18 Jul
2014
18 Jul
'14
3:17 a.m.
Hi, I'm running Arch Linux 64-bit with jack2. I have a USB UA-25EX to
which I connect a Shure SM75. I don't do much recording, and at a very
amateur level for various volunteer projects.
The maximum volume I get from my Shure SM75 seems very low. The result
of this is when I normalize I get fairly significant background hum.
Increasing the UA-25EX's gain just causes peaking at louder volumes,
so no solution there. This happens with both Audacity and Ardour, so
should not be software-related.
Any suggestions as to what I should investigate? A bad mic (I did
check, its not a knock-off)? Electrical noise from my laptop (used to
use a different laptop but from the same manufacturer, same results
from both). Jack settings?
18 Jul
18 Jul
3:39 a.m.
On Fri, 2014-07-18 at 09:17 +0800, Oon-Ee Ng wrote:
Increasing the UA-25EX's gain just causes peaking
at louder volumes
Jack settings?
Dynamic microphones do cause noise, nevertheless the maximum volume
shouldn't be low. I guess the hardware mixer isn't set up correctly.
Since I don't know the card I searched the web and found this:
"Using mixer settings on card 0 will return:
$ alsamixer -c 0
no mixer elems found
Unfortunately these is no software control over the hardware mixers on
the device (like in any USB device), nothing will show up in mixer
programs. Fortunately, Alsa offers the softvol plugin to create a
software volume control. We will also define this control as the default
mixer." - http://alsa.opensrc.org/Edirol_UA-25EX
What ever mixer you're using before the signal gets into Audacity or
Ardour, are the mixer settings ok?
7:23 a.m.
On Fri, 18 Jul 2014, Oon-Ee Ng wrote:
Hi, I'm running Arch Linux 64-bit with jack2. I
have a USB UA-25EX to
which I connect a Shure SM75. I don't do much recording, and at a very
amateur level for various volunteer projects.
SM75? or SM57? Everything I look up on sm75 turns out to be an sm57... So
a dynamic mic. (Phantom off)
The maximum volume I get from my Shure SM75 seems very
low. The result
of this is when I normalize I get fairly significant background hum.
Increasing the UA-25EX's gain just causes peaking at louder volumes,
so no solution there. This happens with both Audacity and Ardour, so
should not be software-related.
Any suggestions as to what I should investigate? A bad mic (I did
check, its not a knock-off)? Electrical noise from my laptop (used to
use a different laptop but from the same manufacturer, same results
from both). Jack settings?
I get that you did not buy this mic, but that it is whatever is around.
There are a number of mics that look like the sm57. The only shure mic
with a 75 is the pe75 (looks sm58 - ish) If you have a shure PE75H, it is
a high impedance mic (30k plus) and probably comes with an xlr to 1/4 inch
cable. If so, try pluging into input 2 and setting high impedance (HI-Z).
Note: on this mic pin 2 is not connected, so using an xlr to xlr cable
will not work right. (there is a PE75L that is properly connected inside
the mic)
Please note that whatever mic you have, (PE75 or SM57) it is designed for
close mic work, not for area mic use.
You say the mic causes peaking at higher levels, yet I would suggest it
needs to be almost to the top. The odd peak from touchong the mic or
plosives is probably not a problem. (use the limiter provided - peak LED
green) Use your ears above looking at flashing LEDs or even waveforms.
As you may have guessed... I am mostly guessing :) we need to know what
you are recording... how far from the mic, what are the settings on the
UA-25EX... all of these things. As you can tell it even matters what kind
of cable and which input you are using.
--
Len Ovens
www.ovenwerks.net
9:43 a.m.
Thanks Lens,
On Fri, Jul 18, 2014 at 1:22 PM, Len Ovens <len(a)ovenwerks.net> wrote:
I did buy this mic, but that was a long time ago and as I mentioned, I
rarely record. It was just so I would have a mic when I needed one (as
opposed to the headphone-jack mics I was using prior to that.
Yes it comes with a XLR to 1/4 inch. I will try the Hi-Z and see if that helps.
On Fri, 18 Jul 2014, Oon-Ee Ng wrote:
My typo, SM57 it is.
Hi, I'm running Arch Linux 64-bit with jack2.
I have a USB UA-25EX to
which I connect a Shure SM75. I don't do much recording, and at a very
amateur level for various volunteer projects.
SM75? or SM57? Everything I look up on sm75 turns out to be an sm57... So a
dynamic mic. (Phantom off) The maximum volume I get from my Shure SM75 seems
very low. The result
of this is when I normalize I get fairly significant background hum.
Increasing the UA-25EX's gain just causes peaking at louder volumes,
so no solution there. This happens with both Audacity and Ardour, so
should not be software-related.
Any suggestions as to what I should investigate? A bad mic (I did
check, its not a knock-off)? Electrical noise from my laptop (used to
use a different laptop but from the same manufacturer, same results
from both). Jack settings?
I get that you did not buy this mic, but that it is whatever is around.
There are a number of mics that look like the sm57. The only shure mic with
a 75 is the pe75 (looks sm58 - ish) If you have a shure PE75H, it is a high
impedance mic (30k plus) and probably comes with an xlr to 1/4 inch cable.
If so, try pluging into input 2 and setting high impedance (HI-Z). Note: on
this mic pin 2 is not connected, so using an xlr to xlr cable will not work
right. (there is a PE75L that is properly connected inside the mic)
Please note that whatever mic you have, (PE75 or SM57) it is designed for
close mic work, not for area mic use.
You say the mic causes peaking at higher levels, yet I would suggest it
needs to be almost to the top. The odd peak from touchong the mic or
plosives is probably not a problem. (use the limiter provided - peak LED
green) Use your ears above looking at flashing LEDs or even waveforms.
As soon as the peak LED activates I can audibly hear peaking,
unfortunately. I've tried the built-in limiter but it seems to produce
the same audible result (to my ears).
As you may have guessed... I am mostly guessing :) we need to know what you
are recording... how far from the mic, what are the settings on the
UA-25EX... all of these things. As you can tell it even matters what kind of
cable and which input you are using.
Thanks. This is a busy weekend for me, but I'll reply on these very
soon! Mic distance is anywhere between 2-6 inches from the (solo)
speaking voice beint recorded.
12:14 p.m.
On Fri, Jul 18, 2014 at 09:17:39AM +0800, Oon-Ee Ng wrote:
The maximum volume I get from my Shure SM75 seems very
low. The result
of this is when I normalize I get fairly significant background hum.
If this is really hum - a constant low frequency drone like sound -
then the first thing to check is the cable.
Or is it noise - a hissy sound with no particular frequency ?
The UA25 is not really low noise, but for speaking close to the
mic it should be perfectly OK.
Could you make a short (30 second or so) example available
somewhere ?
--
FA
A world of exhaustive, reliable metadata would be an utopia.
It's also a pipe-dream, founded on self-delusion, nerd hubris
and hysterically inflated market opportunities. (Cory Doctorow)
12:22 p.m.
On Fri, Jul 18, 2014 at 10:14:36AM +0000, Fons Adriaensen wrote:
On Fri, Jul 18, 2014 at 09:17:39AM +0800, Oon-Ee Ng
wrote:
In a later post I see you have an XLR to TRS cable. This will not
work well as the TRS input on the UA25 is attenuated before is goes
into the preamp. You really need an XLR to XLR cable.
--
FA
A world of exhaustive, reliable metadata would be an utopia.
It's also a pipe-dream, founded on self-delusion, nerd hubris
and hysterically inflated market opportunities. (Cory Doctorow)
The maximum volume I get from my Shure SM75 seems
very low. The result
of this is when I normalize I get fairly significant background hum.
If this is really hum - a constant low frequency drone like sound -
then the first thing to check is the cable.
Or is it noise - a hissy sound with no particular frequency ?
The UA25 is not really low noise, but for speaking close to the
mic it should be perfectly OK.
Could you make a short (30 second or so) example available
somewhere ?
28 Jul
28 Jul
11:30 a.m.
On Fri, Jul 18, 2014 at 6:22 PM, Fons Adriaensen <fons(a)linuxaudio.org> wrote:
On Fri, Jul 18, 2014 at 10:14:36AM +0000, Fons
Adriaensen wrote:
To conclude, once I got the time to do another spot of recording, the
noise is a hissy sound. After taking Lens' advise on the high-Z
(that's input 2 of the UA-25EX, as he mentioned), the volume is much
improved, enough so that I don't have to amplify the signal to get
usable output (and hence almost no audible noise). Using an XLR to XLR
cable.
Looks like a 'simple' impedance matching issue. Probably blindingly
obvious to most here (at least to Fons, Lens, and the other regulars),
but something my googling did not show up. Will file that away in
memory as something else to check in future.
Thanks all!
On Fri, Jul 18, 2014 at 09:17:39AM +0800, Oon-Ee
Ng wrote:
In a later post I see you have an XLR to TRS cable. This will not
work well as the TRS input on the UA25 is attenuated before is goes
into the preamp. You really need an XLR to XLR cable.
The maximum volume I get from my Shure SM75 seems
very low. The result
of this is when I normalize I get fairly significant background hum.
If this is really hum - a constant low frequency drone like sound -
then the first thing to check is the cable.
Or is it noise - a hissy sound with no particular frequency ?
The UA25 is not really low noise, but for speaking close to the
mic it should be perfectly OK.
Could you make a short (30 second or so) example available
somewhere ?
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days inactive
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7 comments
4 participants
participants (4)
-
Fons Adriaensen -
Len Ovens -
Oon-Ee Ng -
Ralf Mardorf