John Sayers' Recording Studio Design Forum Archive

Hey guys!:) I have a room that I'm trying to treat as much as possible. Spent quite abit of money on the acoustics but still unhappy with the result , I'm always constantly thinking of ways to improve it. It's definitely better than a bare room , but not quite good enough . I also bought 2 vicoustic wave wood , thought of having them at the back of my room. However I have yet to place them up.


Problems :
-When I listen to music some bass notes are louder than others (probably need more bass treatment cause there are still peaks?)
-When I clap in the room I can hear flutter echo from the (middle to end of the room) side walls which has no treatment .

Questions:
- Should I bother about acoustic foam ? Eg. Vicoustic pulsar https://www.vicoustic.com/product/pulsar-panel
- Should I have 4inch thick panels for the rear wall ? Corners or just on the wall?
- First Reflection point , 2 inch or 4 inch panel?
- Should I have 2 inch panels mounted horizontally for the side walls?
- Do I need the panels on my front wall , behind the speakers ?

Dimensions : Height - 260cm (8.5ft) Width - 260cm (8.5ft) Length - 470cm (15.4ft)

Thickness of Acoustic panels placed: (Rock wool panels)

-Left & Right corners - 4inch w membrane
-Ceiling intersection - 4inch
-Clouds - 2inch
-1st reflections - 2inch
-Front wall - 2inch

(1st reflections point's panel has a 1 inch gap behind them. )


Thank you all in advance!!:)

TLDR; Spent some time and money on acoustic panels but still unhappy about the results. Advice please !:)

Hi "paramourcheng", and Welcome!

From what you say, it seems that you are talking about a control room? Is that correct? You didn't say for sure, but that's what it sounds like, from some of the things you say.

Spent quite abit of money on the acoustics but still unhappy with the result ,

You probably won't like what I'm about to say, but it's the truth. Trying to treat a room without first analyzing it and understanding it, is like trying to treat yourself for a serious disease without ever going to a doctor. Buying this medicine and that, trying some remedy and then some other, not eating this, eating that, drinking that but not this... None of it will cure you until you go to a doctor and get the relevant tests done, and a proper diagnosis. In fact, treating disease at random with unknown products is likely to make you MORE sick, not better.

Treating a room by purchasing and installing expensive treatment here and there is the exact same thing: It is not going to solve the problem, unless you first know what the problem is, understand what that means, and build a treatment plan.

OK, maybe I'm being a bit harsh, but that's the truth. I'm not trying to insult you or what you have done: I'm just pointing out that the reason you are not getting results is because you don't have a diagnosis yet, so you are treating things that probably don't need treating, and NOT treating the things that do.

For example, that panel you mentioned would NOT do anything useful for your room, and in fact it would make the situation worse.

So let's start from the beginning, and analyze your room to find out why it is sick, what sickness it has, then we can make a plan to cure it.

Height - 260cm (8.5ft) Width - 260cm (8.5ft)

There's your problem! The room is square. The height and width are identical. That implies that you will have huge problems in low frequencies, because your modal spread is terrible. All of the room modes related to height line up perfectly with all of the room modes related to width. You will have sever bass issues at 66 Hz, 75 Hz, 99 Hz, 128 Hz, 122 Hz, etc.,, and at all other frequencies associated with the wavelength of 260 cm. At those frequencies, there will be major peaks in intensity at some locations in the room, and major dips in intensity at other locations, because modes are standing waves: they create patterns of high and low intensity in the room, and as you move from place to place you will experience those as louder or quieter spots in the room, but different spots for each frequency.

So that's your most basic problem: The "room ratio" is bad. That refers to the relationship between the dimensions of a room. There are good ratios and bad ratios. Yours is one of the bad ones. The general rule is that no two dimensions should be the same, or multiples of each other, or within 5% of being the same or being a multiple.

Next, it is a small room so it will need large amounts of bass trapping. You did not mention any bass trapping in your list of treatment, and what you describe is the typical symptom of insufficient bass trapping.

I also bought 2 vicoustic wave wood

Send them back and get a refund. They are no use for your room. They are good products, yes, but no use for your room. Your room is small, and numeric-based diffusion cannot be used in small rooms. Many people still do it, of course, but only because they don't understand acoustics. Then they end up wondering why their room still does not sound right...

When I listen to music some bass notes are louder than others

Yup. Classic problem with all small rooms, except that in your case the problem is multiplied by having two identical dimensions.

When I clap in the room I can hear flutter echo from the ... side walls which has no treatment

Yup. That one is easy to fix.

(probably need more bass treatment cause there are still peaks?)

I'm not sure about "more", since you don't seem to have any at all at present! But you certainly will need a lot of bass trapping in that room.

OK, so we have a partial diagnosis: the room is sick for two reasons: 1) it is square, and 2) it is small.

Now we need to get X-rays and a CAT scan, to see just how sick it is!

First, I will need some photos of your room the way it is at present, showing how you have it set up, and the treatment that you currently have in there on each wall. I also need to know what speakers you are using (make and model), and their positions at present in the room (distance from side walls, distance from each other, distance from front wall, height above floor). I also need to know the location of the mix position: distance from front wall.

Next, I need you to run an acoustic analysis of the room, using the REW software package (which is free). Download that, calibrate it correctly for 86 dBC with both speakers on (80 dBC for each individual speaker), and run one test with just the left speaker on, one with just the right speaker on, then one with both speakers on. Then remove ALL of the treatment and furniture from the room, leaving ONLY your speakers and the chair that you normally sit on, and do another set of three tests (left, right, both). The room must be absolutely empty for this test. Take out everything, so you only have bare walls, bare floor, bare ceiling, the speakers and the chair.

After you have done those tests, save the MDAT file that has all six tests in it, upload it to a file sharing service such as DropBox, then post the link here on the forum so I can download it and analyze it.

Based on that I can give you a diagnosis of how sick the room is, and what you can do to cure it. It is a small room, so it will not be possible to cure it completely, but we can make it well enough to work decently.


- Stuart -

Hi I am having trouble uploading pictures and all , I know the rule is to upload the photos but.. yeah having troubles.

http://imgur.com/a/aUm2L

Here is a link to my room and some of the graphs. Im using presonus E5.

These graphs are done by another person , he helped me with these graphs however i dont know what exact settings he chose. It was done at my listening position with a portable speaker. So these are probably not very accurate ?
If I were to do it again with my Monitors , I need to purchase a omni directional mic right?

If it's necessary I'll get the mic and redo the graphs and all.

Hi I am having trouble uploading pictures and all , I know the rule is to upload the photos but.. yeah having troubles.

Where is the problem? What happens? When you select the file on your computer and press the "Add the file" button, what happens?

These graphs are done by another person

I don't see any graphs there., Only photos of the room.

If I were to do it again with my Monitors , I need to purchase a omni directional mic right?

Yes. You need a proper acoustic measurement mic, such as the Presonus PRM1.

From the photos, I do not see much treatment in the room at all! Just a few absorption panels on the front, but no bass trapping.

But first, you need to set up your speakers correctly. Get them OFF the desk! Put them on stands, and move the desk. Set up the speakers and mix position as follows:
When you have that done, set up the mic where your head will be, aimed 60° up, do a set of three tests: Left only, right only, both. Then upload the MDAT file to a file sharing service, and post the link here:

- Stuart -

Hi first off I just wanna thank you so much for the pictures and everything. I appreciate it alot and am very grateful.

When you say there's no bass trapping , 4inch panels at the corners plus the intersection from my wall to ceiling doesn't count at all?

Would the behringer ecm8000 suffice? I got a blue yeti which has omni , I don't think that works right ? Haha

I have the iso acoustics stands for my presonus eris 5, isn't that good enough as stands ?

Having the speakers so near to the wall, won't it cause more bass problems?

And this room is meant as a recording/control room. The only room I've got to do work in haha.

Home studio frequency https://imgur.com/gallery/UkC64

These are graphs done by somebody else.

When you say there's no bass trapping , 4inch panels at the corners plus the intersection from my wall to ceiling doesn't count at all?

The rear wall is totally bare in your photos. That's the most important wall, and there is nothing at all on it. No bass trapping or anything else.

The 4" panels across the front corners help a little, but they do not go up to the ceiling or down to the floor: they only cover part of the middle of the corner, which is the least effective part. The triple-corners at the top and bottom are the most effective.

Would the behringer ecm8000 suffice?

Yes.

I have the iso acoustics stands for my presonus eris 5, isn't that good enough as stands ?

No. They are very light weight, not solid, and that's only part of the problem. As I said, you need to get the speakers off the desk: That's the problem. You should never have your speakers on the desk itself, for many, many reasons. Vibrations, reflections, comb-filtering, distance, geometry, etc....)

Get them off the desk, get some proper stands that are very, very heavy (Some people stack up bricks. Some people stack up concrete blocks. Some people get hollow steel stands and fill them with sand and/or rocks...) The stands go on the floor, behind the desk, up against the front wall with just a small gap, and the speakers sit on top of the stands.

These are graphs done by somebody else.

There is nothing at all useful there. The graph cuts off at 100 Hz.! So it does not show the region where all your bass problems are. The scale is also way too high, and the tests were done at the wrong level. Useless.

Having the speakers so near to the wall, won't it cause more bass problems?

No. It will fix the bass problems taht you are having. For large rooms, yes, the speakers should be a long way away from the walls: at least 3m. But your room is way too small for that, so the only other option you have is to put them tight up against the front wall, except for that 10cm gap.

The problem is SBIR. You will get a large SBIR dip in your bass response due to the phase cancellation caused by the front wall. The greater the distance from the front wall, the lower the frequency, so if you can get the speakers at least 3m away from the wall, then the frequency will be below the audible spectrum. If you have it less than 2m away, then the SBIR hole will be somewhere between 40 Hz and 180 Hz., in the worst possible place in the spectrum, where it causes serious issues with bass response, and there is no way to fix it with treatment. If you put your speaker even closer to the wall, then the problem moves higher and higher. With the speaker right up against the wall, the problem is in the mid range, above 200 Hz, and hopefully close to 400 Hz. It does not matter so much there, and at that frequency range it can be treated with acoustic absorption.

Yes, putting your speaker that close changes the loading from full-space to half-space (4*pi to 2*pi), which changes the power balance below the baffle step frequency for your speakers, but that's easy to fix by using the acoustic space correction switches on the rear panel. That's what they are there for! Set those to -4dB.

So do the setup I laid out for you, install REW, calibrate it correctly to 86 dBC with a good-quality, accurate hand-held sound level meter set to "C" and "Slow", run the tests, upload the MDAT file to a file sharing service, and post the link here.

- Stuart -

You mentioned that bass trapping I would need to cover floor to ceiling but I've got the power socket on both sides plus on the left I've got the plastic covering for my aircon. Would you recommend that I make some modifications ?

I should probably sell the stands I have then? Would something like the Onstage monitor stands work? Or do I have to spend more money on something else ?

If i were to do the tests do you recommend me to do it with my panels up ? Or should I remove everything?

It will probably be awhile till I can buy both the mic and stands to do the tests. I'm actually an audio student so not everything I can afford ! I'm sorry! But I really thank you for your detailed replies.

I went and ordered a measurement mic and I'm still wondering if stands like this would work ?

You mentioned that bass trapping I would need to cover floor to ceiling but I've got the power socket on both sides plus on the left I've got the plastic covering for my aircon. Would you recommend that I make some modifications ?

Right- Modify as needed. You can leave small gaps in the bass traps for access to your plugs, or you could run additional plugs just outside the edges of the bass traps using surface-mount electrical raceways and outlets. Neater, but a little more expensive.

If i were to do the tests do you recommend me to do it with my panels up ? Or should I remove everything?

If possible, do one set of tests with the room as empty as possible, to get a good "baseline" reading of how it behaves in its raw state, then another set of tests right after you put each device in the room, so you can see for yourself what each device is accomplishing, what works, what doesn't work, and how much more you still need to do.

I went and ordered a measurement mic and I'm still wondering if stands like this would work ?

How much do they weigh? They need to be massively heavy.... and very rigid, sturdy, robust.

If you want cheap stands that look good and work really well, then stack up some bricks or concrete blocks, cover the stack with nice fabric or carpet, and put your speakers on top...

- Stuart -

https://on-stage.com/products/view/10638

Some specs here, apparently the only weight here is 90lbs, I assume one stand is 45lbs.
So would these stands work? If they do I'll probably try to sell my isoacoustic and get these.

Thank you for replying once again! Really am learning alot from your replies. I know that I should probably measure my room first , but the mic is gonna take awhile to get here. So I wanna ask some questions first

The front wall to ceiling have 2 X 4inch panels , currently there's abit of space from the tri corners on the top left and right.
Do you think If I flushed each to the sides covering the tri corner will help? I cant do anything to the air con piping thats on the left side, So i cant exactly have panels from floor to ceiling.

Since you mentioned the tri corners are most troublesome, I should probably move my corner panels further down till they reach the floor, that would be more effective?

That means it's gonna leave the middle section which the 4 inch panels are right now, sort of bare, is that okay?

For the back wall , I'm pretty confused cause there's this edge that comes out. So I have quite a few corners there. Should I be fixing the extreme top tri corners first or the lower ones?

THANK YOU!!!

I did the test after placing the speakers to the position that you said and also changed the stands. I left the panels and my bed still intact, I'll do one as bare as possible next week !
Did it with a superlux ecm999.

First one was just the left speaker
Second one just the right speaker
Last one BOTH speaker

I hope I did it right, cause my waterfalls seems really super bad to me haha

'the extension mdat is not allowed'? what's this?

I uploaded the file on wetransfer
https://we.tl/nEWI6hdZc7

'the extension mdat is not allowed'? what's this?

Yup! That's why I said: "...upload the MDAT file to a file sharing service, and post the link here."

Are you sure you calibrated REW correctly? There's something wrong with your measurements:
That's not right. The noise floor is way too high. So either your studio is VERY noisy, with no isolation at all, or there's something wrong with the way you did the measurements. Did you follow the complete procedure for calibrating REW; using your hand-held sound level meter to set the levels? Did you set the levels at 80 dBC for each individual speaker, measured with your hand.held sound level meter?

- Stuart -

paramourcheng wrote:I went and ordered a measurement mic and I'm still wondering if stands like this would work ?

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Some of the products in this review are not cheap but worth checking out.

Hopefully, you can find the best one for you.

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