Why PCM recording? (1 Viewer)

Hello,
as many others that have posted in this area, I'm intending to begin with some outdoors recordings. I've read most of the threads on the subject already, but I'm afraid my knowledge is even worse than that of all previous posters. E.g. PCM recorders are pointed by many as the right choice, but to be honest I don't really know why should that be true? Is it really that better that I should be ready to pay the significant price difference just because it's PCM?

My apologies in advance if this question was already answered before (I just failed ton find it), or if it goes beyond the limits of "reasonable ignorance".

What would you use instead of PCM?

willito said:

PCM recorders are pointed by many as the right choice, but to be honest I don't really know why should that be true? Is it really that better that I should be ready to pay the significant price difference just because it's PCM?

Click to expand...

PCM or Pulse Code Modulation has pretty much become the standard method by which most audio is digitized. You would be hard pressed to find a modern digital recorder of music quality in this day and age that is not based on PCM technology.

No, you do not need to buy a PCM recorder, folks did fine for many years with analog tape recorders however advances in technology has brought us modern PCM digital audio recording methods which has advanced the potential to record at audio quality that far exceeds the older methods for little increase in cost, in many cases, comparable cost. No tape hiss, wow, and flutter, they are a thing of the past with the new PCM technology. Most modern PCM recorders have less self noise than most microphones. Case in point, I use Sennheiser and R0DE microphones and can operate at maximum sensitivity and maximum mic gain with an Olympus LS-11 or Marantz PMD661 PCM recorder and recorder self noise is low enough not to be an issue or even heard for that matter...

In most instances, if your interest is in bird and wildlife sound recording, you want a recorder capable of full music frequency range. A recorder, be it digital or any other type that is designed for voice recording such as dictation or lecture recording does not have adequate frequency range for use in wildlife recording therefore most people find the full range PCM digital recorders designed for music recording have typically lower internal noise and adequate frequency range to work best. And typically with today's low power digital electronics, battery life of the small PCM digital recorders is vastly improved along with using SDHC card technology as a recording medium, makes these new recorders extremely economical to operate without sacrificing sound quality. PCM digital with SDHC memory cards buys you top sound quality with many hours of recording capability at a time and prices, at least to me, are not any more than other technologies in this day and age...

Here is a link that explains about PCM technology:
http://en.wikipedia.org/wiki/Digital_audio

Hello,
thanks for your reply, fmhill. Although I must apologize for a bad question formulation, thus leading to a slight misunderstanding, your post most answers to my concern.

Anyhow, my question was more on the lines of finding out whether a PCM recorder, as the renowned LS-11, is actually that better for the purpose than say a VN-8100PC, from the same maker, which although having a narrower frequency range and not featuring WAV recording, should (at least nominally) be enough for decent results, and costs only 1/5 of the former one. I admit that, although US$ 300,- are not a great deal for me, I'm the kind (like most, I think) that doesn't like to spend any single penny without being convinced it's worth.

Regards

Willito,

I can not offer a valid comparison of the Olympus LS-11 and the VN-8100PC as I have never seen or operated a VN-8100PC.

However after reading your post, I did go to the Olympus web site and looked at the specifications of the VN-8100PC and I have to admit, this recorder looks like it has the capability to work for recording nature sounds within limitations. Olympus states the frequency response range in MP3 high resolution mode (192Kbps) as being 70-19Khz and this would be sufficient based on my own experience.

However, in looking at the specifications and information, it would appear the VN-8100PC is a single channel mono recorder and I did not see any mention of internal microphone. Nor does it appear to use plug in SDHC card memory, it appears to have only 2Gb internal memory which, as highest resolution mode is MP3, a compressed file format, I would expect 2Gb memory to be very adequate.

In comparison, the Olympus LS-11 has three file formats available, WAV (uncompressed) as well as MP3 and WMA, both compressed formats. Whether this would be important to you would depend on what you plan to do with the sound files after recording them. In my case, I do a lot of post processing and sonogram analysis of my recordings and find there is a distinct benefit in the WAV format for lower noise when displaying sonograms. This is especially important when studying the harmonics of bird calls. It really boils down to what your use of the recordings you make will be.

Another plus of the LS-11 recorder vs VN-8100PC is that the LS-11 is a stereo, two track recorder and uses plug-in SDHC memory cards to augment the internal memory. I use 8Gb SDHC cards in my LS-11 and recorded files can be either downloaded over the USB cable (which works extremely well) or if you prefer, unplug the card and use a card reader on a computer. This option allows you the flexibility of not having to remove the recorder from the project, simply swap memory cards and the recorder can stay in use while you are processing sound files it has recorded. As I do a lot of overnight recording at remote locations, I find the SDHC card swap to be invaluable.

Another plus to the LS-11 recorder compared to what I read about the VN-8100PC, is that the LS-11 has an excellent pair of built in sensitive microphones(stereo), I have used the LS-11 internal microphones to make bird sound recordings of birds 7 meters to 15 meters or so away from my position as well as ambient field sound recordings and these recordings are full fidelity and of excellent quality. From what I read of the VN-8100PC, it does not have this capability but that may be as I could not find mention of internal microphone which I assume it must have of some sort.

I caution you, this is a comparison based on what I read of the VN-8100PC and of my own needs in nature recording which I find are filled quite adequately by the LS-11.

Now if you want to consider a step up in recorder capability above the LS-11 which is pretty basic, if you have a need or plans to do remote wildlife recording, I find the Marantz PMD661 to be the ideal PCM recorder and is what I use for overnight recording sessions where automated controls such as "pause on quiet" and "autotrack" can greatly reduce the amount of data when downloading and doing post processing. However, the PMD661 is a larger recorder, too big for a shirt pocket, if your need is for a shirt pocket recorder, the Olympus LS-11 is ideal.

Hi again fmhill,
thanks again for the time spent on this. Although I understand your caution note, your arguments "sound very sound" indeed. I've already read the tech specs of these and other models, but it didn't give me at first glance the impression of being that different, but now I've really understood where the advantages are and why is Olympus pricing their gadgets that way, so thank you very much once more.

Regards.

Hi,
the PCM (=WAV) is lossless. It records the variations in pressure (= sound) measured by your device more or less one to one provided that your measurements are not saturated. If you want to edit your data or publish it some day or do some serious analysis with it then go WAV. If you need the sounds only for your own library then feel free to go with a compressed (lossy) format such as mp3. But if you do so then use the highest possible bit rate 192bps or higher. For the hearing of most people and even for some sound libraries this is sufficient.

Note that you can always make a mp3 from a wav recording, but you cannot recover a wav recording from a mp3 recording.

Lossless recording was a default even in the tape era. When effective A/D converters became available then quite a lot of people switched to virtually noiseless DAT tapes – this is also when PCM format became commercially available. The DAT tapes were very good – and they still are. Recording became progressively easier with new recording media such as minidisks, hard disks and various digital cards. Early on it was realized that one can pack more sound if using a suitable lossy compression algorithm, and this is how e.g. mp3 came about.

regards
Harry J

Hello again,
after further searching among the many models featured by Olympus, there's a DM series (DM-2, DM-4, DM-420, ...) under the rather misleading group "recorders with music player" that, at least from their listed features and specs, should have interesting advantages compared to the renowned LS-11. While having PCM lossless stereo recording as well with a still wide freq range, some feature battery recharge through USB port, wider file management capabilities and so on.

Any outdoors experience with any of them?

Hi Willito,

Sorry, I have no experience with the Olympus DM series recorders.

If you want to learn more about recorders and their suitability for nature sounds recording, I would suggest you go to Yahoo Naturerecordists group to ask questions and look through the archives. This would be:

http://groups.yahoo.com/group/naturerecordists/

This group maintains an archive area with a lot of recorder information including results of comparison testing as well as microphone data. Dr. Raimund Sprecht (hope I have spelled his name correctly) of Avisoft has made available a lot of very good information based on testing he has conducted for his own work that is a great help when considering a recorder as well as shotgun and other type microphones commonly used for wildlife recording. Rob Danielson maintains a very good and complete FAQ as part of the Naturerecordists Group archive.

These well experienced folks are usually quick to answer questions with very informative and accurate answers and people new to nature recording are most welcome...

willito said:

Hello again,
after further searching among the many models featured by Olympus, there's a DM series (DM-2, DM-4, DM-420, ...) under the rather misleading group "recorders with music player" that, at least from their listed features and specs, should have interesting advantages compared to the renowned LS-11. While having PCM lossless stereo recording as well with a still wide freq range, some feature battery recharge through USB port, wider file management capabilities and so on.

Any outdoors experience with any of them?

Click to expand...

From the specs you may note that DM-2 and DM-4 can record in PCM format whereas DM-420 cannot. The frequency range in DM-2 and 4 is OK. While I cannot speak of any experience of using these in the field, I have some experince of USB charging. One of my first PCM recorders was a Sony minidisk MHZ-1 (If I recall correctly). It recorded on spinning minidisks. It was chargeable though a USB. I liked it quite a lot.

I would like to mention a nice tutorial to new recordists at
http://www.wildlife-sound.org/
It contains a good selection of information and a set of useful links.

Regards
Harry J