help me get my room more stable so I can mix

[HalfBlacko0000]

I drew a outline of my room with the dimensions I rounded off some of the measurements due to the radiators and not having someone to hold the other side of the tape measure I have a lot of muddy bass going on and my monitors don't sound strong I'm in the process of getting a new mixing desk so my monitors don't have to be so far apart and want to make my own bass traps but if ya could help me with placement I would really be greatful

 

[sheggs]

I drew a outline of my room with the dimensions I rounded off some of the measurements due to the radiators and not having someone to hold the other side of the tape measure I have a lot of muddy bass going on and my monitors don't sound strong I'm in the process of getting a new mixing desk so my monitors don't have to be so far apart and want to make my own bass traps but if ya could help me with placement I would really be greatful

I would highly recommend looking up some acoustic primers on google. there are quite a few out there. If you are wanting to get a great sounding room there are a lot of aspect to deal with -

a) Positioning (although I think this is the best position for your room)
b) Monitor placement - Small guide -

• Speakers too close together: narrow stereo image. No real sense of where things are panned in the mix. Basically mono except for the most extreme-panned elements.
• Speakers too far apart: marked left/right localization (mix elements panned left/right are “stuck” there with no real sense of larger ambience). No real sense of mix depth, and in some cases no sense of a center-image. It extreme cases a sense of “big mono” where all elements of the mix are localized left and right with little or no center image.
• Speakers too low/too high: dull, muddy mid-range; source material sounds “shallow”. Speaker-under-a-blanket effect. Sound changes radically with small vertical head movements.
• Speakers unequal distance from the listener: marked comb filtering, the effect of which could be an ice-picky mids/highs or dullness in the mids/highs; localization in the left or right speaker

c) Room treatment, a lot in this

Those primers will give you a really good idea how to start

 

[HalfBlacko0000]

My monitors are 2 far apart right now I'm not in a perfect triangle my monitors are almost facing in ward and I used a test osc. And walked around my room and there are spots that the sound completely disapeers and other parts that just sound like muddy mess

 

[sheggs]

My monitors are 2 far apart right now I'm not in a perfect triangle my monitors are almost facing in ward and I used a test osc. And walked around my room and there are spots that the sound completely disapeers and other parts that just sound like muddy mess

Yep, they are most probably created by room modes. These standing waves are created by the way the sound responds to the room. You need room treatment to clean this up. I would definitely recommend some reading to get you started

 

[bandcoach]

1) I need the whole short wall length at the bed end of your room before I can do a room mode analysis for you (it takes all of 10s to punch the numbers into my programme and spit out the results)

2) can you put the bed into the shortened end of the room (against the closet or is there a problem doing that)?

3) sheggs has covered most of the rest

as for reading, try this as a first primer https://www.futureproducers.com/forums/content/55-sound-proofing-versus-sound-treatment.html

 

[HalfBlacko0000]

Do you mean between the closet and the dresser? that's 3 ft, yea after my new desk is built I can switch sides of the room, is it better to be on the more open end of the room? Between my Dresser and door there is a in the wall book shelf that I thought would be problematic but I was planning on buying some 703 and building my on panels I could prob build one the same size as the book shelf so I have panels on both sides.

 

[bandcoach]

so I either missed it the first time or you added it toto the drawing either way 11.5' for total width is cool

Height	Width	Length	Speed of Sound
7'5"	11'6"	16'	1130fps
Volume	1364.67	cubic feet
Axial Modes
Dimension	H	W	L
Frequency	76.18	49.13	35.31
Tangential Modes
Dimension	HW	HL	WL
Frequency	90.65	83.97	60.50
Oblique Modes
Dimension	HWL
Frequency	97.28

i.e. your room has resonance issues at 35.31 Hz, 49.13 Hz, 60.50 Hz, 76.18 Hz, 83.97 Hz, 90.65 Hz, 97.28 Hz

if we take these out to the 10th harmonic of each resonance point we see the following trend of issues

35.31, 49.13, 60.50, 70.62, 76.18, 83.97, 90.65, 97.28, 98.26, 105.93, 121.00, 141.24, 147.39, 152.36, 167.94, 176.55, 181.30, 181.50, 194.56, 196.52, 211.86, 228.54, 242.00, 245.65, 247.17, 251.91, 271.95, 282.48, 291.84, 294.78, 302.50, 304.72, 317.79, 335.88, 343.91, 353.10, 362.60, 363.00, 380.90, 389.12, 393.04, 419.85, 423.50, 442.17, 453.25, 457.08, 484.00, 486.40, 491.30, 503.82, 533.26, 543.90, 544.50, 583.68, 587.79, 605.00, 609.44, 634.55, 671.76, 680.96, 685.62, 725.20, 755.73, 761.80, 778.24, 815.85, 839.70, 875.52, 906.50, 972.80

Creating bass traps to cover the range below 100Hz will help to tame most of the issues you are hearing

as for first reflection points until you set your room these are not going to be easy to situate.

your best way forward is that once you have set your desk and your speakers to a usable equilateral triangle with your listening position as one of the vertices of the triangle (the other two being your speakers angled at 60[sup]o[/sup] to your listening position); you then use the older string and nail/tape method to identify where the speakers are focused on the walls behind your listening position; i.e. to the top of your speakers tape a piece of string and then run it in a straight line to the wall that lies behind your listening position that is your point of first reflection for that speaker. you also extend the string backwards form that position to the wall behind the speaker to find the rear position for the first reflections (speaker cabinets radiate in all directions but mostly along the axis of the the direction the speaker is facing)

enjoy and, as always, ask if you do not understand something

 

[HalfBlacko0000]

What is the 10th harmonic of each division, like what does it mean

 

[bandcoach]

What is the 10th harmonic of each division, like what does it mean

First let me add some commentary on what each of the modes are

Axial modes are the ones along the center lines of each room dimension and are your basic room resonances
Tangential Modes are the ones where any two walls or a wall and the floor/ceiling meet - these can create problems that interact with your main resonances
Oblique mode is the one where two walls and either the floor or the ceiling meet, i.e. a corner, this can also interact with the other two modes of resonance

Now, to your question

Just as in a musical tone, any room resonance can have harmonics, whole number multiples of the initial resonance frequency.

So, taking each of the modes and creating a harmonic series up to the 10th harmonic shows the following profile

Harmonic	H	W	L	HW	HL	WL	HWL
1	76.18	49.13	35.31	90.65	83.97	60.50	97.28
2	152.36	98.26	70.62	181.30	167.94	121.00	194.56
3	228.54	147.39	105.93	271.95	251.91	181.50	291.84
4	304.72	196.52	141.24	362.60	335.88	242.00	389.12
5	380.90	245.65	176.55	453.25	419.85	302.50	486.40
6	457.08	294.78	211.86	543.90	503.82	363.00	583.68
7	533.26	343.91	247.17	634.55	587.79	423.50	680.96
8	609.44	393.04	282.48	725.20	671.76	484.00	778.24
9	685.62	442.17	317.79	815.85	755.73	544.50	875.52
10	761.80	491.30	353.10	906.50	839.70	605.00	972.80

I then rearranged the sequence of harmonics so that it was an ascending set

35.31, 49.13, 60.50, 70.62, 76.18, 83.97, 90.65, 97.28, 98.26, 105.93, 121.00, 141.24, 147.39, 152.36, 167.94, 176.55, 181.30, 181.50, 194.56, 196.52, 211.86, 228.54, 242.00, 245.65, 247.17, 251.91, 271.95, 282.48, 291.84, 294.78, 302.50, 304.72, 317.79, 335.88, 343.91, 353.10, 362.60, 363.00, 380.90, 389.12, 393.04, 419.85, 423.50, 442.17, 453.25, 457.08, 484.00, 486.40, 491.30, 503.82, 533.26, 543.90, 544.50, 583.68, 587.79, 605.00, 609.44, 634.55, 671.76, 680.96, 685.62, 725.20, 755.73, 761.80, 778.24, 815.85, 839.70, 875.52, 906.50, 972.80

if we add identifying information the sequence becomes clearer and we can begin to see how each range interacts with the others

35.31 L 1, 49.13 W 1, 60.50 WL 1, 70.62 L 2, 76.18 H 1, 83.97 HL 1, 90.65 HW 1, 97.28 HWL 1, 98.26 W 2, 105.93 L 3, 121.00 WL 2, 141.24 L 4, 147.39 W 3, 152.36 H 2, 167.94 HL 2, 176.55 L 5, 181.30 HW 2, 181.50 WL 3, 194.56 HWL 2, 196.52 W 4, 211.86 L 6, 228.54 H 3, 242.00 WL 4, 245.65 W 5, 247.17 L 7, 251.91 HL 3, 271.95 HW 3, 282.48 L 8, 291.84 HWL 3, 294.78 W 6, 302.50 WL 5, 304.72 H 4, 317.79 L 9, 335.88 HL 4, 343.91 W 7, 353.10 L 10, 362.60 HW 4, 363.00 WL 6, 380.90 H 5, 389.12 HWL 4, 393.04 W 8, 419.85 HL 5, 423.50 WL 7, 442.17 W 9, 453.25 HW 5, 457.08 H 6, 484.00 WL 8, 486.40 HWL 5, 491.30 W 10, 503.82 HL 6, 533.26 H 7, 543.90 HW 6, 544.50 WL 9, 583.68 HWL 6, 587.79 HL 7, 605.00 WL 10, 609.44 H 8, 634.55 HW 7, 671.76 HL 8, 680.96 HWL 7, 685.62 H 9, 725.20 HW 8, 755.73 HL 9, 761.80 H 10, 778.24 HWL 8, 815.85 HW 9, 839.70 HL 10, 875.52 HWL 9, 906.50 HW 10, 972.80 HWL 10

 

[BrotherJunk]

I used to do competition car audio. Sound Quality competitions. Aside from a large cave, a vehicle is probably the worst place to design a system that reproduces music accurately. To this day the only thing I've hear as good (or better in one case) is my JH-Audio in ear monitors & a $110K home audio system in a perfect room. If you are wondering about my pedigree I've won world championships in Semi-Pro class. I've never took less than 2nd or 3rd at world finals in any class, with cars that I did. I never had the funds to go to world finals with my own car, but I won Nationals every time I went, & won best sound quality of all classes below Pro (Pro is fully sponsored, unlimited funds) This means of all the classes that people had to pay for their own cars or at least subsidized only partially, my car sounded the best (by far I was told)

The above is not to brag, just explaining I know how to work around environments to make things work. No other way to prove that than what I posted above.

I'm going to post what is ideal. You can choose what is possible for you to do.

First off you want to cover all your walls with egg crate (or better) foam. You don't have to glue or staple it to the wall. Cut it to the right length & it will stay in place. You want to get rid of any reverb/echo. Depending on the resonant frequency of the room you will also end up with frequency boosts that don't belong. Unless you have an RTA (I do, you aren't from Boston are you) or golden ears it will be hard to pick up. When you master you will be cutting frequencies that you shouldn't be...because 50hz for example is getting a 5db boost from the room. You can fix the sound with a 30 band eq, but it's not going to help your mastering problem.

Corners are bad news. Even with dampening (foam) you still get frequency bounce which = boost. If you can cut a piece of the above foam & place it in the corner at a 45 degree angle.

Unless the floor is carpeted they make cork board to put on the floor (again I'm posting what is absolutely optimal, just do what you can do) If you need a picture of what I'm talking about email me claythrow1 gmail I have boxes of the stuff for this specific reason. Hardwood is worse than painted sheetrock walls.

As far as your studio location, that is a trial & error thing. If you can find someone with an RTA in your area (it's a car audio tool, email higher end shops or find a way to borrow one. If you are really intent on doing it right, & RTA is a good thing to have. You need a small 2 channel mixer, a special mic, a windows 7 or under laptop, & a $100 program. The whole package costs about $300 & is just as accurate is a $1000 purpose built unit. I've tested them against each other.

With this, you can measure where your studio location produces the most accurate sound. Sometimes in a corner somewhere ( a closet knockout ) produces the most accurate bass response, other times it causes unnatural gain. You don't want any unnatural gain or cut. You want to hear exactly what is being played, exactly HOW it is being played. What we are talking about here is called cabin gain/cut. What the room wants to boost or cut. Any environment will do this, we are trying to minimize it.

As far as the speaker placement, so long as you are in the middle, equidistant from each speaker, you are in the central area of the crossfire you will be fine. This does not mean they should be pointed directly at you. The dispersion pattern of speakers varies. For example, in my car, the speakers had to be pointed directly at your ears. One of the cars I did that always took 2nd at world finals the speakers were pointed 30 degrees off center. That is where the dispersion patter for those particular speakers 'centered' for the listener. Your monitors you will have to play with. Dispersion patters may not be listed in the monitor's specs, but you can find out what drivers are in the monitor & look them up to find out the dispersion pattern. Reading the graph for the driver is pretty self explanatory. Whatever "off center" angle produces the flattest wave is where it should be set. This could be 0 (firing directly at you) 30 degrees off center, or 60. These are what the graph will normally show. If you find that it seems like between 30 & 60 is the best compromise go 45. But it's usually somewhere between 0 & 30 degrees.

Another thing, & this I would advise you to do, is to decouple your speakers from whatever you have them resting on. This is not done with spikes. This is done with non-hardening modeling clay. You can order it from any on-line art supply place (Dick Blick has it) It's clay that will never harden. You want to create a base no less than 1/2" for the speaker to sit on. Speakers enclosures will vibrate, that creates resonance at a certain frequency. That vibration will carry through (even with spikes) to whatever the monitors are resting on. Decoupling that transfer point will stop the transfer.

If you want to get really crazy...if you have monitors with rear facing ports & the port output fires towards a wall mount what is called a "deflex" pad directly behind the port. Parts Express or Madisound still sell them I believe. If not check ebay. The port is basically a "cheat" for a smaller woofer to create low frequencies. You want the initial wave for this. You do not want back wave reflections as this will cause unnatural boost. That low frequency is bouncing all around creating boost that is actually not present in the track. Deflex pads REALLY work at stopping back wave problems, it virtually eliminates them. I've measured the difference & it is considerable. Truth be told this is how I won against many of my competitors who spent much more on their setup. They had back wave & reflection issues that they thought Dynamat would resolve. It doesn't. Any flat surface will produce a back wave>reflections>unnatural boost. Egg crate foam behind the monitor will help a lot, deflex pads behind the port are optimal.

To truly do it correctly, you need an RTA (Real Time Analyzer) to measure the frequency response of the room as you change different aspects. There is no other way to know (unless you are blessed with golden ears) which way is optimal. On paper, keep your setup out of a nook. A corner would be better, but again not ideal. You want to be firing towards a flat area & against a flat area with foam, or you can be firing towards a corner that is pointing this way ^ so the waves hit it & disperse further back & die out. Firing into an area that is the opposite can cause gain.

Any questions just ask.

 

[bandcoach]

Your post is filled with inaccuracies and generalisations at all levels - what may suffice for the car audio industry is not what is required for small studios aka small rectangular box rooms

A port on a speaker is not a cheat but a tuning device to ensure that the free air resonance of the speaker is never reached - i.e. it is designed to vent at the lowest desired frequency and to retard output at lower frequencies.

Real Time Analysers have been around long before the car audio industry began using them I was using them in the early 80's to analyse rooms for gigs and concerts - please do not gloss over your facts

Covering all of your walls may work well in a car situation where you are tying to control an environment that is by definition atypical compared to the rectangular box that we are dealing with here. We are not aiming to deaden the room or otherwise make it uncomfortable to work in, but to tame the points where reflections begin to multiply, hence the need to trace where the speakers are radiating most of their energy - directly in front and directly behind on the same axis based on the center of the large driver.

Also, unlike car audio, where are you trying to fill the space and the air outside as well, in a small rectangular box, you do directly aim the speakers at your listening position: you do this so that you do not have to drive them hard, instead operating at low levels, increasing the time that you can sit and listen without fatigue.

For corners (the points where two walls meet) we have these things called bass traps specifically designed to go into corners - no need to cut a panel into two halves and place across the comer to make a a right angled triangle they make them that way to begin with.

At the point where three surfaces meet in the same room (wall-wall-floor or wall-wall-ceiling) we have even more specialised bass traps that are designed for the potential broad band of frequencies that may be present in different sized rooms

Plus side
Decoupling speakers from the surface they are placed on is good advice and the auralex speaker mats are ideal for this

to help you - I have been studying acoustics since the late 1970's, building custom speaker boxes and rooms and treating them along the way, as well as mixing and mastering in the days of tape and digital in studios and at live gigs.

 

[BrotherJunk]

Calm Down

First of all, calm down.

"Your post is filled with inaccuracies" Doubt it, maybe some misunderstandings...

"and generalisations at all levels" You should have inferred that by my introduction into my audio knowledge.

"What may suffice for the car audio industry is not what is required for small studios aka small rectangular box rooms" Never said it was.

"A port on a speaker is not a cheat"

Did I call it a cheat? Dunno, maybe I did...

"but a tuning device to ensure that the free air resonance of the speaker is never reached- i.e. it is designed to vent at the lowest desired frequency and to retard output at lower frequencies."

See, now I could go off on all the reasons you are incorrect, but I understand what you mean so lets just leave it. However free air resonance is often reached. What I believe you are talking about is unloading, when the driver is trying to produce frequencies below the tuning frequency of the port. This will work against the suspension & cause the driver to exceed it's mechanical limits. Best bet is to use a a filter to prevent it. The purpose of the port (basically) is to boost bass frequencies the driver can't reproduce accurately on it's own, or in a different enclosure. Cut off of the lower frequencies is a result of the box & port size restrictions, not designing the speaker NOT to play flat down to 20hz. (which I did once, that was pretty cool) Otherwise the cabinets & ports would be monstrous. Why would you want a speaker that filters out at 40hz? Unless you've got cabin gain making up for it, which I doubt. So, basically, I disagree with you that the ports purpose is to act as a very low HPF, because why would you want that...unless you have a sub somewhere else.

"Real Time Analysers have been around long before the car audio industry began using them I was using them in the early 80's to analyse rooms for gigs and concerts - please do not gloss over your facts" When did I state otherwise? I was just trying to help the guy find one he could use. Getting a hold of a car audio shop is going to be a lot easier than a sound engineer.

"Covering all of your walls may work well in a car situation where you are tying to control an environment that is by definition atypical compared to the rectangular box that we are dealing with here. We are not aiming to deaden the room or otherwise make it uncomfortable to work in, but to tame the points where reflections begin to multiply, hence the need to trace where the speakers are radiating most of their energy - directly in front and directly behind on the same axis based on the center of the large driver."

I never said anything about deadening the room. & you don't cover your walls in a car? They do in studios though. You are disagreeing with me for no reason...

& the last part of what you just said makes no sense on several levels. If they "are radiating most of their energy - directly in front and directly behind on the same axis based on the center of the large driver." why do you need to trace the reflections? You just stated you know where they are? Directly behind I don't disagree with if it's rear ported, in front, you need to look at the off axis response of your speakers. Directly in front is incorrect. 30 degrees off axis for each speaker at an 8 ft distance is quite a spread.

"Also, unlike car audio, where are you trying to fill the space and the air outside as well" No idea what you are talking about. Sound quality competition is in a closed vehicle.

"In a small rectangular box, you do directly aim the speakers at your listening position" No you don't, it depends on the speaker.

"You do this so that you do not have to drive them hard, instead operating at low levels, increasing the time that you can sit and listen without fatigue." It will make very little difference having them off axis. Fatigue is going to come when fatigue comes, doesn't matter if your speakers are directly on axis or a little off. Look at the way line arrays throw, or a ribbon. Speakers/monitors are the same. You need to optimize the throw pattern & your seating position. Aiming them directly at you is an assumption that might work out, but it might not.

If you are pointing your drivers directly at you without looking at the throw pattern of the speaker/monitor you are doing it wrong. You want the best frequency response, that may mean not aiming the speakers directly at you. Look at the on/off degree axis response of the drivers. If they respond better 30 degree's off axis (which MANY do) you are doing yourself a disservice aiming them directly at your head.

"For corners (the points where two walls meet) we have these things called bass traps specifically designed to go into corners - no need to cut a panel into two halves and place across the comer to make a a right angled triangle they make them that way to begin with."

So you are saying you have something that does what I suggested...why are you arguing with my advice about dealing with corners?

"At the point where three surfaces meet in the same room (wall-wall-floor or wall-wall-ceiling) we have even more specialised bass traps that are designed for the potential broad band of frequencies that may be present in different sized rooms"

Good idea

"Plus side" Yes massa?

"Decoupling speakers from the surface they are placed on is good advice and the auralex speaker mats are ideal for this"

I would argue "ideal." They might look nicer, but they would be hard pressed to beat the density & price of non hardening clay. They may be aesthetically more pleasing, but not perform as well. What is "ideal" is subjective.

"to help you - I have been studying acoustics since the late 1970's, building custom speaker boxes and rooms and treating them along the way, as well as mixing and mastering in the days of tape and digital in studios and at live gigs."

I've read your posts, I can see you know a good deal about what you are talking about. I've built so many speakers, enclosures, passives, I can't even recall them all. I've made enclosures out of fiberglass, carbon fiber etc, I've done ever sort of ported enclosure you can think of, every order, & there is only a handful of drivers I have not worked with. A handful.

I just added my input to help the guy & you jumped all over me for what in most cases was nothing. I'm not here to "take your crown." There is all kinds of audio knowledge in the world, it's possible I might have some. Have a good night.

 

[bandcoach]

Firstly, I do not need to "calm down"

Secondly, do you know anything abut small rooms and how to treat them or do you think that they are just the same as treating a car for dope audio?

Thirdly, I do not care about a crown - I do care if you spread mistruths and misrepresent what works in a specialised area of acoustic treatment as the only way to treat all problems in audio

now if you can demonstrate that you have treated real rooms then by all means share the insight that you have

ps - you did realise that we did a base analysis of his room resonances? and that we had spent some time explaining why the various modes of resonance will affect his room performance

most small room design for control and tracking use the on-axis equilateral triangle design for speaker-listener layout - so to suggest that we use a car audio approach flies in the face of scores of years of research in architecture, physics and practical room treatment.