Q-SYS Corner

[Steve Guttag]

Separate Surround Settings for Different Formats
While we’re exploring possible ways to modify the Sample 7.1 Design, and, in particular, the Surrounds, what about having separate level and EQs for the Surrounds when you have mono, 5.1 and 7.1 surround formats?

In theory, what we’ve been doing since the days of the CP650 and Surround-EX, should work. That is, calibrate the surrounds, using our established reference pink noise to 82dBc, per quadrant, referencing the RLP (2/3rds back from the screen and slightly off-center). Then, presume that when Left-Side and Left-Rear sum, acoustically, to 85dBc (which is why we have the offset to bring it back down to 82dBc). How well does that work, in practice? How about the tuning? Does the tuning change when you have two quadrants playing at the same time? How about when you have all surrounds playing at the same time (mono surrounds)?

Setting your EQ up to have three different sets of EQs/Levels will allow you to exactly match the conditions of a mono/stereo or 7.1 surround system.

How hard would that be to implement within Q-SYS?\ Here is an example:

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The first thing you should have noticed is that I moved the levels, delays and High Pass filters over past the router that selects which set of Surround EQ to use. The High Pass filter, if needed at all, will be the same regardless of surround format as it is there to protect the speaker(s). Likewise, if there is any needed delay on the surrounds, by zone, they will be the same regardless of format.

By setting the levels for 7.1, we will better balance out the room. Odds are, if your theatre is long and skinny, the rear surrounds will be set louder than a squarer room.

I’ve put the surround level offset with their respective modes (-3dB) so we should omit any other Surround Offset if this scheme is used. The output levels for 5.1 and Mono Surrounds are really just offsets to take into account any imperfections in how the speakers sum, particularly after the various configurations are tuned with their pairings.

The output of the three modes feed into an Audio Router with 3 inputs and 1 output (set to multichannel with 4-channels). You will need to tune 7.1 first. Tune for 82dBc per quadrant.

Then select 5.1 and tune for 5.1 and set the 5.1 offset levels for 82dBc/side.

Finally, select Mono and tune the Mono Surrounds and set them to 85dBc.

Be sure to place the Surround Mode router in the Format Snapshot bank and configure/save the Snapshots such that it is in the correct mode on each format.

Again, this is an example and since it is not compatible with the unmodified Sample 7.1 Design, I am not leaving it in but it is something that you could implement into your designs, if so desired.

Clearing Past Settings
If you are copy/pasting your design to a different theatre, you will likely want to zero out your previous settings so you can start fresh. There are several techniques. For an EQ, select all of the levels (click and drag left-to-right, or shift-click each level control). Type the number 0 and they should all go to 0dB (no boost or cut).

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And then bypass them all. It is important to first zero them out. If you don’t and decide to use one of the bands, the moment you unmute it, you’ll apply, possibly, an undesirable boost/cut to your signal before you can correct it.

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If you find that you have a standard complement of components per channel, build up a channel with everything in your starting settings and save it into your User Components. Then, drag that user component onto your schematic. Use “Copy All from Component”/“Paste All to Component” component-by-component.

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If you find that your EQ group is always the same, save a copy of the whole thing in your User Components. Drag the whole thing into your design and then cut/paste the Signal Names and delete the ones that have the old settings.

Cut/Paste Signal names is not as complicated as it may sound. Select them all in one selection, “cut” <CTL+X>…then select the pins of your standard EQ group that you drug in from your User Components, and paste <CTL+V>.

Conclusions
Hopefully, this blog has given you some insight on how you can configure your design for tuning a theatre. Regardless of method (or methods), you should be able to tune your theater with Q-SYS as well or better than any other system out there. If you adopt using PEQs for your equalization, I think you’ll get a better/more uniform outcome.

You have the flexibility with Q-SYS to customize and optimize your sound processor to get the most of your theatre’s capabilities.
©2025 by Steve Guttag

[Blog-10, Page 4 of 4, End of Blog]

[Steve Guttag]

Q-SYS updated their Sample 7.1 design yesterday (3/18/25). the only changes were, effectively, cosmetic (component alignment) and they zeroed out the EQ left behind in Left Channel. Though they updated the version number to 4.3, I would have thought that 4.2.1.0 would have been more appropriate since there is no substantive change. They did use QDS 9.13.0 for the updated version but it should work just fine in 9.4.8 LTS.

[Steve Guttag]

Q-SYS For Cinema

Blog-11, QDS–Part-7, Sample 7.1 Part-6, Audio Flow Part-5, B-Chain Part-2

Current QDS Versions: 9.13.0 and 9.4.8 LTS.
Sample 7.1 design version: 4.3.0.0 Introduction

This blog will finish up the audio portion of the Sample 7.1 Design with the Outputs and Speakers sections. This blog is a direct continuation of my previous blog on the Equalization section.

Disclaimer

If any of the content in this blog happens to show up in a Q-SYS exam, it is not my intention to provide an answer-sheet beyond the discussion of good practice. I have not seen any form of the cinema final exam (my Level-1 was before there was a cinema version).

Disclosure

I do not, in any way, work for QSC/Q-SYS. These thoughts are my own based on my own interactions with the product(s) and implementing Q-SYS within actual cinema environments. I do work for a dealer that has sold QSC products since the 1980s, including Q-SYS and its predecessors. For the purposes of this blog, I represent only myself and not my employer(s) or any other company.

Amplifiers and Speakers (Outputs)

Really, these two go together. Since this particular blog is about working with QDS rather than sizing/choosing amplifiers, I’m going to keep the discussion to how you work with them once the amps and speakers are chosen.

Planning for Minimizing Failure Impact.

Unlike with conventional cinema processors, with Q-SYS, we can strategically plan out how the system fails to minimize how it can affect the presentation. We have all of the controls over the signal path.

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In this design, there are just two amplifiers and they are 8-channels each. This can be a very economical way to handle a typical 7.1 sound system with bi-amplified screen channels. However, you are putting a lot of “eggs” in one “basket.” Planning on the day that one of those amplifiers fail should guide you on how you choose what channels to place on each amplifier.

The number one thing to remember is to never put any part of the Center channel on the same amplifier as Left and/or Right. Your entire bypass scheme relies on either Left and Right working when Center is not or vice-versa. The Sample 7.1 Design honors this concept. Left and Right are on Amplifier-1 while Center is on Amplifier-2.

What else? You should try to balance out your amplifier so if one fails, the system will remain balanced. That is, the sound stage shouldn’t feel like it shifts all to the Left or Right. While it is not ideal to have a failed component, how you lay out your design can minimize its impact so patrons won’t notice it as much. If you look at how they loaded their amplifiers in the design, you’ll see this. If Amplifier-1 fails, you will lose Left, Right, half of your side surrounds and half of your subwoofers. By selecting the appropriate Bypass mode in your design (covered in Blog-9), no critical audio will be completely lost; it just will not be optimal.

If you chose to have a second side surround channel due to quantity of speakers and the loading to the amplifier, consider wiring them in an alternating fashion (if you number your speakers around the horseshoe pattern around the room with 1-8 on the left side wall, consider wiring 1, 3, 5, 7 on one amplifier and 2, 4, 6, 8 on the other) so that with an amplifier failed, the theatre remains, somewhat, covered, just less so.

If Amplifier-2 fails, you lose Center, half of your side surrounds, half of your subwoofers and all of the rear wall surrounds. Once again, the system fails in a balanced manner and there should be a Bypass mode to redirect Center to Left and Right. If you want, you could include the rear surrounds in your Bypass scheme so that the rear-surround information is mixed into their respective side surround. It’s not ideal, but you are trying to make the best of a bad situation. And this condition only lasts until you replace/repair the amplifier(s).

It is worth looking at the rear of a DPAQ/CXQ amplifier to see what it takes to swap one of them out. Everything is “plug-in,” with the speaker outputs having the option of securing with a couple of (captivated) screws.

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The swap can be very brisk. All that would need to be done, once physically swapped, is to configure the replacement amplifier’s IP address and name. The Core will immediately update the amplifier to be on the same firmware as the rest of the system and then load the design in.

Alternately, if you set up your system to utilize dynamic pairing, you can make it so once the new amplifier (or any other part of the Q-SYS ecosystem) is plugged in, it self-configures and starts working as soon as the firmware matches and the design is loaded (automatically). The system will take care of the naming/IP portion so no remote technician involvement is required.

Here is a link to a Dynamic Pairing video. It does not discuss, specifically, how to set up for amplifier swaps. It does discuss moving devices from room-to-room (or theatre-to-theatre, for us). So, if you have a lectern for rentals/Power Point/Zoom…etc., it is easy to see how Dynamic Pairing could be a handy tool.

Video On Dynamic Pairing

However, the same concepts can be used for swaps of any equipment, including amplifiers. The key points are:

• Have a DHCP server on the Q-LAN network(s) so when the amplifier is plugged in, its IPs can be set by the DHCP server.
• Have LLDP (Link Layer Discovery Protocol) active on your network switches used for QLAN.
• Configure the Dynamic Pairing (in the Administrator Program that is almost never used in cinema) to use the “Switch Port” method of pairing. This will have the system decide that if a proper device is plugged into a configured switch port, then that device is to be dynamically paired. So, if a CX-Q2K4 is set up on port 3 of the QLAN switch in the sound rack, if a different CX-Q2K4 is plugged in, it will configure it and put it on line. In fact, even if you plugged a different model amplifier that had sufficient specifications (4-channels like a CX-Q4K4) it should work with it.

Another strategy one can use is to increase the number of amplifiers to lessen the impact of any one amplifier failure. This could be very appealing if you split up your amplifiers and locate the screen/subwoofer amplifiers behind the screen, with the speakers (shorter/cheaper speaker runs) and have the surround amplifiers in the booth. A popular configuration for a 7.1 theatre is to use three 4-channel amplifiers (Left/Right on one, Center/Subwoofer on another and Surrounds on the 3^rd amplifier).

You are not compelled to use Q-SYS amplifiers. If you are using either conventional analog/linear amplifiers or digital amplifiers that use Dante or AES67, instead of amplifier components, you’ll need to use the appropriate output components and that will be the end of Q-SYS signal flow as that will be the “off-ramp” to the system.

[Blog 11, Page 1 of 2]

[Steve Guttag]

Speakers

If you are using Q-SYS amplifiers, you’ll need speaker components. If they are QSC speakers, there should be components in the Inventory (LSP) and they will have Q-SYS’ “Intrinsic Correction” as well as the various protection information (limiters, crossovers, high pass filters…etc.). It’s all canned in the one component.

Key Point: Breaking with tradition, Q-SYS makes the top pin on the speaker components as the highest frequency of a multiway system. All of the previous crossovers used with cinema (including QSC) have had the lower-channel be the lower-frequency and one worked their way up (e.g. XC-1, XC-2, XC-3, the entire DCM series, the DCP series, and even going all of the way back in the Series 1 days of the Model 1400). If you use Signal Names, you can easily keep the standard convention. If you use wires, they will cross each other if you keep with standard convention. The Sample 7.1 Design adopted the inverse as it is native to Q-SYS. Just beware when you are first firing up your system that it is very easy, if you’ve been putting in systems for a while, to get an HF/LF being transposed. Keep your levels down until you can verify that everything is connected properly for your design.



As covered in a previous blog, you can create your own speaker components (in the Inventory as a “Custom Speaker” and “Custom Voicing”) and assign the HF/LF as you desire.

DCIO Output



Your ADA channels (HI and VI-N) exit the system (off-ramp) here (DCIO-H Analog Out component). Your booth monitor exits here too. You have the option of a line output for an amplified monitor or a speaker level output to a conventional passive speaker. The DCIO’s speaker output is only a 10W amplifier with no headroom.

If you look over to the speaker group, at the bottom, is an AD-S4T (surface mount utility speaker with a 4-inch woofer, so not too big) that is being used for the Booth Monitor. If you reference back to a previous blog when we covered the Processing group, we have a source selector to feed the MON-PRE-A1 Signal Name. So, from the speaker component, we take the unconventional step of sending the signal back to the left to send it out of the DCIO-H. While the AD-S4T is indeed a speaker, when the speaker is being used as an “in-line” component, it is clearer to have it in-line with the audio flow. That component is representing the tuning of the speaker rather than the speaker itself. So, I’d move it to before the DCIO-H output.



Based on experience, I’d probably drag the “Clip” LED out of the Analog Output for the speaker out.





This way, you’ll know if you are clipping or not if the monitor starts to sound distorted. You may also find that you’ll want to add in a compressor and possibly a limiter (it all depends on the speaker you are using and how the monitor is being used; in many theatres the monitor is almost never used).

As we’ll discover in a future blog on the control of the Sample 7.1 Design, the method controlling the booth monitor volume is by controlling the DCIO-H speaker gain (internal to the “Analog Out DCIO-A1” component). Why do I think that is a bad idea?

• As we’ve discovered in previous blog(s), any component that comes from the Left-Side Pane cannot be copy/pasted to other designs. So, in order to copy this design, at the very least, after adding in the DCIO-H to the new auditorium, you’ll need to open it up and then remap a control to the Monitor fader. If we had an external Gain component, that whole aspect would be eliminated.
• We have no control over the range of the internal Gain. So, depending on the speaker/environment, if we want to restrict the range to prevent clipping, that is not possible.

I’m not going to leave them in the design because I want the control aspect of the design to match for the unmodified versions but this is how I might modify the Booth Monitor if I were to deploy it (I would also clean it up to avoid the diagonal wires and the overall “stacked” appearance):



This sort of scheme eliminates the problems identified.

Tip: If you are using the speaker output for the booth monitor, the line output is a regular balanced line output that you can use for anything else you may need. Just because they labeled it as monitor does not force you to use it as such.

Conclusions

Here we are. All of the audio channels have now exited from the system. You should be able to tune your theater with Q-SYS as well or better than any other system out there. The amplifier and speaker components, be they Q-SYS or your own custom components should provide superior protection to other methods as the limits of the speakers/amplifiers are included into the component.

Hopefully, you will have seen just how flexible the system can be and how much control you have over it. Furthermore, you can make changes, as your needs change, without asking/begging a manufacturer to implement a feature you may want that others may not find as necessary.

And, as complicated as it may seem at first, you can be up and running on a system rather quickly. As we will see in a later blog, cloning a design can be quick for fast deployment.

The next set of blogs will go over the control aspect of the Sample 7.1 Design.

©2025 by Steve Guttag

[Blog 11, Page 2 of 2, End of Blog]

[Steve Guttag]

Correction to Blog-8

https://www.film-tech.com/vbb/forum/...5669#post45669

The Preshow Match pin should be pin 1, not pin 4

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