Bass and the REQ room simulator


I'm a little embarrassed to state that I only learned about a cool feature of the Room EQ Wizard.

Now you can do room bass simulation.  The tool lets you draw a rectangular (sorry, no others) room, and it will simulate the effects of the room modes given a specified listening location and acoustic materials.

This has a number of practical and educational uses.  For instance, instead of doing the sub crawl, you can use the simulator to optimize your sub placement or listening location.  A big win if you have a 100lb sub. You can also, to some degree, simulate the benefits of bass traps or using multiple subs.

Hopefully a lot of what-if situations we regularly get asked in Audiogon can be answered there, allowing the user to try out their ideas, regarding questions about adding more subs, or room treatement, or placement options.

Specific information is here:
https://www.roomeqwizard.com/betahelp/help_en-GB/html/modalsim.html

Hopefully it will help illustrate just why bass is in fact so difficult for most audiophiles, and  why so many would rather have a smaller speaker than attempt bottom octave bass.
erik_squires
I just started using this feature, too. It’s pretty cool, but did anyone see if it’s possible to do any kind of smoothing on the simulation response? I found the raw simulation curves to be interesting but “too raw” to help me visualize a summary of what I was seeing. When I use REQ in measure mode I usually do something like 1/6 octave smoothing. 
Yeah.
That room simulation is pretty good.

I took my calibrated microphone, REW and measured a friends dedicated 2-ch room.

Then I tried the room simulation. Measured the room, listening and speaker position.

I got pretty impressed when I saw the exact bass frequency response! That gave me confidence in that the mathematics behind the simulation were trustworthy.

And as you said it were far easier to move two two bass towers with 4 12" in each tower. Back and fourth to close a dip at 50 Hz in the simulation and in the measurement.

Then it was just to move the speakers to that location.

Not just that I can make the conclusion that the mathematics is spot on. We can also see it the other way around.
That the physics of how the sound reflects/bounce in a room is so predictable so we can use mathematics on it. ;) (Now it were a room of concrete other construction material will absorb/reflect little bit different).
Hi @bache
I did not mean to start a thread on how to make your room better. :)

I just wanted to show how this tool is interesting and how you can use it to learn or place a sub.

Best,

Erik

@erik_squires 
one more less  expensive way to compensate any loudspeakers and room treatment issues. one time provide measurement, you can see any picks and holes and use old fashion, equalizer. Some brands , i dont want to mention offer very chip microphone and electronic device , played equalizer role , but called different name and selling for huge money 
Hi @Bache
That's good to know, but we're talking about simulation, not measurement. :)

Best,

Erik
especially for crossover less full range  , but this guys dont believed in any measurement , just trust own ears   
@erik_squires 

if you choose  miniDSP UMIK-1 calibrated USB measurement microphone ,you dont need additional USB interface 
The room simulator will do normal speakers too, and you can put in your cut offs to see how different main speakers would behave.

I suspect a lot of people will be really surprised what happens when you go from a two way to a full-range, multi-way and how bad it can be.
I haven’t tried this part of REW it’s hard enough learning the basics. I will say I don’t use traditional subwoofers thinking about it though but my speakers will go to 35hz pretty flat until they roll off to 24hz. Dutch and Dutch 8c. I am running 5 filters below 200hz. Good info to know thanks
PS - I encourage everyone to play with it, it’s a great great learning tool and the more we have trying it out, the better.

It does support up to 4 subs, so I’m sure the swarm people will go nuts with it. That’s fine. This is exactly the place for it.  So long as any poster is respectful of the fact that there are multiple ways to get good bass, and different priorities for buyers I do not have a problem with it.