How to boost volume on PA?

[shred]

During band practices (including my sons’ band) we are having trouble hearing the vocalist. Both rock bands do not play too loud (subjectively). My question is, how can we increase volume out of our PA speakers in our basement practice area?

The vocalist(s) use a Sure SM58 microphone into a Mackie ProFX12 v2 mixer and then into two(2) powered speakers, EV ZLX-12P (both on stands which put the speaker at close to human head level).

We’ve moved the speakers around, tweaked and boosted the db level on the speakers to no avail. Is the current setup/equipment inherently not strong enough - I’d hate to have to replace it but if so what are practical recommendations? Is there a way to add another amp in the chain to push more volume? Any other potential solutions to increase volume?

(We do have the capability to use headphones which we do on occasion but prefer not to use them).

Thanks!

 

[Lost In Time]

• vocalist right on the mic
• channel gain turned up
• channel slider turned up
• "main" slider turned up
• speakers turned up

speakers not blown? cables all good?
In a basement, I'd think you'd have out of control feedback before you ran out of headroom.

 

[MYLOWFREQ]

Is your gain staging correct? Do the speakers work fine? If the answer is yes to both, then it's possible that your singers have poor technique. They have to sing loud right into the microphone with no loud sound sources behind them. If they don't sing, they cannot be amplified.

 

[Wasnex]

I would expect the EV ZLX-12P to be able to cleanly play way louder than you can run them in a basement. You can only get so much volume in a small space. Above a certain SPL, you will get feedback. Feedback occurs because sound travels out of the speakers and is picked up by the microphone and amplified over and over again. The distance the sound travels from the speaker to the mic means some frequencies arrive out of phase and cancel, while other frequencies arrive in phase and add. My point here is the distance is an important factor in which frequencies are a problem and which are not. Some moving a mic or speaker can help.

The choice of mic and how the speakers are aimed can have an in impact on gain before feedback. The SM58 has a cardioid pattern, so the best rejection is directly behind the capsule. The problem in a small space is sound bounces of the floor, ceiling, and walls and travels back to the front of the mic, which is very sensitive. A mic with a tighter pickup pattern may help with gain before feedback, but they have two nulls of rather than one null at 180 degrees.

For example you could try a Beta 58 which is super cardioid. Super cardioid has a little tail at 180 degrees and the deepest nulls are at about 126 degrees.

This is the polar pattern from the Beta 58 Spec Sheet:

Try changing your setup and how the speakers and mics are aimed. Consider how you think the sound is bouncing around. In other words, try to figure out the path the sound is taking from the speaker to the mic. Also, if the speakers are used as foldback monitors, they should be placed in the null(s) of the mic.

Another thing you can try is using material to absorb some of the reflections. If the room does not have carpet try some area rugs. Other ideas including adding furniture with soft cushions or hang moving blankets.

I am not familiar with the mixer you are using. The last mixers I used were Yamaha LS-9 digital boards. The LS-9 was set up with 31-band EQs and also parametric EQ. Either can be used to ring the system and notch out frequencies that tend to feedback. Ringing a room works really well in larger spaces. It can help in small spaces, but not as much.

Basically to ring a room, you turn up the gain until the system is on the verge of feedback. Then you notch the frequency that is causing the problem. A notch is a narrow, deep cut.

In a small space the feedback comes on very quick and tends to be very powerful, which makes it more difficult to ring the system safely. If you allow the system to produce a super strong feedback spike, you may wind up blowing a tweeter. You should clear the room and use hearing protection any time you are ringing for feedback.

Proper gain staging and mic technique are some other important factors. If the gain is set too high the system will be more likely to feedback. Ideally the vocalist should sing very close to the mic with a strong voice. Then the gain can be turned down.

Singing close to the mic may make the voice sound too thick and bassy. This is normal and it is caused by something called proximity effect. The solution is to use EQ to correct the frequency response. Essentially you dip the lows using a pattern than is a mirror image of the proximity effect.

This shows the frequency response for the Beta 58, including the effects of proximity effect at different distances from the capsule.

The shape I use for the vocal EQ starts out like this and is tailored to the situation and the singer's voice.

Another gain related factor that increases feedback is clipping. In my experience, pushing part of the vocal signal path close to clipping tends to result in a lot more feedback.

So as you see there are a lot of things you can try. However, ultimately the best answer is probably for everyone to turn down to a level where the system can actually make the vocals clearly audible. IMHO, the only reason you typically need to play louder than this is because you simply enjoy playing loud. Playing loud does not serve any other purpose.

Keep in mind if you are playing too loud for the room and PA, it's not going to be very enjoyable for the vocalist. So in order for you to get what you want, you are essentially taking more than your fair share of available sound quality.

 

[DirtDog]

I’ve used the ZLX12P gigging (as mains) and they have no problem pumping adequate volume for a rock band in a ~100 person room. Rehearsal would be zero problem for these speakers. Overpowered if anything.

possible problem areas:

- proper gain staging (gain before feedback)
- mic technique
- EQ, particularly low cut/HPF and optimizing for vox
- room treatment - trapping bass freqs; dispersion and diffusionm of other freqs, not sound proofing).

One way around much of this (save for proper gain staging) would be using headphones/IEM for monitoring. Creates new problems but hearing oneself well at volume is rarely one of them.

 

[AndyLES]

Check gain staging. Also, you say the band isn't too loud...but maybe they are? Just try asking everyone to turn down (and to tell the drummer to calm down and not hit so hard) and see what happens.

Also - pay attention to the singer's technique. Lots of people can shower sing, but pushing air, in tune, when it counts, is a different skill entirely.

 

[john_g]

Are you only running the vocals into the mixer/PA or all the instruments? Looks like those are 1000W speakers and should be more than enough. The space you practice in could be contributing too. Easy for sound waves to be bouncing around in certain spaces. Also, how loud are the drums and guitar(s)? Could you turn down a little and mute the drums with gels to see if you can control the volume a little?

 

[FullumMusic]

I'm having a hard time imagining how the vocals running through two 1000W powered speakers with 12" drivers aren't blowing out everything else in the band. There's something wrong with the setup.

What's the layout of the room and who can't hear the speakers?
- Is the band setting up like on stage with the amps upstage (back) and the PA downstage (front) facing out towards an imaginary audience? In this case, nobody will hear the vocals because they're facing away from the band.
- Are the PA speakers facing the front or back of the mic? The speakers should be facing the back of the mic, so that the singer in looking at the cones and the back (xlr cable) is facing the speakers. If the speakers are behind the singer, there will be endless feedback.

What's going through the PA? Just the vox or everything? You should only really need the vox going through at a home rehearsal. Amps will fill up a basement just fine.

Without all the details or knowing how the room is designed, here's how i would re-arrange everything:
- If the room is a rectangle, the PA speakers should be on the flanks of one of the short walls, facing the far side of the room. The vocalist should be set up on the opposite side of the room from the speakers, facing the speakers.
- The band can either be set up behind the singer, facing the the PA speakers, with their amps behind the band & facing the PA speakers. Or if there's not that much room and the band has to set up in other places in the room, have the players stand across from their amps, not right on top of their amps, so they can hear themselves.

Set up a proper gain staging. A super basic rundown:
- Zero the mixer. (All gains down. All Faders down. EQ all unity. Aux & fx at negative-infinity.)
- The PA speakers should be set to unity or 0dB if digital.
- On the vocal channel, put the fader up to unity.
- I suggest turning on the Low Cut on the channel to help reduce bass bleed and low freq standing waves.
- Slowly raise the gain on the mic's channel while the singer sings at full voice. When the volume is right for the room, stop. That's where the gain should be.
- Ring out the room. This is key. The ultra-basic version of ringing out the room: With nobody standing near the hot mic, on the mixer's Main EQ, start on the lowest band and slowly bring it up until it feeds back. If it gets all the way to the top, cool, bring it back to unity. If it starts feeding back, stop, and set it to the inverse of how high you had to go to make it feed back. (In other words: If you had to go all the way up to +10dB to make it feedback, maybe only bring it down to -5dB. But if it starts feeding back at +3dB, bring it all the way down to maybe -12dB.) Do that for each EQ band, one at a time. Once the room has been rung out, don't change the Mixer EQ. The Mixer EQ isn't for tone sculpting. It's for tuning the PA to the room.
- Adjust the channel EQ using only negative EQ. If you have the gain correct and boost an EQ band, you've now given too much gain. If it needs more midrange, cut the bass and treble and then boost the gain slightly. This helps avoid feedback.

Really, though, those speakers should be fantastically loud for your purposes.

 

[mambo4]

Young musicians: "I can't hear myself, I will turn up"
Old musicians: "I can't hear my self, lets all turn down"


The rig described sounds like it should be enough
check for

• bad mic
• incorrect input/output usage
• incorrect signal routing

 

[jdjk7]

During band practices (including my sons’ band) we are having trouble hearing the vocalist. Both rock bands do not play too loud (subjectively). My question is, how can we increase volume out of our PA speakers in our basement practice area?

The vocalist(s) use a Sure SM58 microphone into a Mackie ProFX12 v2 mixer and then into two(2) powered speakers, EV ZLX-12P (both on stands which put the speaker at close to human head level).

We’ve moved the speakers around, tweaked and boosted the db level on the speakers to no avail. Is the current setup/equipment inherently not strong enough - I’d hate to have to replace it but if so what are practical recommendations? Is there a way to add another amp in the chain to push more volume? Any other potential solutions to increase volume?

(We do have the capability to use headphones which we do on occasion but prefer not to use them).

Thanks!

It seems like the issue has been covered pretty comprehensively by others... but holy carrots. If vox are the only thing going to PA and 2x1000W mains is not sufficient for basement rehearsal, my ears would be bleeding. I think the assessment that your acoustic space may not be allowing you to get the volume needed before feedback is the first thing I would look at.

 

[Guitalia]

Young musicians: "I can't hear myself, I will turn up"
Old musicians: "I can't hear my self, lets all turn down"

It's all the old guys I've ever played with who insist on turning up.

 

[Guitalia]

If the vocals are being buried at rehearsals, the band is too loud. That's the definition of a rehearsing band being too loud. People like to play loud. Boo hoo.

Drummers should cover the snare and toms with tea towels (see the Let It Be movie). Maybe the cymbals also. Or get electronic drums.

Guitarists should turn their amps to face the walls (and should depend on pedals, not overdriven tubes, for lead solo tone).

In small rehearsal spaces, I always persuade the guitarists to turn their amps around. After they get over pouting, they usually realize that they can hear themselves better.

 

[Bullitt5135]

It starts with a quiet drummer. Electronic drums or hot rod sticks. In-ear monitors or headphones can be set up relatively inexpensively with something like an ART Headamp6 headphone amp.

 

[brianrost]

I am not familiar with the mixer you are using.

Wasnex,

The Mackie ProFX series is their low end line, the ProFX12v3 sells for under $400. About 100,000,000 miles from a Yamaha LS9 Standard Mackie 3-band fixed EQ (80, 2.5K, 10K). No graphic EQ for the mains. The mixer does have PFL (pre fader listening) so the OP can use that to check the gain settings on each channel.

 

[Wasnex]

@shred

Here is another important factor. It's common in live music to not be able to hear as well as you like. This is because most people want to be about 6-10dB louder than everyone else. In many live music situations, it's not possible for everyone to get the desired 6-10dB because the distances between players are not and cannot be sufficient.

Let's assume everyone is playing at exactly the same volume and standing 3' from their personal amp or monitor. SPL drops of by 6dB for each doubling of distance. So if you are standing 3' from your amp, another band member needs to be at least 2 x 3' = 6' from you amp for the SPL to drop off -6dB . If they want the full -10dB difference, they need to be about 9.5' from your amp.

Here is a crude drawing to make the point.

Consider the orange oval to be your head, which is 3' from you amp. In order for someone else to perceive your level 10dB lower than you do, their head has to be outside of the green circle, with is about 9.5' from the acoustic center of your amp.

Imagine this is a bass player and a guitar player and a vocalist. Each person is 3' from their monitor and about 4' from each other. But notice that none of them can get the desired 10dB, because they are closer then 9.5' to two other sources beside their own amp.

 

[mambo4]

If we accept the OP's statement that they are NOT too loud
then the issue is user error or bad hardware

I just googled the ZLX manual and see 2 things:

1. you *can* just plug the Mic into the power amp directly. Do this to remove the Mixer and ensure the mic works
2. the ZLX has an input trim:

It got one of those annoying digital display screens with "pages" and may be hiding some volume draining settings from you

 

[mapleglo]

I used to gig with the next EV 12" powered speakers down from the ZLX line. I have to imagine there's something wrong with the mixer - the EV's put out quite enough volume. I agree with the above - plug the mic directly into one (or both) of the speakers and see if that helps.

 

[devnulljp]

EQ

 

[TomB]

During band practices (including my sons’ band) we are having trouble hearing the vocalist. Both rock bands do not play too loud (subjectively). My question is, how can we increase volume out of our PA speakers in our basement practice area?

The vocalist(s) use a Sure SM58 microphone into a Mackie ProFX12 v2 mixer and then into two(2) powered speakers, EV ZLX-12P (both on stands which put the speaker at close to human head level).

We’ve moved the speakers around, tweaked and boosted the db level on the speakers to no avail. Is the current setup/equipment inherently not strong enough - I’d hate to have to replace it but if so what are practical recommendations? Is there a way to add another amp in the chain to push more volume? Any other potential solutions to increase volume?

(We do have the capability to use headphones which we do on occasion but prefer not to use them).

Thanks!

So turn down everything else. That should do it.

 

[SoCal80s]

A lot of good info here, I suspect there is a setting on the mixer that you're not catching or there's bad equipment somewhere. Another thing to consider is EQ. If only vocals are running through it, you don't need much bass even for a male singer. Turn on the low cut filter, turn down the bass EQ (and maybe even some of the mids). That will add clarity by removing some of the muffled sound and will give the speakers less workload.