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"Beeping" sound in recordings
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Author:  dogmusic [ Sun Oct 29, 2006 7:44 am ]
Post subject:  "Beeping" sound in recordings
I have just experienced the dreaded unwanted "beeping" sound in a recording. This phenomenon was first reported in another thread by Mooseherder who described it thusly:

"there is a quiet but very clear "beep"-like sound once every second corresponding to the access light."

I was making an environmental recording using the highest mic setting. I could see the pulse of the access light registering in the meters. When played back, the beep was audible.

I will email tech support at Samson about this and report back here when I receive a reply.

Has anyone else experienced this "beeping" or is it confined to just some units?
Author:  SteveC [ Mon Oct 30, 2006 1:01 pm ]
Post subject: 
What bitrate are you recording?
Author:  dogmusic [ Mon Oct 30, 2006 3:22 pm ]
Post subject: 
SteveC wrote:
What bitrate are you recording?


I was recording at 16 bit/44.1 khz.
Author:  Zoetrope [ Mon Oct 30, 2006 3:44 pm ]
Post subject: 
Can you post a recording of the beeping? I've never experienced it with my H4, others have. I have to think that there's a few bad units out there.
Author:  dogmusic [ Mon Oct 30, 2006 5:02 pm ]
Post subject: 
Zoetrope wrote:
Can you post a recording of the beeping? I've never experienced it with my H4, others have. I have to think that there's a few bad units out there.


I'll try to do so. Do you know where I can post it?

I should say that "Beeping" doesn't quite describe the sound because it's not as sharp a sound as that implies. It's more like a tone, repeated at one second intervals. It's hard to isolate at first, but after watching the meters pulsating, you can pinpoint it.

It makes a quiet environmental recording unusable.
Author:  dogmusic [ Mon Oct 30, 2006 5:12 pm ]
Post subject: 
I have a recording of the "beeping" now. Please let me know how or where I can post it. Thanks.
Author:  Zoetrope [ Mon Oct 30, 2006 5:57 pm ]
Post subject: 
dogmusic wrote:
I have a recording of the "beeping" now. Please let me know how or where I can post it. Thanks.
Try http://www.box.net/
Author:  dogmusic [ Mon Oct 30, 2006 6:51 pm ]
Post subject: 
Here are the links for the posted sounds at two different recording frequencies, both at 16 bit:

1. access light tone 44.1.wav
http://www.box.net/public/xe7yvzpezb

2. access light tone 48.wav
http://www.box.net/public/sobave36ct


Please be sure to play this at your loudest volume setting.

It is easier to pinpoint the tone if you can see the volume levels onscreen.
Author:  Zoetrope [ Tue Oct 31, 2006 8:58 am ]
Post subject: 
Well, you must have better ears than I do. With my computer speakers cranked and my ear right against the speaker I couldn't hear anything other than the background noise in the recording. No periodic beep or tone. Maybe on better speakers; I'll have to try again when I'm at home.
Author:  dogmusic [ Tue Oct 31, 2006 9:10 am ]
Post subject: 
Try it on headphones. I can hear it through my iMac Intel speakers at full volume.

Can you see the volume level onscreen? It's easier to catch the sound while watching the periodic volume level change.

If you're only recording loud sources at medium to low mic levels, this is probably not an issue.

For my uses -- environmental field recordings -- this is a real downer.
Author:  Mooseherder [ Tue Oct 31, 2006 7:53 pm ]
Post subject: 
Hey dogmusic, thats the sound I was getting. Thanks for capturing it and posting it.
I've sent a message to tech support at samsontech about the "beep" and some new sdcard access problems I'm having - I'll let folks know if I get a response.
Author:  SteveC [ Wed Nov 01, 2006 1:27 am ]
Post subject: 
I also can not hear it.

After opening your files in Sound Forge can I "see" a repetitve periodic noise pulse at one second intervals rising from -60dB and peaking at -38dB. Frankly I do not hear the pulse as audible - also realise this pulse attains a peak of -38dB only during the highest sensitivity/gain "H" mic mode setting, which may be suitable for capturing flapping butterfly wings at 3 meters distance@ ;)

In other words - I see no problems if you are recording music at suitable recording levels.

I run my Mic at "L" (=low) setting to capture live concerts, or "M" at home with voice and acoustic guitar and I do not see nor hear ANY repetitive pulse noise or "beep" artifacts in any of my recordings. And I have recorded using DAT, Minidisc, Hard drive recorders - as well as 30 year old reel to reel decks. I would rank the H4 recording characteristics as extremely good, even better than the others mentioned due to no moving mechanical transport noise of any kind.
Author:  dogmusic [ Wed Nov 01, 2006 9:04 am ]
Post subject: 
SteveC,

I've been a musician and composer for forty years. I find that it's best to remain neutral about equipment and, most of all, to respect other peoples' uses of it.

If there is a setting on a piece of equipment, like the "H" or highest mic level setting on the H4, it is there to be used. So your attempt to denigrate the idea of making recordings using that setting ("...which may be suitable for capturing flapping butterfly wings at 3 meters distance@ Wink ") is immature and unhelpful.

And your further remark: "I see no problems if you are recording music at suitable recording levels" smacks of cultural fascism, i.e., what YOU do is what everyone should do.

There is no such thing as "suitable" for an artist. The world is there to be explored, and some of us do so through sound. If you are saddled with the concept of suitability, you do not learn anything or go beyond the mediocre.

I really like the H4. I want to use it for recording all sorts of sounds, not just music. I have encountered a problem with it and look forward to a solution. The fact that you can see the tone, or periodic noise pulse, is a helpful addition to solving this. The fact that YOU cannot hear it does not mean it's not audible to others.
Author:  dogmusic [ Thu Nov 02, 2006 5:23 pm ]
Post subject: 
Here's another user who experienced the same problem from

http://www.taropatch.net/forum/topic.as ... hichpage=3

Quote:
Just a quick note that I finally had a chance to start testing with an external mic using the 4-track mode and I am hearing the access light noise that Mark mentioned earlier. It's only going to be an issue if you're recording in a quiet environment but it's definitely loud enough to be annoying in that scenario.
Author:  shtreimel [ Thu Nov 02, 2006 6:13 pm ]
Post subject: 
Dear Lord. I almost purchased the H4 yesterday. Thank God we have BB's (and early adopter consumers) who'll give us the goods on new products.

I knew the price tag was too good to be true.
Author:  Mooseherder [ Fri Nov 03, 2006 3:48 am ]
Post subject:  It is fantastic for the price
I think that the price is great.
I'm the one who first noticed the "beeping" as far as I can tell, and I still think it is great for $300.
If you are not going to record crickets, thunder, opera, classical or baroque, or stage plays then this "beep" that has been mentioned is not likely to be an issue.
I do these things and It still wouldn't keep me from buying the recorder.
I'm concerned about the increasing errors that show up now when recording and saving WAVs...but that's another story.

Another tidbit regarding the beeping; it is strongest when headphones or external microphones are plugged in while recording.
Author:  pajen [ Fri Nov 03, 2006 5:48 am ]
Post subject: 
hello all,

just wanted to look into this; i dont have a H4 (cant get it here in sweden right now), but i am interested in getting one.

analyzing the files dogmusic posted, the following seems to be the case:

the 44.1 kHz recording has a 689 Hz tone that has small periodic "breaks" in it.
the 48 kHz recording has a 750 Hz tone that has small periodic "breaks" in it.

looking at the waveform, the peak SteveC is referring to is roughly once every second.
this should correspond to the blinking of the "access" LED.

so this is my theory:
689 Hz at 44.1KHz corresponds to 64 samples.
750 Hz at 48 kHz corresponds to 64 samples.
49152 samples (48*1024) gives the exact rate of the "1-Hz peak".

the DSP collects 64 samples, and then does something to those samples. the workload during that processing differs from the workload during "collection phase". this leads to a periodic fluctuation in the digital supply voltage, which sneaks back into the analog circuitry.
after collecting 49152 samples,data gets written to the SD card. the LED flashes, and even more current is used by the card, leading to the big visible peak. this happens about once per second. during this small access time, the audible 689/750-Hz disturbance is completely drowned out.

this effect should be present in 96kHz, and should be at 1500 Hz.
(or perhaps in 24/96 mode at 750*2*3/2 = 2250 Hz)

to me, it looks like the digital supply voltage is impropely buffered from the analog.
the following could possibley affect performance:

batteries. high internal resistance could make it worse. try NiMH or
"digital grade" alkalines with lower R, or try running it off the power supply. any difference?

SD card brand/model.
perhaps different SD cards consume different amounts of current when writing to them. some people report hearing the noise all the time, without "access light synced breaks". perhaps their SD cards have different power characteristics.

just some ideas...

/p
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