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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => Audio Measurement and Testing => Topic started by: Jonathan Barrett on May 07, 2019, 09:59:08 pm

Title: dbx Drive rack 360 Venue
Post by: Jonathan Barrett on May 07, 2019, 09:59:08 pm
Hey all,

I'm super curious to know if this little drive rack could do a decent job at tuning a PA? What kind of results do you think you could get from a product that advertises 'wizard' to measure a room response and auto correct it? I know this question sounds ridiculous being posted in a professional sound measurement forum but I'm curious to know if this is a gimmick or maybe has some value as a quick tool to measure and correct room/PA responses?

For those who may not know about the DBX venue360, the unit has a RTA mic input and asks you to place that mic in various places around the speaker system. A sine wave sweep is played from the unit and measured. The resulting measurements are averaged and inverted through auto EQ correction. You're then able to tweak the settings a bit and even pull from a library of speaker/amp manufacturers.

Are SMAART guys/gals out of a job or are they safe? J/K :P    I AM NOT WITH DBX
Title: Posting rules
Post by: Mac Kerr on May 07, 2019, 10:16:10 pm
Hey all,

I'm super curious

Please go to your profile and change the "Name" field to your real first and last name as required by the posting rules displayed in the header at the top of the section, and in the Site Rules and Suggestions (http://forums.prosoundweb.com/index.php/board,36.0.html) in the Forum Announcements section, and on the registration page when you registered.

Mac
admin
Title: Re: DBX Drive rack 360 Venue
Post by: Roland Clarke on May 09, 2019, 11:54:11 am
I think we are all safe.  Half the problem with the taking of measurements is making sure the ones we take are useful and knowing what to do with the measurements.
Title: Re: DBX Drive rack 360 Venue
Post by: Jonathan Barrett on May 09, 2019, 06:37:50 pm
I think we are all safe.  Half the problem with the taking of measurements is making sure the ones we take are useful and knowing what to do with the measurements.

Yeah, I don't think the unit would be able to differentiate a comb filter from any other dip and adjust accordingly. Maybe there's little use in the DBX but I'm not sure about PA Tuning.
Title: Re: DBX Drive rack 360 Venue
Post by: Tim McCulloch on May 10, 2019, 01:23:47 am
Yeah, I don't think the unit would be able to differentiate a comb filter from any other dip and adjust accordingly. Maybe there's little use in the DBX but I'm not sure about PA Tuning.

I'm told the Otto Eque function is better than it used to be (I'd hope so).  It's still time-blind but apparently does the averaging better (secret sauce).

There are ways to make use of this tool if one is aware of its limitations and accordingly makes *valid* measurements, but it is not a replacement for a dual channel FFT analyzer and knowledgeable operator.
Title: Re: DBX Drive rack 360 Venue
Post by: Steve Litscher on May 15, 2019, 12:53:19 pm
The VENU360 does OK at tuning, but... it introduces eight (8) EQ adjustments any time you run it. A lot of the changes overlap one another, which could cause some phase issues. EQ introduces phase shift, so the more you EQ, the more shift there can be.

Sound-wise, it lends itself to the brighter end, so we always used the "reflective room" setting, which tames down the high frequencies a bit.

I have used the AutoEQ in the VENU360 to tune our JTR rig (3TX over Orbit Shifters), as well as Smaart V8 and TEF. I've also worked with Jeff from JTR to tune our rig and we A/B'd the results from the VENU360 and Jeff's TEF equipment - both were pretty similar with their end result.

dbx seems to have done a decent job with the VENU360 AutoEQ. Is it perfect? Nope, but neither is Smaart or any other tool.
Title: Re: DBX Drive rack 360 Venue
Post by: Jonathan Barrett on May 16, 2019, 06:23:20 pm
agreed that the human element is what makes the largest difference but interesting to know that it's semi decent at tuning a PA, maybe I'll give it a whirl and just listen for myself.
Title: Re: DBX Drive rack 360 Venue
Post by: Tim McCulloch on May 20, 2019, 03:04:31 pm
agreed that the human element is what makes the largest difference but interesting to know that it's semi decent at tuning a PA, maybe I'll give it a whirl and just listen for myself.

What do you mean by "tuning a PA"?  This phrase gets used a lot but I'm not sure the same definitions are always used...

Kind of like "tuning the room."  Really?  We have an EQ for that:  the D9.

Title: Re: DBX Drive rack 360 Venue
Post by: Russell Ault on May 20, 2019, 09:09:58 pm
We have an EQ for that:  the D9.

How many rackspaces will that take? I don't think I can spare that many...

-Russ
Title: Re: DBX Drive rack 360 Venue
Post by: Dave Garoutte on May 20, 2019, 11:18:50 pm
How many rackspaces will that take? I don't think I can spare that many...

-Russ

The road case is HUGE!
Title: Re: DBX Drive rack 360 Venue
Post by: Russell Ault on May 20, 2019, 11:52:24 pm
The road case is HUGE!

I didn't look closely enough at the diagram. It's 90U. My bad.

Requires an extra deep rack, too. Definitely need the rear rails. The good news is that it comes with tracks...  :D

-Russ
Title: Re: DBX Drive rack 360 Venue
Post by: Tim McCulloch on May 21, 2019, 12:45:42 am
I didn't look closely enough at the diagram. It's 90U. My bad.

Requires an extra deep rack, too. Definitely need the rear rails. The good news is that it comes with tracks...  :D

-Russ

It's not carry on friendly. :D

After working in Memphis a few times, I got to see one of my least favorite places, the Municipal Auditorium, being torn down.  When I saw the proscenium and house left side (because the house right wall was rubble) I thought of the D9 EQ and how much better that standing wave/flutter echo nightmare room was sounding already!  It's an extreme tool but sometimes that's what it takes. 8)

The discussion about the use of the word "tuning" is semantics, but words have meanings.  If Jonathan is concerned that his system does not sound the same in different venues it's probably a good idea to understand what venue differences could account for the changes he is hearing.  Once you know why, you can then assess corrective measures and whether or not Electronic Intervention is appropriate.

For example, if one problem is subwoofer behavior - in one venue the low end is nice and tight, has a power alley down the middle and the subs are 12 feet or more from the back wall.  The next weekend they play shallower stage and the subs get moved further upstage (say, 4 feet from the back wall) for whatever reasons, and they pound the hell out of the sub amp(s) and out front, it's wimpy.  Otherwise the rooms are roughly the same size with similar furnishings and decor...  What's happening here, and would letting Otto Eq put a big bump at 50Hz help?  What alternatives are there?

Title: Re: DBX Drive rack 360 Venue
Post by: David Allred on May 21, 2019, 10:09:44 am

The discussion about the use of the word "tuning" is semantics, but words have meanings. 

Yes they do, but as my dad always said, "Words do not convey meaning.". 
For example:
Appropriate
Good
Bad
Love
Cold
Hot

"Tuning" - Adjusting until acceptable to the adjustor (or person in charge).
Title: Re: DBX Drive rack 360 Venue
Post by: Jonathan Barrett on May 22, 2019, 05:45:36 pm
What do you mean by "tuning a PA"?  This phrase gets used a lot but I'm not sure the same definitions are always used...

Kind of like "tuning the room."  Really?  We have an EQ for that:  the D9.

I don't consider myself a Pro Systems Technician, I'm inquiring about the Drive Rack's Auto EQ functions after all. When I think of "PA Tuning" I think of using equalization to coax as much a linear response from my speaker system whilst taking the room response into account. Do you mean to say PA and room tuning are two different processes?
Title: Re: dbx Drive rack 360 Venue
Post by: Mac Kerr on May 22, 2019, 05:52:52 pm
I don't consider myself a Pro Systems Technician, I'm inquiring about the Drive Rack's Auto EQ functions after all. When I think of "PA Tuning" I think of using equalization to coax as much a linear response from my speaker system whilst taking the room response into account. Do you mean to say PA and room tuning are two different processes?

I think he is saying 2 things:

1 - Room tuning isn't done with user adjustable electronics. It may be enhanced with certain sophisticated electronic treatment if the room is too "dry", but other acoustical issues are handled by physical changes to the environment. That can be as mild as surface treatment of walls, floors, and ceilings, or as extreme as the "D9 eq"  which involves bulldozing and building a better venue.

2 - There is more to system tuning than eq.

Mac
Title: Re: dbx Drive rack 360 Venue
Post by: Jonathan Barrett on May 22, 2019, 07:00:45 pm
I think he is saying 2 things:

1 - Room tuning isn't done with user adjustable electronics. It may be enhanced with certain sophisticated electronic treatment if the room is too "dry", but other acoustical issues are handled by physical changes to the environment. That can be as mild as surface treatment of walls, floors, and ceilings, or as extreme as the "D9 eq"  which involves bulldozing and building a better venue.

2 - There is more to system tuning than eq.

Mac


I see...I'm big on nomenclature too so I'd like to get it right. Sooo room tuning involves things such as PA physical placement, characteristics of the space, and adjustments made to that space with no electronic intervention?

I guess I've always broke up in my mind the process of correcting the PA (Mid build up from arrays, etc) and then moving on to correcting the PA for the "room"? Like a low mid problem in larger reverberate spaces. Is it safe to say that no amount of system processing can correct for larger "very live" spaces? To not digress a whole lot I'm often out of time the moment I'm finally in front of the console/laptop and the idea of a quick and dirty PA tune is alluring...It took me a good minute to learn about the D9...too many minutes really  :-\

Thanks
Title: Re: dbx Drive rack 360 Venue
Post by: Tim McCulloch on May 23, 2019, 12:59:20 pm

I see...I'm big on nomenclature too so I'd like to get it right. Sooo room tuning involves things such as PA physical placement, characteristics of the space, and adjustments made to that space with no electronic intervention?

I guess I've always broke up in my mind the process of correcting the PA (Mid build up from arrays, etc) and then moving on to correcting the PA for the "room"? Like a low mid problem in larger reverberate spaces. Is it safe to say that no amount of system processing can correct for larger "very live" spaces? To not digress a whole lot I'm often out of time the moment I'm finally in front of the console/laptop and the idea of a quick and dirty PA tune is alluring...It took me a good minute to learn about the D9...too many minutes really  :-\

Thanks

Commenting on the text in bold...

That's a system tuning point and if the rig is put together the same way every time (you don't change the number speakers/array elements) any correction needed will be the same every time, regardless of venue.  That's tuning.

Voicing is making the rig sound the way you want it to - any subwoofer haystacking, emphasis or de-emphasis of HF, scooping mids or leaving them relatively flat - and is not tuning as voicing is subjective and therefore subject to changes in a give acoustic environment.

No, there is no electronic/electrical correction of architectural or finish choices that were inappropriate for your use of the venue.  Yes, you can avoid exciting certain frequencies if they cause flutter echoes or other anomolies but you can't *fix* them.  You can Eq your signal into oblivion (and beyond!) but you can't fix the 3:2:1 dimension ratio of the hall, for example.  You can aim the PA to minimize direct reflections, but you can't fix the reflective nature of the room finishing.

Acoustic solutions are needed for acoustic problems.
Title: Re: dbx Drive rack 360 Venue
Post by: Jonathan Barrett on May 23, 2019, 04:54:35 pm
Commenting on the text in bold...

That's a system tuning point and if the rig is put together the same way every time (you don't change the number speakers/array elements) any correction needed will be the same every time, regardless of venue.  That's tuning.

Voicing is making the rig sound the way you want it to - any subwoofer haystacking, emphasis or de-emphasis of HF, scooping mids or leaving them relatively flat - and is not tuning as voicing is subjective and therefore subject to changes in a give acoustic environment.

No, there is no electronic/electrical correction of architectural or finish choices that were inappropriate for your use of the venue.  Yes, you can avoid exciting certain frequencies if they cause flutter echoes or other anomolies but you can't *fix* them.  You can Eq your signal into oblivion (and beyond!) but you can't fix the 3:2:1 dimension ratio of the hall, for example.  You can aim the PA to minimize direct reflections, but you can't fix the reflective nature of the room finishing.

Acoustic solutions are needed for acoustic problems.

I've had this idea in my mind for a long time now that dispersed sound may be the only way to mitigate huge reflections in tough rooms, would it make sense to deploy more relays and fills at a lower volume as to not "excite" the space? I also feel like drape might help a little but to what degree and placement (first reflection points?)

Trying to stay on topic, I'm assuming at this point that the DBX 360 needs a lot of human intervention in order to pull out EQ adjustments that were maybe incorrectly suggested, 50hz bumps because of poorly placed subs, timing issues etc, etc..

Side story: I just finished a show where my room was fairly large (170'x80'x24') but and I was getting the oddest, really short, flutter echo? It sounded almost exactly like a spring reverb, even from a single source of sound like a clap...odd.  :-\ The room was airwalls on all 4 sides.
Title: Re: dbx Drive rack 360 Venue
Post by: Len Zenith Jr on May 23, 2019, 08:02:21 pm
Trying to stay on topic, I'm assuming at this point that the DBX 360 needs a lot of human intervention in order to pull out EQ adjustments that were maybe incorrectly suggested, 50hz bumps because of poorly placed subs, timing issues etc, etc..

My experience with the Venue 360 auto eq is that it does a pretty good job from 200 Hz and up with an overemphasis on high end as was previously mentioned. I usually use (as mentioned already) the "reflective room" setting to mitigate that and then usually need to place a high shelf band starting around 3.5k - 20k with about a -6 dB cut gradually from 3.5k to 20k. Below 200 hz you are on your own. I believe indoors in a small to medium room with the longer wavelengths and reflections in the bass region even smaart rigs offer questionable measurements down low. After the eq is done I also inspect what the professor has done and will seriously question high Q massive boosts. Using my ears I will enable/disable those boosts while listening  to see if they are necessary or are just an attempt to boost a null in the room. If not needed they get tossed as that is just making a bigger argument and cause all sorts of problems (less amp headroom, driver heating, feedback, etc). Overall the venue 360 auto EQ with the sine sweeps is a massive improvement over the old pink noise solution of old. It is actually usable.
Title: Re: dbx Drive rack 360 Venue
Post by: Tim McCulloch on May 24, 2019, 01:07:15 am
I've had this idea in my mind for a long time now that dispersed sound may be the only way to mitigate huge reflections in tough rooms, would it make sense to deploy more relays and fills at a lower volume as to not "excite" the space? I also feel like drape might help a little but to what degree and placement (first reflection points?)

Trying to stay on topic, I'm assuming at this point that the DBX 360 needs a lot of human intervention in order to pull out EQ adjustments that were maybe incorrectly suggested, 50hz bumps because of poorly placed subs, timing issues etc, etc..

Side story: I just finished a show where my room was fairly large (170'x80'x24') but and I was getting the oddest, really short, flutter echo? It sounded almost exactly like a spring reverb, even from a single source of sound like a clap...odd.  :-\ The room was airwalls on all 4 sides.

Distributed systems are a valid approach to system design; when there is no practical point source design (hotel ball rooms/salons) and when a point source system cannot achieve sufficient intelligibility are a couple of good reasons. :D

Regarding your hotel acoustics:  many acoustic "charms" can be heard with simple impulse excitation - hand claps, dropping a book on a table or hard floor - but a lot of the time the noise floor of the room masks it.  A little "for instance" moment:  I had to do some physical measurements of our PAC's concert hall auditorium and under balcony area.  I've been in that space hundreds of times, but always with the air handling system running.  At 2am, it was silent and the flutter echo under the balcony (side to side, the up/down wasn't as bad) was plainly audible.  Similar acoustic charms were found in the middle of the house, too.  {/moment}  I'd encourage you to do a 'walk/clap/listen' next time you encounter something like that, it's very revealing.  Here's another "when you have the chance" things - hook up 1 subwoofer put it on a cheap furniture dolly and set it against a physical boundary like a wall (ideally in the center of a 40' long wall, but we can't be picky here), play some pink noise and listen as a helper moves it away from the wall (closer to you).  Baby baby, where did our sub go?  This is something I mentioned earlier - you don't need a DSP for physics to bite your butt here - and is how Otto Eq and a lot of humans get fooled into thinking the problem can be fixed with Majik Electronik.  Remember:  acoustic solutions to acoustic problems.

Marty McCann, the now retired clinician from Peavey Electronics has a white paper on boundary cancellation here:
http://assets.peavey.com/pv/support/soundsystems/new_boundary_cancellation.pdf

Getting back to tuning - tuning is getting the system to play nicey-nice with itself and my preference is that it exhibit linear operation.  That's when a change in the electrical input to the system results in an identical change in the acoustic output of the loudspeaker system.  That's the tabula rasa of PA.  Notice that I didn't say "flat", either...  With most "top box over a sub" type systems tuning is a one-time thing, or at least not a routine exercise.  It's the idea that you have a consistent and acoustically valid starting point every time.  The room may change but until you see what the room presents you, don't automatically assume the *PA tuning* must change.

Next comes voicing, making the PA tonally conform to your sonic desire.  This is where we might haystack the subwoofer send, where you might decide less 400Hz in L/R is what you need, or that with your band maybe a cut at 6.3kHz is the thing to do... but these are mostly subjective, artistic decisions you make based on how the rig sounds to you and how you want the band to be presented.  This is also where you'd make temporary main EQ changes based on venue variables.

Finally, if you need more gain before feedback, this is the time you ring out those last 2 or 3 feedback points.  Corrective EQ, so to speak.

PA tuning - transducer/pass band delays, drive levels, polarity, etc, once determined, get set in your 360.  If you find the system *always* needs a particular EQ change, make that at the 360's input EQ.  Do your voicing EQ with the console output EQs.

The way I might do things is certainly not the only way to achieve the desired result and I encourage thoughtful experimentation.
Title: Re: dbx Drive rack 360 Venue
Post by: Rob Spence on May 24, 2019, 05:13:41 pm
Distributed systems are a valid approach to system design; when there is no practical point source design (hotel ball rooms/salons) and when a point source system cannot achieve sufficient intelligibility are a couple of good reasons. :D

Regarding your hotel acoustics:  many acoustic "charms" can be heard with simple impulse excitation - hand claps, dropping a book on a table or hard floor - but a lot of the time the noise floor of the room masks it.  A little "for instance" moment:  I had to do some physical measurements of our PAC's concert hall auditorium and under balcony area.  I've been in that space hundreds of times, but always with the air handling system running.  At 2am, it was silent and the flutter echo under the balcony (side to side, the up/down wasn't as bad) was plainly audible.  Similar acoustic charms were found in the middle of the house, too.  {/moment}  I'd encourage you to do a 'walk/clap/listen' next time you encounter something like that, it's very revealing.  Here's another "when you have the chance" things - hook up 1 subwoofer put it on a cheap furniture dolly and set it against a physical boundary like a wall (ideally in the center of a 40' long wall, but we can't be picky here), play some pink noise and listen as a helper moves it away from the wall (closer to you).  Baby baby, where did our sub go?  This is something I mentioned earlier - you don't need a DSP for physics to bite your butt here - and is how Otto Eq and a lot of humans get fooled into thinking the problem can be fixed with Majik Electronik.  Remember:  acoustic solutions to acoustic problems.

Marty McCann, the now retired clinician from Peavey Electronics has a white paper on boundary cancellation here:
http://assets.peavey.com/pv/support/soundsystems/new_boundary_cancellation.pdf

Getting back to tuning - tuning is getting the system to play nicey-nice with itself and my preference is that it exhibit linear operation.  That's when a change in the electrical input to the system results in an identical change in the acoustic output of the loudspeaker system.  That's the tabula rasa of PA.  Notice that I didn't say "flat", either...  With most "top box over a sub" type systems tuning is a one-time thing, or at least not a routine exercise.  It's the idea that you have a consistent and acoustically valid starting point every time.  The room may change but until you see what the room presents you, don't automatically assume the *PA tuning* must change.

Next comes voicing, making the PA tonally conform to your sonic desire.  This is where we might haystack the subwoofer send, where you might decide less 400Hz in L/R is what you need, or that with your band maybe a cut at 6.3kHz is the thing to do... but these are mostly subjective, artistic decisions you make based on how the rig sounds to you and how you want the band to be presented.  This is also where you'd make temporary main EQ changes based on venue variables.

Finally, if you need more gain before feedback, this is the time you ring out those last 2 or 3 feedback points.  Corrective EQ, so to speak.

PA tuning - transducer/pass band delays, drive levels, polarity, etc, once determined, get set in your 360.  If you find the system *always* needs a particular EQ change, make that at the 360's input EQ.  Do your voicing EQ with the console output EQs.

The way I might do things is certainly not the only way to achieve the desired result and I encourage thoughtful experimentation.

Well, most know I agree with Mr Tim....
Back when I bought my EV QRX212s, I consulted with EV on the best bi-amp settings for MY DSP. I then set up a pair outdoors and using the SMAART Spectrograph, I figured out the best compromise for cabinet splay doing the least comb filter damage I could.

These days, a long time from my configuration days, there are only 2 changes I make to the DSP for a gig. The routing (dual PA or not, Aux sub or not), and mains delay depending on placement of the mains vs stage. Thatís it. As Tim said, voicing is done before the DSP.


Sent from my iPad using Tapatalk Pro
Title: Re: dbx Drive rack 360 Venue
Post by: Jonathan Barrett on May 30, 2019, 02:44:05 pm
Distributed systems are a valid approach to system design; when there is no practical point source design (hotel ball rooms/salons) and when a point source system cannot achieve sufficient intelligibility are a couple of good reasons. :D

Regarding your hotel acoustics:  many acoustic "charms" can be heard with simple impulse excitation - hand claps, dropping a book on a table or hard floor - but a lot of the time the noise floor of the room masks it.  A little "for instance" moment:  I had to do some physical measurements of our PAC's concert hall auditorium and under balcony area.  I've been in that space hundreds of times, but always with the air handling system running.  At 2am, it was silent and the flutter echo under the balcony (side to side, the up/down wasn't as bad) was plainly audible.  Similar acoustic charms were found in the middle of the house, too.  {/moment}  I'd encourage you to do a 'walk/clap/listen' next time you encounter something like that, it's very revealing.  Here's another "when you have the chance" things - hook up 1 subwoofer put it on a cheap furniture dolly and set it against a physical boundary like a wall (ideally in the center of a 40' long wall, but we can't be picky here), play some pink noise and listen as a helper moves it away from the wall (closer to you).  Baby baby, where did our sub go?  This is something I mentioned earlier - you don't need a DSP for physics to bite your butt here - and is how Otto Eq and a lot of humans get fooled into thinking the problem can be fixed with Majik Electronik.  Remember:  acoustic solutions to acoustic problems.

Marty McCann, the now retired clinician from Peavey Electronics has a white paper on boundary cancellation here:
http://assets.peavey.com/pv/support/soundsystems/new_boundary_cancellation.pdf

Getting back to tuning - tuning is getting the system to play nicey-nice with itself and my preference is that it exhibit linear operation.  That's when a change in the electrical input to the system results in an identical change in the acoustic output of the loudspeaker system.  That's the tabula rasa of PA.  Notice that I didn't say "flat", either...  With most "top box over a sub" type systems tuning is a one-time thing, or at least not a routine exercise.  It's the idea that you have a consistent and acoustically valid starting point every time.  The room may change but until you see what the room presents you, don't automatically assume the *PA tuning* must change.

Next comes voicing, making the PA tonally conform to your sonic desire.  This is where we might haystack the subwoofer send, where you might decide less 400Hz in L/R is what you need, or that with your band maybe a cut at 6.3kHz is the thing to do... but these are mostly subjective, artistic decisions you make based on how the rig sounds to you and how you want the band to be presented.  This is also where you'd make temporary main EQ changes based on venue variables.

Finally, if you need more gain before feedback, this is the time you ring out those last 2 or 3 feedback points.  Corrective EQ, so to speak.

PA tuning - transducer/pass band delays, drive levels, polarity, etc, once determined, get set in your 360.  If you find the system *always* needs a particular EQ change, make that at the 360's input EQ.  Do your voicing EQ with the console output EQs.

The way I might do things is certainly not the only way to achieve the desired result and I encourage thoughtful experimentation.


Great info, particularly the highlighted, thanks