Rational Acoustics



theguitarfreak
November 10th, 2014, 01:26 AM
Hi, i have been using DnB arraycalc to design virtual sub arcs to achieve equal sub coverage on the venue. The software gives you the distance between two subs and the delay times from the centre sub cluster to the outer ones. But i have seen this delay calculation being done with Smaart. Can anyone shed some light on this? Thanks.

Chris Tsanjoures
November 10th, 2014, 03:16 PM
Hi, i have been using DnB arraycalc to design virtual sub arcs to achieve equal sub coverage on the venue. The software gives you the distance between two subs and the delay times from the centre sub cluster to the outer ones. But i have seen this delay calculation being done with Smaart. Can anyone shed some light on this? Thanks.

Array prediction software on the whole (MAPP, EASE, ArraCalc, etc) can give you an idea of what to expect, but as you know in practice, YMMV. In general, they are a great way to get started, often their most significant use is determining the pin positions or general starting configurations in a venue. There are, however, significant shortcomings with these platforms, specifically in the of axis response, and again with regards to room dimensions. Others here can shed more light on that topic I'm sure. That being said, Smaart is not an array calculator, think of it more as a CAT scan for audio systems. It is a relatively easy task to get squiggly lines on the screen, but getting to the point where you have meaningful data and an understanding of the data presented and how to apply that information is when the tool becomes quite useful, and truly indispensable.

With regards to your original question, this calculation can be done in Smaart by finding the arrival time/polarity of one subwoofer, muting it's output, and then turning on the next, finding it's arrival time/relative polarity and comparing the two. Your application priority will determine your operational process. If you are new to system measurement, getting to the point where you can clearly find LF energy takes a fair amount of experience in operating Smaart, especially viewing and interpreting the phase response of a transfer function measurement. I encourage you to seek out a training seminar if this is the case. Using the data from the D&B software is surely a great place to start, where Smaart is an ideal tool to verify that the system is in fact working non-destructively.

- C

theguitarfreak
November 10th, 2014, 10:17 PM
Array prediction software on the whole (MAPP, EASE, ArraCalc, etc) can give you an idea of what to expect, but as you know in practice, YMMV. In general, they are a great way to get started, often their most significant use is determining the pin positions or general starting configurations in a venue. There are, however, significant shortcomings with these platforms, specifically in the of axis response, and again with regards to room dimensions. Others here can shed more light on that topic I'm sure. That being said, Smaart is not an array calculator, think of it more as a CAT scan for audio systems. It is a relatively easy task to get squiggly lines on the screen, but getting to the point where you have meaningful data and an understanding of the data presented and how to apply that information is when the tool becomes quite useful, and truly indispensable.

With regards to your original question, this calculation can be done in Smaart by finding the arrival time/polarity of one subwoofer, muting it's output, and then turning on the next, finding it's arrival time/relative polarity and comparing the two. Your application priority will determine your operational process. If you are new to system measurement, getting to the point where you can clearly find LF energy takes a fair amount of experience in operating Smaart, especially viewing and interpreting the phase response of a transfer function measurement. I encourage you to seek out a training seminar if this is the case. Using the data from the D&B software is surely a great place to start, where Smaart is an ideal tool to verify that the system is in fact working non-destructively.

- C

Thanks a lot. Your logic makes a lot of sense. I have basic understanding and operational experience of aligning subs and tops with the transfer function in smaart. So if you could tell me a step by step process of creating a virtual sub arc with smaart, i would have tried it before attending a seminar early next year. Thanks.

Chris Tsanjoures
November 11th, 2014, 11:26 AM
Thanks a lot. Your logic makes a lot of sense. I have basic understanding and operational experience of aligning subs and tops with the transfer function in smaart. So if you could tell me a step by step process of creating a virtual sub arc with smaart, i would have tried it before attending a seminar early next year. Thanks.

I apologize, perhaps I wasn't clear - Smaart does not have the ability to create any sort of virtual sub arc/arrays of any type. Smaart's use as a tool is in verifying that the modeled configuration is in fact provided the intended coverage.

theguitarfreak
November 14th, 2014, 04:38 AM
Hi, i have been using DnB arraycalc to design virtual sub arcs to achieve equal sub coverage on the venue. The software gives you the distance between two subs and the delay times from the centre sub cluster to the outer ones. But i have seen this delay calculation being done with Smaart. Can anyone shed some light on this? Thanks.

If you can still give me a step by step guide to measure the response of the sub arc by confirming on where to place the mic and take the readings to check response of the arc it would be of great help.

Chris Tsanjoures
November 14th, 2014, 11:14 AM
If you can still give me a step by step guide to measure the response of the sub arc by confirming on where to place the mic and take the readings to check response of the arc it would be of great help.

Mr. Freak,

I gave you a process in my original reply, I've rewritten it here for clarity:

First, find the phase arrival/polarity of one subwoofer at the frequency you wish to align to, then mute its output and turn on the next. Repeat that process with the next sub system and compare the two. At this point I will have enough information to make a decision.

Others may use a different process than me, I just have the best success with this method. If this is still confusing to you, I implore you to do some more research. Perhaps you may start here: http://forums.prosoundweb.com/index.php?topic=139234. Most importantly, practice making measurements.

Microphone placement is a matter of were I wish to time the sub energy to. Most engineers want the whole system timed to FOH, but I will verify individual system in the near field (if deemed necessary/there is time). Any near field stuff can be taken care off off site of a gig. If you are using the same subs all the time you may want to have some default configurations for them, that you can repeat on a show.

This is a fairly onerous topic. For me it all started to click after I had made a good deal of measurements, and a good deal of mistakes. Go to a training, and practice.