So far the only interviews I’ve posted here on ProTooler have been with developers. For this one I thought it would be interesting to talk to an acoustician and ask about a little of everything regarding good and bad rooms. Tom Jansen, a great guy I first met at Musikmesse last year, was happy to answer.

What does the optimal mixing room look like?

We all would love to know, right? I would build one asap! To be honest a mixing room always should cater to the specific needs of the person that´s working in there. Those “needs”, ideas of a comfortable listening/working experience differ a lot! Some people for example enjoy a fairly “dry” heavily treated room for mixing, other´s are put off by such a room and tend to prefer a more live room with a more “mastering suite / living room”-like feel! Who´s right, who´s wrong? the only answer: “It depends!”

Through the last 2 or 3 decades studio´s have always changed, as have their preferred acoustical concepts, so besides different opinions of the engineers working there, we also have about just as many different opinions to this answer as there are studio-designers! They all have there own “right” answer to the perfect mixing room and they can often be even diametral. Besides all science and acoustic theory a designer´s perspective is always also based on the outcome of the projects he has completed, so over time they all have their own way of thinking. (So the designer might be happy with a room he finished, the client maybe perfectly happy and uses it for years, then engineer XY walks into the room and thinks: “WTF???”)

Really new approaches to studio-acoustics are rare, because of the financial situation of big recording studios. There´s hardly any revenue to be made in the biz for new big studios, so there´s virtually NO budget for any sort of acoustics R&D, of course universities do a lot of related physics-studies and software development (e.g. auralisation programms) has come a long way, but the direct scientific impact on studio-acoustics is small, because there´s just no big money to be made in this industry.

My personal preference, if you´re curious, is a more balanced approach. I don’t like dry rooms very much and tend to “work against the uncomfortable feeling” so mixes come out with more fx/reverb than I really need, not good! So rather than trapping the living sh*t out of a room, it would be great to avoid early reflections and (therefore) comb filtering in another way. Either by directing those reflections around the sweetspot and disperse or trap them after a certain timeframe, or by diffusing them and making the diffuse soundfield A LOT quiter than the direct signal (-20/30dB). The first approach was used in the studio of my good friend Guy Sternberg in Berlin called “Lowswing Studio” (link), which was designed by Roman Magis and sounds amazing, it´s VERY flat, doesn´t sound dry and mixes translate incredibly well to the rest of the world! Without an unlimited budget that´s probably how I´d build a very nice studio for a reasonable amount of money and effort!

The second approach has been tried and tested really only once so far. It´s basically a concept Dr. Peter D`Antonio (The CEO of RPG Acoustics) and George Massenburg have developed. The (stupidly oversimplified!!) idea is to make the room big enough to take care of the low frequency modes with (32) special tuned basstraps in all 4 corners and to cover the complete!!! rest of the surface area (including ceiling) with diffusers that have enough distance to be effective! To be more precise the whole surface became really 1 single diffuser, because the seperate rods were calculated exactly to NOT be repetitive. (adding more of the same small diffusers next to each other dimishes their effectiveness!!)…(blablablabla….and to cut out more details).

The final room (George Massenburg´s “Studio 3″, Blackbird, Nashville) is diffusive down to 200Hz !!! and all reflections are 30dB below the direct signal, creating what they call an “ambient anechoic space”. Though I haven´t heard it in person yet (hopefully next year), I have spoken in length about it with George Massenburg and have seen & heard HD Videos from recordings done in there (yes….btw. it´s just about as good a recording as a mixing room!!) and have NEVER been so impressed with anything before!

From a paper by Dr. D`Antonio: “The diffuse sound field is very dense and occurs without any time delay, as in a reverberant space which requires time to develop a reverberant sound field It’s like adding reverberation with a level 30 dB below the anechoic direct sound, an interesting perception experiment to perform.”

It maybe financially quite out of range for a “standard studio built” solution, but I´m already 90% sure it´s close to the “optimal mixing room” for me! At least much more than anything else so far. I’m very excited about the future development of this acoustical concept!

Often studios have separate mixing and mastering rooms, and they usually don’t look very similar. What’s the difference between them?

Both cater to the specific needs of the work, that get´s done there! In a nutshell a mixing room should make you able to dive “into the mix”, focus in on details, adjusting different parts & instuments on a very surgical level. Therefore nearfield monitors have become the popular choice as a working tool, the room is supposed to not get in the way, to offer a reflection free sweet spot and as little modal problems as possible to judge the low-end.

A Mastering room is different, though Mastering can be an even more surgical process, the task is to judge the album/music as a whole and predict it´s translation to the outside world (and it´s million different possible listening back systems). So the approach is more in a way of building something like the “perfect living room” to listen music in. The common speaker system used in mastering is therefore a fullrange midfield/farfield-system, with bigger 3-way/4-way speakers (often +subs) further away. Also the goal is to make the room possibly flat in the low frequencies (which really DO get excited by those fullrange systems), but not very dry at all. A mastering room should sound natural and not overly “dry”. The good thing is, there´s often no console, furniture, drummers, tons of marshall amps or band posse crowding the room and messing up the acoustic situation, a control room often serves many different purposes besides mixing, a mastering room serves one special task.

I’ve read about a few studios who doesn’t have the control room separate from the recording room, and I’m not talking about home studios here. What are the advantages and the disadvantages of this approach?

I really, really like that approach! But again the question is what task is the room for? If you record an orchestra for a film score, you need the separation of a control room. You want to sit down, focus on the sound, twist the knobs on your console and let the conductor and his musicians do their magic in the recording room. If you are a producer working with a band, constantly switching between, writing in the studio, recording takes, overdubbing, editing and judging songs on the fly all you can do is push the talk back-button or ask the band to come over to the control room….this get´s annoying VERY fast and is an absolute workflow killer imho. So by setting everything up in 1 room basically the only thing you loose is separation, meaning you can´t judge the sound coming out of your speakers, while they are playing/recording. You´ve got to record, stop, listen back, adjust ….repeat, instead.

What you gain though is instant feedback from the musicians (though that can be a drag, too!) and a very much improved communication! I find it to feel much more natural to work this way and it can be very positive for the songwriting/recording process. Some like it more, others don´t…..as always in music & recording, it´s very personal and all subjective!

What do you think is the biggest problem with acoustics in home studios in general?

The lack of a) knowledge, b) space and c) budget.
The biggest problem of most home studios is that they are small. The walls and ceiling are just not far enough away, they have too big an impact on the acoustics often simply because of their proximity, causing early reflections which create comb filtering, flutter echoes and unwanted coloration to the room sound. Another big problem is modal ringing, every room has room modes defined by the distance between 2 opposite surfaces, the bigger the room the lower those mode frequencies! In a big room those can be so low, that they even might not get excited much by any instrument or speaker so there´s little problems, while in a small room the problematic frequencies can be up in the 60-200Hz area, so those modes DO get excited and their long decay times mess with the room sound as much in the time domain as in the amplitude (peaks & dips in different locations of a room) making it impossible to objectively judge what´s going on in those frequencies on the recording. So what is the basic treatment that can be done??

First of all, the most important, (sometimes) cheapest, often overlooked and most determing single factor is: (drumroll….) “room choice!!” Start with a room that at least sounds decent by itself!! Often simply another room can be much easier turned into a decent homestudio, than the one which might have been the obvious choice (often for non-acoustical reasons). So if you might be able to use a bigger o better sounding room, use it, instead of trying to make the horrible workable by adding tons of treatment. All you can do with treatment is creating a reflection free zone in the sweet spot by using absorbtion and add basstraping to tame the modal ringing, you can´t change the room ratio, the boundary materials or the distribution of the roommodes. Old wisdom still apllies here: “You can put make-up on an ugly ass, but it´s never gonna turn into a pretty face!”

Many try to take care of the acoustics without any outside expertise at all. With that said, what’s your take on the various “room kits” that are available?

Most of those are very expensive for what they really are and most of the time they don´t include any real functioning basstrapping! They are porous absorbers, whether they consist of foam or insulation, there density and effective thickness is what matters, anything 2,5cm thick is worth a sh*t and doesn´t even absorb any mid frequencies but takes (much needed) surface area away, so the roomsound get´s dark and muddy.

If you´re seriously on a budget I´d start with DIY broadband traps at the first reflection points (left / right / ceiling) and add some more straddling the front and rear corners (10-15cm thick) and behind the speakers!

Also a good idea is to sign up to a forum like gearslutz (link), which has a dedicated acoustics subforum (link) and read, read, read as much as you can! There´s a ton of great knowledge out there in the www for free, though everything has to be taken with a grain of salt! But if you read something over and over for the nth time, chances are it´s probably not too far from being useful. There´s also some knowledge online how to test your room with software and a measurement mic, which can be a great help when setting up your room.

Btw. moving the relative listening position and the position of the speakers changes the interference with the room and can make far more drastic changes/improvements than a few acoustic panels!

Read, measure, listen!!
Acoustic knowledge can only improve your whole understanding of recording! I always wonder about how easy some problems during tracking can be solved, just by knowing what physically or acoustically is causing the problem.

Often a little expert advice and consultation actually saves money, though it´s not free…..prices are reasonable!

Something that’s becoming increasingly widespread on the internet is that you simply should throw up as many basstraps as you can fit. What do you think about that?

I truly enjoy working in some rooms that nearly have no basstraps added, simply because they were designed from the start to sound great and they DO!

It´s true that in a bad room, in order to make it workable/usable/better you can´t add too much, because it can only get better (the modal ringing get´s more and more reduced and peaks&dips become less pronounced and broadened throughout the room!)

But one has to ask oneself where the point is to rather design & built a room from scratch than to spend a fortune on prefabricated panels. I have never seen a pro studio with basstrap-panels allover the room, and that´s for a reason! They are a perfect fix for a non-alterable room, they are not the holy grail of room acoustics unfortunately. Also there are different kinds of basstraps, some porous, some membrane-traps, some combine both, also there are helmholtz and slot-resonators etc. all of those can be more or less tuned/broadband. That´s where measurement and professional consultation is your friend and will save you tons of money in the end!

Regarding tracking rooms, don´t forget what I said about a good sounding room to beginn with, some great records have been cut in rooms with hardly any treatment, for some general inspiration I highly recommend Daniel Lanois DVD “Here is what is” (link.)

Any final words?

The importance of room acoustics is often overlooked by lesser experienced people, the gearlust takes over and the improvements are small and the frustration is often high, because the basics aren’t taken care of: room acoustics, great speakers, great monitor controller in the control room……and great sounding, well tuned instruments in a nice sounding live room, captured by good mics! ….that´s 85% of a great record for my way of working!

But my final advice (to quote the wonderful Greg Wells): “The best sounding sluttiest gear of all time… is a great song!”

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Tom organises the HI-END GEAR, an alternative European pro audio conference based in Germany, focusing on professional and hi-end solutions and gear for music recording, mixing and mastering studios. In the spirit of the US Tape-Op Con they focus most of all on getting together, meeting other freaks and networking while having a beer. Everybody with a demand in quality in music production is welcome. The next show will be in Fall 2009.

Hi-end Gear website

Tom has an engineering degree in architecture and has consulted, designed and outfitted studios throughout the last years, though now tries to get more free time for recording, producing and making records again, which is what he’s really passionate about.

To contact Tom, email him at:
tom [at] hi-endgear [dot] com