloff selected on the spsb battery box, and divide it by 3.7.  I was at a VERY bass heavy show the other night, and was running CMC-8> spsb-3 > jb3.  After I found out how bass heavy the gig was, i got out the screwdriver, switched rolloff from 69 to 195.  I am going to play around with this next recording session as well, I am gonna try a 999 bass rolloff setting, and see if that helps for the extreme settings...
Title: Re: AT853 & spsb bass roll off
Post by: wsphansam on May 01, 2005, 01:15:03 PM
Quote
Keep in mind if you go line in the rolloff settings will have no effect.

I personally have never experienced any problem when I've recoreded with my (whatever the SP version of the 933's) mics and batt. box with roll off on into my JB3. Do as dhora suggested and tape some song being played back on a stereo and change the  roll off during it, you'll notice a difference.
Title: Re: AT853 & spsb bass roll off
Post by: dklein on May 01, 2005, 04:11:06 PM

paging someone with that better answer... i am not liking the sound of that.  $20 out the window if be true.  i may have to inquire with chris at sp to get the scoop.  i mean, he knew my gear and that i was recording line in and still was supportive of the roll off... hmm...

The rolloff frequency is a function of the capacitors used in the battery box and the input impedance of the recording device.  SP quotes their rolloff frequencies referenced to a recording device with a 10k input impedance.  I measured the JB3 input impedance at 37k.  That's where the "divide by 3.7" comes from. It's not that it has no effect...just less...check these threads
http://taperssection.com/index.php?topic=38663.0
http://taperssection.com/index.php?topic=34938.0

and this thread has a spreadsheet you can use to determine rolloff http://taperssection.com/index.php?topic=22222.0