corrective EQ curve generation based on calibration mic

[bduersch]

Today's kinda-random-but-seemingly-useful idea:

You know how you can run white nose through a set of speakers and use a calibration mic to see how "non-flat" the power amp/speakers are? Seen how some home theater receivers can use a calibration mic to set the proper levels for all the surround sound speakers in the room? I'd love to have a way to plug a calibration mic into the AxeFX and have it automatically generate a corrective EQ curve based on what's coming out through the power amp/speakers. Granted, it wouldn't be for everybody, but it would help folks get closer to the desired intent for how the patches are "supposed" to sound, then tweak to taste from there.

The reason I mention this... when I first got my AxeFX I plugged it into a small PA system and thought it sounded horrible. After some exploration, I realized it was more a function of how the PA was designed than how the AxeFX was configured (i.e., the AxeFX sounds great through other PA's). Said another way, I'm sure there are many systems on the market that claim to be more FRFR than they really are.

Thoughts?

--B

 

[dk_ace]

I don't know if the Axe-FX is even set up to do such a thing, but it won't work worth anything even if it could honestly.

The system you're referring to has been championed by DBX as a feature of their Driverack series. Talk to just about any pro system engineer and they'll tell you that this feature is almost useless. It is extremely susceptible to room nodes and other room acoustics issues that the system cannot detect or repair.

The only system tuning tools such as this that I've seen that actually work pretty well are things like SMAART which rely on an appropriate number of test mics in the listening area (generally far more than one) and compare the responses they pick up to the source track. These setups work, but they're complicated and require failrly extensive training to be able to use them with any proficiency.

Suffice it to say the necessary tools to accomplish this are far beyond the scope of the Axe-FX.

D

 

[sjaak]

hi
I'm not quite sure if this fits your intentions.....
put the pink noise generator on my home system and eq'd my set up as good as I could
ever since I did that (maybe in combination with ver 9.0) my patches sound much more what I want on our pa system
it's far from a professional room correction but improved my sounds very much

 

[Dutch]

Wouldn't say such systems are useless. Any FOH tech will tweak the EQ for a room. That's exactly what the driverack will do for you, if you do it right. You should definitely position the mic in several places and have it calculate the best common denominator. I don't know if the driverrack will do that, but the older and cheaper Behringer Ultracurve can do it. It's true that that still is only a band-aid, but those acoustic nodes are there anyway. Whether you process the source or not. As a sound tech you can't do much to improve the acoustics, all you have to work with is the soundsource. As a starting band we used to use an Ultracurve. I think it improved our tone.

I think it's more a lack of time or laziness on the tech's part that makes them scoff at it. It's a chore to do that every time and it takes a couple of minutes to do it. And some knowledge to do it right.


Anyway, dedicated units aren't that expensive and you're not going to run all the FOH through your Axe-FX, are you? Putting that correction only on the guitar tone is only slightly useful.

 

[randocaster]

We have a hand held unit to set EQ for FOH and monitors. In my experience (medium sized PA, smallish rooms) it has made a huge improvement in our sound.

 

[Cradleplayer]

I have an handheld from phonic (paa3) and use it to set different systems to nearly have a flat response in a given room.
when i work on my patches, i make sure the system that monitor me, is as flat as possible, so i can drag the axe to serveral places. that i mind, i know i'll have a well balanced sound on different systems.
i send pink noise through the axe with all blocks and eq set to bypass. then i make up to 6 memories with the internal mic of the paa3 and use the average mode to get an "idea" of the room. i use the global eq to set the room correction.
so i don't have to go to the amp block eq everytime i think something sounds not right, or there is too much or less of low or high end.
i do that only, when i work on patches. when it comes to live situation, i make sure, the pa system is set flat with it's own eq, often a 31-band and then i leave the axe global eq unused.
my monitor are an atomic FR, RCF Art 312A, an my yamaha studio monitor. i check my patches through an 2x12" and 4x12" cab also, with cab sim off.
when all this works, then i go out and play and i know, i have done everything to make it sound great on all possible systems i plug into.
it's a long way to tweak, but it works for me.

 

[dk_ace]

Wouldn't say such systems are useless. Any FOH tech will tweak the EQ for a room. That's exactly what the driverack will do for you, if you do it right. You should definitely position the mic in several places and have it calculate the best common denominator. I don't know if the driverrack will do that, but the older and cheaper Behringer Ultracurve can do it. It's true that that still is only a band-aid, but those acoustic nodes are there anyway. Whether you process the source or not. As a sound tech you can't do much to improve the acoustics, all you have to work with is the soundsource. As a starting band we used to use an Ultracurve. I think it improved our tone.

I think it's more a lack of time or laziness on the tech's part that makes them scoff at it. It's a chore to do that every time and it takes a couple of minutes to do it. And some knowledge to do it right.

Your post reveals that you fundamentally misunderstand the point of system tuning, and the processes involved in doing it correctly. Explaining all of that is well beyond the scope of this forum and has been extensively covered elsewhere. If you genuinely want to understand it all, I suggest you go to Pro Sound Web and start reading. That's a great place to get started.

These devices are designed FOR lazy people, not scoffed at by lazy techs. They are for people too lazy to learn how to effectively tune a system. They generally appeal to small bands getting started who can't hire a qualified engineer to tune a system or mix for them and who aren't interested in educating themselves to do it properly. Do they produce results? Yes. Are they professional results? No. The Axe-FX is a device aimed at achieving professional results.

As I said in my initial post, there are systems designed to do this accurately and effectively (SMAART), but they are far beyond the scope of the Axe-FX and it's users.

D