Comparison Olympus WS-852 vs Olympus DM-670

The capacity of the voice recorder's own storage. The larger the built-in memory, the more material can be recorded on the recorder without the need to free up memory or use additional cards. This parameter is also important if you want to use the device also as a portable flash drive (many modern models allow this).

— SD. One of the formats used in audio, video, computer technology, etc.; Almost every modern laptop has an SD card reader. However, the dimensions of such cards (32x24 mm) are relatively large for portable equipment, and therefore they are used relatively rarely in voice recorders. And they are often represented by more modern SDHC or SDXC cards with increased memory capacity and support for the high-speed UHS bus. Accordingly, SDXC support guarantees comfortable work with SDHC and SD, and SDHC support will not fail when connecting SD cards.

— miniSD. A slightly reduced (up to 22x20 mm) variation of the SD standard, otherwise completely identical to it (up to compatibility with SD-card readers when using simple adapters). It is rare due to the widespread use of even smaller microSDs.

— microSD. The most compact version of SD memory cards to date, have a size of 15x11 mm and a capacity of up to 4 GB. Due to their small size, they are widely used in portable electronics: in fact, they are the standard for mobile phones, and are also widely used in voice recorders. Like miniSD, they can be read by original SD card readers using an adapter.

— microSD HC. The second generation of the microSD standard; characterized by increased capacity, reaching 32 GB. In a voice recorder (and in general any card reader), ordinary microSD cards can also be used for microSD HC cards, but it is impossible to do the opposite — the card will not be read.

...— CompactFlash (hereinafter referred to as CF). One of the first memory card standards, it is still used due to its decent data transfer speed and impressive volumes (up to 128 GB). However, the dimensions of these cards are no less impressive — 42x36 mm. As a result, they are poorly suited for pocket format equipment and are rarely used in voice recorders — mainly in advanced models, where the priority is functionality and recording quality, rather than compactness. If the recorder is designed for CF Type II cards, it can work with all types of CF, and devices under Type I are only compatible with this type.

— memorystick. A proprietary standard developed by Sony and used primarily in its devices. It has a number of variations that differ in dimensions, volume and compatibility, and therefore, when buying a card for such a voice recorder, it is worth clarifying the specific MemoryStick specification used. The standard is rather poorly spread: firstly, because of its closeness (that's why, by the way, full compliance with it is guaranteed only in original Sony cards), and secondly, because of the high price of the cards themselves.

xD-Picture. Cards originally made by Olympus and Fujifilm for their digital cameras. The advantages of such cards are high reliability and compactness (20x25 mm), the disadvantages are high cost and relatively small volumes (up to 2 GB). As a result, dictaphones for xD-Picture are very rare.

The built-in microphone type determines the mode (number of channels) in which the voice recorder records sound.

— Mono. The simplest option: one microphone that records sound in mono format, i.e. without separation into left and right channels. It is impossible to provide a "surround" sound with such a recording, however, in the case of voice recorders, this is not decisive, because. usually in such a recording it is not the volume of the sound that is important, but the intelligibility of speech — and it is fully provided by a monophonic microphone.

— Stereo. In this case, a pair of microphones is usually used, spaced apart on the sides of the case; the sound is recorded in stereo, and the volume of the sound is achieved due to the difference in the sound reaching the left and right microphones. Considered somewhat more advanced than mono, although it does not provide better speech intelligibility by itself.

Separate input for connecting an external microphone. See "Connecting an External Microphone" for details.

— MP3. The most common digital audio format today, supported by the vast majority of digital audio devices, regardless of size. Provides medium quality compression and medium sound quality. When saved, it compresses information with loss of quality, but these losses are almost imperceptible to the ear, especially when recording speech from a non-specialized microphone.

— WMA. Format developed by Microsoft. It surpasses MP3 in terms of data compression capabilities, providing good quality at a low bitrate and, as a result, a small file size, but is less popular, in particular, due to sensitivity to errors in the file. At the same time, it is very common in digital audio equipment, it can be reproduced on computers without problems (it is a standard audio format of Windows OS).

— WAV. Technically, it is not a format, but a "container" into which you can "pack" sound processed by any codec; however, it is most commonly used to store uncompressed PCM audio. Thus, WAV provides the best sound quality comparable to Audio CD, however, such files, usually, take up much more space than in the above-mentioned formats. It also plays on a computer without any problems.

— Own. Some voice recorder models record audio in their own format, which is different from common standards. Technically, a proprietary format can provide a good r...atio of recording quality to file size, however, listening to such materials often causes inconvenience: you either need to listen to it on the recorder itself, or install a special player or codecs on your computer, or convert it into one of the "generally understood" formats with possible quality loss.

The higher the amount of data per unit of time that is used to transmit the audio stream, the higher the quality of the MP3 recording is provided. So, the base bitrate of 32 Kbps means encoding one second of sound using 32 thousand bits of information - it is used only for speech transmission. Much more common in portable audio recording devices is the recording quality of 128 Kbps, 192 Kbps and 256 Kbps. The maximum possible bits rate for the MP3 format is 320 Kbps. The pursuit of the highest quality of sound recording makes sense for advanced models of recorders; for a conditional voice recorder for recording lectures, the basic bitrate parameters will be quite enough. Also keep in mind that the quality of sound recording affects the size of the resulting files and the duration of the voice recorder.

The maximum continuous recording time for the voice recorder. It depends primarily on the amount of memory (see "Built-in memory", "Memory card slot"), it is also directly related to the recording quality: the higher the quality, the more space the material occupies and the shorter the maximum recording time. In this regard, manufacturers usually indicate in the specifications the maximum possible recording time, that is, the recording time with minimum quality; with higher quality and time will be less.

The range of sound frequencies that the recorder is capable of perceiving and recording. A person is able to hear sound on average from 16 Hz to 20 kHz, but the range of the actual human voice is much narrower — approximately 100-3500 Hz. Therefore, if you plan to use a voice recorder to record speech, these frequencies will be enough. If the purpose of the recorder is not limited to this, you should pay attention to models with a wider range — and in this case, the wider it is, the fuller and richer the recording will be.

— Change microphone sensitivity. The ability to change the sensitivity of the microphone allows you to optimally adjust it to the surrounding conditions. So, with a low level of extraneous noise (for example, at a lecture or a press conference), sensitivity can be set to the maximum in order to guarantee that everything that is needed is recorded, and in a noisy environment (for example, an interview in a cafe), on the contrary, it can be reduced in order to reduce outsiders noise to a minimum.

— Change the quality of the recording. Possibility to change the recording quality (usually the bitrate of recorded materials). The volume of the file is directly related to the quality: the higher the quality, the more space the recording takes up. Thus, this function allows you to achieve the optimal balance between sound and memory occupied: for example, for loud intelligible speech without extraneous noise, you can use low quality, in a noisy environment, on the contrary, increase it in order to achieve maximum intelligibility; if there is not much memory left, and nothing can be deleted, lower the quality of the recording, etc.

— Voice activated recording. When using this function, the recorder only records when its microphone captures a significant level of sound — in principle, this can be any source, but since human speech is most often recorded, the name of t...his function refers specifically to the voice. With such a recording, the recorder does not record long pauses, which saves both the occupied memory and time (and sometimes nerves) when listening to the recording. The disadvantage of this feature is that activation takes some time and the first sounds may not be recorded on the recording.

— Setting record labels. Ability to assign a unique label to each file. This can be either a number or a time and date, or both. Tags organize entries and make them easier to access, making it much easier to find the right file.

— Recording timer. The timer allows you to set the start time of the recording; when it occurs, the recorder will turn on automatically. Thus, you will be able to record the material you need (for example, a speech or a lecture) from the very beginning, even if you will not be there by the time you start.

— Ring record. The name of this function comes from its resemblance to recording on a magnetic tape closed in a ring. In this mode, the recorder can record regardless of the amount of free memory: new materials are simply recorded instead of the oldest ones. This eliminates the need to clear memory manually and can come in handy if your records quickly become out of date — for example, if you have to take surveys by phone and process the results on the same day. At the same time, this function requires caution, as increases the likelihood of accidentally erasing necessary, but old records.