Skol303

STEP 1: Construct the frames, fitting the lengths of stripwood together using angle brackets. I find it helps to secure the joints using wood glue and panel pins (being careful not to split the wood when hammering in the pins). Add a length of wood as a support along the rear and bottom of the frame: this will help to hold the mineral wool in place and prevent sagging. Larger panels may also need additional support struts on the sides and front - for example, the upright panel frame in the photo (right-hand side), which also has a wooden base for attaching 'feet' later on (you don't need a wooden base on panels that are being hung form the wall or ceiling). Don't add a plywood or other solid backing to your acoustic panel. You want the back to be 'open' so that the sound can pass through it.

A thread for anyone wanting to DIY-build their own acoustic panels. This method uses mineral wool (glass fibre) to convert low frequency sound energy to heat, thereby reducing the energy of sound waves and their reflection off the hard surfaces of your room. When sound waves encounter reflections it causes peaks ('boominess') and nulls (big dips) at certain frequencies, which can give a misleading interpretation of what you're hearing. This can make accurate mixing very difficult, which is why acoustic panels are recommended: because they help to give a more even and accurate frequency response, so that what you hear in the room is as close as possible to what's happening inside your software or mixing desk. Before you read on, note that: In order of importance, acoustic treatment applies to mix rooms, recording rooms and practice rooms. In a practice room you can get away with the sound not being so accurate - it doesn't stop you from practising. In a mix room, if the sound is inaccurate then your mixes will be too (or you'll need to spend a lot of time referencing your mixes). A well-treated room also results in good quality recordings, but you might want to treat a recording room slightly differently to a mix room, ensuring the sound retains some reverberation and 'liveliness'. It's a big topic and too much to go into here! But suffice to say, think about what you want to achieve and read up on the subject a little before you dive in. Acoustic treatment is not the same as soundproofing. If you want to create a soundproof room, then you'll need to take a different approach. Right, let's get started... Tools and materials needed: Stripwood for the panel frame (I like to use 20x20mm or thereabouts) If you’re making a free-standing panel, you’ll also need planed timber for the panel base and ‘feet’ A vice, saw and tape measure for cutting the wood Angle brackets (aka corner braces) for constructing the frame (a combination these and these work great). Box of wood screws (I use 4 x 16mm) An electric drill for drilling pilot holes for screws (to avoid wood from splitting) Screwdriver Panels pins and wood glue (neither are essential essential, but both useful for strengthening the frames). You’ll need a hammer for banging in the panel pins - or an exceptionally hard stare! Fabric dust sheet for panel inner fabric (not essential but useful) Cheap ‘breathable’ fabric for rear of panel (I use cheap craft felt) ‘Breathable’ acoustic fabric for main panel wrap (Camira Cara and Lucia fabrics are what’s used on most commercial panels, available here). Mineral wool - use Knauf Earthwool Dritherm Cavity Slab (density ~15kg/m3) when building panels 8"/200mm or deeper; and use Knauf Earthwoold Building Slab (density ~48kg/m3) if building panels around 4"/100mm deep. Gloves and mask (for use when cutting/handling mineral wool) Staple gun and staples Large pair of scissors Jack chain and pliers Pair of screw eyes per panel Heavy duty picture hangers (if you want to mount your panel on the wall). IMPORTANT note on fabrics: whatever fabric you use, it must be as 'acoustically-transparent' as possible. A simple way to test this is to hold a piece of the fabric tight over your mouth and attempt to breathe! If you can breathe easily, the fabric is good to use. If you find yourself suffocating, it's not. Finally, some notes on panel thickness: In small rooms (and by that I mean nearly every UK household), you want to focus on treating the low frequencies and that means applying as much depth as possible. Aim for a minimum of 4” / 10cm thick panels, but ideally 8” or more: 25” or around 64cm is generally considered to be ideal, albeit a bit impractical in most homes. But the general rule is, don’t scrimp! If your panels are too thin, they’ll become what are known as ‘broadband absorbers’ (affecting just the mid- and high-frequencies) rather than ‘bass traps’ (affecting below 100Hz or so). You’ll almost certainly need some broadband absorbers (e.g. left/right and above your mixing position), but bass traps are what you want to focus on first. Here’s a very approximate guide to how thick your panels need to be in order to treat certain frequencies: 25” effective down to ~30Hz 16” effective down to ~40Hz 8” effective down to ~65Hz 4” effective down to ~100Hz *By effective I mean it will have some affect on the sound, not that it will absorb all of the sound at that frequency. As always, "more is more" when it comes to acoustic treatment!

Nobody strictly needs a compressor. But I'm of the opinion that every bass player can benefit from one.

“Great” tone is wholly subjective. The “right” tone is what matters - and is always dictated by the song itself. None of which makes for a very engaging discussion on an internet forum. So carry on. As you were

Haha! Yeah.... it's either very far away or sounds like one of these:

Yes! I remember that add from Kerrang (I think). A nice shot in the arm of nostalgia

Good call. Mike is a friend of mine and a phenomenal player... fairly sure there's nothing he can't play! (I put this down to him having one of those bendy thumbs that Jaco had. And maybe something to do with a zillion hours of practice, or whatever).

The more coverage the better when it comes to bass traps, so built is as big as you can. It at least needs to cover your head/ears and give you a little room to move at the mix spot. Better still if it also covers the direction of the monitors; but that might not be practical in terms of size. What you're basically doing is creating a treated back wall behind your mix spot, to help deal with rear wall reflections that are often the most troublesome. You're going to get a whole bunch of other reflections in that room without other acoustic treatment - basically any area of wall/ceiling that you can see from your mix spot will cause reflections - but we're not looking for perfection here; we're just trying to help reduce the null that's sucking the bass out of your Yamahas at that point in the room. I reckon a suitably chunky bass trap will buy you around +10db of level (based on my own experience of trying to treat a -30db dip in my room). Not huge, but it can make the difference between certain low end frequencies being at least audible, rather than nonexistent. I'm about to use this exact this same method myself, so if you want to wait a week or so I can report back here with my own findings and some frequency measurements. My own back wall is pretty much treated as far as it can be, so I'm going to build one or possibly even two free-standing bass traps that I can put behind my listening spot when mixing - adding a second or even third layer of rear wall treatment (adding up to >60cm of mineral wool). ---------- PS: there's a totally different method of treating low end frequency balance that involves using multiple subwoofers. Really good paper on this by Salford University (available online last time I checked); works in rooms of all sizes. Tricky to set up and of course expensive; hence I haven't really gone into it here or tried it for myself. One sub on its own can also help 'fill in' some of the modal nulls, because the sub can be positioned elsewhere in the room away from the main monitors (low frequencies being omnidirectional). You needed a treated for that however, whereas with multiple subs room treatment is less essential. Honestly, when you start getting into this stuff it's worse than GAS

PS: I should add that you guys are producing great mixes anyway... despite any problems with your mixing environments! (or the colour of your leather sofas)... so always keep that in mind I found myself disappearing down the rabbit hole of acoustic treatment a few years ago until a mate of mine just shrugged and said, "well your mixes sound ok to me". Since then I've continued my pursuit of acoustic nirvana, but with less of a crazy look in my eye.

Hmmm... I doubt the sofa would do much as it's probably stuffed with the wrong sort of material (Rockwool works because the fibres are light enough to become 'excited' by the bass frequencies and so the sound energy converts to heat). But hell, if it's just a case of moving your sofa then give it a shot! Best if you can stand it on its edge upright somehow. Keep a camera running in case of accidents to score your £250 from You've Been Framed But yeah, don't expect an earth-shattering difference. One bass trap on its own - and especially one sofa - won't have a huge impact, but it will have some impact. And in my limited experience, acoustic treatment is about seeking every advantage you can get. Small victories winning the war, etc. If you do decide to build a trap, try to make it as thick/deep as possible and tall enough to cover your head when at your mix position. 60cm of Rockwool is often quoted as the ideal - but that's super thick and I don't have any traps that deep myself (although I have some that are close to that at the front of my room). Aim for a minimum of 20cm thickness, which would be two slabs of the Knauf mineral wool I linked to above. And of course the good thing about gobo-style traps is a) you can move them out of the way when not in use and b) they don't need fixing to a wall, which makes them ideal for rented and/or multi-purpose spaces.

I've seen photos of a room where a guy filled loads of cardboard boxes with Rockwool and stacked them up. Worked for him! Important point to note: the mineral wool needs to be in a vessel that allows air to pass through it - keeping it in the plastic wrapper will be no good, and leaving it in a loose container will cause the fibres to get into the air and may irritate your lungs (the Knauf stuff I linked to is one of the safest available - used by commercial acoustic companies - but it's always best to play it safe). If you can make a wooden frame, you can make a bass trap! Just get some stripwood and metal angle brackets to join them together. You could rustle up a portable bass trap for around £50.

That's not a bad place to have your set up at all (i.e. on wall with the white door in the graphic). Your problem is lack of a cream leather sofa! Did I not mention how crucial that is?! Has to be cream or salmon pink mate, take your pick. Any other colour messes up the bass frequencies something rotten Brick is no different to plasterboard to be honest. Bass frequencies just pile on through plasterboard and bounce off the brick anyway... and travel through the brick too (as anyone who's ever lived next to me in a semi-detached house will testify).

PS: I understand that acoustic treatment isn't possible in your room (Mornats), but I bet if you put a hefty 'gobo' style bass trap immediately behind your mix position (i.e. a portable bass trap on stands) then you'd spot a noticeable difference in the low end, as it would help to cancel some of the back wall reflections where currently they are free to cause havoc. Just an idea. You could very easily DIY a bass trap for this purpose: Build a wooden frame of the size you want (20mm strip wood is ideal) Fill it with this stuff or equivalent. Wrap the wooden frame with any fabric that allows air to pass through it - this stuff is great. Add some feet to it stands up. Bob is your uncle!

You'll struggle to get a meaningful recording of the frequencies that are causing problems! (typically 60hz or so). But give it a shot, why not. The middle of the room should always be avoided for mix/listening position. Bass frequencies tend to build up at the back wall (as you're noticing), which is why it's always a good idea to add a lot of acoustic treatment there - it helps to prevent back wall reflections that cause phase cancellation elsewhere in the room. I'm trying to fix this very issue myself at the moment - planning on DIY-building a new batch of bass traps this weekend in fact! The often quoted 'golden rule' is to put you mix/listening position 38% of the way down the length of the room, but take that with a large pinch of salt. I started there in my own room but have since crept forwards towards the front wall - and my frequency response improved. But my room is a different shape. That's one of the problems with acoustic stuff... one size most definitely does not fit all! And hence experimentation is the key to happiness. Or a whole new world of GAS (you have been warned!).

You're welcomer! PS: this is the suggested set up for L-shaped rooms, with the speakers firing down the length of the longest section. Better still if you can position yourself facing into in the top-right hand corner, so your desk would be at an angle rather than flush with the wall. That way you’d get a more even response from the left and right speakers.

Your room shape isn’t actually too bad! Notice how it’s close to the ‘Bolt Area’, which indicates that the room modes are quite evenly spaced. It does however suffer from the classic home studio issues (as does mine and I’ll bet everyone else’s here): potential for ‘boominess’ or nulls around 40-45Hz (not too problematic unless your monitors are truly full range) and 65Hz (exactly where I also have a room null - and difficult to treat with bass traps). It looks like your monitors are as close to the wall as possible. Every centimetre does count (!), so if there are any to spare then use them. It’s not a terrible room… and you can certainly use your monitors for mixing; you need to be aware that the low end is always going to involve some guesswork/ referencing. Again, this applies to everyone including some pro mix rooms. If acoustic treatment is out of the question, then my suggestions would be to: Keep your monitors. Despite low end guesswork, they’re far better than headphones alone for working out stereo placement and other mix decisions. But yes, get some good headphones too! I’m in the market for a pair of Sennheiser HD 600 or 650s myself. Consider investing in Sonarworks room EQ software. “It’s no substitute for acoustic treatment” wail the hordes of acousticians… but it does help. In my room, it helped a lot. And while it can’t fix room nulls (no EQ can), it can do a great job of flattening the peaks in your room, making your monitors more worthwhile. I have friends who run commercial studios who use it, so it’s not just for kids. I also have a friend who recommended me a professional equivalent (a hardware DSP) that cost £4000, which I politely declined. Sonarworks costs around £250 for the full version with measurement mic (which you’ll need) and is worth every penny in my opinion. The mic also sounds nice on acoustic guitars That room might actually be good in terms of acoustics mate! Irregular-shaped rooms and vaulted ceilings can sometimes work in your favour. Only snag is you won’t be able to use any of the tools linked above to work out your room modes ‘cos they all assume a regular box-shaped room. A very rudimentary test you can try is play some low frequency tones (say, somewhere around 60-100hz) or play a track you know well that has a lot of low end - and walk slowly around the room. Listen for where the bass sounds boomy, where is sounds weakest and where is sounds most even - the latter is your new listening/mixing spot! I just hope it's not in front of the TV

Good recommendations guys. And let's not forget that a lot of this comes down to price bracket. The old recommendation that you should "spend as much as you can afford on monitors" rings true; followed by "and then spend the same again on acoustic treatment". Big difference in quality between monitors sub-£500 and those upwards of £1500. But whether your room allows you to hear that difference is another matter Some amusing thoughts on this from Mike Senior over at SounOnSound: https://www.soundonsound.com/people/sounding-monitors "...a large number of home-studio owners spend more on cheese than they do on monitors and acoustic treatment, and, despite the importance of good dairy products in everyone's diet, I think this is a false economy... monitoring and acoustic treatment may be dull as digital dither through a low-pass filter, but unless you can hear what you're doing you'll be haemorrhaging money, time, and engineering skills."

Contrary to popular belief, you want your monitors as close to the front wall (i.e. the wall you're facing) as possible. Think mm rather than cm! [EDIT: this applies even if they are rear ported] Better still, you want your monitors inside the front wall (soffit mounting), but that's beyond most home studios. Why? Because it helps to reduce what's called SBIR (speaker boundary interference response), caused by out of phase reflections - mostly from the back wall - causing a BIG dip in the low end somewhere between 60-100Hz. Having your monitors either very close or >2m or so away from the wall pushes this dip to higher frequencies (monitors close to wall) where it can be more easily treated with broadband traps, or to lower frequencies (monitors far from wall) below the audible spectrum. Most home rooms don't have sufficient space for monitors being 2m from the front wall, so pushing them up close is by far your best bet. Link here with great explanation: http://arqen.com/acoustics-101/speaker-placement-boundary-interference/ EDIT to say that having your monitors close to the wall will cause a big boost in low frequency response. But that can be fixed with EQ... the big null caused by SBIR can't be fixed with EQ (the more you try to boost the null frequency, the more it will cancel out resulting in the exact same null: 10-10 is no better than 1-1).

Very welcome It's one of the best room mode simulators I've found. Similar thing here too, but not quite as useful: https://www.hunecke.de/en/calculators/room-eigenmodes.html There's also a 'Room Sim' tool in the Room EQ Wizard (REW) free software that's useful and requires only the room dimensions - gives an approximation of the frequency response below 300Hz based on speaker position/ speaker frequency response/ listening position etc. All of these are very approximate and no substitute for taking acoustic measurements in the room itself, but they're a useful starting point.

Firstly, every domestic room is 99.9% guaranteed to be a “rubbish room”! Unless you’re lucky enough to have an especially large space, or even luckier a large space with non-parallel walls, then you’re going to suffer a plague of room mode and reflection problems, that will have greatest impact on the low frequencies (sub-300Hz or so). These cause certain frequencies to be in phase - causing ‘boominess’ - or to be out of phase and cancel each other out (called nulls or nodes). Cancellations of -30db or more are not uncommon and can sometimes cause certain frequencies to disappear altogether. These are the peaks and troughs in bass level that you're hearing as you walk around the room. So don’t fret! What you’re describing is totally normal Also, what you’re describing is almost certainly a modal issue - i.e. caused by low frequency standing waves resulting from your room dimensions and acoustic treatment (or lack thereof). Switch the speakers around and I’d bet the same issue persists to a large extent. [Side note: sealed cabinet monitors are often a better option that ported cabinets (although ported designs have come a long way since my youth, when they tended to have a huge yet flabby low end). Notably, sealed designs are a better option because they have a more gradual low frequency roll off, so they tend to produce low frequencies with more clarity than ported designs. And contrary to popular belief, you can push rear-ported monitors much closer to the wall than is often advised]. But anyway. Here’s a really useful tool that I’ve used when working on my own acoustic treatment at home: https://amcoustics.com/tools/amroc And here is the equally useful notes page that companies it: https://amcoustics.com/articles/roommodes Type in your room dimensions and it will calculate your problem frequencies and where in the room they are likely to cause most havoc ('high pressure zones'). Read the results and weep! If your room is square - as you mention - then unfortunately you’re going to suffer the worst of these modal/reflection issues. Acoustic physics is a cruel mistress. Ultimately, if you have an untreated room, your mixing is always going to be based on guesswork to a large extent. And that might be perfectly fine - we are, after all, a community of hobbyists. Just bear in mind that what you hear through monitors - and especially the detail of what's happening in the low end - is a lie to some extent (or in some cases, a large extent). Take comfort from the fact you are in good company - every home studio suffers these problems and a lot of professional studios do too; that's why so few pro studios are happy to make their room frequency/decay measurements public If acoustic treatment isn't an option, just reference on headphones as much as you can. That's by far the best 'Plan B'. PS: acoustic treatment is a big topic, so I might combine this tread and other into a sticky on the subject in due course.

My god they're hideous, but I salute your sense of joie de vivre!

We now have a great photo from Bleat! Which makes the above messages somewhat mystifying to anyone arriving here now. Which is perfectly fine

I’m sure you guys are familiar with this… John Cage’s famous composition, 4’33”

February's Composition Challenge is now underway! Here’s the image for your inspiration, chosen by last month's winner, Bleat… Rules: Avoid any content that other forum users may find offensive. Make sure you have permission to use any 3rd party sounds and samples in your track. Entries should be no more than five minutes long and written/produced during the month of the competition. No bagpipes. Seriously. The deadline for entries is midnight on Wednesday 21st February.