A recent patent filed by Townsend Labs makes for some intriguing reading. If what it suggests becomes a new product then it could be a new must-have for project studio owners recording in less than ideal spaces. We investigate.

If the patent for a Microphone Sound Isolation Baffle and System is anything to go by, the clever people at Townsend Labs might have developed a way to fix a problem many of us encounter daily - poor acoustics in our recording spaces.

The Patent refers to:

The microphone modeling device, system, and method, can account for the effects of a microphone modeled with a microphone sound-isolation baffle and reduce unwanted audio coloration.

So it sounds as if Townsend Labs have been working on a way to correct the colouration reflection filter style baffles introduce allowing us to reduce the influence of the room on the recorded sound without compromising the sound of our recordings as much. This sounds like a very interesting idea. Clearly, there is a desire from project studio owners for drier recordings, particularly for vocals and VO but the options for those who aren’t lucky enough to have a properly treated room have always been limited and imperfect.

The Problem

When recordings are coloured by the room reflections the temptation is to work closer to the mic. This isn’t necessarily a good idea as proximity effect becomes more pronounced, and non-voiced elements of the performance like breath, esses and mouth noises become more prominent. Compression only makes things worse and the results usually leave something to be desired.

The cardioid response of microphones varies with frequency. All mics tend towards Omni at low frequencies in cardioid and this uneven off-axis response combined with the typical boxiness prevalent in typical-sized project spaces result in the characteristic sound of a less than ideal recording space.

To counter these issues, reflection filters, which attempt to isolate the microphone from off-axis sounds, have been popular for years. I’ve never been a fan of these devices as the colouration they introduce can be as bad as the colouration they are attempting to reduce, particularly when used without enough care.

The Solution

The quality of Townsend Labs mic modelling is largely based on the detailed work they do on the contribution of off-axis sound. Off Axis Correction has always been a feature of the Sphere system. In this blog post Chris Townsend discusses how off axis correction can be used to significantly improve results when recording in typical “boxy” spaces.

Using a combination of a physical baffle with the real-time processing Townsend are already known for could give the benefits of using a reflection baffle without the disadvantages. This sounds like a practical solution to a common problem.

We asked Chris Townsend, the company's CEO and CTO, for a comment, and he had some exciting news to share:

Great detective work, lads! I'm happy to talk about the new patent a little bit. We have an update release of our Sphere plug-in coming up soon with a great new feature based around the patent. The feature will work with your existing reflection filters and give you better results in challenging spaces. Best of all, this feature will come at no additional cost for all customers and will add even more value to the Sphere system.

So it seems that a software update for the Sphere L22 will soon be helping to reduce the effect of your reflection filter and best of all it’s going to be free. The timing of such a feature couldn’t be better for the many people who find themselves working remotely in untreated spaces recording VO and working in radio as well as musicians.

Future Developments?

That’s not all. While it’s important to bear in mind that a patent isn’t the same thing as a product announcement, there is an interesting reference to a design where a dual diaphragm reference microphone has an additional socket on the mic body to which auxiliary microphones can be attached and mounted in a, presumably foam, sphere. The on-axis side of the mic is open but the auxiliary mics can be mounted at known positions relative to the microphone and these can be used for noise cancelling purposes.

This isn’t a new idea. A similar concept is used by Mike Exeter in this technique for eliminating spill from toms in a drum recording but this proposal by Townsend Labs refines this idea by using multiple auxiliary mics at predetermined positions and potentially using far more sophisticated processing than just a polarity inversion and a delay.

Lastly, if you look at the patent you’ll see that the possibility of extending the idea of reflection filter cancelling processing by using it with a Townsend designed “reference filter”. This could be of a known design with known absorption and reflection behaviour, attached to a reference mic at a known distance and orientation. This could further improve the performance of the software processing. It looks from Chris’ comment that neither of these hardware products are expected any time soon but it shows that this might be the beginning of a whole chapter of room-taming developments.