Rat-tat-tat on the wall...how do you stop it?

[TwinSpinDJ]

:sqconfused: When you are playing a large venue and are set up along the short wall (think rectangle) have you ever had a problem with the "beat" coming back at you from the opposite wall? If so, what did you do to cure the problem? :sqerr:

Question 1: What would appear to be the primary cause?

Question 2: What is the remedy?

 

[Guest]

Question 1: What would appear to be the primary cause?

Basically, echo.

Question 2: What is the remedy?

Angle your speakers so they are not pointing directly at the back wall. Angle the left one towards the left wall and the right one towards the right wall. That way the sound will bounce at least twice. This may not negate the problem but will minimize it.

 

[Hank Davidson]

I agree with Tom, but if that doesn't work, one of these will...

 

[TwinSpinDJ]

Wouldn't the sound directed away from the dance floor have an affect on how loud it is ON the dance floor?

 

[WaydeWest]

Maybe it's just the neighbors banging on the wall trying to get you to turn it down.

 

[soundinmotiondj]

Slap back from the far wall tends to come from the mid/highs rather than the subs. There are several ways to help mitigate this:

1) Toe in.
Do not point the speakers perpendicular to the far wall.
Point the speakers so the line of sight is at lease a 20-30 deg angle on the far wall. If that is not possible, then aim the speakers to hit the side walls about 2/3 of the way down the room.

2) Tilt the speakers down.
Based on little more than a hunch, I think that most of the slap back is actually coming from the wall-ceiling corner, rather than from the back wall directly. Tilting the mid/highs down will send less of the directional sound into that corner and reduces the slap back. Keep in mind that a mid-range compression driver horn will have a 40-50 deg vertical dispersion....that is a lot of sound going to the ceiling.

3) EQ the specific frequency down.
Most slap back is happening >10kHz. If you can identify the specific frequency, pulling that EQ down by 3-6dB will greatly reduce the problem. Trial and error with a 31-band EQ is typically sufficient to ID the specific frequency that is causing the issue.

 

[TwinSpinDJ]

soundinmotion...appreciate your response and will try this next time. However, it's kind of hard to get the angle of the speaker "down on the crowd" on the dance floor without "flying" them. Suggestions anyone?

I don't use a 31-band EQ but may consider investing in one. What about a Driverack PA from DBX? Would that help?

 

[soundinmotiondj]

soundinmotion...appreciate your response and will try this next time. However, it's kind of hard to get the angle of the speaker "down on the crowd" on the dance floor without "flying" them. Suggestions anyone?

Depending on the speaker cabinet....you can swap the top hat:


http://www.parts-express.com/pe/showdetl.cfm?Partnumber=290-670&FTR=adjustable%20top%20hat&CFID=15871933&CFTOKEN=70445207

I don't use a 31-band EQ but may consider investing in one. What about a Driverack PA from DBX? Would that help?

The Driverack DRPA has a Parametric EQ (PEQ). A PEQ is too course to really use to remove feedback or slap back. If you are open to Behringer products, the DEQ-2496 is a good option.

 

[TwinSpinDJ]

I have a pair of Yorkville NX-750P. Speaker pole fits up inside of the base. There are no means of tightening speaker in case of "wobble."

Not sure if the "top hat" would work? Comments, anyone?

Thanks for your useful post, however.

 

[Mark Beecher]

announce that there will be no extra charge for hearing the music twice tonight.

 

[WaydeWest]

soundinmotion...appreciate your response and will try this next time. However, it's kind of hard to get the angle of the speaker "down on the crowd" on the dance floor without "flying" them. Suggestions anyone?

The QSC K series has an adjustable top hat.

 

[NLFX Pro]

The Driverack DRPA has a Parametric EQ (PEQ). A PEQ is too course to really use to remove feedback or slap back. If you are open to Behringer products, the DEQ-2496 is a good option.

The DRPA also has a dual 28 band graphic EQ.

Ben

 

[soundinmotiondj]

The DRPA also has a dual 28 band graphic EQ.

I stand corrected. A 28 band EQ is sufficient to notch out slap back from the far wall.