Corner bass trap and broadband absorbers plus foam above.

The Problems
Small rooms are more likely to have acoustic problems than larger ones, primarily flutter echo, room modes and early reflections that are too short. In my room, I knew there was a very bad flutter echo problem and room modes may be a problem but were predictable. The room is symmetrical which was an advantage the old room didn’t have. The measurements are approximately 11ft long x 9ft wide x 8ft tall. There is a door and a closet on the back wall and 6 x 4 window on the front wall.

Flutter echo happens whenever there are parallel reflective surfaces. The sound repeatedly bounces off each wall and creates a series of bright echoes. In this room it was almost like a spring reverb. I was getting it off the side walls, floor and ceiling and from the window and back wall. When this was used as a bedroom the flutter echo was unbearable, I actually had treatment in here just to be able to sleep, but that might just be me being weird. Luckily this is easy to fix.

Room modes, also known as standing waves, are again when sound bounces between parallel surfaces. When the wavelength is a multiple of the room dimension, you will have a standing wave. It’s an acoustic phase problem. This frequency will be amplified twice as loud close to the walls and cancel out completely in the center.
For example, The wavelength of 60Hz is 18.83ft. If the width of a room is exactly 18.83, the exact center of the room will have complete cancellation of 60 Hz. If we multiply the frequency by 2, then there are two dead spots at 120 Hz, and 4 dead spots at 240. The dead spots are called Nodes.
There are 3 types of room modes, each with more complex calculations, but the worst kind, and easiest to calculate is the Axial mode. Axial modes are calculated: Half speed of sound (1130/2) divided by room dimension (length, width or height in ft)
Calculate all three dimensions and multiply each result by 2x, 3x, 4x until above 300Hz. Room modes are only a problem in the low frequencies below 300 Hz.

Small rooms tend to have the worst standing wave problems, and not enough room to treat them effectively. Axial modes happen across the entire surface of the wall, and bass tends to accumulate in corners.

Early reflections, are the first bounce off a wall to your ear. So when the sound comes out of your speaker, goes past you, reflects off the wall and back to your ear. There is a certain acceptable time range for early reflections in a mixing position called the Haas zone, 5-30ms. Longer early reflections are ok because our ears and brain can separate them from the original sound, but if they are too short, like in an untreated small room the sound is blurred by the echo. Btw, leather chairs with headrests can also be a problem.

Symmetry
You might think that because there are all these problems with parallel surfaces bouncing sound around that we should avoid rooms with them. Perfectly square rooms are the worst. Two dimensions the same is bad and anything else can be treated. The benefit of parallel surfaces is that we can easily predict what the problems will be and more easily set up a balanced room. A room with one wall that angles out will prevent flutter echo in one dimension, but will make perfect stereo imaging from the speakers much more difficult. You can still get standing wave issues with non-parallel walls, it’s just way harder to predict and measure.

Acoustics resources

The Solutions
Window
In the middle of the front wall of this new room I had a roughly 6 ‘x 4′ single-paned window. Two problems with this: reflects sound within the room, leaks sound in and out.
A while ago I scored some free acoustic ceiling tiles from a store that was being gutted. When cut to size these are very effective at reducing sound transmission through the window. They are non-reflective so sound doesn’t bounce off and they also work well for blocking sun and therefore heat. The downside of these is that they’re fragile and crumble easily.
I cut 6 of them to size and stuck them in the window 2 layers thick. I left room on one side to open the window for a fan. This is then covered with a curtain.
If you don’t want to go through all that, you should still cover all windows with thick curtains, which will not help much with isolation but will stop the reflection from the glass.

The RFZ
What tends to be a good, affordable plan of attack for most rooms, large or small is to create a “Reflection Free Zone” (RFZ) with a “Live End, Dead End” treatment concept, meaning the majority of acoustic treatment is positioned to the sides, ceiling and front wall of the room.
By installing the sound absorbing panels in this way, the flutter echo and early reflection problems are eliminated and the standing wave issues are greatly reduced, at least when in the mixing position. You only need to absorb on one wall to stop flutter echo. You can stagger the treatment on opposite walls if you’re short on materials.
I have 64 sq ft of 2″ rigid fiberglass panels on the sidewalls and front corners and another 56 sq ft of 1.5″ foam on the ceiling. Likely this is more than most people will have available and it is probably slightly more than I need, but it makes such a huge improvement.

Rigid Fiberglass
Rigid fiberglass is the best bang-for-buck acoustic absorption material. It absorbs well down to the lower mids. A few years ago I built several 2ft by 4ft broadband panels with fabric covered wood frames that are mounted to walls easily by just hanging off a drywall screw.
In my new room I have two panels across the front wall corners, then 3 panels across each side wall covering the first 8ft of the room. These are across the middle of the wall providing coverage for both sitting and standing listening. Mounting the corner traps is easy with a few hooks and a bungee cord.
You can increase the effectiveness of fiberglass absorbers by creating an air gap between the panels and wall of an inch or two. I have not tried this yet.

Foam
Foam is less effective than rigid fiberglass and is often not any cheaper and can be harder to work with. If you don’t have tools to build fiberglass broadband absorbers, then foam will still make a big improvement. I found a box on craigslist for a good deal a year ago so I use it in the less critical spots in the room, where I need to kill early reflections or flutter only. I have three panels hanging above the desk and mix position, this is called a cloud and it helps focus the sound from the speakers. I have 2 more foam panels above the fiberglass sidewall panels squeezed into the corner between wall and ceiling. I’m not sure of the effectiveness of these in this position but it looks pretty cool at least.

Monitor positioning
Monitor positioning can be tricky in a small room, especially if it is not symmetrical. When setting up a studio, have the short walls at your sides and speakers firing lengthwise. Don’t put the speakers directly in corners, as that will exaggerate the low frequencies coming from them. Instead set them up with enough distance to walk beside and behind them if you can. Use the same measurements for each side. My speaker stands are exactly 27 inches from the closest sidewall, 21 inches from the front wall and 60 inches apart (measuring from the pole). I started mine a little narrower than that but it didn’t sound as good. 50 to 70″ is where yours should be, not narrower than 4ft.
Speakers should be “toed in” at a 30* angle towards you.
If you think of your pair of monitors and head as points of an equilateral triangle, then where your head is should be within 18″ of that 3rd point.
The tweeters should be at ear level. Your speakers can be vertical or horizontal (I prefer horizontal) with the tweeters on the outside.

The Results
Having a dedicated space is great. At first I was worried that the small room wouldn’t sound as good but it turned out to actually sound better. I have better noise isolation, clearer sound from my monitors and still enough room to record acoustic and electric guitars and vocals here. Without all the acoustic treatment, this room would be a disaster.
With a more limited budget I could get by with 2 corner traps, 4 side panels and two foam cloud panels. The more absorption the better.

I really need that curtain…and a pro photographer!

Ahh that's better. A couple months later, this room is great!

The invention of reverb itself is impossible to pin-point in time. Gregorian monks knew it sounded great and so does anybody who sings in the shower. As soon as recording started, it was natural to record music in its most pleasing setting. Early recording engineers followed music wherever it went, frequently ending up in spacious churches and music halls. When electronic recording began to gain ground over the phonograph, interns started complaining about hauling tube tape machines to every church in the city. Subsequently, marking the first and last time anybody listened to an intern, dedicated recording studios started being built to house the gargantuan, over-heating recording equipment.

When it came down to live rooms, flexibility was the biggest concern. An 80-piece orchestra sounded great in a room with a lengthy reverberation, but it was hardly desirable for a rock band. Specially made reverb chambers were developed using a send (called an echo send) from a console, the engineer could adjust how much signal would be sent to that chamber and what channel would receive the treatment.

Note: Most audio engineering text books will refer to “echo” as a small number of repeats, each discernible. This is a misnomer in the case of “echo” chambers. Most echo chambers provide reverb, which is usually accepted as thousands of repeats that are unable to be individually picked out by the human ear.

A view inside an Echo (or Reverb) Chamber

How It Worked:

The rooms were not nearly as large as you would expect (or as they sounded). Studio architects used what little trickery they had at their disposal to exaggerate the acoustics of what was often little more than a large pantry. Echo chambers would have shellac or tile on all surfaces of the room, much like a shower. The loudspeaker (playing what was being sent from the echo send on the console) would usually be placed not facing the room, but facing a reflective wall. This increased the reflections in the room, and also decreased the amount of direct signal that would be picked up by the microphone(s). In the early days of recording the echo chambers would be mono send, mono return.

Famous Examples:

Gold Star Studios is arguably the most famous example of a reverb chamber. Phil Spector made Gold Star his home while recording the early hits of his career, and its reverb chamber played a key role in Phil’s infamous Wall of Sound. If other studios included reverb chambers as fringe benefits, Gold Star included it as a downright necessity. A cramped room where elbow room amongst musicians was a legitimate concern, the reverb chamber was the saving grace. In a Mix Magazine article, Larry Lavine testifies to the speaker in the chamber being a cheap 8-inch speaker being picked up by an equally cheap ribbon microphone (bi-directional). The chambers were a mere 2×3 feet, but the cement lining did wonders to enlarge that. You can hear this reverb on The Ronettes’ Be My Baby, parts of Pet Sounds, and other staples of that era in recording.

Try getting away with a fart in this room.

EMI Studios (later Abbey Road Studios) was a studio complex built by a record label at a time when it was hard to imagine a better business model than recorded music. There were 3 reverb chambers built inside the complex, one for every studio live floor.

• Chamber One was built first for Studio Three (the smallest live floor in Abbey Road) and it made use of a single Tannoy speaker being heard by a Neumann KM53. It was approximately 11′ wide by 19′ long and was rectangular except for a diagonal reflective wall on which the speaker was focused.

• Chamber Two was built to satisfy reverb needs for Studio Two (home of The Beatles). It likely made use of the same Tannoy and KM53. It’s dimensions were rather unflattering for an acoustic environment, featuring two pairs of parallel surfaces measuring 12′ x 21′. To make up for this, engineers pointed the Tannoy at one corner, and used sewer piping to diffuse standing waves in the room. Crude, but it hasn’t hurt sales of The Beatles catalogue.

• Chamber Three was built for EMI’s classical studio work, mostly being done in the gigantic Studio One. It used staggered, nonparallel surfaces coated with the same reflective tiles as the other chambers. Measuring 17’8” by 12′, it was suitably the biggest chamber in the building.

Capitol Studios, located in the basement of Capitol Tower, was the frat house of Frank Sinatra, The Beach Boys, and the equally charming Beastie Boys. Its four identical trapezoidal rooms were designed by musician cum technological-soothsayer Les Paul. The rooms were built using reinforced concrete and coated with metal lath and cement plaster on the interior. Even the ceilings were sloped to ofter flutter or standing waves.

Other Famous Reverb Chambers:

Motown Records’ Hitsville USA complex is rumored to have used a hole in the ceiling as a jerry-rigged echo chamber. This wasn’t a traditional reverb chamber, it wasn’t controlled from the board, adjusted by positioning mics to pick-up the desired amount of reverb.

Joe Meek, the English producer of the 1962 hit, Telstar was well-known for using cavities in his house, like beneath the stairs or in the bathroom, to supply the reverb he needed.

An example of a staircase reverb set-up

Build Your Own:

Dave Simons over at Electronic Musician wrote a great article on his experience building a reverb chamber in the basement of his home studio.

http://emusician.com/tutorials/reverb_effects_studio/index.html

What are some reverb chambers that I left out? Do you have any favorite examples of reverb chambers?

What is phase?
I’m going to consult my Engineering school textbook Audio In Media for this.

The time relationship between two or more sounds reaching a microphone or signals in a circuit. When this time relationship is coincident, the sounds or signals are in phase and their amplitudes are additive. When this time relationship is not coincident, the sounds or signals are out of phase and their amplitudes are subtractive.

No wonder people are confused about phase. Even I got confused at that, looking up other entries on phase in the book were even worse. I guess I shouldn’t read books.

I’ll try to break it down more simply.



Phase VS Polarity

OK, so lets define things a bit more starting with Phase and Polarity. These two terms are often used interchangeably but they ARE different.

• Phase is an acoustic concept that affects your microphone placement. Acoustical phase is the time relationship between two or more sound waves at a given point in their cycle. Phase is measured in degrees. When two identical sounds are combined that are 180° out of phase the result is silence, any degree between results in comb filtering.

• Polarity is an electrical concept relating to the value of a voltage, whether it is positive or negative. Part of the confusion of these concepts, besides equipment manufacturers mislabeling their products, is that inverting the polarity of a signal, changing it from plus to minus is the basically the same as making the sound 180° out of phase.

In case you missed that: Phase is the difference in waveform cycles between two or more sounds. Polarity is either positive or negative.

In and out of phase

When two sounds are exactly in phase (a 0° phase difference) and have the same frequency, shape, and peak amplitude, the resulting combined waveform will be twice the original peak amplitude. In other words, two sounds exactly the same and perfectly in phase will be louder when combined.

Two waves combined that are exactly the same but have a 180° phase difference will cancel out completely. Silent output. These conditions rarely happen in real world recording, more likely the two signals will either be slightly different, like two different mics on the same source, or the phase difference will be anything other than 180° out of phase.

In cases where the signals are not 0° or 180° or the signals are somehow different, you get constructive and destructive interference or comb filtering. The peaks and nulls of the waveforms don’t all line up perfectly and some will be louder and some will be quieter. This is the key to combining mics on a single source.

Examples

Here are some examples using sine waves
this is a 250Hz sine wave with a peak amplitude of -20dB: LISTEN

If I add another the exact same and combine them (in mono) the output is the same but louder, a combined peak amplitude of -14dB. They have a 0° phase difference, amplitudes are additive.  LISTEN

Now if I change the phase, the time and waveform relationship of these by having the second track start 2 milliseconds later it’s like this: LISTEN
Silence, this is 180° out of phase.

Here is the same kind of thing with some white noise, -20db, the same audio file is copied to another track and combined. Louder same as before -14dB combined.

Now I’ll use the invert function on the second track and since these sounds are exactly the same it the completely cancel out.

I think everyone understands that now, so here’s something slightly more interesting. I’ve taken the first 1 second of the white noise clip and repeated it 9 more times. The second track is the same, but on each repeat I’ve delayed it by an additional 1ms. Now you can get an idea of the constructive and destructive interference and the comb filtering. If you look at the frequency spectrum in an analyzer you will actually see notches cut out like the teeth of a comb. LISTEN

Real world examples
Here is a bass guitar going into a DI box, the signal splits and goes to an amp and to the audio interface. The amp is miked and the mic is going into the interface too. This is a very common way to record bass, but you may run into phase problems when the fast as light signal from the DI box is combined with the air pushing out of a speaker into a mic some distance away signal.

Here is the bass DI Signal: LISTEN
Here is the Microphone signal: LISTEN
Combined they sound a bit funny, definitely some hollowness going on: LISTEN

Correction By Inverting Polarity

The first thing I would try to troubleshoot this is to invert the polarity of one of the tracks and see if that’s better or worse. I know that because there is a time delay with these tracks that inverting alone won’t fix everything.
I can invert the polarity in two different ways, I can either use an offline process and invert the whole wav file or I can insert a plugin on the track. Some DAWs have a polarity reverse button on each channel of the mixer that will do the same thing.

I’m just going to play the tracks and invert the polarity a few times so you can hear the difference: LISTEN

Correction By Time Adjustment

I’m going to keep it the way it was and then go to the next strategy. That is moving the tracks around in time. The microphone track is delayed compared to the DI track just slightly. So I can either nudge the microphone track earlier or delay the DI track a little.
I’m going to delay the DI track just slightly. To do this I’m going to insert a delay plugin that works in samples, such as the Time Adjuster plugin in Pro Tools.

I’m going to invert the phase, then scroll through the delay value 1 sample at a time until I achieve the most cancellation, then switch the phase back to normal. I found that 152 Samples did the trick. You can also zoom in really close on your waveforms and nudge a track until it lines up. LISTEN

Processing delay

Another common cause of Phase cancellation is when doing parallel processing with delay causing effects or external gear. If the delay is long enough you will hear it as a discrete echo, if it’s short then you will get the comb filtering problem. The way to get around this is to delay all the other tracks by the same amount so they all reach the master bus at the same time. See HERE for more on handling DAW delay compensation.

Multiple mics on a single source

When using two mics on a speaker cabinet you need to be aware of the phase relationship. You can never get the mics to perfectly cancel out, but you find a place where the two mics work together really well. Start by positioning the first mic in any way you like. Put on headphones and start moving the second mic around, you’ll hear all kinds of phase cancellation but there will be at least one placement that sounds really good. It helps to invert the polarity of the second mic while doing the listening in headphones find the place where you get the most cancellation then flip the polarity again for a nice big sound.

Phase issues with a single mic?

Believe it or not you can also get phase issues when using just a single mic. Reflected sound from nearby surfaces like the floor or walls can get into your mics and cause partial phase cancellation. There is only one way to deal with this, and that is at the source. Put down carpet, sound damping materials, lift the amp off the floor whatever you have to do to get rid of the problem reflections. This is one of the only things you can’t fix after it’s recorded. Never time adjust when using multiple microphones, especially for things like drum mics, get it right with your mic placement.

That’s just the beginning

Wow, this article got really long, congrats if you followed along to the end. It was exhausting preparing this article and I feel like I’ve only covered about half of what I should. I didn’t talk about drum miking, stereo, M/S or tricks using phase.

I hope this has been a helpful guide to phase and the importance of the concept has been understood. Comments, praise and concerns are always welcome. Thanks for reading.

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Whenever we use two or more microphones on a single source we need to be aware of phase cancellation and comb filtering. Due to the time delay of the sound waves hitting the microphone elements at different times, partial phase cancellation will occur.

When the signals from the microphones are combined you may find that the result is a thin, boxy, or hollow sound. This is called comb filtering. Due to the complex waveforms being combined, some frequencies will be in-phase and some will be out of phase.

Here’s an example.

I have a guitar combo amp miked with a 57 style dynamic mic, positioned right up against the grillcloth.

(clip-1)

I have an AT 2020 condenser microphone about 9 inches back from the grill and 1 inch to the right of the 57.

(Clip 2)

I also have a second AT 2020 at the rear of the amp.

(Clip 3)

All these clips sound ok on their own, but the point of this is to combine the tonal qualities of these different positions to make one guitar sound.

Lets play them all together.

(clip 4)

Not too pretty, that thin, boxy, hollow sound is really not what I’m looking for.

So what do we do? We play around with the phase invert buttons in our DAW.

Here is the sound with the 57 phase inverted.

(clip 5)

With the 2020 in the front inverted.

(clip 6)

and with the 2020 in the back inverted.

(clip 7)

That last clip is pretty much the sound I’m after much thicker and aggressive, some EQ and I’ll be happy.

For emphasis on the sound of comb filtering here is a clip of the 3 mics combined while I move one of the mics further away and then closer to the amp.

(clip 8 )

You can minimize the effects of phase cancellation by getting the microphone capsules as physically close together as possible.

Also using different kinds of mics will color the sound differently.

One last thing, keep in mind that you can get this kind of comb filtering when using just one mic on a guitar amp if reflections off the floor or nearby wall get into the mic. Moving the amp, tilting it, and putting down carpets under the amp will all help eliminate that problem.

Let’s discuss.

Epiphone SG, Behringer V-Ampire, GLS ES-57, Audio-Technica AT2020, Pro Tools LE, digi 002r were used in this article.

For not a lot of money I made a big improvement to this situation. Rigid fiberglass is the most cost effective way to acoustically treat a room. Foam only really makes a difference with mid and high frequencies, the panels I made are effective down to about 125 Hz according to the specs of the material.

Click any photo to enlarge

Here is a great site with specs for various materials: http://www.bobgolds.com/AbsorptionCoefficients.htm

What I got for my room: http://www.ofigroup.com/products/can_pdfs/can_ofi_48_rigid_fibre_board.pdf

I spent about $200 for the rigid fiberglass, fabric, wood, and staple gun. I this made 96 ft², which comes out to $2/foot compare that to Auralex foam which is at least $4/foot and is less effective. If I got cheaper fabric it would cost even less. Anyway, I think I’ve made my point. Each panel takes about half an hour to make, faster if you have help.
So what do you need to build these acoustic panels?

• Rigid fiberglass sheets (Owens Corning 703/705 or OFI 48)

• 3/4″ plywood cut into 2″ wide strips (2 4′ long pieces, 2 25.5″ long pieces per panel)

• a staple gun and wood staples (electric preferred, Arrow or Powershot)

• fabric for covering the panels, 4.5Meters was just enough for 6 panels (I used black speaker cloth, normally $9/M, I got it half price) Any fabric that is breathable will work, hold it up a blow through it to test it.

After the wood is cut up, drill holes on each end of the shorter pieces, even spacing of course. Countersinking helps with the appearance, drill through once, then with a large gauge bit drill in just far enough for the screw head to sit in flush. After all the drilling is done screw the pieces together into a frame. Yes I know there are technically better ways to build this that will be more sturdy etc. This is not a barn we’re building, it’s not load bearing, it doesn’t matter, so don’t even start. Below is a closeup of a corner, and 4 constructed frames below a completely finished, mounted panel.

Alright, so now here’s the hard part (not really), lay out the fabric on the floor or on a large table if you prefer. Lay the frame on top of the fabric so there is an even overlap on the right about 2.5 inches. Begin stapling from the middle at an angle. Move over to the other side. Pull the fabric tight slightly and cut off the excess leaving about 2 inches. Staple as before but make sure you are keeping the fabric pulled tight and even. Do the same on the ends.

For the corners, there’s not much to it, just fold neatly and put a bunch of staples in. Cut off the excess fabric if you want.

Now put on some gloves before you handle the fiberglass sheets. Think about it fiber-glass/glass-fibers. Common sense. Its not going to hurt you but will make you itchy.

Lay the frames down on the floor and drop the sheet of fiberglass on top. Push down from the middle to fit it in. Try not to aggravate the sheet because you don’t want the stuff floating around the room or on your floor.

A few of my panels I made to be free standing. They mount on mic stands. Because of my room is so large and L shaped its difficult to get a symmetrical mix position. These panels on the stands help make an RFZ (relection free zone), as well as blocking out noise somewhat from the kitchen.

To make them I just added some spare brackets to the frames 16″ down from the top and bent them downward slightly. There’s some pictures of that below.

I also have two panels without frames, one for in the window and one hangs above my desk. They look pretty ghetto now with the fabric just loose around them, but I’ll figure something out.

My room still isn’t great, but I’ve made a huge improvement for not that big of an investment. I now need to fine tune the placement of the panels and possibly do some furniture rearranging. I’m pretty happy with the results so far.

I hope this was helpful.

Solution: A device that helps to isolate the room from the mic, that’s much more sophisticated than making a fort out of blankets to record in.

There are several companies making room reflection reducing solutions, each with their own take on it.

1 -SE Electronics – Reflexion Filter. (List $399) The most well known out of the bunch. Expensive and heavy, but seems to work surprisingly well.

The Reflexion Filter is basically a portable device for recording live sound sources with reduced room ambience. It is an advanced composite wall which is positioned behind any microphone by means of a variable position stand clamp assembly which ships with the product. The main function is to help obtain a ‘dry’ vocal or instrument recording. This is especially useful in studios without proper acoustic treatment, but can also be used to help record takes in control rooms, where the performer also has to operate the recording device, or in rehearsal studios to reduce ambient noise.

2 – SM Pro Audio – The Mic Thing. ($319) Not quite as professional looking, but lighter and is adjustable. Available in Black or White.

The Mic Thing is a portable multi-purpose acoustic treatment panel suitable for minimizing room artifacts and improving separation during microphone recording sessions. Great for a range of applications including helping to control room ambience, minimizing spill from instrument amplifiers, or even creating temporary control rooms the Mic Thing is certainly one handy thing!

3 – RealTraps – Portable Vocal Booth. ($299) Lightweight and XL size sets this one apart from the rest. See site for a comparison with the Reflexion Filter.

Since the RealTraps Portable Vocal Booth is larger than competing products, it blocks unwanted sound and reduces room ambience much more effectively. As you sing or speak into the booth, it prevents your voice from getting out into the room in the first place. This is far more effective than trying to block room ambience and reflections after the fact.

4 – ModTrap. ($99 small $149 large) A newcomer to the market, they come in 2 sizes, and are the most affordable.

The most versatile acoustic panel in the world. ModTrap acts as an absorber to tame unwanted room reflections, and as a tool to shape your sound. What makes ModTrap so special, is that it fits directly on to your microphone stand, enabling you to place it where you need it most.

5 – DIY Vocal booth ($235) An example of what not to do, not only is it huge and bulky, it will likely increase reflections to the mic.

4 x 100 cm x 100 cm cheapest acustic foam = 10X4 + 10 (from germany) euros = 72 USD
8 x 200 cm x 50 cm wood panels = 8 x 8 euros = 93 USD
furnitures +/- = 16 + 2 + 30 (scratch) euros = 70 USD
so it’s 235 USD and 2/3 hours of “work” taking your time.

I think the both the RealTraps and ModTraps are an excellent value. They are large enough to work well for vocals or to improve isolation between instruments, they are lightweight and portable, and they are both USA made products.

Built inside of a large road case, it houses a Celestion G10L 10″ speaker and a short mic stand on a baffle close to half way across the box. The purpose of the box is for recording loud electric guitar amps without all the volume and leakage. Its a great piece of gear for re-amping tracks as well.

I’ve been thinking of building one of these myself, those road cases are always on ebay or craigslist quite cheap.

The original post is here.

Noise and interruptions: Even big studios have to deal with this, outside noise getting into the mics. Things like big trucks driving by and construction. Here I have plumbing, fans, garbage trucks, and neighbors to deal with. All I can really do is close all the windows and turn off all the fans, but then it quickly becomes hot in here.

Monitoring: If you are recording anything in a one room studio that means you are tracking with headphones on, both you and the artist. Remember to listen back both on headphones and on speakers, but remember to mute the speakers while tracking. Its really easy to ruin a good take with bleed this way, as I learned today.

Acoustics: Likely its a rectangle, you can’t do much to change the shape of it, but you can use some acoustic treatments to improve the sound. My recording room is a large rectangular room with big windows and hard painted concrete walls. Needless to say, its a little bright with a noticeable echo. To lesson the effect of the room on the recording, heavy blankets, Baffles, and close micing helps a lot.

Lack of isolation: Both you and the artist are in the same room, while he is playing you have to sit still, make sure you don’t cough, sneeze, or squeak your chair. Benefits of this closeness is being able to instantly give feedback on the performance and not need to worry about a talkback system as well as being able to give visual cues to the artist.

Space: You likely have very little space to spare, you probably don’t have room to record a drumkit. Maybe you love the sound of a cranked Marshall stack, lets sit right beside it, right thats a good idea. There really isn’t much you can do about this other than going to a real studio for drums or bed tracks.

Privacy: This is your home, how many band members are you comfortable with wandering around your home, clogging your toilet, eating your food, etc. You will need to limit the amount of musicians to one if you want to maintain any control.

These are just some of the many downfalls of recording at home.

Room and positioning

Different types of mics

Mic placement

Miking different speaker cones

Ambient mics and The Vortex

Using Phase

Check it out here: Sound On Sound Magazine

So here’e the situation, you want to build a home studio, you want it to be isolated from outside sounds, and have a balanced sound, and you want to build it yourself. Problem is, you have no idea where to start. Luckily Auralex wrote a handy practical guide for just this sort of thing. www.acoustics101.com is where to get it.

The pdf provides plenty of information on acoustic terms and construction materials, as well as building the floor, walls, and ceiling. It is a great guide to studio construction, and great acoustics primer for everyone else. Auralex also has an easy way to figure out which acoustic treatment package is right for your room here. They also provide free room analysis via email.

www.acoustics101.com