Acoustic nightmare!

[Ash Taylor]

Hi guys, I'm just launching my new studio and its opening in about 10 days However, I seem to be struggling with the acoustics in my room.

The control room is a large rectangle with angled ceilings meeting at a point in the middle. (probably about 30 m2 room size) The front wall where my monitors are have windows all along the front wall (believe this may be a problem). Also because the ceiling is angled the ceiling is very low along the front and back walls.

Ok, so I've been working on getting the flattest frequency response in a room possible, I've been following Ethan Winers advice and videos on the real traps website for a year or 2. I've gone through pretty much all the advice on the long acoustic article written, in fairness, I wont contest to understand everything as a lot of it can get confusing with room modes etc..

I haven't yet made made my monitors completely symmetrical and my listening position is not yet 30% from the front wall but I still want to get some advice first.

After having spent/wasted a considerable amount of money on over-expensive auralex foam at my home studio I wanted to make sure I did it properly for my professional studio. I knew the cheapest way was to build my own traps. After soundproofing my two live rooms I had quite a bit of mineral wool left over. 6x 1200x600x50mm (2 inch, 2x4) slabs with a density of 60kg p/m3. I understand that 45k p/m3 is better for taming mid to high frequencies and a thicker 4 inch slab at 90kg p/m3 is better for bass trapping but I thought the 60kg would be fine.

After the basic frames were built and the rockwool was inside I covered and stapled a thin stretchy polyester fabric as advised by Ethans site. As also advised I made sure you could breathe through the fabric. There was air passing through but not a huge amount..

I hung the first 6 traps, 3 on one side wall, 1 on the back horizontally as there was a sofa infront of it, 2 on the other side wall (windows compromised space for traps). There isn't really space to put treatment on the front wall as its a mezzanine floor all with windows looking down on the first live room , but these windows were obviously like this when I moved in. I have insured around a 2 inch air gap between the traps with offcuts of rockwool but would prefer to have a more substantial spacers (open to suggestions!)

After playing some heavy rock and string pieces etc I noticed quite a harshness in the high end, and not an awful lot of definition in the low end. I had in the back of my mind to make sure I used ETF to get the rooms frequency reponse but after hearing Ethan mention about 8 traps in medium size room is about right I thought because there are only 6 it wouldn't hurt to make more. I bought 6 more slabs of 45kg m/3 rock wool and built 6 more traps in the same spec.

After reading about angled rooms acting like a parabolic dish affect I firstly decided to treat the ceiling and hang two new traps from the dip, unfortunatley I can't cover all of the dip due to there being a ceiling fan in the way, but I've covered about 2/3s of it. I put two of my 60kg traps on wooden stands I had built and put them in the corners of the front wall. I moved two 60kg traps to the back wall, and put the other traps in various places where there was more bare wall.

I just tested this today with the same music and I think the problem is worse!! I'm going to take down my PC tomorrow and do a frequency test and upload the results, but I simply can't believe the room is this much of a problem! I'd say a good 50-60% of the room is covered now. I'll upload some pictures to accompany this post so you guys can get a good idea of my explanation.

I'll post the test results tomorrow and upload the picutres soon, however, any initial thoughts?

Ash

[Ethan Winer]

Originally Posted by Ash Taylor

I'll post the test results tomorrow and upload the picutres soon, however, any initial thoughts?

Without photos it's difficult to comment, so I'll wait. In the mean time, are any of those bass traps straddling corners? Or are they all flat on the walls?

--Ethan

[Glenn Kuras]

yes photos would help.

Hi guys, I'm just launching my new studio and its opening in about 10 days However, I seem to be struggling with the acoustics in my room.

I love how acoustics are always the last thing people think about. lol lol lol lol. If I had a nickle for every phone call or email that went something like this "Hey man we are opening next week and the room sounds horrible........................" I could retire.

[Ash Taylor]

Apologies for picture quality and the studio being a bit of a mess. The monitors wont be that wide aswell I was just experimenting. As you can see the traps on stands which are 2inch 60kg can be moved around if needs be.


Yfrog Image : yfrog.com/caimgp2082vj
Yfrog Image : yfrog.com/jdimgp2083sj
Yfrog Image : yfrog.com/7dimgp2084j
Yfrog Image : yfrog.com/jyimgp2085j
Yfrog Image : yfrog.com/61imgp2086aj
Yfrog Image : yfrog.com/baimgp2087j
Yfrog Image : yfrog.com/izimgp2089aj
Yfrog Image : yfrog.com/2pimgp2088j
Yfrog Image : yfrog.com/fvimgp2090j

[Fumblefingers]

I'm going to let the experts weigh in on this, but aren't those monitors placed a bit far away?

There are a lot of very hard surfaces, parallel walls etc. I would imagine you need to treat those more, maybe even have some angled baffles on the ceiling.

But I wanted to ask about the space. Do you have the downstairs area as well? What is that, a warehouse or workshop/factory type space? It looks awesome, lot's of character.

I have seen several articles on studio's in the UK that are set up in old buildings like this and they look like such cool places to go be creative.

[Ash Taylor]

Originally Posted by Fumblefingers

I'm going to let the experts weigh in on this, but aren't those monitors placed a bit far away?

There are a lot of very hard surfaces, parallel walls etc. I would imagine you need to treat those more, maybe even have some angled baffles on the ceiling.

But I wanted to ask about the space. Do you have the downstairs area as well? What is that, a warehouse or workshop/factory type space? It looks awesome, lot's of character.

I have seen several articles on studio's in the UK that are set up in old buildings like this and they look like such cool places to go be creative.

Yeh they are, I've tried bringing them in closer, and even brought them in for a very small stereo spread but that causes a very bass heavy mix.

I do have the downstairs area aswell yes, thats over looking live room 1 and directly beneath me is live room 2. The whole studio doubles as a 2 room rehearsal space and a recording studio. Thought I might also mention the floor aswell is not very solid. I'm considering getting a load of 75mm rockwool and putting that under the floor/ceiling to prevent sound bleed of drums/guitar cabinets etc coming up through the floor.

[Smithcok]

I didn't look at all the pictures, but some general observations:

You are going to need a lot more bass trapping, emphasis on "a lot". After you've conquered some of that frequency range, more treatment for other frequency ranges will be needed too.

The speakers look way too far apart. They should be in an equilateral triangle with the mix position. While spreading them may change (not fix) some bass problems in that setup, it will also wreck the integrity of the stereo image (among other anomalies).

Also - adding insulation to the floor/ceiling is not the same as adding isolation. You'll need mass. The insulation may help a tiny bit (by starting to tame the reverberations in the live room), but additional massive materials (more layers of GWB, plywood, etc) would be needed for any worthwhile transmission loss upgrade.

Have you shot the room with an analysis program? That could help you target the biggest problems first.

[Ash Taylor]

Originally Posted by Smithcok

Have you shot the room with an analysis program? That could help you target the biggest problems first.

Thanks for the advice. I've considered building the 4inch thick 90kg corner bass trap models.

In regards for more high end absorbtion, there aren't that many more places they can go.

I brought my pc down with etf on to do the test the other day but my m-audio card has only phono connections and I left my adaptors at home! Don't have interenet at the studio yet because the phone companies messed about! So I'm just going to download REW or something and put that on a usb stick so it will work on my mac. Will REW work ok with a digi 003?

[Glenn Kuras]

I haven't yet made made my monitors completely symmetrical and my listening position is not yet 30% from the front wall but I still want to get some advice first

First thing I would do is work out your monitoring and where you will sit. For that I would use the following program to test the room and move things around until you find the best response.
Room EQ Wizard - REW Home Page
After that you want to place as many bass traps in corners as possible, hit the early reflection points and back wall with thick panels.

[slymo]

Originally Posted by Ash Taylor

I haven't yet made made my monitors completely symmetrical and my listening position is not yet 30% from the front wall but I still want to get some advice first.

Follow Glenn's advice and get this done first. You will be amazed at the difference. Cart before the horse and all that stuff......

[Ash Taylor]

I'm at the studio now but i cant get REW to select the microphone thats plugged into my digi 003, I have selected digi 003 as the input interface but it doesnt seem to be picking anything up. (yes the 48v phantom is on before anyone asks :p)

[Weasel9992]

Originally Posted by Ash Taylor

I'm at the studio now but i cant get REW to select the microphone thats plugged into my digi 003, I have selected digi 003 as the input interface but it doesnt seem to be picking anything up. (yes the 48v phantom is on before anyone asks :p)

Doesn't REW have an issue with Digi? I seem to remember something about that...

Frank

[Ash Taylor]

Originally Posted by Weasel9992

Doesn't REW have an issue with Digi? I seem to remember something about that...

Frank

I sure hope not! haha. My lt-adat card arrives tomorrow hopefully so I can try and use it with my lynx.

If not, might have to bring back the PC from home and try it that way?

[SAC]

Calibrating REW with Digi 003 Rack


I am beginning to think that the vast majority of posts are simply requests for others to take their time to either look in the appropriate support forms or to Google the web.

[Ash Taylor]

After reading quite a few more threads/posts its quite clear adequate bass trapping is required. I was at the studio earlier and doubled up 2 bits of 2inch bare rock wool and placed them in the front corners, I could already notice a difference and it sounded tighter.

Unfortunately due to the rooms layout there are actually 5 corners. 2 of those 5 corners also have doors in them aswell which makes it tricky to bass trap, I've considered building tri-corner traps but I haven't read up on how effective they are against the 2x4 traps yet.

I've given REW a blast but due to rigging up and old m-audio interface I had I forgot that I need 4 phono cables so I was only able to connect 1 monitor. However reading on one of the stickies it mentions for the sine wave basic frequency test measure it in mono anyway with one speaker. I'll do the waterfall test tomorrow and now internet is at the studio I can upload both results.

At a glance though there appeared to be a fair bit of comb filtering and some huge dips, I put the 1/24 smoothing on it though so it could be clearer, it appears my biggest problems are below 1khz where it looks as much as +/- 15-20dB peaks and nulls are apparent.

I've spoken to the local building supplier RGB who are right down the road from me and have advised they can get me 100mm/4inch thick 2x4 100kg p/m3 panels. There are 2 in a pack and its £16.

My first questions is: Is 100kg too dense? Secondly, will 4 inch thick 45kg rockwool still be ok for bass trapping? (That would be cheaper as I'm now on an extremely tight budget)

Thirdly, I've read a minimum of 4 bass traps will be required, however due to slightly odd shape of the room I'm concerned it may not be enough. I'm considering hanging one horizontally from the front wall slightly infront of the glass. I'm concerned because the whole of front wall is covered in glass this may be a problem?

I'm also concerned now about the balance of 2inch panels vs bass traps. There are currently 9 2inch 45kg 2x4 traps, 3 on the side wall, 2 on the other side wall, 2 on the back wall, and 2 from the ceiling. Will I also need 9 bass traps? Or will taking away some of the 2 inch traps help to balance it out? I don't want to kill too much of the highs as I've been doing before.

My current plan is 4 bass traps and to take it from there for now.

[Ash Taylor]

Not sure if I have measured this correctly because the waterfall is only going up to 12khz.

Here is also attactched a number of tests I've done
Download mono and stereo tests 2.mdat from Sendspace.com - send big files the easy way

[Weasel9992]

100Kg/m3 is okay, but if you can get 60kg/m3 that would be better.

As for the plot, it looks like what I'd expect it to look like. Treat the room in all the usual ways and shoot again.

Frank

[Ash Taylor]

Ok so I've just bought 4 100mm/4 inch thick rockwool panels for bass trapping. I also have 4 spare bits of 2inch which I'll use to make bass traps with.

Here below are places I plan to put these traps, obviously they will be hung, on stands, or suspended. But judging on the room layout are there any other suggestions you guys have?

Thanks







I'm thinking of possibly replacing the two traps there with bass traps, and move those 2inch traps elsewhere.

[localhost127]

that couch looks very reflective, no?

[Ash Taylor]

Originally Posted by localhost127

that couch looks very reflective, no?

Yes it does, I've considered throwing a rug or cover of some description over it. Please note, the plot is before I put the bass traps in. It's sounding better and more tight now with it like this but still isn't to my satisfaction.

Does anybody know the absorbant coefficient of a leather sofa by chance? Google didn't yeild many results.

[Ethan Winer]

Originally Posted by Ash Taylor

Does anybody know the absorbant coefficient of a leather sofa by chance?

It depends on how the sofa is constructed. But:

1) Even if it absorbs a lot of bass, it's not in the best location for bass traps. So it won't help much at bass frequencies just because of the location.

2) The larger problem is mid- and high-frequency reflections off the seatback that cause comb filtering for the listeners. See the last section in this article:

Early Reflections

--Ethan

________________
The Acoustic Treatment Experts

[Weasel9992]

The locations of the panels look fine.

Frank