I have been mixing for our band with a CQ20b for about a year now. I have mastered a good amount of things (thanks to the users manual and YouTube), but the RTA remains a mystery to me.
Problem: I’m not happy with my mix results in larger rooms (we sound great in smaller clubs). I’m assuming I can use the RTA to reduce resonant frequencies of the room, but I’m not sure how to do it.
Once I see the RTA curve, am I supposed to reduce the peak frequencies I see? Is the goal to get the RTA “curve” to be closer to a straight line, or am I missing the point completely?
Also, since I am adjusting to the room, can I run the RTA on just an MP3 playing through the system, or should I be running it when the band is playing?
I’ve looked for info on this in the manual, online, and on YouTube, but I’m coming up short. Any guidance anyone can provide would be greatly appreciated.
Hi. You’re gonna need a reference. Usually it’s done with pink noise, a reference microphone, and a calibration software (like SMAART or Open Sound Meter).
You need to get the linear representation of a pink noise in your software, and then get a reading of the the pink noise from your speaker to the reference mic into the same software, then compare those two and then adjust.
I’d suggest checking out Michael Curtis on YouTube for more details.
Interesting I’ve been asking myself the same. The RTA showing me the frequency fluctuations and the peaks, so was working with the EQ to target the flattening of the curve assuming it would solve some of the bad sound in room. I think I may have some learning to do re that assumption. So your post and any replies from those more expert in these matters is welcome.
Up to a week ago I didn’t even know what the term RTA was lol.
Look up “ringing out the room” or versions of that.
Best done with a vocal mic and check 1 2’s through the system.
Once you get the feel for it you can hear when the room has a lot build up and or as the name suggest “ring” and then notch those out on the EQ.
The parametric EQ lets you dial in more precise to the needed frequency.
You can get more high tech with SMARRT ect. but check 1 2’s can go a long way once you get the feel and ear for it.
My understanding is that the RTA is just showing you signal strength of frequencies in the incoming signal allowing you to direct your ears EQ’s cut and boost choices.
The FBA is, as you suggest doing a “ringing out the room” function if Im reading the term correctly lol. (haven’t done the reading Mike suggested yet) The two things are linked to a degree because they are both modify frequencies heard for different purposes.
If you’re like me you’ll find a lovely EQ for your vocals at home but find it won’t translate to the Live room you end up in, giving you feedback all over the place so the FBA has just cancelled your preferred frequencies lol.
I clearly need to play all my stuff in places with no walls (or “anechoic” chamber ) lol. But thats probably a whole other set of LIVE challenges. I take my hat off to LIVE engineers the unsung heroes of a bands good sound.
The short answer is no, you cannot use an RTA to make accurate decisions about what the “room or PA” is doing. So when it comes to questions like “how can I reduce resonant frequencies of this room”, an RTA is the wrong tool to use. There are lots of reasons for this…
First, unless you have a “room mic” that you have PAFLed, the RTA graphs you see in the console are not a representation of what the room is doing. It’s showing an internal audio path.
Second, even if you have a room mic that you are using the “RTA” purposes, it is only showing you what is going on in that exact spot. Move the mic 6 inches in any direction, and the RTA output will likely change dramatically.
Third and most importantly, even with a room mic being used for RTA purposes the RTA graph shows WHAT is happening but not WHY it is happening. When it comes to room/PA acoustics, there are too many variables that affect what an RTA graph might look like. Without understanding the “WHY” it is very likely that you will make things worse if you only use an RTA to make audio decisions for the overall room/PA system. This is why system tuners use more robust software that includes a lot more information than just a frequency response element. Software like SMAART and OpenSoundMeter are the correct tools to use for this purpose, not just an RTA graph.
In other words, if you want to be able to answer questions like, “how can I reduce resonant frequencies of this room,” you need to start learning about “system tuning”.
If you want to start this journey, the suggestion to check out Michael Curtis’s Youtube channel was a good one. There are lots of other good resources too - like Michael Lawrence’s site/videos/book or the instruction guide for the SMAART software (found on Rational Acoustic’s website).
