how can I replicate natural comb filtering?

[stellar]

sitting in the mix position my monitors sound like they do outside of the studio. If I move out of the mix position strange things start to happen! a few feet back the bass really picks up ! How can I use EQ to duplicate this and make the kick really thump! is it a matter of cutting certain frequences or what ? when I try to do it with EQ the bass (instrument) gets in the way and everything sounds muddy. if I just move back a few feet the kick becomes crystal clear!

[Waltz Mastering]

Sounds like your room needs some work.

[Ethan Winer]

Originally Posted by stellar

if I just move back a few feet the kick becomes crystal clear!

Tom nailed it. You'll benefit greatly from bass traps, and probably first reflection absorbers too.

--Ethan

[Key]

Eh I would disagree if you are dealing with a small place. Bass waves are very large. You are just probably sitting closer than the size of the bass waves. I don't think treatment really helps this. Only getting a larger space.

[Audiop]

Originally Posted by Key

Eh I would disagree if you are dealing with a small place. Bass waves are very large. You are just probably sitting closer than the size of the bass waves. I don't think treatment really helps this. Only getting a larger space.

Let's assume a small room.. 3x4 meter. The lowest axial mode means that from aprox. 40Hz and up is FULL of bass resonances. The modal density is worse in small room hence the need for acoustic treatment is bigger in small rooms than in bigger.

I don't know what you mean about the listening distance being "closer than the size basswaves". I assume you mean something about the wavelengths but I can't see your point.


/Peter

[Key]

I mean as the tones get lower the wave forms get larger. At a certain point these wave forms become to large to form before hitting the sweet spot. I believe they also get larger than the dimensions of small rooms (hence standing waves) if you are trying to get down to 20Hz

[Audiop]

Hi Key, your thinking is flawed. That's not the way it is.

Also we don't talk about size of waveforms but wavelengths at various frequencies.


How do you think you can get down to 20Hz with headphones? ;-)
According to your idea we would only be able to hear above 2-4kHz with such devices.


/Peter

[Key]

Well yeah there is more to it than that I guess. I just woke up give me a break haha. He is probably sitting in a spot with phase cancellation. Who's thinking isn't flawed? Kind of a non point if you ask me

I don't think headphones actually get down to 20Hz in a real sense. Every headphone I have heard kind of distorts and gives the impression of 20Hz but nah I don't think that is the real 20Hz. Maybe I am flawed in my thinking with that one as well. It's totally possible.

[Ethan Winer]

Originally Posted by Key

Bass waves are very large. You are just probably sitting closer than the size of the bass waves. I don't think treatment really helps this. Only getting a larger space.

As Peter explained, it doesn't work that way. In fact, bass traps are most needed, and do the most good, in bedroom size spaces. Another common myth is that levels don't change much at low frequencies over small distances due to the long wavelengths. The top graph below shows two points in the same room only four inches apart. You can see that the peak at 42 Hz varies by 3 dB for these two nearby locations, and there's still a 1 dB difference even as low as 27 Hz.

The reason the frequency response changes so much even at low frequencies is because many reflections, each having different time and phase delays, combine in different amounts at each point in the room. In small rooms the reflections are strong because the reflecting boundaries are all nearby, so that further increases the contribution from each reflection. Also, nulls tend to occupy a relatively narrow physical space, which is why the nulls on either side of the 92 Hz marker have very different depths. Indeed, the null at 71 Hz in one location becomes a peak at the other.

The lower graph pair shows the same room with and without bass traps. This type of graph shows both the raw response and the modal ringing. The ringing is shown by the "mountains" as they come forward over time.

--Ethan

[Key]

What way are you guys assumming I think this "works"?

I am saying something very simple. That at a certain point in a small room if you are expecting to have your system create a 1:1 recreation of a wavelength that is larger than the actual space you are occupying you are just asking for trouble. You can't suck an elephant through a straw. If the wave length is 30ft long and your room dimensions are smaller than that what makes you think you can accurately reproduce that wavelength in your room? And do you really want to?

Man I am in the wrong thread again. Don't get me started on that bass trap room treatment stuff because I don't think it is considering the entire chain. You can take measurements sure but is that what you are actually hearing? I doubt it.

[Key]

Haha and no one is really helping him out. Okay here ya go. This thing works for me KVR: Ohm Force Frohmage - Virtual Effect

[Audiop]

Originally Posted by Key

I don't think headphones actually get down to 20Hz in a real sense. Every headphone I have heard kind of distorts and gives the impression of 20Hz but nah I don't think that is the real 20Hz. Maybe I am flawed in my thinking with that one as well. It's totally possible.

Check this thread for a mesurement of HD600/650 I did a while ago. :-)


/Peter

[Key]

Well for me once you get lower and lower it starts to sound fake to me if I don't get a little bit of a tactile response. I think it's where I start to differentiate "real sound" from tones. It's like yeah I can get tones but is it a real sound or some reproduction? I don't hear low frequency transients with really any headphones yet either. I can hear them clear as day on my speakers but when I put on the headphones it just sounds like uppermid and high transients/ambience.

Headphones to me get close but I am not sure that it is actually the same thing when you get down to it as generating a 20Hz-30Hz tone in a space that can accommodate that sort of thing. There is a huge difference in the sound that is very obvious.

[Audiop]

Originally Posted by Key

Well for me once you get lower and lower it starts to sound fake to me if I don't get a little bit of a tactile response.

Well that ws not the discussion now was it? The question was bandwith of said devices and the fact that small spaces have no problems with low frequencies.

I think it's where I start to differentiate "real sound" from tones. It's like yeah I can get tones but is it a real sound or some reproduction?

I don't get it. Recorded sound is always reproduced sound and as sound it is as real as can be, otherwise it would be hard to hear!! ;-)

I don't hear low frequency transients with really any headphones yet either.

Try other headphones? Have you listened to a good car stereo? Low bass can have excellent quality in cars since the low bass area is free from standing waves in a car cabin. The same goes for headphones. Due to the extremly fast decay in the lowest two decades headphones have really good reproduction of transients. Resonances and slow decay ruins the perceived dynamics and transients of music more than a couple of per cents of actual compression from nonlinear suspensions of transducers and thermal compression due to heating of voice coils.

I can hear them clear as day on my speakers but when I put on the headphones it just sounds like uppermid and high transients/ambience.

Have you measured the bandwith of the headphones you have used?
The HD650 has good extension as can be seen from my measurements.

Headphones to me get close but I am not sure that it is actually the same thing when you get down to it as generating a 20Hz-30Hz tone in a space that can accommodate that sort of thing. There is a huge difference in the sound that is very obvious.

Yes of course, the room have tons of resonances that typically blurs the LF area and can give gain up to 15dB or more on some specific frequencies. Also the tactile thing you mentioned obviously has an effect on perception of power and "realness". BUT headphones still have high resolution of the actual LF region which I felt the discussion was about.


/Peter

[HookedOnHardware]

Originally Posted by Key

Eh I would disagree if you are dealing with a small place. Bass waves are very large. You are just probably sitting closer than the size of the bass waves. I don't think treatment really helps this. Only getting a larger space.

It's clear you need to read up on acoustics. A larger room will certainly help (low end problems) but you would still need to treat it accordingly.

[HookedOnHardware]

Originally Posted by stellar

sitting in the mix position my monitors sound like they do outside of the studio. If I move out of the mix position strange things start to happen! a few feet back the bass really picks up ! How can I use EQ to duplicate this and make the kick really thump! is it a matter of cutting certain frequences or what ? when I try to do it with EQ the bass (instrument) gets in the way and everything sounds muddy. if I just move back a few feet the kick becomes crystal clear!

I suggest you go over to the acoustics forum and search how to build some affordable basstraps. There is a lot of good info, often catering to small(er) rooms.

Good luck.

[Key]

How would me reading something make something sound better or worse?

[HookedOnHardware]

Originally Posted by Key

How would me reading something make something sound better or worse?

Reading + learning = knowledge
Knowledge + implementation thereof = experience
Experience =

Unless it is what you are trying to achieve, don't be ignorant.

You do the math.

[Key]

Okay give me something to read that supports your case. And I will attempt to improve my small listening space - which honestly already sounds flat with the exception of the lowest bass region. ONLY if you read my case and consider that you might be wrong. I am totally open to the idea that room treatment can help I just honestly don't think it does much unless you are trying to rememby some glaring problem. And even then it might be better to just rellocate the system. I have read some on the subject I just disagree with you guys.

[HookedOnHardware]

Originally Posted by Key

Okay give me something to read that supports your case. And I will attempt to improve my small listening space - which honestly already sounds flat with the exception of the lowest bass region. ONLY if you read my case and consider that you might be wrong. I am totally open to the idea that room treatment can help I just honestly don't think it does much unless you are trying to rememby some glaring problem. And even then it might be better to just rellocate the system. I have read some on the subject I just disagree with you guys.

I didn't say you should (have to) improve your listening space. If you think your room is fine, fine. Stellar asked a question which was basically answered by the 2nd and 3rd post.
Could your room drastically improve? Most likely, but you would want it to. To do so, you would have to gain knowledge to replace your (current) flawed thinking.

It's fine to have an opinion, just make sure you have enough knowledge to back it up.

Originally Posted by Key

ONLY if you read my case and consider that you might be wrong.

I know for a fact that I am not wrong.

Originally Posted by Key

I have read some on the subject I just disagree with you guys.

Read more.

You 'sound' like a very young person. All I suggest is to educate yourself. I feel in no way obliged to prove to you that your thinking is flawed. You will find that out for yourself. Links? Ethan Winer's site is a good start.

No offense to the OP but this thread really belongs in the acoustics forum.

I'm done here.

[Key]

So you call me young and dumb but you have absolutely no study or research to site? I asked you with all sincerity to show me something to read and I would try it out. Only with the agreement that you read what I have read which supports what I think about room treatment with an open mind. I am willing to consider the possibility that I am wrong. But it seems like you are not.

Oh I missed the name. Really I don't understand why you have to insult me though and get mad. I really just have a difference of opinion on bass traps and room treatment.

The whole thing about wavelengths seems to be taking my words a little too literally. I just think that bass sounds "bassier" when you give it a little breathing room. That's not to say that the listening position isn't perceived as flat. Just that's sort of the nature of large waves - they sound larger when you give them space. I don't see how this makes me some idiot.

[HookedOnHardware]

Originally Posted by Key

So you call me young and dumb but you have absolutely no study or research to site? I asked you with all sincerity to show me something to read and I would try it out. Only with the agreement that you read what I have read which supports what I think about room treatment with an open mind. I am willing to consider the possibility that I am wrong. But it seems like you are not.

Oh I missed the name. Really I don't understand why you have to insult me though and get mad. I really just have a difference of opinion on bass traps and room treatment.

The whole thing about wavelengths seems to be taking my words a little too literally. I just think that bass sounds "bassier" when you give it a little breathing room. That's not to say that the listening position isn't perceived as flat. Just that's sort of the nature of large waves - they sound larger when you give them space. I don't see how this makes me some idiot.

Just to clarify: I didn't call you, or imply anywhere that you are dumb. I did imply that your knowledge seems to be too limited in the subject matter. Nothing more, nothing less.
I could post a plethora of links for you to read. However, it makes much more sense to search for yourself (I did give you a start with Ethan's site). You will most likely (I do) question things you read and read up on the things you do. This way you will learn a lot! Things you read before but didn't quite understand become clear (and is retained as new found knowledge).

As I said before: It's fine to have an opinion but in this case your opinion is flawed (due to lack of knowledge). I'm not the only one who said that your thinking (in this particular case) is flawed.

The facts of physics aren't altered by opinions.

Feel free to post what you read but I am too busy to post what I have read in the last 8 or so years. I know I'm right in this case. However, that does not mean I'm always right. I'm knowledgeable. Not ignorant. My apologies if you felt attacked.

I'm out.

[Ethan Winer]

Originally Posted by Key

at a certain point in a small room if you are expecting to have your system create a 1:1 recreation of a wavelength that is larger than the actual space you are occupying you are just asking for trouble. You can't suck an elephant through a straw. If the wave length is 30ft long and your room dimensions are smaller than that what makes you think you can accurately reproduce that wavelength in your room?

Again, it doesn't work that way. What you're talking about is the frequency at which sound in a room goes from being a wave to being only pressure. The smaller the room, the higher that transition frequency becomes. But sound can still exist in a room smaller than the wavelength! Our ears response to pressure, not wave velocity. In fact, once you get below that transition frequency, the LF response actually becomes more accurate because there aren't any reflections to cause peaks and nulls.

--Ethan

[fader8]

Key,
Relax, and try to listen to what Peter and Ethan and others are telling you here. First, an axial dimension of a room only needs to be the same length as 1/4 the wavelength of a sound to enable a room mode, (standing wave) at that frequency.

Second, if you're moving a few feet away from your mixing position and you're getting reinforcement in the bass, that is a standing wave, (anti-node) and has nothing to do with comb filtering. It also means that it's very likely that when you're sitting in the mix position that you're sitting in a "node", meaning that bass frequency is getting sucked "out" of your mix.

Do yourself a favor and get some help with getting that room fixed.

[Ethan Winer]

I think that's half a wavelength, but who's counting?

--Ethan

[Key]

I never said you could not hear a wavelength that was longer than the listening position. I can understand how you get that from what I said but that was not the underline point I intended. Audiop said this not me. He said this jumping to a conclusion based on what I said.

I was just trying to say that to me this effect of bass getting larger in random spots in a room or further than the listening position does not mean he is actually having problems in the listening position to the point he needs room treatment. Nothing more really. Any attempt at me to guess what is happening with his listening position is just that a guess. When you start getting into wavelengths that are larger than the room you are in, I said there will be problems not that you can't hear the tone. I got distracted with the headphone thing and really that is another tangent all together so I am not going to get into it. To me it seems obvious that when you are dealing with bass flying around the room you could actually be sitting in a point of phase cancellation.

So how is what I am thinking flawed again? You guys just keep assuming I don't understand acoustics but that is not what I am saying. I am saying that they are not as important as you think they are. That is my opinion and I have some very valid reasons why I believe this to be the case. While I may be in the minority I am not alone on this and there is reading that supports my case. I think a lot of mixing engineers who have been forced to mix in a variety of rooms would also agree with what I think is the most important part of dealing with rooms - acclimation.

[fader8]

Originally Posted by Key

A paper that says room treatment is detrimental to the listening environment? I have. Who is ignorant and uninformed now? I have read both sides of the argument but you seem to think there is no other side of the argument at all. Well there is. So get to searching.

There is plenty of debate (years of it) regarding absorption vs diffusion, etc., which will never be settled. But there is no debate whatsoever regarding low frequency room modes. Acclimation can't compensate for a 24dB hole at 110Hz, for example. Of all things in room acoustics, it's the thing you've got to fix first as it has deleterious effects on the entire band, meaning you can't isolate other problems (or have any debate about them) until you've fixed these!

[Key]

So I assume HookedOnHardware has left the building not taking me for my word. Not a single paper to site or technique for me to try out even though I said I honestly would give it a try.

So now that is out of the way, for the few people who DO have an open mind and don't resort to calling anyone who might disagree with them a "troll", here is a link to presentation done by someone who is most likely more experienced than both of us combined. This paper is the closest I have read to what I havebeen thinking about reflections and how to deal with audio reproduction in a real home environment as well as a studio environment.

Optimized stereophonic reproduction

When I am pressed and challenged on the subject I guess I can get a bit dry but I honestly am not trying to come off as authoritative. I just have my theories and what has worked for me. I am genuinely curious about this stuff and am actively experimenting with every aspect of sound I can when I can.

And I should probably avoid a thread like this or just disagreeing with people who recommend room treatment. It just seemed to me to be a bit of an assumption based on what the OP said to automatically treat the room. I am not even sure if he said the audio was inaccurate at the listening position just that he couldn't get it to sound like it did in the other spot - which to me seems natural and not exactly a problem.

[HookedOnHardware]

Originally Posted by Key

So I assume HookedOnHardware has left the building not taking me for my word. Not a single paper to site or technique for me to try out even though I said I honestly would give it a try.

So now that is out of the way, for the few people who DO have an open mind and don't resort to calling anyone who might disagree with them a "troll", here is a link to presentation done by someone who is most likely more experienced than both of us combined. This paper is the closest I have read to what I havebeen thinking about reflections and how to deal with audio reproduction in a real home environment as well as a studio environment.

Optimized stereophonic reproduction

When I am pressed and challenged on the subject I guess I can get a bit dry but I honestly am not trying to come off as authoritative. I just have my theories and what has worked for me. I am genuinely curious about this stuff and am actively experimenting with every aspect of sound I can when I can.

And I should probably avoid a thread like this or just disagreeing with people who recommend room treatment. It just seemed to me to be a bit of an assumption based on what the OP said to automatically treat the room. I am not even sure if he said the audio was inaccurate at the listening position just that he couldn't get it to sound like it did in the other spot - which to me seems natural and not exactly a problem.

I'm like having syphilis. I'm never really gone (first thing I came up with. Just ignore it). This thread is comparable to the first few episodes of idols, x-factor etc. It's like when people look at car accidents. It's horrible but you can't take your eyes off of it.

I read your paper. My biggest critique is the fact that it doesn't cater to recording studios. Two huge differences between what was written in the paper and the acoustics in professional recording studios are:

1: Critical listening, and
2: Critical listening

The paper is written from an audiophile's home listening system perspective. Not a recording/mix studio's perspective.

As I've mentioned before, the acoustics in a recording/mix studio are controlled to be as flat as possible. This includes the monitoring system which differs from listening rooms and even mastering studios (compared to rec/mix studios). A flat room response across all frequencies (going as low as the monitors go) is preferable because this way you are mixing the music, not the room. You will compensate for the frequencies that correspond to the room modes. Huge null at 60Hz? You'll boost 60Hz. Huge rise at 100Hz? You'll attenuate 100Hz (just to keep it simple).
The worse modes happen in certain, calculate able to an extent, areas in normal rooms. Dead centre will give you huge problems. 25, 50, 75% in will give you noticeable problems. Having the speakers too close to hard surfaces will give you problems (comb filtering etc). The back wall being too close will give you problems. A room with too many reflections will smear your stereo imaging (again, I'm talking about untreated rooms).

Treatment (both absorption and diffusion) is to minimize nasty reflections and room modes. Can a room be designed to have as little modes/problems as possible? Yes, but it will cost you. A lot. http://www.amsterdammastering.com/ You can find this guy’s thread on here too. The design is so good that you can stand anywhere in the room and the bass stays the same. Spatial imaging is said to be amazing. The design in simple terms is a 'non-environmental' design, which basically means it minimizes room interaction.

Sure mastering rooms are slightly different than rec/mix rooms (still controlled but arguable slightly more neutral/'real').

To fall back to the differences between a normal home listening room and a studio CR:
As mentioned, the CR is treated to cater to critical listening. Not necessarily enjoyable listening. That is another big difference between home stereo sets and professional recording monitors. The former is made to be enjoyable to listen to, not necessarily accurate. The latter is made to be accurate, not necessarily enjoyable to listen to.

Treatment in a less than ideal room will flatten out (attenuate) the modes to give you a more accurate representation of the source material. It won't alleviate your (main) problems unless you either, build a properly designed room, or trap the shit out of it with tuned traps.

I didn't call you a troll anywhere so don't put words in my mouth. I provided you with at least one source (Ethan Winer's site).

A random search gave me (I'm currently not at home so I can't send you my bookmarked pages):

Acoustic Treatment and Design for Recording Studios and Listening Rooms

GIK Acoustics presents Acoustics Primer: Some Basics on Acoustics.

Acoustics 101...Practical guidelines for acoustic construction: building a sound studio, listening room, home theater room, and any other sound control room project.

RealTraps - Acoustics Information and of course the forum on GS:

http://www.gearslutz.com/board/studi...ing-acoustics/


(Google room modes, comb filtering etc and you should get helpful links)

[Jon Hodgson]

It seems to me people here are misunderstanding the poster's original question, he's not asking how to fix his room acoustics (though it sounds like he probably should) but how to replicate one of its effects in his mixes.

So in an attempt to answer that question...

It's all down to delays really, so you could experiment creating comb filtering with a short delay and seeing what that gives you. I suspect that the reason you're not getting what you want with EQ is that the comb filtering is boosting some frequencies while cutting adjacent ones, the SPL Vitalizer does this to some degree as I understand it, as you boost the bass the lower mids are cut at the same time, keeping things clear.

Or since it sounds like your room gives you what you want, before you treat it, why not take some impulse responses that you can use in a convolution reverb? All you need is a good mic, and if it works you'll have something that is uniquely yours.