Can REW/BFD be used to tune home studio?

2115 Views 16 Replies 5 Participants Last post by brucek, Jan 29, 2009

packerfans4

Discussion Starter · Jan 21, 2009

Found this site and the REW software doing a search to find info on EQing my home studio. I know this is a home theater site, so please excuse me if I'm overstepping my bounds. I've treated the walls with acoustic panels and need to graph out the frequencies at the mix position with my nearfield monitors. I have both a Galaxy SPL meter and the Behringer ECM8000. I used the software to graph a response last night, but see that the majority of the targeted use of REW and BFD is the sub. I have smaller Event TR5 (5-1/4" woofer) monitors, and it does not appear bass is the issue. Rather, some of my mid-highs are being lost. My main question is if the REW/BFD combo is applicable to adjusting all the frequencies across the spectrum 20-20, and if anyone has used it to this level. In my case, I may need more than 12 freqs. to adjust per channel.

If there are already threads on this, please excuse my redundancy. I've done some searching but have not yet found something similar. Again, if I'm out of line posting this here just let me know. The goal is the same...using the tools to measure and tweak frequencies (in this case, I want flat), it's just that I want to extend well beyond the sub range. BTW - I have no sub in my mix setup.

I'll try and post my first graph taken last night.

Thanks in advance for any advice or direction you can provide. The REW/BFD looks like a great option, and or the REW and a 31-band dual EQ.

TeeJay

See less See more

1 - 17 of 17 Posts

brucek

· #2 · Jan 21, 2009

My main question is if the REW/BFD combo is applicable to adjusting all the frequencies across the spectrum 20-20, and if anyone has used it to this level.

Lots of our members use REW to setup their studios with REW.

The BFD is not really suitable for EQ'ing full range and is limited to subwoofer duties.

But the bigger issue is that you want to use EQ at all on your studio monitors?. What's up with that?

I thought this was taboo for mixing music. REW has been used by most members with studios, to place the monitors correctly and install room treatment panels to get the smoothest response as possible at the mixing chair (pseudo near-field).

BTW, for REW graphs use the standard Vertical graph axis of (45dB - 105dB) and the Horizontal graph axis of (15Hz - upper limit in your case 20KHz).
For full range, as this is, enable 1/3rd octave smoothing to remove comb filtering. (don't use filtering when creating filters for a sub though).
Hopefully you are using the CM-140 calibration file, if that's the meter you're using.

brucek

See less See more

packerfans4

Discussion Starter · #3 · Jan 21, 2009

Thanks much, Brucek. You are correct in that my preference would be NOT to do any EQing at all. This room is doubling as a recording space (which has different requirements) so I'm trying to strike a balance between the two. I appreciate the info on the graph and smoothing settings. I'll try working directly with panel locations and quantity. (I knew I shouldn't have drilled all those holes!)

Thanks again!

TeeJay

packerfans4

Discussion Starter · #4 · Jan 21, 2009

I'll look for the calibration file as well.

Wayne A. Pflughaupt

· #5 · Jan 21, 2009

Welcome to the Foroum, TeeJay! Not to worry, we’ve had quite a few people come through here usng REW for their studios. :T

packerfans4 said:
I used the software to graph a response last night, but see that the majority of the targeted use of REW and BFD is the sub.

The program is designed to automatically recommend parametric filters for equalizing subwoofers in the residential environment, but that’s just one of its features, as you’ve probably figured out.

I have smaller Event TR5 (5-1/4" woofer) monitors, and it does not appear bass is the issue. Rather, some of my mid-highs are being lost

Doesn’t look that way to me, but it’d be easier to tell if you re-posted your graph to our default standard with a vertical scale of 45-105 dB. It helps us compare “apples to apples” if everyone’s graphs are the same.

My main question is if the REW/BFD combo is applicable to adjusting all the frequencies across the spectrum 20-20, and if anyone has used it to this level. In my case, I may need more than 12 freqs. to adjust per channel.

As mentioned, REW will only auto-EQ for the low frequencies. Above the bass frequencies, you’ll have to analyze the graph and determine for yourself what equalizing is needed, if any. If you don’t know how to do that, we can help.

Typically, the BFD is not recommended for the main channels, as it is a cheap equalizer. It’s fine for subwoofers, where less-than-stellar performance won’t be heard, but if you have to EQ the mains you’ll want a better quality equalizer.

If there are already threads on this, please excuse my redundancy. I've done some searching but have not yet found something similar.

Threads on full-range equalizing are a bit scarce here (not sure what I’d enter in the search engine to find them!). Here’s one from a while back that might shed some light.

Regards,
Wayne

See less See more

packerfans4

Discussion Starter · #6 · Jan 21, 2009

Thanks much, Wayne. I found the file Brucek mentioned, and will read through the thread you included. I'll also recalc my graph tonight with the adjusted parameters and re-post for your comments. Really appreciate it, gentlemen.

brucek

· #7 · Jan 21, 2009

You can add the meter calibration file to a previously taken measurement without re-measuring too.

Simply load the CM-140.cal file and then load the saved measurement. Then select IR Windows popup (top right hand corner of REW) and press APPLY Windows, and the cal file will be added to the results.....

brucek

packerfans4

Discussion Starter · #8 · Jan 21, 2009

Great info....thanks again!

tonyvdb

· #9 · Jan 21, 2009

Wayne A. Pflughaupt said:
Typically, the BFD is not recommended for the main channels, as it is a cheap equalizer. It’s fine for subwoofers, where less-than-stellar performance won’t be heard, but if you have to EQ the mains you’ll want a better quality equalizer.

And these would do a fantastic job, right Wayne. I have two of them and they are the cleanest EQs I have ever used and I have used many (Yamaha, Ashley, White audio, Urie and more)

Wayne A. Pflughaupt

· #10 · Jan 21, 2009

Yup. If you want a 1/3-octave EQ, I expect it'd be hard to beat the C-131 for anything remotely close to their original purchase price.

Regards,
Wayne

packerfans4

Discussion Starter · #11 · Jan 22, 2009 (Edited)

Okay. Ran the test again tonight and I think I'm doing a better job of getting all the specs in the software lined up and working closer to accurate. I also made the changes to the graph limits, loaded the .cal file for the ECM8000, and smoothed 1/3 octave. This is from my listening position, ECM8000 at tweeter height, equilateral triangle 51" per side, about 75 db. Thoughts?

Thanks.

TeeJay

See less See more

Wayne A. Pflughaupt

· #12 · Jan 22, 2009

Fifty-one inches - wow, that's a pretty expansive work station you have there!

Probably best to position the mic at about ear level, not tweeter level. Presumably, the speakers have a wide-enough dispersion pattern that it won't matter, but you never know.

Considering your original complaint, that the mid-highs are being lost, that would be about at the 6 kHz range, where you're showing a 6-dB dip in response that's nearly 2/3-octave wide, which is fairly significant, audibly speaking.

So, looking at the graph, I'd agree with your original observation.

Regards,
Wayne

packerfans4

Discussion Starter · #13 · Jan 23, 2009

Thanks once again to everyone for all the great feedback. Before I head down the the path of adding an EQ (which is last-ditch and only fine tuning), I'm going to do some serious experimentation with the mix position, speaker placement/height, panels, etc. this weekend. I'm also going to try and build some bass traps for my front corners to see if that dip at 300 can be addressed. I'm also going to contact Event to see if they can get me a graph of the speakers themselves so I know what the inherent tendencies of them are. Lots to do. I'll keep you posted.

TeeJay

brucek

· #14 · Jan 23, 2009

I'm also going to contact Event to see if they can get me a graph of the speakers themselves

You can do your own near-field test by placing a monitor in the middle of the room away from any surfaces and measure at about a foot away. Outside is better, but not always possible...

brucek

packerfans4

Discussion Starter · #15 · Jan 23, 2009

Thanks, Brucek. I will attempt to do that as well.

TeeJay

ElectroKinetic

· #16 · Jan 29, 2009

I just made a makeshift anachroid chamber on my futon and tested my Sony SS-U3030 monitors. I placed the meter and the speaker on the futon. I threw a blanket over them, calibrate, and measured. I then took the blanket off and did the same. The difference is night and day. I'll post a thread about it up when I get five posts and can upload pics.

brucek

· #17 · Jan 29, 2009

I just made a makeshift anachroid chamber on my futon

Not really the best idea. There will still be reflections defendant on the frequency. The idea indoors is to place the speaker and mic about a foot apart, and away from any surfaces. Then adjust your REW gating after the measurement to remove the possibility of reflections having the time to affect the measurement. Using a 6msec gate should be fine to eliminate surfaces over a meter away.

when I get five posts

That's why we have the post-padding thread, so you can create dummy posts.

brucek

1 - 17 of 17 Posts

This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.