So here's the list; In the order of importance as I see them they are as follows:
- Audio Interface
- DAW Software
- Power Conditioner
- Acoustic Treatment
- Studio Monitors (speakers)
- External Hard Drive
- Cables & Accessories
Today's topic is probably the lengthiest to date, and some may find it could be longer. It's also sure to cause some thought as we'll be discussing part #7 Sound Management aka Acoustic Treatment. Notice I didn't call it sound proofing. Unless you have the knowledge of NASA, and large pile of funds available to back it - you will not be sound proofing your space.
Sound Management is all about minimizing the sound you are creating, and the sound that wants to jump into your recording from outside. There are some inexpensive ways that leave plenty of room for growth until you can build that studio of your dreams. Contrary to popular belief, the goal of sound management is not to have a completely 'dead' space to record in. You ultimately want a mix of absorptive, diffusive and reflective surfaces - which is what you'll typically find in professional recording studios.
So Let's Get Started with Home Studio Equipment Reviews and Recommendations - Part 7 - Acoustic Treatment.
Step 1 - Don’t think in terms of a room – start think in terms of a telephone booth - larger or smaller depending on what you need to fit inside with you. Now, I know this will grab the attention of many Audio Engineers who will tell you that a minimum 10' x 12' space is required to hear audio properly. I can't agree more. But, for those who are getting started - it's doubtful you have a space that has been custom built with a high density mass loaded vinyl barrier like Auralex Sheetblok or a poly-weave sound diffuser with a thick resin sound blocking back like Mutex, maybe some double walls of QuietRock with Celotex Sound Stop behind them and even loads of isolating Sorbothane 'pucks' or Auralex U-boats that your floors and walls are 'floated' on. Next your walls are covered with a decoupling foam or faced with the standard Auralex Roominator kit with Bass traps in the corners or even Next Acoustics foam. If you are starting with that - then you're far ahead of this article and you're either reading it to pick it apart, or you think you may have missed something. For the rest of you who are unprepared or live in apartments - where you can't build anything permanent - read on. as you learn, you can start planning ahead for that amazing studio you will build one day!
Step 2 - Manage the noise you are creating *inside* the room. Keep computers away from your microphone(s). Some keep their desktop in a large box (you can find these online or build one yourself) that allows for airflow around the computer plus in and out of the box. Some claim their laptop doesn't make any sound, but that's only when it isn't under load. Put some heavy recording time on your laptop and the fan will kick into high speed, pumping out lots of noise. It's more likely you can't hear the fan noise because of all the other noises. Getting your computer out of the room/area is best. You can purchase extended cables online or at your local Radio Shack, Best Buy, etc. These allow you to have all the function you need, just with the computer sitting away from you and your microphone(s). Some just build a tiny 'booth' to record in and get a KVM switch (Keyboard, Video and Mouse) so they can have full use of the computer inside and outside of the 'booth' area.
Step 3 - Manage the noise inside the home, but outside the room. Temporarily turn off your Heat/AC anytime you are recording to avoid the ‘hum’ in the background while recording (I set an alarm to remind myself to turn it back on). Refrigerators make a considerable amount of noise and vibration - avoid turning them off, just don’t record near them if at all possible. If you have to record on the other side of a wall from a refrigerator, there's a great Recycled Rubber Mat that's meant to sit under washing machines and reduce vibration that can help - especially if it's on both sides of the offending wall. If it's applied with an adhesive like TubeTak, it's best. Other attaching will give mixed results.
Step 4 - Manage the noise coming into the room from outside. This one initially seems complex, but the number on culprit is windows, followed by doors, outlets, venting, cables or other 'holes' in the building. If you have windows – try blocking them with plywood, carpeting, exterior grade rigid foam insulation, etc. Combining those materials is even better (insulation , then plywood and mount the carpet on the plywood). Whatever you use - leave a 'dead space' between the glass and the material so they do not touch. It might not seem like much, but even a half inch of dead space will help tremendously. Put weather stripping around the door to your room to prevent noise seeping in around the door’s frame. Replace a hollow core door with a heavy solid wood door, and mount the Recycled Rubber Mat to the door (use screws or staples to hold in place) and adhere it with TubeTak to prevent vibrations. Doors also aren't very expensive - especially from Craigslist.org or a local architectural salvage. If you rent, replace the door that's there with one that you can 'beef up'. You can bring it with you, toss it out if you have to or sell it to someone else.
Step 5 - Manage the space you have now created. How you do that depends on your budget.
Let's start with Free or Cheap:
First is something I would definitely *not* recommend. Packing foam. Many don't realize it is not intended for interior use and so it is not fire rated. While it may approach the thickness, durability and look of acoustic foams, it likely does not do the job well. It could be dangerous and burst into flames if a spark or heat source were ever exposed to it - something that is fairly common around the equipment and light sources needed for a studio. when it burns it will give off fumes and burns quickly. If you insist on using it, get a flame retardent spray to treat the material. Be prepared to buy several cans.
Another in the 'do not recommend' section are ‘Memory Foam’ mattress pads, 'egg crate' foam bedding pads and egg crates themselves. Non-scientific tests that I've done seems to put these material about parallel to a thin cotton blanket. Actual Scientific tests show there are enormous spots in the audio that are completely unaffected. Basically - it's for you to have the feel/mock the appearance of a studio. I've even heard of people purchasing automotive fabric paint to give the appearance of a higher end product. The problem is that they can only help soften/reduce sharp echoes to a small degree (perhaps trivial) and give you some sound diffusion. Absorption is likely minimal. Two layers of the foam are no doubt better than one, though perhaps egg crates mounted over memory foam would work to a degree? Again, we have the issue of flammability. Not all bedding products are treated and egg cartons most definitely aren't. Again, if you insist on using it, get a flame retardent spray to treat the material. Again, be prepared to buy several cans.
Something I constantly see people insisting on using are acoustic tiles. You can find some that actually will work, though I have found some that most definitely do not. What they do provide is a dead space in between. Because most acoustic tiles are mounted in a suspended ceiling configuration, it is the suspension system and dead space that actually provide the acoustic treatment, not the tiles.
On to the next - Cubicles, Office Partitions and Portable Room Dividers. They manage sound to a degree (offices use them to keep noise at an acceptable level for phone use after all) and can often be found free or cheap on Craigslist.org. The number one problem is, they are heavy and difficult to find in a convenient size. You can also look for wall panels that can be hung like a message board (just much heavier) and give you some convenience and options on where to place them.
Carpeting is a good way to reduce echo and add a bit of mass, especially if it's the kind that has a thick foam-rubber backing. As an example - many Radio stations I've worked at are very thrifty in preparing a studio. Beyond heavy doors and double or triple windows, all they do it mount industrial carpeting with foam rubber backing on the floor and walls and use ‘blown in’ or cotton batting insulation in the walls between studios. It’s not perfect, but is very inexpensive compared to other options. I've even seen a rolled up carpet remnant placed in the corner to act as an inexpensive ‘bass trap’. Does it work as well as the pros use? Probably not. There are frequencies that will no doubt pass through, but they will likely be decreased.
*Heavy Duty* packing blankets that are double sided and lined on the inside with cotton batting are fair, better in multiple layers. The lightweight bluish ones you likely get when you rent a moving truck are no good for a studio. Thick down comforters are actually good and high quality (in other words heavy) lined/insulated/light blocking curtains work fairly well too. I have heard, and even recorded my own VO, in 'studios' that were no more than a booth made from two layers - and some room preparation. The talent had weather stripping around the interior door and foam insulation in the window. In the room were heavy light-blocking curtains and a down comforter(suspended from the ceiling with hooks and grommets), with a small lamp, a throw rug on the floor and a couch cushion hooked in above. Not only was I impressed, but so was the VO talent's own clients. With the curtain/comforter combination they had a studio quality sound and had bought only the grommets for the comforter and weather stripping for the door - everything else they had on hand. [EDIT] Another Great option is the sound barrier blanket from AudiMute (and more) Also a big thanks to John T. at Towne House Studios for the link to sound blankets from Movers Supplies. He recommends them highly, and they start at a very low cost! His Quote, "My first booth was lined with them to great effect."[EDIT]
A closet or 'nook' area lined with bookshelves full of books (mix up the sizes) will give you mass, absorption and diffusion as well. Often putting these on three sides allows you to be the fourth side of the wall, and there are several top end Voiceover talents who admit to recording in such an environment.
Some even less expensive alternatives would be a a box filled with high density foam pillows around your microphone. Likely the inspiration for Harlan Hogan's Porta Booth and Porta Booth Pro This can give you a great sound by preventing outside noises from reaching your microphone, preventing sharp echo's too. Don’t overlook materials you already have. You can upgrade with income generated and create a studio that has paid for itself and looks professional.
Ready to start preparing or upgrading your space - here's what you can add to it.
A High density mass loaded vinyl barrier like Auralex Sheetblok or a poly-weave sound diffuser with a thick resin sound blocking back like Mutex,
For the walls QuietRock and/or Celotex Sound Stop behind them
To isolate the floors and walls - Sorbothane 'pucks' or Auralex U-boats
Acoustic foam - there are a few choices. Something like the standard Auralex Roominator kit (includes Bass traps for the corners) or even Next Acoustics foam. You can also have alternating waves, lightweight Skyline Diffusors, floating panels and bass traps.
Rigid insulation like Owens Corning 703 series insulation is great. While not recommended, these can be mounted in their raw form, however they work best when placed in frames and wrapped with material. It gives you an easy to clean & professional look that can be mounted easily. Two outlets with decent prices and their own 'off brand' versions/multiple configurations are ATS Acoustics or Ready Acoustics.
Now, before you go shopping for everything, you need to learn about two very important topics Noise Reduction Coefficient and Sound Transmission Class. Why? Because without knowing what these are, and without knowing the NRC or STC of a product you are buying, you may not be picking up the right product for your space.
Thanks for reading and stay tuned for next week's topic; Studio Monitors.
Comments, thoughts, anything you have found that works well not mentioned here? Disagree completely? Sound off in the comments below!
- Mel - Your Audio Pro