Bass Traps & Acoustic Absorbers Pt. 3 - Mounting & Overall Costs

Over lest the last couple of weeks I’ve written up about how I designed and constructed the acoustic treatment for my home studio. Last week I even put together a short video about the difference that it makes.

Today I’m going to give you a quick rundown on how I fixed these panels to the walls and ceiling of my room and the overall costs involved in doing such a project.

Mounting

Here are a couple of pics showing you how I fixed my acoustic panels to the ceiling of my room.

As I stated last week, I have an i-beam running down the centre of my studio. I fashioned some brackets out of 6mm threaded rod and used stiff wire to hang the panels. In your studio, you might need to screw hooks or eyelets into your ceiling to hang the panels.

The panels on the walls were then hung with fishing line from the upper skirting board. You can then use stiff foam or leftover wood to displace the panels about 100mm from the walls.

The bass traps were simply wedged into the corners. My ceilings are 2200mm high to I made my panels to fit snuggly.

Costs

This is a breakdown of the overall costs of the project. All prices are in Australian dollars and the best prices were sought where possible.

The overall project cost about $500 but this is assuming that you have access to the required tools: saw, angle grinder, staple gun, drill and scissors.

From these prices, you can estimate that each floor to ceiling bass trap cost about $110 to construct and each 600mm x1200mm acoustic panel cost about $44 to construct.

Doing a quick search on the internet, I have found that an equivalent commercial 600 x1200mm panel costs about $200US. If you’ve got the time and you’ve got a good DIY attitude, I would highly recommend building your own panels.

I hope you’ve enjoyed these articles on DIY acoustic treatment. Feel free to leave a comment or shoot me an email about your own projects!

DIY Acoustic Treatment - Before and After Comparison

I just created this video so you can see and hear the effect of the acoustic treatment on my studio.

Enjoy!

Read about it here and here.

Bass Traps and Acoustic Absorbers Pt. 1 - Concept Design

Now, I am by no means an acoustics expert so I think that these articles can stand as a good discussion forum. Make sure you leave a comment if you have any suggestions for the design and we can help anyone that is keen to build their own.

Background

When designing these acoustic panels I had a few limitations:

• I am renting so any panels need to be attached with minimal damage and easily removed when I move out.
• Panels need to be suited to different rooms as I don’t know what my next studio will be like.
• I am only working part time, so all costs need to be minimised ie. little or no wastage.
• The two corners behind my listening position are difficult to access as one has a window and the other has a large piece of immovable furniture

My room is square, 4.6m x 4.6m x 2.25m with two brick walls and two plasterboard walls. As you can imagine standing waves and flutter echoes are serious problems in my room. I’ve done a few quick calculations using a room mode calculator and have found that axial room modes occur at around 37Hz, 74Hz, 158Hz, etc. as well as other complex derivatives. I could aim to tackle these frequencies individually using tuned bass traps but I have opted for more versatile broadband bass traps and acoustic panel designs. This involves using insulation to absorb troublesome frequencies.

As standing waves peak at the walls and in the corners of the room, this is where I want to place my traps. Try it. Stick your head into the corner of your room and hear how the frequency response changes. I have considered the use of Superchunk bass traps but have opted to build self standing panels that don’t require being built into the room. It will also make it easier to move to my next studio.

Concept

After much deliberation I decided to build two floor to ceiling 600mm wide x 150mm thick bass traps and six 1200mm wide x 600mm high x 100mm thick broadband absorbers. One of the main reasons for this arrangement was due to the size and availability of acoustic insulation. The insulation that I have chosen to use is Tontine Acoustisorb 3. It is comparable to Owens Corning 703 (one of the most used studio insulation materials used in the USA) and comes in 1.2mx2.4mx50mm sheets.

I briefly looked at normal house insulation products but couldn’t find a material that had the density that I required. Acoustisorb 3 is 48kg/m3 and does not require personal protective equipment to handle or cut, which is a bonus. It also means that I don’t have to worry too much about covering. Acoustisorb 3 comes in a pack of three sheets so I will use one pack to construct the bass traps and a second trap to construct the broadband absorbers.

Design

Many DIY bass traps use 100mm or 150mm wide pine as a simple and strong way of framing the insulation. However, any sound waves contacting these frames is going to be reflected so some people then cut holes and patterns out of the wood to increase the effective surface area of the traps. As Acoustisorb 3 is fairly rigid I can get away with having a fairly simple frame. Rather than framing the insulation, I am going to provide a skeleton for it to be mounted to. I can then use this frame to attach it to the wall.

Down at my local Bunnings there are dozens of different wood cross sections to choose from. I finally decided on 18mm x 38mm x 2.4m lengths of pine as they are rigid enough in both axes as well as being reasonably priced at a convenient length (about $4.80 /length).

You could then construct the frames using pre made L-shaped brackets but I have opted for the simplest and cheapest option. Each corner requires two 50mm wood screws (8 per frame) which minimises drilling and provides enough rigidity to not need cross bracing even on the floor to ceiling frames.

Further Reading

http://www.ethanwiner.com/basstrap.html - Great DIY bass trap article.
http://www.gearslutz.com/board/bass-traps-acoustic-panels-foam-etc/ - forum community dedicated to acoustics and production.
http://www.stereo.net.au/forums/forumdisplay.php?f=17 - An Australian based forum dealing with acoustics.
http://www.radford.edu/shelm/acoustics/bass-traps.html - Fantastic article on building similar acoustic panels.
http://www.spec-net.com.au/company/tontine/acoustic/acous6.htm - Specs for the Tontine Acoustisorb 3.

Next Week

So next week I'll go through the construction process and outline a few tips to help you build the panels a bit quicker and easier. I'll have some pics then too so you can see what they look like. Got any suggestions / questions? Just leave a comment. Do it!

Click here to go to the next installment.

Templates For The Win

I often visit different forums to learn new tricks, keep up to date with new technology and techniques and sometimes just to hang out and talk trash amongst other fellow producers and studio junkies.

A few days ago a user posed the question "Which part of the song do you write first?". Now after a few responses it was clear that there was no one way to start a song. Some people start with a bassline. Some people start with drums or a groove. Some people start with a synth riff. I've even heard in an interview with the french producer, Martin Solveig, that he would start by sitting in front of a microphone and make random sounds and noises until he found one he liked.

So that's all well and good; everyone is different and we each work in different ways. Eventually one user mentioned that they load up their basic template and go from there. This made me think about my own template and how I use it. I know that it has saved me a lot of time in the studio. After starting a few songs I realised that I would be grabbing for the same effects and presets for different tracks. So, why not turn that base set into a template?

I'll take the time to tell you about my template, how I have everything set up and why. Once again, this isn't the only way to put together a template but it helps me and it may help you.

My base template consists of 8 tracks (Kick, Bass, Snare, Hats, Percussion, Synth 1, Synth 2, and Vocals) and 3 return tracks (Reverb, Delay, Perc).

1 - Kick

This audio track is solely for my main kick drum. On this track I've got a high pass filter to cut out all the muddy frequencies below around 25Hz. I've also got a frequency analyser to help me EQ the bass to get it with sit with the kick.

2 - Bass

This midi track is for my main Bass synth; Blue, Bassline, Elek7ro etc. As with the Kick track I've got a high pass filter to cut out all the muddy frequencies below around 25Hz. Using a frequency analyser and an EQ I can then EQ the bass to get it to sit with the kick. See my previous post on Kick and Bass EQ.

3 - Snare

As I tend to write my drums first the next audio track is for the snare drum. There are no effects on this channel but it is routed only to the C Perc return. More about this later.

4 - Hats

This midi track is loaded with an Impulse to look after all my hat samples. There are no effects on this channel but it is routed only to the C Perc return.

5 - Percussion

This audio track is ready for chopped up percussion styles. Sometimes I'll even duplicate this track depending on how many layers I end up working with. There are no effects on this channel but it is routed only to the C Perc return.

6 - Synth 1

This midi track is ready for my main synth line. On this track I've got a high pass filter to roll-off frequencies below about 150-350Hz. This gives the kick and bass room in the mix. Send A is then set to send the track to both the Master and the A Reverb return. I'll then adjust this send to raise or lower the amount of reverb I want.

7 - Synth 2

Same as above.

8 - Vocals/Samples

This audio track is for the vocals or any melodic samples that I end up using. On this track I've got a high pass filter to roll-off frequencies below about 150-350Hz. This gives the kick and bass room in the mix and also removes those popping sounds that you get in some vocals. Send A is then set to send the track to both the Master and the A Reverb return. I'll then adjust this send to raise or lower the amount of reverb I want.

A - Reverb

This return generally has Reverb with the Ambience Medium preset. I'll generally follow it up with a Side Chain Fakey to get it to pump a bit with the mix.

B - Delay

This return generally has a Filter Delay with the Go Mid preset. You could always use a Grain Delay or even a Ping Pong delay for something different.

C - Perc

This is where all of my drum sounds are sent (except for the kick). First and foremost this return has a high pass filter to roll-off frequencies below about 150-350Hz. This gives the kick and bass room in the mix. I may also apply some compression to get the percussive parts to gel nicely. Send A is then set to send the track to both the Master and the A Reverb return. I'll then adjust this send to raise or lower the amount of reverb I want on the percussion.

So once you've got you template setup you are going to want to save it such that it loads everytime you start up your DAW. Now I am not completely sure about other DAWs but in Live you can save your template quickly and easily. Just click on that top button in the File/Folder Preferences. Do it!

So give the template a go. It might work for you, get you writing songs quicker or you might totally hate it and the way it might makes you write. I must admit that sometimes I don't use the template. I'll start up Live, delete every track and start from scratch. This is completely healthy too. It gives you the chance to try out new things. new routing strategies and new techniques. Hey, sometimes I'll even just start up one synth on one track and tweak sounds for hours and hours on end. Enjoy it.

Things to try at home

- Pay attention to what you consistently pull into your sets when you start a new one. Are there some things you always do? Why not throw them into a template to help get you writing quicker.

- Try my template. Download it here and give it a go. If you like it, just save it as your own template in Live. It will work on Live 7 and above.

Pumping Reverb

This next little trick is so fresh, it's still hot from the oven. I've only just started using this one on some very recent tunes.

So, you've got a nice little synth stab, a clean guitar riff or maybe just a little plink sound like the one just here:

Bland, boring and doesn't have any character whatsoever. The first thing you then think of is "Hey, I'll put some reverb on it just like I learnt last week. It will then have it's own space and maybe even a bit more character." Let's see how that sounds...

Yeah not bad. It certainly sounds a lot better but it is still not quite enough, is it?. The technique that I've been using to make it more interesting involves setting the original sound to trigger the pumping of the reverb using a sidechain compressor. Sound complicated? It's not really. Have a look at this picture.

You can see that from the input sound (ie. your synth stab, guitar etc.), the unchanged signal goes directly to the master output. However, this sound is also routed to a reverb that is set to 100% wet. Before we sum this with the unchanged signal, however, it is run through the compressor which, with the sidechain, lowers the signal each time the stab hits or the guitar is strummed. Think of it as the reverb only being heard when the original signal is not.

This is what it sounds like:

See how the reverb has now got it's own rhythm? And in the context of the song, it sounds like this:

Much more interesting than the bland plinking sound we had originally. Can you hear the reverb pump?

The easiest way to set this signal path up is to use your returns (sends) with the reverb and compressor sitting on one return. In Ableton Live, however, you can utilise the racks by having one chain for the dry signal and one chain for the reverb and compressor. You may even want to save this rack for use in future projects.

In this song I have even used a similar technique on the bassline but instead of the sidechain compressor, I used the sidechain fakey to keep a constant pump. Can you hear it here?

For those of you who were paying attention you may have noticed that I have an EQ in front of the reverb in the chain above. Now you don't have to EQ the reverb chain every time (and you could even use the EQ in the reverb itself) but it can be useful to throw a high pass filter on it. This cuts out the low end of the reverb and gives the reverb more of an air-like wooshing sound.

Things to try at home

- Adjust the levels of the dry signal and the compressed reverb signal to taste. Sometimes less reverb is more.

- Adjust the EQ of the reverb signal. Sometimes you want that rumble in your reverb

- Try out the compressor settings above but also try different thresholds and attack and release times.

- Why not sidechain fakey if you want a constant rhythmic pump.

Saturated Phat

Okay, so you have heard me ramble on about how to get your kick and your bass to sit tight together, but what do you do if you just want your bassline to sound fat, dirty and generally warble around like our friends, The Crookers? I have discovered one of the simplest tools around that can push you a little closer towards the PHatness. Yes, that’s right with a capital P.H.

Enter Saturator!

Now the trusty Ableton manual says,

“Saturator is a wave waveshaping effect that can add that missing dirt, punch or warmth to your sound. It can coat input signals with a soft saturation or drive them into many different flavors of distortion.”

Fairly straightforward hey? Think of the saturator as an effect that adds colour and warmth to the sound you run through it. If you are hunting that dynamic, analog-esque sound from your stale digital synths and effects, then keep reading. If you’ve got no idea what I am on about, keep reading.

Let me show you with an example. Here I have the 1st unsaturated bass riff:

I have used the wonderful TAL-Bassline for this riff and dropped a sidechain fakey on it to get it to pump with the kick. It’s nice. It’s got a solid square wave and it could almost pass as the real Roland SH-101.

But is it enough? You’ve heard the sound before on every 2^nd electro house tune out there but you are one of the few producers who strive to be different, strive to be unique.

Now with the Saturator and the “A Bit Warmer” preset:

Did you notice the change in temperature? Can you feel the warmth. The low end of the bass feels more whole and certainly has a lot more character. Here is the riff in the context of the song:

Now this second sample is a slightly different sounding bass:

It’s run though a low pass filter to cut all the high frequencies. Don’t worry though; the distortion provided by the Saturator will bring back all the high frequencies we want.

Now with the Saturator and the “Rectifier” preset:

Now this sound gets me excited. You’ve got the bass driving through underneath with plenty of portamento. With this riff, however, I’ve automated the cut off frequency and resonance on the low pass filter to give the saturator something to bite onto. The bass is moving and opening up over the eight bars. Here it is in the context of the song:

Now it’s time for you to try it at home:

- Throw any sound at the Saturator, see what sticks and remember what sounds good.
- Experiment with the dry/wet mix of your saturated and unsaturated sounds. Especially useful for big dirty build ups.
- Mess around with the settings. Especially with the Color Frequency.
- Experiment with high pass or lo pass filter before or after the Saturator. You’ll be amazed how drastically the sounds change when you cut a few frequencies out.
If you like what you’ve read, tell a friend. Email, post, carrier pigeon or just hit the "Share" button below.

Video, What?

What is this? A video? Pretension doesn’t make videos. ENjOY Productions, however, do make videos. Damn fine ones at that!

Jacob and the guys at ENjOY were kind enough to throw a little bit of their talent around and came up with this fantastic music video for Winston & Yoddy vs. Pretension “What You Do ft. Kyla Sexton”. Unbelievable, hey?

Here is a little blurb about them:

“We’re an established, full service, award winning Film Production Company based in Brisbane, Australia. Working on boutique and mainstream projects, our mission is to enjoy the art of film making to create unique and timeless motion pictures.

We approach all projects with a fresh creative edge from small run DVD projects to big budget music videos and films. With a solid team of directors, producers, cinematographers, designers, composers and performers, we have the means to bring quality projects to the screen, web, iPod, iPhone and any other new media you want to throw at us.”

So that’s enough words for today. The proof is in the pudding. Go check out their films here and be sure to keep them in mind for your next music video!

ps. Do you recognise anyone in this video?

Pretentious Lessons Begin!

Okay guys, I am about to start writing a set of production lessons that outline a few techniques that I use when writing and producing tunes. I'll try to keep them relevant to my style and give examples of where I have used them in actual songs.

So, I use Ableton Live 7 with a few different plugins but most of the lessons will use the stock effects that are provided with Live. Not using Live? Don't worry. You should be able to transfer the techniques over to your own special DAW.

Enjoy!

Disclaimer:

I am by no means saying "my style is the best" or "my technique is the best". I am just sharing a few ideas that help me make better sounding tunes, faster. Have you got an opinion or further ideas? Feel free to leave a comment. 

Also, a big thanks must go to Natalie at Utopian Vision Photography for the stunning photos!

DIY Speaker/Monitor Stands

Between Christmas and New Years of 2007 I bought myself a pair of Yamaha HS80M powered monitors. Sweet sound, and at a fairly decent price. It has certainly been an improvement over the dodgy book case hi-fi speakers I was running before and after recently buying a MOTU Ultralite, the signal chain has improved ten fold.

I decided to make up a pair of speaker stands to match the monitors. I took inspiration from one of the threads on SoundPunk.com (http://www.soundpunk.com/index.php?topic=518.0), ran out to the local hardware store and started piecing these together.



So down at Bunnings, I picked up two 1 metre lengths of 100mm diameter PVC pipe, four PVC end flange joints, a couple of bits of pine and two lengths of M16 threaded rod and nuts and washers to suit. I chose 100mm PVC over the standard 90mm just to make the stands a little more stable and solid. The flange joints were fairly cheap ($3-4 each) and helped considerably with the stability and meant that I did not necessarily have to cut the ends of the PVC straight (which is a bit difficult for anyone that hasn’t tried it).

So I measured everything up such that the tweeters would be at the right height. I also made sure the size of the top of the stands would be the same size as the bottom of the monitors, and the base slightly larger to help with stability once again. I wanted to make sure that the speakers I just spent my hard earned cash on didn’t topple to the floor.

I cut holes in the base to mount the spikes. I got a bit slack and just used small bolts and countersunk them into the base, rather than professional speaker spikes. However, they seem to have worked out alright.



After a bit of fiddling to get them all level, I puttied up the top surface and sanded the whole thing down.



You could even sharpen the ends of the bolts to get a good spike. A bit of measuring to get the hole right in the centre for the threaded rod and I was able to tie the stands together and check the height.

I then centered the PVC on the base, sealed it with sellastic and wiped off the excess. I then bolted them together again and waited for the sellastic to cure.



In the meantime, I went down to the beach and pinched a crate of sand. I totally over estimated how much sand I would need. Now because I got sand from the beach (Salt) I thought I would protect the rod inside the speaker stand and give it a good coat of KillRust. It may be the difference between these stands lasting five and ten years.



I used a funnel and a sieve to put the sand in the stands. I only filled them up about two thirds of the way as they were getting pretty heavy. The stands ended up weighing about 13kilos each (the same as the speakers). The funnel is a great idea because it centers the booker rod in the PVC and helps you align the top board, and the sieve makes sure I don’t get any dirty Gold Coast beach debris in my stands.

Roughly, I ran some sellastic around the top because I knew this area was not going to be seen and stuck the top on. Lined up the top with the base and let it cure again. A day later I grabbed a tin of black paint and sprayed the stands. Make sure you give the PVC a good sand to ensure the paint really sticks to it.

I then went out to Clark Rubber and grabbed some pieces of foam. The main reason was to clear the nut on the threaded rod but to also aid in sound quality. Best way to cut it is using a good sharp kitchen knife, preferable a long one as short Stanley knives or scalpel blades tend to tear rather than cut.

So yeah that's it. It cost about $80 for materials and a few hours labour on top of that. I set them up in my room and they are looking and sounding nice.



Time to go make some tunes!