Too much bass

[rschultz]

Cory is correct on all accounts. No bass amp on stage. 2 wedges, and 2 guitar amps are the only amp/speakers on stage. Electric amp is mic'd, volume not too loud. Acoustic amp is actually off or very low, using acoustic amp for effects and DI... sending acoustic sound back to wedge for acoustic guitar monitoring.

[audiomatic]

If I understand this correctly, the main outs go to the sub, and the main speakers are fed from the sub. We once had a Peavey rig like this; the crossover is built into the sub (open up the sub cabinet and check it out).

You have two problems. Your low pass filter is set way too low. The fundamental frequency for bass notes goes up to 175 Hz (if played all the way up the neck) and the harmonics are even higher. Harmonics are essential for discerning the pitch of bass notes as well as for musicality. Without harmonics, the bass will sound a lot like a sine wave (pure tone, unmusical, difficult to discern pitch). Try setting the low pass higher to see if the bass SOUNDS better. Also, bass players often inadvertently turn down their tone control (cutting higher frequencies) when they intend to turn down volume, then forget to turn the tone control back up. I've disconnected the tone control on our bass to prevent that.

High frequencies are more focused in front of the loudspeakers, low frequencies wrap around loudspeakers and can reflect off walls behind the sub, increasing the apparent loudness of low frequencies. Loudspeakers are designed to be in a free field, not placed near reflective surfaces. A bass amp placed back against a wall will have louder apparent low frequencies than if moved away from the wall and CLOSER to the congregation (!).

If you can increase higher frequencies produced by the bass/sub by increasing the low pass frequency, disabling the tone control on the bass and moving the sub away from reflective surfaces, it should sound better. When people tell me "the bass is too loud," what they really mean is that "the bass sounds bad, turn it down."

[Tim Padrick]

Have the bassist play scales while you slowly walk the room, so you can locate the spots in the room where there's "too much bass", and what frequencies are hot in those spots. IME it is seldom if ever the instrument as a whole, but just certain narrow frequency ranges.

I had this problem just yesterday with two bands - one with a bass amp and one just running through the wedges. At sound check everything was reasonable and I had a decent amount of bass in the PA. But during the sets both basses developed a very nasty hot spot, and I had to pull them out of the house, as I was unable to "build around" the garbage coming off the stage without making the bass way too loud across the entire spectrum.)

[Brad Weber]

Originally Posted by audiomatic

You have two problems. Your low pass filter is set way too low. The fundamental frequency for bass notes goes up to 175 Hz (if played all the way up the neck) and the harmonics are even higher. Harmonics are essential for discerning the pitch of bass notes as well as for musicality. Without harmonics, the bass will sound a lot like a sine wave (pure tone, unmusical, difficult to discern pitch). Try setting the low pass higher to see if the bass SOUNDS better.

Subwoofer crossovers should not be set that high, subs usually reproduce only the lower octave or two with the mains reproducing from there up. It is not as though the higher frequency sounds are not reproduced, just that they are reproduced by the mains rather than the subs.

Originally Posted by audiomatic

High frequencies are more focused in front of the loudspeakers, low frequencies wrap around loudspeakers and can reflect off walls behind the sub, increasing the apparent loudness of low frequencies.

Right idea but misleading in the mechanisms involved. Speakers do indeed tend to be more directional at high frequencies but the pattern provided by a speaker is more a result of intentional design. Low frequencies tend to be less directional but not due to 'wrapping around' the speaker.

Originally Posted by audiomatic

Loudspeakers are designed to be in a free field, not placed near reflective surfaces. A bass amp placed back against a wall will have louder apparent low frequencies than if moved away from the wall and CLOSER to the congregation (!).

Loudspeakers are not necessarily designed to be used in free field, in fact look at how many subwoofer specs show the sensitivity and sometimes even response for half space conditions. Also, space loading (the reflective surfaces) is theoretically the same for all frequencies but because of the physical distance from driver to reflecting surface and the resulting phase interactions you typically get coherent summation at low frequencies and both summation and cancellation at higher frequencies. As the distance from driver to surface increases, the lower the frequency where you get interactions other than just summation and can start getting boundary cancellation.

It is quite possible to have much higher bass levels in some areas of a room than another. This can be due to a number or reasons from simply being closer to the low frequency drivers to room modes to phase interactions from multiple drivers. As Tim noted, to that seems to be the first step, to identify if the problem is related to specific locations in the room. If it is you can try some pretty simple things like reducing the level of one channel and listening to the effect of that change or moving one sub and seeing of the changes anything. You may start to see that certain changes significantly affect the resulting low frequency levels at particular points in the room.

[WaynePflughaupt]

The problem might be nothing more than poor equalization of the overall mix. Listen to each instrument and vocal separately, with nothing else playing. Do the guitars, keyboards and male vocals have a nice, warm, “bassy” sound? If so, once you combine all that and get everything going at once, you have too much going on in the low frequencies, and it drowns out the bass guitar. So there is no option but to turn it up louder, so that it can overwhelm the bassy “swamp” caused by everything else on the stage.

If this is the problem, the solution is easy: Roll out the lows for everything else on stage except the kick drum and bass guitar. Then the bass will be clearly heard, and you can turn it down.

Regards,
Wayne A. Pflughaupt