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Edirol R09, R09HR & R44 Internal Mic/Preamp Comparison

Aim

To compare the relative noise levels of the R09, R09HR and R44 internal microphones using a simultaneous ambient field-recording method.

Methods

1. Levels

I attempted to match all recorders so that the peak-meters hit the same max levels = -12 dB (see the post processing section below). The recorder settings used were:

• R44 = High-Gain (Sensitivity, 6th stop from minimum)
• R09 = High-gain @ 20 (66%)
• R09HR = High-gain @ 43 (53%)

2. Other settings

All recorders: Low cut off, plugin power off, screens minimum brightness, 44.1 kHz @ 24 bit.

3. Source

I recorded ~ 2 minutes of street noise from my front verandah, the 'talent' were children playing in the street, they were ~ 15m/50' to 50m/160' away (hey kids move fast!), all recorders were laid on the ground facing the street as shown below. The children serendipitously hit a large metal garage door, on several occasions, with a volley-ball for bass-response testing:

4. Post processing

It turned out to be difficult to see the displays in bright-sunlight, and so I was not as accurate in matching the levels as I needed. Consequently I had to make a +2 dB increase to the R09HR to match the loudest, R09. The R44 required ~ +1 dB increase).

Results

For listening comparisons I would recommend a good set of headphones:

Download the recording visualized below here --> R44 Recording (320 kbps mp3, 3.7 Meg)

Edirol R44

Edirol R09

Download the recording visualized below here --> R09 Recording (320 kbps mp3, 3.7 Meg)

Edirol R09HR

Download the recording visualized below here --> R09HR Recording (320 kbps mp3, 3.7 Meg)

A-B-C comparison

The following recording cycles between the R44 --> R09 --> R09HR in 2 second samples, taken from across the duration of the original recording. This style of test is particularly useful for comparing the tonal and detailed differences between the recorders as it allows the listener to focus on particular qualities of the sound, then hear very subtle changes as the recordings/units are cycled. In particular you can hear the stereo image from the R44 is far superior to the R09/R09HR units (not surprising given the greater mic separation), however also you will notice the self-noise in the R44 is far worse than either the R09 or R09HR.

Some things to focus on (each in turn as you play the recording):

1. Stereo imaging
2. Background hiss
3. Bass response
4. High frequency detail

Download the recording visualized below here --> R44-R09-R09HR cycle (320 kbps mp, 1877 kb)

Conclusions

1. The internal mics in the R44 have significantly more self-noise (hiss) than either the R09 or R09HR. Dramatically so. I would go as far to say that they are useless for anything other than note-taking/slating or rock-band level recordings. This is a surprise to me as I would have expected them to be at least equal to the R09 since the R44 appeared after the R09 but before the R09HR.
2. The R09HR appears to my ear, to have more bass and less hiss than the R09.
3. The R09HR seems to be more sensitive.

Share and enjoy :)

PS: The R09HR internal mics can also be heard in this recording at freesound - People swimming in Lake Eacham. You will need to set up an account to download the original or you can listen online at reduced quality.

Scott Fisher

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