2 Apr
2009
2 Apr
'09
7:16 a.m.
Hi
I tried measuring my latency with jdelay. Started in on the commandline,
first it said
Signal below threshold...
Then I connected it's input to the output of system:capture_1 with my
microphone connected and it output to the input of system:playback_1+2.
Now I get a squareish tone and when "singing" into the microphone I get
reading like these:
22442.483 Inv
58010.411 ??
43602.390 ?? Inv
43474.474
43474.474 ?? Inv
Signal below threshold...
Signal below threshold...
Signal below threshold...
25549.731 ??
25549.731 ?? Inv
37749.225 ??
37749.225 ?? Inv
37749.225 ??
24653.357 ??
24653.228 ?? Inv
25677.165 ??
11013.134 ?? Inv
25677.153 ??
2821.046 ?? Inv
2821.046 ??
The man page says the values are in samples, so for instance a value of
37749.225 should be 0.77 seconds at 48000, right? This seems bogus
(qjackctl reports 10 ms).
What am I doing wrong?
--
Atte
http://atte.dk http://modlys.dk
2 Apr
2 Apr
7:27 a.m.
On Thu, 02 Apr 2009 11:16:39 +0200
Atte André Jensen <atte.jensen(a)gmail.com> wrote:
Hi
I tried measuring my latency with jdelay. Started in on the
commandline, first it said
Signal below threshold...
Then I connected it's input to the output of system:capture_1 with my
microphone connected and it output to the input of
system:playback_1+2. Now I get a squareish tone and when "singing"
into the microphone I get reading like these:
22442.483 Inv
58010.411 ??
43602.390 ?? Inv
43474.474
43474.474 ?? Inv
Signal below threshold...
Signal below threshold...
Signal below threshold...
25549.731 ??
25549.731 ?? Inv
37749.225 ??
37749.225 ?? Inv
37749.225 ??
24653.357 ??
24653.228 ?? Inv
25677.165 ??
11013.134 ?? Inv
25677.153 ??
2821.046 ?? Inv
2821.046 ??
The man page says the values are in samples, so for instance a value
of 37749.225 should be 0.77 seconds at 48000, right? This seems bogus
(qjackctl reports 10 ms).
What am I doing wrong?
Hi Atte.
I made the same mistake at first.
Simply don't use a microphone, just a patch cable.
Latencies are calculated by frames/samplerate, the resulting numbers
are milliseconds.
What interface are you using? Maybe some comparison would be possible
(I have a usb interface).
Best regards,
Philipp
7:37 a.m.
hollunder(a)gmx.at wrote:
On Thu, 02 Apr 2009 11:16:39 +0200
Atte André Jensen <atte.jensen(a)gmail.com> wrote:
Aside from that, make sure that you don't have any hardware monitoring
enabled on the channel the jdelay signal is generated on.
Greets,
Pieter
Hi
I tried measuring my latency with jdelay. Started in on the
commandline, first it said
Signal below threshold...
Then I connected it's input to the output of system:capture_1 with my
microphone connected and it output to the input of
system:playback_1+2. Now I get a squareish tone and when "singing"
into the microphone I get reading like these:
22442.483 Inv
58010.411 ??
43602.390 ?? Inv
43474.474
43474.474 ?? Inv
Signal below threshold...
Signal below threshold...
Signal below threshold...
25549.731 ??
25549.731 ?? Inv
37749.225 ??
37749.225 ?? Inv
37749.225 ??
24653.357 ??
24653.228 ?? Inv
25677.165 ??
11013.134 ?? Inv
25677.153 ??
2821.046 ?? Inv
2821.046 ??
The man page says the values are in samples, so for instance a value
of 37749.225 should be 0.77 seconds at 48000, right? This seems bogus
(qjackctl reports 10 ms).
What am I doing wrong?
Hi Atte.
I made the same mistake at first.
Simply don't use a microphone, just a patch cable.
Latencies are calculated by frames/samplerate, the resulting numbers
are milliseconds.
7:41 a.m.
hollunder(a)gmx.at wrote:
I made the same mistake at first.
Simply don't use a microphone, just a patch cable.
You mean creating a feedback loop on the sound card, by connecting it's
input to it's output?
Latencies are calculated by frames/samplerate, the
resulting numbers
are milliseconds.
Makes is even worse, I don't consider myself picky, but 37 seconds seems
like a bit much :-)
What interface are you using? Maybe some comparison
would be possible
(I have a usb interface).
I have just gotten an edirol fa-66 firewire interface to replace my old
edirol ua-1a usb interface.
--
Atte
http://atte.dk http://modlys.dk
7:57 a.m.
On Thu, 02 Apr 2009 11:41:45 +0200
Atte André Jensen <atte.jensen(a)gmail.com> wrote:
This sounds pretty impossible. In my case it was usually the calculated
latency + a few ms. There were cases when it was below the calculated
latency that I can't explain myself (see my thread here on LAU from
about a week ago).
I'd be interested in some values from the USB interface for comparison,
interesting settings would be:
64/2
4096/2
512/2
1024/2
512/3
1024/3
the last two are where the oddness happens here.
Best regards,
Philipp
hollunder(a)gmx.at wrote:
Right, just use a cable to connect one output to one input, connect
that input to the input of jdelay, jdelays output to the output with
the cable.
Pieter Palmers advice is also very good. For example my interface
(Edirol UA-25) has a direct monitoring switch, which has to be disabled
for this to work correctly.
I made the same mistake at first.
Simply don't use a microphone, just a patch cable.
You mean creating a feedback loop on the sound card, by connecting
it's input to it's output? Latencies are
calculated by frames/samplerate, the resulting numbers
are milliseconds.
Makes is even worse, I don't consider myself picky, but 37 seconds
seems like a bit much :-) What interface
are you using? Maybe some comparison would be
possible (I have a usb interface).
I have just gotten an edirol fa-66 firewire interface to replace my
old edirol ua-1a usb interface.
6:20 p.m.
On Thu, Apr 02, 2009 at 11:57:14AM +0200, hollunder(a)gmx.at wrote:
I'd be interested in some values from the USB
interface for comparison,
Edirol UA-5, 48kHz/24bit
p n delay (frames)
-----------------------------
64 2 387.904
128 2 515.904
256 2 771.904
512 2 1283.904
1024 2 2355.904
64 3 451.904
128 3 643.904
256 3 1027.904
512 3 1795.904
1024 3 3379.904
Ciao,
--
FA
Io lo dico sempre: l'Italia è troppo stretta e lunga.
4 Apr
4 Apr
5:08 a.m.
Fons Adriaensen wrote:
On Thu, Apr 02, 2009 at 11:57:14AM +0200,
hollunder(a)gmx.at wrote:
> I'd be interested in some values from the USB interface for comparison,
Edirol FA-66 firewire, 48 kHz, 24 bit
Edirol 1A-UA usb, 48 kHz, 16 bit
p n fa-66 1a-ua
-----------------------------
64 2 318 360
128 2 477 531
256 2 799 919
512 2 1362 1519
1024 2 2379 2543
64 3 369 423
128 3 604 659
256 3 1055 1175
512 3 1881 2031
1024 3 3403 3668
64 4 446 487
128 4 732 787
256 4 1311 1431
512 4 2393 2543
1024 4 4440 4591
--
Atte
http://atte.dk http://modlys.dk
23 May
23 May
9:31 a.m.
Hi,
Can you actually use your usb soundcards
at p=64, n=2, 48kHz without crackling noises?
Tnx & regards,
Karsten
25 May
25 May
8:38 a.m.
Hi,
I'd like to extend that question :) What kind of stability are you getting
out of the firewire interface, and what firewire chipset are you using?
Extended thanks and regards,
Robert
2009/5/23 Karsten Wiese <fzuuzf(a)googlemail.com>
Hi,
Can you actually use your usb soundcards
at p=64, n=2, 48kHz without crackling noises?
Tnx & regards,
Karsten
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2 Apr
2 Apr
7:30 a.m.
On Thu, Apr 02, 2009 at 11:16:39AM +0200, Atte André Jensen wrote:
I tried measuring my latency with jdelay. Started in
on the commandline,
first it said
Signal below threshold...
Then I connected it's input to the output of system:capture_1 with my
microphone connected and it output to the input of system:playback_1+2.
Now I get a squareish tone and when "singing" into the microphone I get
reading like these:
22442.483 Inv
58010.411 ??
43602.390 ?? Inv
43474.474
43474.474 ?? Inv
Signal below threshold...
Signal below threshold...
Signal below threshold...
25549.731 ??
25549.731 ?? Inv
37749.225 ??
37749.225 ?? Inv
37749.225 ??
24653.357 ??
24653.228 ?? Inv
25677.165 ??
11013.134 ?? Inv
25677.153 ??
2821.046 ?? Inv
2821.046 ??
The man page says the values are in samples, so for instance a value of
37749.225 should be 0.77 seconds at 48000, right? This seems bogus
(qjackctl reports 10 ms).
What am I doing wrong?
As far as I know you are not supposed to sing (at least to get proper
results from jack_delay it is not needed). :)
Just make a closed loop. jack_delay generates its own testing signals
(which are probably much easier to analyze than what you sing).
Hope this helps.
Jan
5444
days inactive
5497
days old
linux-audio-user@lists.linuxaudio.org
9 comments
7 participants
participants (7)
-
Atte André Jensen -
Fons Adriaensen -
hollunder＠gmx.at -
Jan Weil -
Karsten Wiese -
Pieter Palmers -
Robert Jonsson