Contributor - Level 2

XR18 Recommended compressor and settings

I have been using XAir on my MacBook Air for controlling our mix for both services and other events mostly free of drama for about 2 years.

We have recently selected a settled minister who has been at our pulpit for about a month. Her delivery of the sermon is different from other parts of the service. To my ear, it is slightly strident and has more changes in volume than I am used to.

The sanctuary is a very reverberant place, consisting of lots of glass, concrete block and ceramic tile floor. We have tamed a significant part part of the reverberation with two line arrays for the mids and highs on the centerline of the long dimension of the room and with acoustic panels on tha back wall. The line arrays do a fairly good job of keeping sound off of the long walls which are mostly glass. The acoustic panels have reduced the first reflection off of the back wall, however the room will resonate at right around 2 KHz.

Stability is generally not a problem during the sermon, as the sound level at the pulpit are generally more than adequate.

We are using a Countryman hypercardioid pulpit mike. We are very pleased and the performance of this mike. It is fairly good at rejecting the reflected sound from the back wall, lots better than our former mike, but will pick up two people standing side by side at the pulpit so long as the mike is between them.

Our minister has been very cooperative with her delivery in the "meditative" portion of the service by her speaking a little louder and closer to the mike during these times. This has improved the stability and eliminated a "ring" at about 2 KHx which occurs when the channel gain was increased to try to obtain intelligibility.

The lounder portions of the service during the sermon remain as a problem. I try to ride the level of the pulpit mike to reduce the louder portions and raise the quieter parts, but with only partial success.

It seems that a compressor inserted into the pulpit mike channel would help. However, I have been leary of using a compressor due to the ever present instability that is not fully tamed.

What compressor should I use, and what settings should I start with? We are dealing with all spoken material and no music.

I believe that I can probably do a little on-the-job learning if the settings are pretty modest to begin with. I need particularly to keep the ratio low so that during parts where there is no speech that the gain is not raised to the point of feedback.
StephenM_Shirle Contributor - Level 2 2018-08-28

2018-08-28

XR18 Recommended compressor and settings

I have been using XAir on my MacBook Air for controlling our mix for both services and other events mostly free of drama for about 2 years.

We have recently selected a settled minister who has been at our pulpit for about a month. Her delivery of the sermon is different from other parts of the service. To my ear, it is slightly strident and has more changes in volume than I am used to.

The sanctuary is a very reverberant place, consisting of lots of glass, concrete block and ceramic tile floor. We have tamed a significant part part of the reverberation with two line arrays for the mids and highs on the centerline of the long dimension of the room and with acoustic panels on tha back wall. The line arrays do a fairly good job of keeping sound off of the long walls which are mostly glass. The acoustic panels have reduced the first reflection off of the back wall, however the room will resonate at right around 2 KHz.

Stability is generally not a problem during the sermon, as the sound level at the pulpit are generally more than adequate.

We are using a Countryman hypercardioid pulpit mike. We are very pleased and the performance of this mike. It is fairly good at rejecting the reflected sound from the back wall, lots better than our former mike, but will pick up two people standing side by side at the pulpit so long as the mike is between them.

Our minister has been very cooperative with her delivery in the "meditative" portion of the service by her speaking a little louder and closer to the mike during these times. This has improved the stability and eliminated a "ring" at about 2 KHx which occurs when the channel gain was increased to try to obtain intelligibility.

The lounder portions of the service during the sermon remain as a problem. I try to ride the level of the pulpit mike to reduce the louder portions and raise the quieter parts, but with only partial success.

It seems that a compressor inserted into the pulpit mike channel would help. However, I have been leary of using a compressor due to the ever present instability that is not fully tamed.

What compressor should I use, and what settings should I start with? We are dealing with all spoken material and no music.

I believe that I can probably do a little on-the-job learning if the settings are pretty modest to begin with. I need particularly to keep the ratio low so that during parts where there is no speech that the gain is not raised to the point of feedback.

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Contributor - Level 2

Re: XR18 Recommended compressor and settings

Compression can be your arch enemy if you do it wrong. The first thing is to understand compression and what the different terms are and how each function works. Someone posted a really good write up on compression here 6 or 8 months ago that was really good.

You can cause major feedback issues with compression if you have the threshold too low and then try to bring the volume levels back up using the channel fader.

The combinator could be your friend in this case since you can compress different bands and maybe compress the 2khz bands more than the others? Something you'll have to play with. I have only mostly used the te comp built into the channel strips and sometimes the dual leisure compressor. I do all live music so I don't have any experience with a church setting but knowing that, I usually use most of the default settings and just lower the threshold as needed being careful not to see it compressing more than around 5db.

The 3 to 1 ratio seems to be a good ratio for most music. Really hard rock or a real screamer vocal I'll squash them more and use a 4 or 5 to 1 ratio. If you want to use it as a hard limiter set the ratio to 99 to 1.

I like to use integer numbers as an example. Lets say the level coming into the mic is 16 and I have the threshold set at 10 and I have a 2 to 1 ratio. The result coming out of the comp would be 13.

The way I came to that is the comp does nothing to the sound until it exceeds the threshold which in this example is 10. Anything that goes over that level gets compressed at 2 to 1 so the part that exceeds the threshold(10) gets cut in half(6/2=3). It takes the 6 over the threshold and cuts that in half.

If I had a ratio setting of 3 to 1 then the result in this case would be 12. Again, nothing happens if the vocal stays under 10 but when the preacher gets excited and belts out at a 16 level the part that goes over the 10 threshold gets cut 3 to 1 so 6 over the 10 would get divided by 3. 6/3+10+12

You can see how much is being squashed on the meter for the comp. I would start out setting it so most of the time it does nothing and you only see it exceeding the threshold when the preacher really gets excited and make sure if you feel the need to get more volume out of the channel fader that the comp isn't what's limiting the volume by looking and the meter and seeing if you are exceeding the threshold first.

I would guess your preacher would like some dynamics in his or her vocals so don't squash them too much. When they belt out "praise Jesus" it should be a little louder I would think? You just are trying to keep them from rattling the windows when they do.
Volunteer Moderator

Re: XR18 Recommended compressor and settings

If the major problem is your 2khz peak then the first remedy is to notch that frequency out from your system.

If you need compression to soften the dynamics of her voice then you should be able to use the channel strip compressor with a soft knee (5) and a fairly high compression ratio and the attack/release set to auto.

The soft knee will let the compressor ease in on the dynamics rather than just cut to the game and this allows you to set a much higher ratio and a lower threshold.
Robert Lofgren | Did you find my post helpful? Give kudos and/or mark it as a solution!
Contributor - Level 2

Re: XR18 Recommended compressor and settings

Thanks Robert.

On the pulpit mike channel, under Compressor tab:

I'm starting with knee at 5, "auto time" engaged,, threshold at -25 dB, ratio at 3, mix at 100% and gain (make up gain?) at 0 dB. Side chain is off.

Then, look for max gain reduction of 5 dB and adjust threshold to get that.

Gain envelope: peak or rms?

Does this look about right? I would like the effect to be unnoticeable with just a more consistent level.

The reason I would plan to use gain (make up gain) at 0dB is that based on my elementary understanding of compressors that is the cause of excessive gain leading to feedback. Is this correct?

We already have pretty aggressive cut at 2 kHZ to deal with the room resonance. The only time that the resonance appears is when the sound level at the mike is so low that a great deal of gain is needed to approach some degree of intelligibility. This problem seems to be cured as our minister has followed my instructions of speaking a little louder and closer to the mike in the "meditative" portion of the service. The meditative effect of that portion still sounds "meditative" even with the speech at a slightly higher level and the resonance beast is tamed.
Contributor - Level 2

Re: XR18 Recommended compressor and settings

I don't know if your minister has a monitor or not but one of my tricks when the vocal backs away from the mic is to turn down their monitor. They get back on the mic quick. You can train them pretty well doing this.

I wouldn't use any make up gain, not at first anyway. Maybe after you get a better handle on the compression you can play around some. Some others here might disagree with me on that. My experience is make up gain works better in a recording environment when feedback isn't an issue.

With compression less is often better. I would try not to compress more than 5db but I wouldn't be adjusting the threshold lower to achieve 5db unless my ears tell me I need it. My only experience is with musicians but my thinking would be to set the threshold so it only goes above the threshold when the minister starts getting exciting and belting out a "praise jesus" that rattles the windows or wakes up the people nodding off. You don't want to take the dynamics out his voice completely or the congregation will fall asleep. Everything starts to sound the same if you squash it too much.

I will also add that you should be keeping an eye on the comp each week since its not a set and forget type of thing.
Contributor - Level 2

Re: XR18 Recommended compressor and settings

Lots of good suggestions here. From my experience from performing in many types of rooms and singing at quiet and loud volumes:

1) Less or no compression is best on live microphones.
2) Use EQ to tune the mic to the minister. Roll off the highs and find out where resonant frequencies for the room are and lower them by -6 dB or so with a medium Q width. You can also use X-Air Snapshots with different EQs for different vocalists.
3) Keep encouraging your minister to "work the mic" like a rock star .... it comes with practice and will have the biggest impact on your problem.
4) Use the Combinator FX module (as wisely mentioned already) on your main output. Here's a great video on how to set it up.
5) If you can find a used dbX goRack, get one. It has excellent pre-programmed EQs (try each for your room and use it), a gentle and very effective compressor (you can dial in a gentle amount), an emergency Mute button, and automatic feedback control (which works great). I never perform without mine. Patch it in between your X-Air output and the PA, and you can learn how to use it in 15 minutes.
Volunteer Moderator

Re: XR18 Recommended compressor and settings

Stephen M. Shirley;151287 wrote:
Thanks Robert.

On the pulpit mike channel, under Compressor tab:

I'm starting with knee at 5, "auto time" engaged,, threshold at -25 dB, ratio at 3, mix at 100% and gain (make up gain?) at 0 dB. Side chain is off.

Then, look for max gain reduction of 5 dB and adjust threshold to get that.

When you work with a soft knee the 'normal' compressor settings that you are used to does not make sense any longer.

You should try and set the ratio to 1:100, knee:5, threshold: same level as your channel target level (e.g. -18dBFS), timing: auto, envelope: rms.

When you have a soft knee the compression ratio is variable rather than fixed so at the threshold point the compression is still close to 1:1, not 1:100. The higher the input level the more compression is applied, up until it starts to limit.

This will give you a very smooth compressor unless the pastor is beatboxing. If you were to do this with a knee of 0 or similar you will get a lot of pumping. Using RMS ensures that the occasional peaks doesn't trigger the compressor. You could also experiment with side-chaining the compressor with a hpf in case there are a lot of plosives that otherwise could trigger the compressor.

This will allow you to keep a proper base level avoiding feedback. Keep the threshold so that it starts to compress ever so lightly when the pastor speaks. Adjust to taste afterwards.
Robert Lofgren | Did you find my post helpful? Give kudos and/or mark it as a solution!
Contributor - Level 2

Re: XR18 Recommended compressor and settings

Thanks for all the contributions. I'm printing the thread and packing it with my MacBook Air for Sunday.
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Contributor - Level 2

Re: XR18 Recommended compressor and settings

Stephen M. Shirley;151342 wrote:
Thanks for all the contributions. I'm printing the thread and packing it with my MacBook Air for Sunday.

If I understand correctly, the problem you are trying to solve is when the minister is more aggressive in the presentation, correct?
Compression can for sure cause feedback when make-up gain is used during soft passages. Sounds like no, or minimal, make-up gain is needed to accomplish what you need. And yes notch the 2K. Depending on the construction of the podium (and if it is NOT acrylic / clear) you could stuff unused "cubby holes" with sound absorbing material. Even make a thinner (1") platen out of OC703 or 705 (harder) or similar Knauf, etc board, to help with podium top reflections . Properly wrapped, of course. It might not be practical, but it is a possible solution.
Contributor - Level 2

Thanks for all the suggestions: This morning's service

Thanks for all of the suggestions. I mixed this morning's service with the channel compression with very good results.

Settings were: Compression selected; Knee 5; RMS selected; Threshold -22 dB; Ratio 100%; Mix 100%; Make up Gain 0 dB; Gain Envelope Auto Time; Side Chain Filter not selected.

I initially set Mix to about 50% until I established that the system was stable and then increased the Mix to 100%.

I varied the Threshold to get gain reduction of about -9 dB, then worked with channel gain and Threshold looking for peaks of about 72 dB on the sound level meter at row 4 outside seat in the congregation. I am also using an iPhone APP called "Spectrum". Both the sound level meter and the iPhone show a continuously changing instantaneous sound level reading. As long as I see peaks of 72 or 73 dB on these devices, I know the level is about right.

We have one semi-retired physics professor who is sitting with the choir who said the sound is "better" today and that he could not hear any difference in the sound indicating compression (or more precisely limiting) was in use.

The initial part of the service was on the Countryman hyper cardioid mike and then shifted to a Shure wireless mike with an SM58 element. Minister was speaking fairly close miked handheld with no explosives. I had not set up the channel compressor for that channel, but went ahead and set it up starting at a 50% mix and increasing to 100% when no ill effects were noted. Eventually, just adjusting threshold and channel gain while watching the ambient sound level worked fine on that mike also.

With both mikes variations in level were significantly reduced so controlling the sound level was easier and intelligibility was improved.

In summary, thanks again for all suggestions.