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[Woody]

Hello All!
I wanted to initiate a discussion on everyone 's initial audio system setup techniques.  The reason I wanted to find this out is because I'm finding myself bidding on more consultant specs and doing more design builds that have very specific requirements.  

I started out in concert sound, and to be honest, we didn't worry about amplifier levels that much.  We turned them up to "11" and off we went.  Some nights my console was barely bumping the meters and other nights they were pegging.  I wasn't all that concerned as long as I had enough headroom.  I've also done numerous installs for auditoriums, but my designs were based primarily on my experience and the experience of the house guy I was installing for.  I know it's not all that scientific, but when you work alot of shows on a wide variety of rigs, you have a pretty good idea of what works and what doesn't.  We would install the rig, do some initial DSP balancing, some EQ'ing and hand it off to a highly knowledgeable house guy who would tweak it in for him/her self.  

Lately however, I'm bidding alot of school and church auditoriums and the like, with very specific requirements, and designing rooms for users who are very green.  So what I'm asking is a discussion on initial system set ups.  My design principles are solid but on the initial set up, I'd like to hear how everyone goes through it.  I assume that everyone does it a little different.  

For example:
-Are you running broadband noise through your console at 0dB to hit a target SPL and then balancing from there?  

-If the above is your procedure, what is your typical SPL target for different room varieties?  School Auditoriums, churches, performance halls, etc.  

-How much variance in level and/or frequency response are you finding acceptable?  

-How much headroom are you factoring in on the design process? If I don't use enough, aren't I at risk of having my mic pre's cranked too wide open?

-What types of tests from Smaart, TEF or otherwise, are you finding the most beneficial in DSP balancing, EQ and delay settings?  

If anyone can think of any other considerations that I'm missing here, by all means add them to the discussion.  

Thanks for reading!  

[Phillip_Graham]

Woody wrote on Wed, 15 June 2005 22:23

I started out in concert sound, and to be honest, we didn't worry about amplifier levels that much.  We turned them up to "11" and off we went.  Some nights my console was barely bumping the meters and other nights they were pegging.  I wasn't all that concerned as long as I had enough headroom.  I've also done numerous installs for auditoriums, but my designs were based primarily on my experience and the experience of the house guy I was installing for.  I know it's not all that scientific, but when you work alot of shows on a wide variety of rigs, you have a pretty good idea of what works and what doesn't.

This barely qualifies in todays market with good firms.  Any of the firms that I would hire do extensive computer modeling of the space, have a well defined performance spec, and perform detailed measurements to show the client they meet this spec.  The also provide a complete set of CAD drawings for every little nook and cranny of the system.

Quote:

Lately however, I'm bidding alot of school and church auditoriums and the like, with very specific requirements, and designing rooms for users who are very green.  So what I'm asking is a discussion on initial system set ups.  My design principles are solid but on the initial set up, I'd like to hear how everyone goes through it.  I assume that everyone does it a little different.   For example: -Are you running broadband noise through your console at 0dB to hit a target SPL and then balancing from there?

Consultants typically design systems backwards, starting with SPL goals on the audience area, and then tailoring the speaker systems and amplifiers to match.  This may mean undersized speakers and/or amplifiers relative to a concert rig.  Any "excess" reduces the chances of being the financially competitive bid.  Now, as a practical matter, many install systems in churches and performance spaces are spec'ed as stoutly as a concert rig these days.

As for your console gain structure, everything needs to clip at the same time.  This maximizes the systems signal to noise ratio, an important consideration in quiet boardroom-type environments.

A practical example:
Your spec says the system will do 110dbC from 40hz-15khz and be  within +/- 2dB across the seating area from 150hz to 12khz, using a pink noise source with a crest factor of 6dB.

Your FOH console clips at +22dB, and your DSP analog front end clips at +20.  This means that, with your stimulus, the system must be running 110dBA with the console output at +16dB, and the clip lights just tickling on peaks.  It also means that you need 2dB of input attenuation for your DSP.  While most people don't cut the margins quite this close, there are rigid mathematics to set all these requirements.

Quote:

-If the above is your procedure, what is your typical SPL target for different room varieties?  School Auditoriums, churches, performance halls, etc.

That has a lot to do with the venue content.  I work with one church where a system that does 105-110dBA gives them the headroom to cover all their events.  They don't normally run that loud, but some of the acts they have into their room do.

Quote:

-How much variance in level and/or frequency response are you finding acceptable?

A good firm should easily be able to do +/-3dB across all the seating area above the Schroeder frequency up to at least 12k.  And they need to have the tools to properly verify this.

Quote:

-How much headroom are you factoring in on the design process? If I don't use enough, aren't I at risk of having my mic pre's cranked too wide open?

Well, lets start by defining what you think of headroom.  Headroom is a ratio of the peak to average levels in a system, a dimensionless parameter.  If the average level is 92dB, and the peak 107, the system needs 15dB of headroom.  A peak to average ratio of 15dB is a decent starting guideline in my book.

I'm not really sure what the preamp gain levels have to do with this, but this post is not about the subtleties of console gain structure.

Quote:

-What types of tests from Smaart, TEF or otherwise, are you finding the most beneficial in DSP balancing, EQ and delay settings?

NONE if they aren't measured properly!!  I would expect delay zones set by smaart, and properly measured transfer functions of the as tuned system, possibly including some ground plane measurements.

Quote:

If anyone can think of any other considerations that I'm missing here, by all means add them to the discussion.

Don't take this the wrong way, but I don't feel like you have a good grasp on the fundamentals that many consultant types will take for granted.  You might want to take a Syn Aud Con class, buy a copy of sound system engineering, and learn some of the fairly easy math behind a more formal system design process.

[Woody]

Phil,
Thanks for the information.  However, I have to say that your condescending reply is precisely the reason I typically stay away from these types of boards.  For your information, I have been an audio engineer for over 15 years.  I've taken numerous audio classes, including Syn Aud Con and I'm CTS certified.  I have a college degree including numerous calculus classes.  I'm  well versed in acoustics, gain structure, EASE and SMAART.  The only reason I threw this topic out there is to open a discussion on techniques that people are using and see how people may be approaching the same processes differently.  

My early concert sound examples were just case studies on how I did things in the early days.  I'm well aware that they aren't up to snuff in today's market.  I wouldn't think of designing a sound system today without prior room modeling and CAD diagrams right down to floor pocket connections.  I have been concentrating on boardroom designs and video conferencing systems for the past five years.  I've done a number of small auditorium sound systems on bid spec, but I'm finding more opportunities for design build.  The questions that I asked in the post weren't from an "aw shucks" perspective.  I understand how sound system design and balancing is done.  The questions were asked to elicit a response from others to compare techniques and best practices.  

In short Phil, don't assume that you know someone's background when you post your response.  You don't.  Your curt response can only hurt this online community.  If this is the type of information I can expect on the live board, I'll compare notes with my local community of supportive audio engineers instead of visiting here.  Thanks, but no thanks.  

[Mac Kerr]

Woody, if your skin is so thin that you were offended by Phil's polite and carefully considered reply, you probably are better off just talking to your local community of supportive audio engineers. If the description of yourself that you gave in your first post was not a reflection of your current abilities, you can hardly blame Phil for not being able to read your mind. The direction of questions also implied a lack of understanding of what those tests were. Would someone with the skill set you implied be helped by a discussion of the measurement and prediction of ALCONS? Have you read the rest of the posts in these forums?

As Phil suggested, if you have not taken the Syn-Aud-Con classes, it is something you should pursue as a system designer/installer. It is a very comprehensive learning experience. As a self learning experience, Syn-Aud-Con's founders, Dan and Carolyn Davis's book Sound System Engineering is good reference.

Mac

[Phillip_Graham]

Woody wrote on Thu, 16 June 2005 19:12

Phil, Thanks for the information.  However, I have to say that your condescending reply is precisely the reason I typically stay away from these types of boards.  For your information, I have been an audio engineer for over 15 years.  I've taken numerous audio classes, including Syn Aud Con and I'm CTS certified.  I have a college degree including numerous calculus classes.  I'm  well versed in acoustics, gain structure, EASE and SMAART.  The only reason I threw this topic out there is to open a discussion on techniques that people are using and see how people may be approaching the same processes differently.

My reply was comensurate with the apparent level of experience in the parent post.  Even if the parent post was hypothetical, it should have been phrased in a manner that would not lead inexperienced readers astray.  There is a correct way to do what you asked, which it appears you already knew!

Quote:

I understand how sound system design and balancing is done.  The questions were asked to elicit a response from others to compare techniques and best practices.

Then phrase that question exactly as you just did above!  It is very hard to read minds on a message board.

Quote:

In short Phil, don't assume that you know someone's background when you post your response.  You don't.  Your curt response can only hurt this online community.  If this is the type of information I can expect on the live board, I'll compare notes with my local community of supportive audio engineers instead of visiting here.  Thanks, but no thanks.

Brad, your first post made you seem like a total newbie, and any curtness in my reply is a reflection of tiredness from "been there, done that" topics.

I have been an active member of the live audio board, which became prosoundweb.com, since 1999.  I probably have thousands of posts in the archives.  I have my real name in the signature, am easily accessible, and have met a diverse group of people active in the community.  Heck, I've referred people to the moderator of this forum!  I have "street cred" for lack of a better term, and that is why you see people, like Mac, who I don't know personally, come to my defense.  BTW, i'd listen to Mac, he knows what's up, and has a resume that I will never come close to achieving.

I know I tend to presume the worst when posting, I would rather start at the beginning and cover something familiar than leave the person feeling lost.  That's all I've done here, please don't take it personal.

[Woody]

Mac,
Thanks for your reply, but it really doesn't have anything to do with the the thickness/thinness of my skin.  I threw some topics out there, and wanted to create a discussion from all parties.  What I got in return was a  reply that assumed a lack of knowledge and skills.  As I mentioned, I have taken Syn Aud Con.  I understand the concept of ALCONS and how to calculate it.  

I'm not asking for anyone to read my mind.  I didn't mean to throw topics out there that would assume a lack of understanding. I just threw topics out there to get a discussion going, not to have someone tell me that I don't know basic math.  In the future, I guess I'll be more direct.  

And to Phil, I don't mean to be touchy.  I appreciated 99% of your reply.  I took offense to the last part however.  I just would rather that you had started asked me a few questions, rather than just assuming a lack of fundamental knowledge.

[Geri O'Neil]

Woody wrote on Thu, 16 June 2005 22:16

I appreciated 99% of your reply.  I took offense to the last part however.  I just would rather that you had started asked me a few questions, rather than just assuming a lack of fundamental knowledge.

Odd that you would choose to respond to the 1% of Phil's post that you found objectionable. Mac has quite the extensive track record in this business and while Phil may not have the miles on his backside that some of us do, he has demonstrated an unbelievable amount of knowledge as well as the same amount of "saavy" for the nuts and bolts of this business. If it were me, I'd say "Drive on as you are, my friend" because most likely it would be great for my business in the long run. And I'll bet that I ain't the only guy with that attitude.

Maybe you should try again from the top.
Fire away, I'm done.
Geri "not that I really care" O

[Too Tall (Curtis H. List)]

Woody wrote on Thu, 16 June 2005 23:16

Mac, Thanks for your reply, but it really doesn't have anything to do with the the thickness/thinness of my skin.

Actually, it does.
Text by nature gives a very “stick figure” view unless you invest in writing a book each and every post. We can only go by what is there on the page. Filling in the details takes time and on a practical side a bit of a thick skin if everyone does not recognize you as a pioneer in the field from the demeanor of your post.

Woody wrote on Thu, 16 June 2005 23:16

I threw some topics out there, and wanted to create a discussion from all parties.  What I got in return was a  reply that assumed a lack of knowledge and skills.

And fair comment considering the post.
And back to skin thickness, no one insulted your family and I don’t see any flame damage to speak of so please don’t jump to presuming it’s an insult.

Woody wrote on Thu, 16 June 2005 23:16

As I mentioned, I have taken Syn Aud Con.  I understand the concept of ALCONS and how to calculate it.   I'm not asking for anyone to read my mind.  I didn't mean to throw topics out there that would assume a lack of understanding.

Well that is how I read them too.

Woody wrote on Thu, 16 June 2005 23:16

I just threw topics out there to get a discussion going, not to have someone tell me that I don't know basic math.  In the future, I guess I'll be more direct.

Direct is good.
How about concise?

FYI throwing out a wide-ranging questions in a professional forum is a typical newbie tactic. It makes it easier to discuss something without having to get specific. In an installation forum it tends to get even more specific, while in the lounge or even Classic Audio the focus tends to pull back.

Now before you read my statement as an insult directed at your professional expertise, I still don’t claim to know any more about your skill level then I did 5 minutes ago. All I can go by is the few lines you have written.

Woody wrote on Thu, 16 June 2005 23:16

And to Phil, I don't mean to be touchy.  I appreciated 99% of your reply.  I took offense to the last part however.  I just would rather that you had started asked me a few questions, rather than just assuming a lack of fundamental knowledge.

[/quote]

Well Phil is guilty of trying to get it all done in one post. Just in case you were a newbie he tried to point you toward some useful reading. If you didn’t need the information, what is the worst that could happen?

NOTE: People in this place tend to only give you credit for a knowledge level you have proven in print over time or by reputation from other people that have proven their expertise. Even then it is tied to specific subjects.

One thing I can promise you. Though it will take some time, if you continue to post people will eventually come up with a clear picture of both your skill level and the thickness of your skin. Such is the nature of this place.

[Dan Timon]

Woody,

Despite the fact that the new LAB has you listed as a Newbie, with a grand total of 3 messages to your credit, I recall that you posted fairly often in the Old Lab, and that your posts revealed that you were a seasoned touring professional with extensive rigging, systems tech and mixing skills, and that you were also getting involved with a nice local club. The only skills that I was aware that you might possess in designing and managing large install projects came from your first post in this thread.

It is reasonable to think that the other posters are not aware of the "cred" you had developed on the old Lab. But I work regularly with several (maybe a couple of dozen) seasoned touring professionals with skills similar to what I have been able to estimate you might have, and I often see that there are several areas where their skills are lacking, when it comes to the comprehensive specifications necessary to design a well integrated PA. Fortunately, these skills are not difficult to attain for somebody with your skills, but you would need to be able to demonstrate them before a big AV Consulting firm would give you a long length of rope with a big client. Most often, the experienced touring professionals I see become Project Managers or Installation Managers before getting promotions to System Designer of a large AV firm, and spend a lot of time advising consultants about sound before becoming a Senior Consulatant in a large AV consulting firm. Any verbal responses like your response to Phil might result in a delay of said promotions. Clients sometimes ask questions that are much less polite, when they need to be convinced of someone's skills and character.

I realize that you are not like the people I know, and that you are not in a similar situation. This is offered so that you may be a stronger competitor to these people, when facing a client or a future employer.

Regarding your initial questions:

I do not think it is enough to rely on generalities, when deciding about the conflicts between system gain and system noise. The designer should do a very thorough needs analysis with the client, and with the operators and other people indirectly impacted by the project, and design the system to meet as many of those needs as possible. If the corporate auditorium is used for 150 speech events a year and 6 music events a year, it probably has to do both events extremely well. Those 6 events are when the big dogs bring in their rich friends to get more business, and do not want to be embarrassed. If the system works perfectly for the speech events and 4 of the music events, maybe you could recommend a "rental add-on package" for those events when they do a heavy metal or rap concert. But if the main PA is optimized for the 4-6 music events, and the hall is very quiet, everybody who attends the 150 annual speech meetings will complain that the system is crummy because it has a lot of hiss. We are lucky that we can now pre-set different tunings in DSP-land, so the problem is not as thorny as it used to be.

Regards,

Dan Timon

[Andy Peters]

Dan Timon wrote on Sat, 18 June 2005 15:20

Woody, Despite the fact that the new LAB has you listed as a Newbie, with a grand total of 3 messages to your credit, I recall that you posted fairly often in the Old Lab, and that your posts revealed that you were a seasoned touring professional with extensive rigging, systems tech and mixing skills, and that you were also getting involved with a nice local club. The only skills that I was aware that you might possess in designing and managing large install projects came from your first post in this thread.

Dan,

That's a completely different Woody.  The Woody to whom you refer logs in with a lower-case 'w (and he's probably horrified by my connection between him and a certain other Dubya), and in fact IS a seasoned touring pro who does the good work with the great attitude, even in less-than-ideal conditions.

-a

[Dan Timon]

ok.......never mind!......  

Apparently this little cancer thing that I am dealing with has sucked a little more from my brain than I realized!

Regards,

Dan

[thestudio]

"Syn Aud Con class"  I would think that a EE degree would work but I guess that someone needs to make money

[Mac Kerr]

thestudio wrote on Mon, 11 July 2005 20:11

"Syn Aud Con class"  I would think that a EE degree would work but I guess that someone needs to make money

If you thought that you would be wrong. while there are topics covered at Syn-Aud-Con that would have been covered in an EE program, there are many topics that would not. Acoustics, room modeling, audio troubleshooting, audio measurement and analysis and prediction, and speaker physics are all things a good consultant can learn at Syn-Aud-Con that will be hard to find all together anywhere else. Having a degree in EE, or any other discipline that gives you math skills before you take the class can only help.

Mac