I would ask in the pro sound forums, but i feel as if i would get attacked for even thinking about it. I have a drive rack PA2 in the aid to try and bring somewhat better sound to my area with what i have. I was wondering if anybody has used this Dayton Audio OmniMic V2 Precision Measurement System system to set up their pa to align the subs to the tops and fix or adjust other sonic anomalies before a show. Im looking at trying to build 2 othorns to re enforce the low end in my PA and I'm always trying to get better sound but from what I've read they are a different animal when it comes to alignment. People in my area have never experienced good sound, if somebody wants to hear the horror stories PM me. I can give the details to the rest of my system if required. I was wondering if people have used such a system to set up their mobile PA systems. Thanks 
I have a Dayton mic and a copy of REW and I use it with a DCX on all my passive PA speakers systems. But I don't do any testing in venues it's all done beforehand outside in my yard, the idea is to get all drivers in time alignment and add PEQ with the processor to tame the nastiest response peak or dips that aren't a result of mic position. The key points here are you need to spend some time with the gear to see how mic position affects your results, and once you get the system processed flat you probably won't need to do much in a venue besides some general EQ to taste.
Wouldn't doing it in your yard and then disassembling it and then setting it up in a venue affect the settings you made when you had it set up outside? Ive heard the Driverack PA2 (which i own) is pretty good at flattening out a system outdoors, then put the settings in the peq filters (?) and then running it again. I thought that you were suposto use the eq in the room? New to measurement and adjusting when it comes to timing and such. the price for that kit is not so bad i was thinking about diving in. Im the only one in my area that cares about such things it seems. I might even level out my system tomorrow. When i delay my tops to my subs or vise versa depending on the situation i just use a tape measure and eyeball where the voice coils would be and set it to that so its close, but if i could get it more on point I'm sure the difference would be noticed.
Yes and no. Here is the theory behind this method, when you measure the speakers outdoors you are measuring the speakers only and can correct for any response irregularities inherent in the design. When you measure indoors there is no way to know if that big hump at 300hz is because of the speaker design or because of a room node. But after you have that baseline calibration done outdoors if you do measure indoors again you now KNOW that any irregularities are a result of the room, and what you have to understand is that not all of those problems can be fixed with EQ. Matter of fact the first thing you should do is move the mic around and look at the response from different places, if the same problems occur in all those mic positions first change the speaker position to try and fix it.. if that is possible, and then try fixing it with EQ. Experience shows however that once you get the speakers processed flat you will just need general bass and treble adjustments inside to make it sound good, you won't need to go through the whole recalibration process.
I have not heard that, the people I know with a Driverack find the AutoEQ does more harm than good. The problem is the system doesn't know if the response peak or null it is measuring is because of a the speaker, because of interaction between speakers causing comb filtering, or because of a room node. If it is because of the speaker it can sometimes be corrected with EQ but if it's because of the other two it probably can't be fixed and that is when you see these massive boosts or cuts and the system trying to apply several filters at the same frequency. Bottom line the AutoEQ isn't that useful as you're going to have to go in and undo some of what it does anyway so you may as well just do it manually.
Yes there is a bit more to it, the electrical characteristics of the speaker drivers and any passive crossover components also affect phase and time response so the system will often need a bit more delay than physical measurements would suggest. The Behringer DCX has an AutoAlign feature for setting time delays, again this is a feature that is useful but you can't just blindly accept what it generates as being correct. I typically take a response measurement before and after setting delays and if it's correct you will see a flatter response in the crossover region, this is what I suggest you do with your system.
i do this delay /phase adjustment by playing sine waves created with cooledit and converted 2 mp3 or bunt to cd. i do a file for every 190hz increase starting from 1 octave below crossover til one octave above.
i put a cheap spl meter between the subs and tops and then adjust delay for maximum cancellation. meter can be cheap since absolute accuracy is not needed. write down the delay values for each frequency and for each delay add half or minus half period time. the setting with the best consistency over frequency is the right one with special focus on the crossover plus minus 20percent area.
i put a cheap spl meter between the subs and tops and then adjust delay for maximum cancellation. meter can be cheap since absolute accuracy is not needed. write down the delay values for each frequency and for each delay add half or minus half period time. the setting with the best consistency over frequency is the right one with special focus on the crossover plus minus 20percent area.
Im retarded, i just got confused i bet, i totally understand what you are saying now.
I believe this was true of the PA+ which used pink noise and a single mic location. The PA2 that i own uses 4 separate mic locations and sine sweeps to measure system response. i took a picture of the first time i used it.
I used it in my garage, which for some reason is a bass vacuum. definitely NOT acoustically treated. lol
From what i have been told is you take your system outside in a big open area if possible away from any boundaries, run the auto EQ, write down the results, plug the results in the PEQ(speaker tunings), then run it again outdoors to see if it made changes and from there depending on what it dose you can save it or get it as flat with the PEQ and then run the auto eq in the venue to try and take care some of the acoustic properties of the venue. Of course there is never going to be a one button push fix it all solution, i understand that. i will admit i have yet to do it this way and have only used it a few times in venue before a show, i am not a professional, but from what myself and others attending have said it sounded pretty good next to amazing. I also had one guy amazed a PA could sound so good. Then again, the primary DJ system for the local company in town is B-52 matrix with no processing. But i digress.
The problem i am running into is it seems as if not to many people are using them, so nobody knows much about the PA2 specifically. If anybody happens to know somebody using a DBX DriveRack PA2, if they don't know already, please inform them that their is a firmware update as well as a software update for the remote control features using laptops and mobile devices.
i saw this yesterday while searching for real world usage:
HARMAN International: HARMAN’s dbx DriveRack PA2 Loudspeaker Management System Makes A Night and Day Difference for Live Sound Engineer Whitney Day
Im just wondering how to get the delay as close as possible to get the best sound out of my system, everything can always sound better.
There is one key point missing from this procedure that I don't think was mentioned. You first reverse polarity of one speaker, then play the tones at various delay settings looking for maximum cancellation at the crossover frequency because it's easier to hear/measure that way, and then flip polarity back to normal.
AHH ok, that makes sense. I looked into it, what is the possibility of doing that and having it being 180 degrees out of time? Is that something somebody would notice? Im going to be putting all this to the test possibly today or tomorrow weather permitting. Where can one get a good spl meter? radio shack has been mentioned, but I'm a sucker for high quality accurate expensive equipment lol.
Honestly there is no great meter accuracy requirement for that test. If the SPL levels for only tops muted and for only subs muted are set equal, then unmuting both ways in cancellation mode can easily give 30 dB attenuation at the acoustic center point - even the crappiest SPL meter can detect that. You can find the timing down to plus minus 100 micro-secs easily.
You're absolutely right - they put the polarity function in the crossover section of the PA2 (I believe it's in the 'Utility' section of my DR260).
Use the wizards to set up your system IN the room. One of the advantages of the dbx PA2 is the ability to use an iPad to move around the room, take measurements and make adjustments without being at the console, manually or via the wizards. There are a ton of videos (YouTube) to aid in set up...gain, EQ, phase alignment, feedback suppression, compression. When its all said and done, the dbx will give you a good baseline, you will ultimately make manual adjustments to your personal ear/taste. DBX tech is a good source of help also. Opinions vary wildly on the dbx Driverack PA2. It is designed to do all the painstaking measurements and calculations mentioned easily.
Wow, new to forum, just realizing this is oooolldd.
Wow, new to forum, just realizing this is oooolldd.
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