EQ to deal with in phase & out of phase freq. instead of expensive construction

[Lakin]

Hello,

I read a very interesting article in the November 2001 article of "Electronic Musician". It talked about using EQ to deal with a in phase and out of phase frequencies, "constructive interference". The article talked about using tools such as SpectraFoo of Metric Halo (www.mhlabs.com) to analyze standing waves and room modes. Then it discussed using EQ to smooth out frequency response in the sweet spot from you are mixing. One thing that struck me was the article said even expensive control room often have serious constructive interference problems. After reading the material on the SAE website I am tempted to do mix downs in my car or suspended in the air by a crane.

Could EQ be an alternative if construction of the perfect control room is too expensive in the short term? I don't want to want to delay my primary goal whish is making music immediately. I don't want to have to wait and save money for months before I can start recording. I am not concerned as much how the mix sounds in other parts of the room as long as I can hear accurately in the sweet spot.

Can this also be useful in determining a more effective strategy for planning studio construction and acoustic treatment? I would like to test various parts of the room with SpectraFoo to determine where the serious problems of constructive interference exist.

Has anyone worked with SpectraFoo or a similar product? If so, what has your experience been? Good? Bad?

I have attached a gif of the room's dimensions to give an idea of the workspace.

Thanks for your help.

Lakin

 

[Blue Bear Sound]

EQ is generally not a good way at all to deal with a bad room. The phase anomalies introduced by the cutting and especially boosting frequencies will do more harm than good....

There's no free lunch -- a bad room can really only be dealt with by acoustic treatment... no cheap way around it, no matter what the mags say.

Bruce

 

[frederic]

EQ is generally not a good way at all to deal with a bad room. The phase anomalies introduced by the cutting and especially boosting frequencies will do more harm than good....

There's no free lunch -- a bad room can really only be dealt with by acoustic treatment... no cheap way around it, no matter what the mags say.

Bruce

I would agree with Bruce, with the exception that MINOR tweeks are okay. If the boost/cut is about 1-2db, thats usually reasonable enough that you're not introducing too many abnomilies that *I* would consider it acceptable.

Of course, this depends on the room itself. If the room is truly acoustically awful, you're going to find that no EQ can really fix it well enough that you'd be satisfied.

This is where a parametric EQ is good for, making up for minor, slight imperfections in the room/monitoring system. But keep the 1-2db adjustment in mind.

Good luck!

 

[Lakin]

Thanks

Thank you Blue Bear Sound and Frederic,

My gut feeling is that the acoustics of the room are not awful despite the fact that the room has a lot of parallel walls. In your opinion, would it be money well spent to invest in a pink-noise generator and a program like SpectraFoo or should I spend that money on drywall and acoustic foam?

I really am not sure if in the current room a boost/cut of no more than 2db can smoothen out the frequency response and eliminate constructive interference in the sweet spot. I really have only a rough idea of the acoustic properties of the room. Thus, this kind of analysis that can be done with SpectraFoo seems as though it would be useful. I just can't figure out where to put my money in the short term.

Thanks for your help. I really appreciate it.

Lakin

 

[Blue Bear Sound]

If you don't consider the acoustics too bad, I suggest you simply learn how to translate your mixes in your current environment, rather than spending money needlessly on a solution that may give you only a marginal improvement....

Bruce

 

[Lakin]

Fear of making a costly mistake

Hello Bruce,

My biggest fear is that I will build something that I will later tear down as I get more experience and gain more knowledge. I do not believe that this room has bad acoustics. However, I have used it primarily for practicing. That means primarily vocals and guitar. So I am still a ignorant of the negative recording qualities of the room. I would rather make adjustments after gaining more knowledge and experience .

If I were to use the room in its current form for the immediate future, where from an acoustics perspective would you put my desk and the studio monitors? Where should the sweet spot be located? Where should I sit while I mix, edit and work with the audio? I have upload a diagram of the rough shape of the room.

Thanks.


Lakin

 

[Blue Bear Sound]

I'll have to defer to our resident acoustic experts Sjoko and John Sayers to field the specifics of this question!

Guys?

Bruce

 

[Lakin]

Pink-Noise Generator and SpectraFoo to determine best sweet spot location

Would it make sense to us a pink-noise generator and SpectraFoo to determine best sweet spot location? I imagine that I could place the monitors and a mike in a couple of different combinations of locations and see which parts of the room have the flattest frequency response. I am thinking in the right direction? If I understand correctly, I am looking for the combination of locations for the monitors and my chair that has the flattest frequency response spot in the room. It seems as though SpectraFoo would be a good investment. Do you agree?

In the short term I am not looking for a situation where others can sit behind me in the control room on a couch and listened to the mix without constructive interference. I just want an ideal sweet spot for myself to mix accurately and effectively.

 

[John Sayers]

Hi - sorry I've been late getting to this but I'm a Gypsy again on theroad and it's Internet cafes again

Look -I'd set my gear up in front of the door to the garage and about 6 feet from the door with the speakers firing down the long room . I'd put as much absorbant stuff (chairs, couches curatains etc etc ) at the back of the room (Top of draft plan) It's a good sized room so give it a go.

I'm really sceptical about pink noise and all that jazz. I got into it when it first came out in the 70s but it never seemed to help and usually hindered.

cheers
John

 

[Lakin]

Desk locations to get least constructive interference

Hello John,

I very much appreciate you helping me. I have only one problem with locating the desk near the garage door. My wife is annoyed that I want to locate the desk in front of the main thoroughfare for groceries. I carry the groceries and don't really see the problem. I don't think that they needed to consider that at Abbey Roads.

What do you think about placing the desk and monitors at the opposite end of the room (Option C in the attached diagram)? My only concern is the door. Maybe we will remove that door. Should I be concerned about the asymmetry behind me? There would be symmetry near the monitors?

For the best frequency response should I try to have a set up that the speakers firing down the length of the room? It seems to me that if the speakers were firing at a wall that was closer, then more of the room modes would be over 300 Hz. However, with the dimensions of my room it seems that even the shortest distance between two walls (i.e. 7'2") will have the fundamental frequency as 78.84, the first harmonic as 157.68, the second harmonic as 236.51, and the third harmonic as 315.35. Why is firing down the length of the room better? I am not questioning your judgment. I am just picking your brain and want to better understand acoustics. Thank God for this forum.

I have also included in the diagram an option of firing the speak diagonally down the room (option E). Is that a stupid idea? I have never seen anyone do that.

I guess that the only advantage to being next to the garage is that I can easily hop into to my car to hear mixes. From reading the SAE information that listening in a car gives you a very flat frequency response. The other option of course is being suspended in the air from a crane. Superman could have made great mixes hovering above the monitors. However, he was to busy saving the world to make music. Unfortunately I probably won't master hovering anytime soon.

Once again, thanks to everyone for your help.


Lakin