Is there a way to check how FRFR is your speaker?

Orbm1

Orbm1

Inspired
So, I'm using an older Behringher 112 pa/monitor speaker with my Axe-fx II and I feel that it is adding some unnecessary eq to my signal. This particular powered speaker has a treble, bass, and volume knob.

I am trying to tweak the old fashion way (using my ears) but I think there may be a way to flat eq using a reference tone and an analyzer of some type? Is there?

Axe-Fx wish: It would be cool if the axe-fx could use its inputs' capabilities to create a signal to play through your speakers/monitors and listen it via a microphone and create an analysis of what your frequencies are and either give you an idea on what to tweak in your speaker (like tuning your speaker) or create an immediate eq tuning to your room/speaker combo.

I would not like to spend money in a new frfr speaker at this time and this could be a great way you have he optimal sound with wahatever set up you have.

Any cuter early available ideas or solutions you use/have?

Thanks!

Omar
 
You could do something just like what you are talking about by getting a Presonus Audio box or something similar and running it into a DAW like reaper and analyze it there. The issue that you are going to run into though is your tone getting colored by the mic or even the room that its in. Because of that, the way that I would do it, if I had your setup, would be to set all of those EQ knobs to noon on your PA cabs and get the sound you want with them set that way. Then only use those EQ knobs to adjust for different rooms.
 
What you are looking for is a spectrum analyzer; it analyzes the frequency spectrum from a source signal and displays it graphically/numerically. You would play a white or pink noise signal which would contain a full spectrum of audio frequencies (easily obtainable as a .wav file) through your speaker and record the speaker's signal to the the spectrum analyzer which is will display the response. You run into a catch-22 because the mic/room has a response itself so in the ideal case, you use a high quality reference mic, with a correction curve for that specific mic's response to nullify the effect of the mic.

Theoretically, the inverse of the resulting response curve relative to zero would "flatten" your speaker's response when applied.

Dunno if there is a plugin etc for this as I have never tried it but that is the best bet on the cheap. The AFX cannot do it without extra tools. It may have a white noise generation ability builtin as part of the IR tone matching stuff.

It would be cool if the tone match block had an invert button. In that scenario you might be able to pull off a crude version of this on the AFX.
 
zenaxe said:
What you are looking for is a spectrum analyzer; it analyzes the frequency spectrum from a source signal and displays it graphically/numerically. You would play a white or pink noise signal which would contain a full spectrum of audio frequencies (easily obtainable as a .wav file) through your speaker and record the speaker's signal to the the spectrum analyzer which is will display the response. You run into a catch-22 because the mic/room has a response itself so in the ideal case, you use a high quality reference mic, with a correction curve for that specific mic's response to nullify the effect of the mic.

Theoretically, the inverse of the resulting response curve relative to zero would "flatten" your speaker's response when applied.

Dunno if there is a plugin etc for this as I have never tried it but that is the best bet on the cheap. The AFX cannot do it without extra tools. It may have a white noise generation ability builtin as part of the IR tone matching stuff.

It would be cool if the tone match block had an invert button. In that scenario you might be able to pull off a crude version of this on the AFX.
Click to expand...

Yup, that would certainly work except I think those can get kind of pricey. I was looking at one of those before for my PA setup. Found a nice Drive rack from dbx. It sends out 2 blips from your speakers and listens to it thru the reference mic and automatically EQs your system for you. Hell of a cool piece of equipment, but still kind of pricey.

http://www.sweetwater.com/store/detail/DriveRackPA2
 
Yes there is - I do this, and I've used the process to make an IR to flatten the cab that I use. I should make a video. What you need is a reference calibration mic. Dayton Audio makes one for $50.

Using the tone match block, the basic process is this:

- Start with a preset that has nothing but one tone match block in it
- Make sure your global EQs and levels are 100% flat
- Put in pure pink noise in the 'reference' section
- Pump pink noise through the axe into your speaker/cab/whatnot and take 5 to 10 averaged measurements into the 'local' block (I'd recommend a different position of the mic for each one to get the maximum averaging)
- Tone match, and you're good to go.

The resultant curve will be an inverse frequency response of the speaker (as best as can be measured using this method). This can be used to 'flatten' out the response of the speaker. You have to use a 2nd cab block in series with a normal cab block and load the 'correction' IR into the 2nd block. I do this with an old Fender 4x12 and it works beautifully. Turns it into something that takes normal IRs perfectly. It won't extend any response, but it'll take care of any nasty resonances or uneven response fairly well. A good test is to pump some music through the axe (using that same tone match only preset) and listening. It should sound very, very normal, not 'guitar cab' like at all.

I'll make a video of this process if anyone is interested!
 
Honestly, Driveracks are kind of cool if you really know how to use them, but most people don't. And I wouldn't get one unless you were trying to run a pro sound reinforcement company.

Here's what I suggest:
- you don't really need full range, just flat response between about 100-10,000hz
- you already have very good reason to believe that your Behringer is not flat in that region, and more than likely no amount of tweaking of the onboard EQ will do away with phase issues and such in the design
- you could spend that $400 on a Driverack, only to find that you would have to marry it to the Behringer for it to be really useful anyway, which is kind of like...I don't know, Billy Joel and Christy Brinkley? Diana Krall and Lyle Lovett? You'd end up with $600 worth of equipment that still won't get you what you really want.
- you could just sell the Behringer and invest that and the $400 toward a CLR and have a known quantity, or even just get a Yamaha DXR10 (Nexo processing) which is going to be a lot closer to FRFR, especially in the critical range for guitar.
 
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Orbm1 said:
I would not like to spend money in a new frfr speaker at this time and this could be a great way you have he optimal sound with wahatever set up you have.
Click to expand...

The drive rack suggestion was actually something that I plan to do. I know a guy that uses them and they rock for quickly EQ'n a PA for live performances. For Omar, I wouldn't suggest any of this cuz of what I quoted above. Since he's looking for a way to do this without purchasing new cabs, best thing he can do is to learn how to control what he's got to the best of his and it's ability.

A trick that a sound man friend taught me that you can also use is to run some music through your system. Music that you know VERY well and use a graphic EQ to make that music sound right in the space you are in. If that music sounds the way that you know it is supposed to then you have at least gotten your speakers close to tuned. Since I am new to the Axe itself, perhaps you could pull a blank patch up with just a graphic EQ and do this. Once you have that sounding right, build your chain in front of it. It won't be perfect but it kind of sounds like you already know that.

Just a thought.
 
Kevinerror, has a great solution... I just went through this process with my Behringers in a slightly different way... Let's acknowledge that the typical Behringer eurolive or other monitor is far from flat, and that there is a long way to go to get there... However, I think you can make good progress rapidly and cheaply.... I know some of you will roll over on your keyboards.... but bear with me.... OP's system can be improved and will sound better - It won't be CLR or Xitone... but it can be better after some EQ is applied. What you need to do is run some pink noise through the system, at approximately the volume you will be playing - I would shoot for about 100 db as a ball park (but that's me). You can find a pink noise generator online (for example: http://onlinetonegenerator.com/noise.html), or you can use the pink noise generator in the synth block (I haven't tried this yet, but it will simplify making connections). Then you need a Fast-Fourier transform Audio analyzer. Yes, these can be expensive... but the miracle of modern smart phones can also make them cheap.... I have an iPhone App from Black Cat Systems (Audio Spectrum Analyzer) that only cost $2.99, and provides all the basic functionality of an analyzer that would have cost thousands in 1980. Its really unbelievable... $2.99. The Black Cat system uses the iPhone microphone, l which seemed to work fine for a quick and dirty leveling in my case ... but if you want you can buy a calibrated measurement mic as indicated above for about $50, and an adapter to use with the iPhone - Behringer makes a mic in that price range (ECM8000). So I set my iphone in front of the speaker (firly close, acknowledging room effects) and looked at the analyzer spectrum, messed with an in-line EQ, and to the extent possible flattened the system by eye. This simple process, using the equivalent of stone knives and bearskins produced serious improvement in the sound quality coming out of that Behringer system. And, that will do, until I have the opportunity to upgrade the amplification system. Kevinerror's solution is better.... but some may not be aware of how cheaply you can get a FFT analyzer on you cell phone.... blows my mind.

Quick edit - when I say close to the speaker, the mic was probably 1.5 - 2 ft away in a position where it would pick both the horn and 12".
 
Hello, yesterday I saw this topic but I could not answer because I'm not friend of my cellphone little keys, I wanted to comment that all the analysis tools that you need are within the Axe, the procedure is similar as shooting an IR and with tonematch block you can balance the response of the Behringer to a certain point, but can't do miracles, the Behringer PA have their limitations. Where I see the biggest problem is in capturing the response of the Behringer, to make this accurately you'd have to spend more money than a decent monitor costs.
If you feel that your Behringer is missing/adding something trust your ears, they're the best analyzer.
What kevinerror did was grab a fender guitar cab and make it more "FRFR", your case is different, you have already a PA system, theoreticaly flat, but you have quality issues.
You can do it in a prehistoric way: put some comercial music in your PA that you know well and tweak until you get the sweetest spot the Behringer can bring you.
Other approach is to look in the manual or in the web of Behringer if they show a Frecuency response graph of your model, but not all the manufacturers do this consistently.
My best advice is invest in a decent active speaker, your Axe2 deserves this and more!
 
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Hmmm...They will never sounds like a system ten times the cost - but they never should. :)
Though this is really old school, I'd just play some of your favourite music through the speaker(s) and eq till it sounds as close to 'real' as you think it should. That will be the point where the speakers are as close to accurate as you'll get them.

Thanks
Pauly
 
I highly doubt that all the eq in the world would not solve the problems inherent in your speaker. You can get the EV ZLX 12p for $400. I have tested a lot of lower priced speakers and this one wins by far.

But if you insist, there is a program called "Room Eq Wizard"; it will generate and analyze the signals for your speaker and its free. This mic, http://www.parts-express.com/dayton...source=google&utm_medium=cpc&utm_campaign=pla will work to capture the signals properly; $38.60 on sale. This mic requires phantom power and a decent Audio interface, ie, http://www.sweetwater.com/store/detail/AudioBoxUSB for $99. You will need a computer of course....

In the end, however, you will find that eq is no remedy for your speaker problem. So, consider the EV...
 
Well, you can not eq a bad speaker into a good one. Also, for truly measuring the speaker, you need anechoic room, otherwise you are measuring the room more than the speaker. The closest approximation is to measure it outside far away from any walls, except ground for practical reasons, and stay pretty close to the speaker. And even then, the forum will lynch your results like I learned last summer.
 
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