SOAS University of London

The Edirol R-09 24 Bit Wave/MP3 Recorder

The Edirol R-09 24 Bit Wave/MP3 Recorder

Bernard Howard, SOAS

Introduction

The Edirol R-09 is a compact solid state audio recorder. It was released in January 2006 and follows the R-01. Its main features are its size, built-in microphones, and up to 24-bit uncompressed audio recording and playback. Although suffering from small controls and some possibly flimsy construction, we found it to have a useful battery life and to be capable of making high quality recordings.

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Figure 1 Front view

Construction and controls

The R-09 measures 102mm high, 61mm wide and 27mm deep, and weighs only 100g. Its hard plastic body features two built in microphones and various controls for digital audio recording and playback. On the top of the unit, between the microphones, are 3.5mm minijack sockets for Line in and Microphone (with an option for plug in power as used for some Sony microphones).

On the front (Fig 1) is the illuminated main display panel, which shows playback and recording times, levels etc., and provides feedback for the button-operated menu system. At 25mm by 15mm, this display is quite small (those who need glasses for reading will need to use them) but is very bright and sufficiently readable, even in daylight. A peak level indicator is provided as a separate LED. Also on the front is a small button for the finder/menu control (giving access to file selection and the menu system), and other buttons for reverb and play mode.

Also on the front are the recording and playback transport controls, on a four-way rocking panel. This is quite large and easy to control, although the panel rattles slightly (see below).

The left side has the power switch, input level up/down buttons, and the DC power input socket covered by a thin rubber flap. The buttons’ labelling is not very easy to read, being simply formed from the raised black plastic of the body, so a user should be well-practised with the R-09 before going to recording situations.

On the right side (Fig 2) is a 3.5mm minijack output socket for headphone and optical out. When an optical link is plugged into the socket, the output is automatically set to optical mode. Output level, like the input level, is via two buttons (up/down). In addition, there is a hold switch which disables the other buttons; this is useful, for example, to prevent the unit being turned off or recording stopped accidentally.

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Figure 2 Right side

Further controls are found on the rear of the unit: AGC on/off, mono/stereo switching for an external microphone, low cut on/off, and microphone gain low/high. These functions are not disabled by the hold switch.

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Figure 3 Bottom cover partly open, revealing SD card and USB socket


The base of the unit forms the cover for accessing the 2 x AA batteries, SD memory card and USB socket. This cover is a complicated device that both slides and hinges. It is slid half way to access the SD card and USB socket. Then, to access the batteries, a tiny release button has to be operated after which the cover can be slid further open when it then hinges up and reveals the batteries. Opening and closing this cover is tricky, and it looks likely to break, especially since it is likely to get a lot of use in accessing the memory card and/or USB socket (see also Fig 5).

Recording

The R-09 has an extensive range of recording formats, with 4 different WAV modes and 7 MP3 modes. WAV modes include 44.1 KHz 16 bit (CD quality) and 48 KHz 24 bit, which will appeal to some audiophiles. MP3 modes range from 64kbps to 320kbps (the latter sounded indistinguishable from WAV for voice and music, although WAV should be used for linguistic purposes wherever possible).

We tested recording at 16 bit, 44.1 KHz using the internal microphones, to make a recording of conversation with speakers at varying distances from the recorder. The recording was of very acceptable quality, with some underlying hiss but with clear un-coloured sound and a good stereo image. The internal microphones appear to be better than those of the Marantz PMD 660 or PMD 671 (some of the previous criticism of the Marantz recorders has been directed at the microphone preamps rather than the microphones themselves).

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Figure 4 Top view, showing stereo microphones

The R-09’s internal microphones are omnidirectional, so better voice recordings in most situations will be made by using a good quality external microphone. As was the case with the Edirol R-1, the external microphone preamplifier output is a little low, making it difficult to achieve optimal recording level for some microphones, such as the Sony ECM-MS957, unless the speaker is close. Nevertheless, we found that recordings made with a Sony ECM-MS957 were perceptibly more detailed than those made with the R-09’s internal microphones, with attenuated background sounds due to the microphone’s cardioid pickup pattern.

When using its internal microphone, the R-09 is subject to some handling noise. It is no more vulnerable to hand contact/movement than most microphones, but does suffer from a sharp rattle from the main transport control if it is touched while recording.

The R-09 provides for real-time monitoring of recording via the headphone socket, which is useful to pick up problems such as clipping or poor connections. Monitoring may also be optically output to a computer or minidisc recorder, for example, to make a backup recording.

When recording is stopped the R-09 names the track, with a name such as R09_0001.WAV, R09_0002.WAV etc... These names cannot be edited; however if existing tracks are downloaded to the unit, their correct names are displayed.

Recording quirks

Outdoor recordings using the internal microphones suffered from considerable wind noise. Since the R-09 does not have a foam windshield, the manual suggests using the low cut switch to reduce the wind noise; however this is not effective, and would be better dealt with by purchasing an aftermarket windshield.

Surprisingly, if recording in mono, there is no increase in available recording time, as the R-09 records the same signal to both channels.

We conducted a test to simulate battery failure during recording, by removing the batteries. Results varied: in MP3 96kbps mode, audio was preserved right up to about one second before the battery was removed; in other MP3 modes the last few seconds were lost. However, when recording in WAV mode, only an empty file was saved and the recording was lost. Therefore when recording in WAV mode (as recommended for linguistic field recordings), make sure the batteries have sufficient charge to avoid loss of data.

Battery life

We found that a pair of fully charged 1800mAh NiMH batteries could power the R-09 for a quite generous 5 hours of continuous recording or nearly 6 hours of playback (2700 mAh batteries lasted 8 hours). Battery life can be extended slightly through the menu settings for the main screen’s display time and brightness.

When its batteries are running low, the R-09 displays a warning approximately one minute before it turns off. For this to work correctly, it is important to set the appropriate menu option to tell the R-09 whether it is using alkaline or NiMH batteries. The R09 cannot recharge batteries, so a separate charger unit needs to be carried.

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Figure 5 Bottom cover fully open

Memory card

The R-09 comes with a Roland-branded SD card of only 64MB, but can take a maximum size of 2GB. A firmware update available at www.edirol.it/europe increases this to 4GB. The recording time, using a 2GB card, ranges from 110 minutes for 48 KHz WAV format to over 60 hours for the lowest bit rate MP3. The manual does not list card compatibility, so take care when buying extra SD memory cards to make sure they will work with the R-09.

Conclusion

We found the Edirol R-09 to be a good all-round performer. The built in microphones are good in comparison to some of its competition. Its small size, low weight, good battery life, use of increasingly inexpensive SD memory cards, together with its ease of use, make it an attractive choice for fieldwork use. Our fieldworker in Nigeria reports that his R-09 has been working well despite the high temperature and humidity.

Its weakest point is the card/battery compartment cover. It is tricky to operate, and it seems weak. Since it provides access to the memory card, USB and batteries, and the unit cannot charge rechargeable batteries, the cover will need to be opened frequently. With care it may survive; however, if you are buying a second-hand R-09, the cover should be closely inspected.

With careful handling the Roland Edirol R-09 should be an asset to the field researcher. While it is likely to be less durable than machines such as Marantz PMD 660, this is reflected in its price which at the time of writing was £267, as compared to £375 for the larger and heavier Marantz PMD 660.

Links

This review first appeared in Language Archives Newsletter No. 9 (February 2007)