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Gear / Technical Help => Ask The Tapers => Topic started by: cgrooves on December 09, 2004, 02:34:53 PM

Title: Line in w/ Battery Box Question
Post by: cgrooves on December 09, 2004, 02:34:53 PM

Recording into a pcm-m1 using SP-CMC-4's:
If I record Line In, does that make the bass roll-off inoperative?
Thanks!

Title: Re: Line in w/ Battery Box Question
Post by: urobouros on December 09, 2004, 02:43:45 PM

Check out this thread:
http://www.taperssection.com/index.php?topic=5534.0

Title: Re: Line in w/ Battery Box Question
Post by: cgrooves on December 09, 2004, 03:03:55 PM

Thanks!  I hadn't seen that thread while searching the archives.
So for my pcm-m1, the main knowledge gained from that discussion is......

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

Is this correlation correct / accurate?

Title: Re: Line in w/ Battery Box Question
Post by: urobouros on December 09, 2004, 03:08:37 PM

I'm still quite a newbie myself, but that's what I got out of it.

Title: Re: Line in w/ Battery Box Question
Post by: cgrooves on December 09, 2004, 06:06:34 PM

I’ve been thinking about this, and as they say…”It’s a 2 way street”.
The chart above only provides a correlation for a ‘generic Mic-In resistance of 10 kOhms’ with the actual resistance of 47 kOhms utilized on Line-In.

To correlate the Mic-In and the Line-In with the roll-off frequencies ‘based on a generic Mic-In of 10 kOhms’, with the Mic-In and Line-In of the pcm-m1, you would end up with the following chart.

Mic-in frequencies (based on the pcm-m1 Mic-In resistance of 4.7 kOhm) :
  (16Hz) >  32Hz    2,3,4   
  (69Hz) > 138Hz   1,4   
  (95Hz) > 190Hz   1,3   
(107Hz) > 214Hz   1,3,4   
(160Hz) > 320Hz   1,2   
(195Hz) > 390Hz   1,2,4   
(888Hz) > 1776Hz 1,2,3   

Line-in frequencies (based on the pcm-m1 Line-In resistance of 47 kOhm) :
(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

Therefore, it appears that any pcm-m1 users that record Mic-In may be rolling off twice as much bass as they think they are.

Any thoughts on this?  Agree / Disagree?

Title: Re: Line in w/ Battery Box Question
Post by: kuba on January 30, 2005, 12:51:40 PM

Agreed. Try this calculator  :P

Title: Re: Line in w/ Battery Box Question
Post by: dhora on January 30, 2005, 10:30:52 PM

I tried to look around a little, but I didn't find it.  Is the line in on a jb3 the same as the line in listed here?
Line-in frequencies (based on the pcm-m1 Line-In resistance of 47 kOhm)

Title: Re: Line in w/ Battery Box Question
Post by: dklein on January 30, 2005, 11:34:11 PM

The JB3 input impedance has been a question for some time - we have to get it measured.  In the meantime, here's another calculator that lets you specify the input impedance and get a value.

Title: Re: Line in w/ Battery Box Question
Post by: fandelive on January 31, 2005, 04:49:11 AM

Quote from: cgrooves on December 09, 2004, 02:34:53 PM

Recording into a pcm-m1 using SP-CMC-4's:
If I record Line In, does that make the bass roll-off inoperative?
Thanks!

assuming you're using cardioids, you don't need any bass roll-off filter at all.
right?