Sony DRE S777 Sampling Digital Reverb 2 (2024)

With Sony's flagship sampling reverb processor you can now sample the acoustic signature of any space you want. Hugh Robjohns puts it to the test by sampling the unique acoustics of an award‑winning concert hall.

At the time of my review in SOS December 1999, the Sony DRE S777 was running version 1.0 software and offered only asingle CD‑ROM of sampled acoustics. However, since then Sony have continued developing it and have since updated the operating software to version 2.0, as well as releasing three further CD‑ROMs (see 'Real Spaces' box, later). The most powerful feature of the new software is that you can now sample acoustic spaces in true stereo, afeature which is likely to appeal to adiverse cross section of the audio industry. For example, recording studios could acquire samples of their various rooms for use when overdubbing in different venues, and post‑production studios could sample the ambience of afilming location in order to be able to reapply it to added dialogue tracks.

Sampling Real Venues

In order to use this new facility, you need not only the DASK S704 self‑sampling software (supplied on aCD‑ROM with a64Mb memory stick to store the results), but also apair of decent microphones, adual‑channel mic preamp, and afull‑range dual‑channel PA system. The DRE S777's analogue inputs need to be connected to the amplified mic signals, while its outputs feed the PA system. The PA rig doesn't need to be anything excessive; it only needs to have areasonably wide bandwidth and be able to output asound pressure level of around 100dBA — roughly the equivalent of aloud instrument, sufficient to energise the room and its characteristic reverberation. However, the higher the quality of both the PA and the mics, the better the end results. I witnessed asampling session in atheatre near Sony's headquarters in Basingstoke, where apair of Schoeps CCM3s and acompact two‑way Sony 'suitcase' system with subwoofer performed admirably! (See 'Sampling In Action' box for further details of the demonstration.)

The Sony system analyses the reverberation pattern caused by atime‑stretched pulse (TSP) — this is essentially arapid sine‑wave frequency sweep lasting acouple of seconds. The reverb generated from this frequency sweep is captured and stored on the memory stick, but requires further internal processing, or 'compiling', before it can become ausable reverb program. Typically, when sampling an acoustic space, the DRE S777 will need to generate anumber of TSPs, because background noise will need to be averaged out in order to make ausable program. This averaging process becomes progressively more effective the more TSPs are used, with amaximum increase in signal‑to‑noise of 18dB being possible when 64 TSPs are used.

When sampling aspace, the speakers should be set up where the sound source would normally be, and the microphones placed in agood listening position. There are three possible sampling modes: standard rate (44.1 or 48kHz) sampling for either 5.5 or 11 seconds; or double rate (88.2 or 96kHz) for 5.5 seconds — however, the 11‑second standard and 5.5‑second double rate sampling modes require an optional DABK S703 DSP expansion board for sufficient computational power. The reverb samples are stored on asupplied 64Mb memory stick inserted into the front of the S777. Given that a5.5‑second standard‑rate sample requires around 2Mb of storage, and that the corresponding compiled reverb program comes out at roughly 25 percent smaller than this, the memory stick ought to accommodate about 40 standard‑rate programs.

The compiling operation is almost trivial — select the relevant samples and start the process. Mid‑way though the procedure, the machine provides the option to delete any data which arrived prior to the direct sound — pre‑echoes. With most natural reverberation, pre‑echoes are irrelevant and should be removed, but if you were sampling plate reverb, for example, pre‑echoes might well be an integral part of the reverberant sound. The software next displays information about the reverb samples, including the level of noise — this should be below ‑60dB, otherwise the sampling process ought to be repeated with more TSPs. However, if everything is satisfactory the compiling process will then produce the final reverb program.

The DRE S777's new operating software also allows you to import reverberation impulse responses by saving them to the memory stick. This data can then also be compiled as described above to produce anew DRE S777 reverb program. It is Sony's intention to create aweb site where users may post and download impulse responses and programs for the S777.

Room For Improvement?

The self‑sampling software for the S777 really opens up the potential of this innovative machine. The whole sampling process is very fast and easy to perform, needing little in the way of equipment and no particular expertise. But, most importantly, the results can be impressively accurate and very usable. Although aspecialised machine, once any studio acquires one, they'll almost certainly wonder how they ever coped without it!