bass too low for PA? :(

[Execut1ve]

Hello all,

I am currently playing a 5 string Schecter which I have tuned to drop A (A E A D G) in my church band. I have no idea why I initially did this, but it's been so long now that I can't imagine going back

I worry that the PA isn't capable of really handling much below 40 Hz, rendering the low A string useless at worst and redundant at best. Are my fears reasonable?

Thanks!

[somedumbguy]

The PA can handle it... maybe. Do they have proper speakers? As in, do they have a few 18s to handle the super lows?

The PA at my church couldn't handle it, but I imagine many could, especially those that mic the bass drum.

[gbarchus]

I haven't personally seen too many churches with 18" speakers in the PA or even dedicated subs. If the PA is a two way system, your bass may be affecting the quality of of the vocals. Worst case, it COULD damage the speakers.

Can you give us more information about the PA?

[somedumbguy]

Originally Posted by gbarchus

I haven't personally seen too many churches with 18" speakers in the PA or even dedicated subs.

A lot of the bigger churches do. But you're right, I've seen more churches with small PAs than I have with big PAs

[Bass_Pounder]

Most bass cabinets cannot reproduce the fundemental of a low A with any kind of volume or authority either, so why worry about the P.A. ?

*Most* of what you are hearing is the 2nd harmonic and above - the brain fills in the rest.

[Execut1ve]

TBH I don't do a whole ton with the low A itself, but I'm all over the C and D at times.

I know there is a sub under the stage but I couldn't be more specific about its size/power. Other than that it's a central hanging cluster of 2 or 3 speaker boxes.

[Bass_Pounder]

Originally Posted by Execut1ve

TBH I don't do a whole ton with the low A itself, but I'm all over the C and D at times.

I know there is a sub under the stage but I couldn't be more specific about its size/power. Other than that it's a central hanging cluster of 2 or 3 speaker boxes.

As long as the system is properly crossed over, you should not be doing any harm to the "mains".

Even if not crossed over properly, unless the mains are cheap speakers, they are probably doing just as well as your rig.

[elavate7]

do you need the PA????? what size speakers does your church use???? mines use 2 112s, but none of the musicians use the mains except the organist.

[B-string]

Originally Posted by Bass_Pounder

Most bass cabinets cannot reproduce the fundemental of a low A with any kind of volume or authority either, so why worry about the P.A. ?

*Most* of what you are hearing is the 2nd harmonic and above - the brain fills in the rest.

^ exactly. Unless you hear someting really bad from the PA don't worry. They may even have the low cut filter engaged on your strip without you knowing it.

[Johnny Crab]

Originally Posted by Bass_Pounder

Most bass cabinets cannot reproduce the fundemental of a low A with any kind of volume or authority either, so why worry about the P.A. ?

*Most* of what you are hearing is the 2nd harmonic and above - the brain fills in the rest.

+1
If not for this "trick" the BOSE PAS I use would be useless. It's a cliff dive cutoff at 40 Hz. It "renders" a 5 string's B and my 4 string "similated/octave down box" imitation 5 string in a tolerable fashion.
The computer speakers here with WinMediaPlayer's psychoacoustic tricks does similar things in making micro speakers "sound" bigger.

Still prefer the ACME's for real bass.

To the OP:
If the church paid for a pro install and the Xover hasn't been fooled with, you should be fine. If you have a wireless, walk out in the auditorium/congregation area during rehearsal and listen. Visit the sound person if needed but be "friendly".

[rbonner]

-1 You guys with the brain fills in all the rest. This is an old wives tail and continually propogated by the old wives on TB.

I realize there has been some testing done, but in all cases the testing was done with limited ability to reproduce the fundamentals.

The popularity of the fEarfull cab and it's ability to reproduce lows and the highs with a two and three way system is proof that dedicated speakers result in a superior product.

I set up a test here a couple months ago with two identical speakers and two identical amplifiers crossed over at 50Hz. When I disconnected the cab with the fundamental you could still tell it was a "low B" but it was limp and lifeless. Sure you could play with EQ on the preamp and try and make it sound better but there was NO WAY it was ever going to sound full range. Yes the brain tells you its a "B" but man it sounded like crap.

When playing the Fundamental cab, cut off above 50Hz, it was all BOOM BOOM of the fundamanetal, once again you could tell it was a "Low B" and it was also lifeless. BUt lifeless for a different reason.

When both cabs were played it was rich and full. I could also pound the notes much harder and get a LOT MORE bottom from the pair than two cabs sent full range signals.

Anybody who has played with a PA that runs subs and had the main channel cut out knows that the subs contain "wierd almost undistinquishable material". It's the same when playing only bass through a sub...

I ran this test with JUST a pair of AMPEG svt-215e cabs an SVT-4PRO and an SVP1600 prower amp.

I would have gained a benefit sending the highs to one of my 810's instead of a 215, however...

I'm limited in the time I can test this system due to neighbor issues, however I am nearing completion of a new Mad Scientist's Lair where I will have an insulated sound room to do full volume testing.

I hypothosize that by separating off the fundamentals of each note on the lower strings and due to the large deflection of the driver cones producing these notes that the highs will reproduce with higher clarity and a player will be able to individually EQ the fundamental.

Gee PA's and high end stereos have been doing this for 50 years with excellent results.

BOB

[will33]

Originally Posted by Bass_Pounder

Most bass cabinets cannot reproduce the fundemental of a low A with any kind of volume or authority either, so why worry about the P.A. ?

*Most* of what you are hearing is the 2nd harmonic and above - the brain fills in the rest.

+1. Most bass rigs and most PA's can't really reproduce the fundamental of any low instrument at an even volume level with the rest of it, save for sub system that are SPL balanced with the mains, taking into account room cancellations, etc. What you need to have is the 1st harmonic/overtone of your fundamental, that's where the power and volume is.

The low b on an electric bass fundamental is 31.something hz. If you're strong at 62hz you've got a solid low B. So solid in fact you need good representation of the harmonics above that to maintain a good sense of pitch. Something with strong response @ 80hz will give room rattling bass from a 4 string. (low E fundamental @ 41hz.)

[Execut1ve]

I'll go back and chat with the sound guy this morning and try to learn more specifics about the speakers. Unfortunately we don't have wireless I might just ask the guitarist to play around a bit on my bass while I roam around the room.

[mulchor]

Originally Posted by rbonner

-1 You guys with the brain fills in all the rest. This is an old wives tail and continually propogated by the old wives on TB.

Your demonstration doesn't disprove it or address the property.

The idea of this property has been around longer than the bass guitar, and is one of the facts that led to and supported the belief that ear/brain works like a filter bank in processing frequency/pitch.

Present a complex waveform. The theory is that the ear/brain does something comparable to a Fourier transform. Remove the fundamental. There is still ALL the information in the harmonics.

In practice, consider the times you've talked to a man or low-voiced woman on a telephone. Could you hear them? Did they sound like themselves? But phones work with very reduced bandwidth, both high and low freqs are dropped. We never miss the lows.

[craig.p]

> I worry that the PA isn't capable of really handling much below
> 40 Hz, rendering the low A string useless at worst and redundant
> at best. Are my fears reasonable?

Yes, your fears are reasonable, but going to the sound person is the best idea. Let that person assess the risk. That's the person who'll have the most intimate knowledge of the PA's limits. You might want to play Good Citizen and ask if there's anything you need to change at your end to mitigate any negatives, even if it's to stay off your low A string. But beyond that, I'd say let it go.

[Execut1ve]

well, the sub turns out to be 2 15's which the sound guy estimates run around 800W, although I'm certain he runs it at much lower volumes. He promises to email me more detailed specs when he can find them.

[OtterOnBass]

Originally Posted by mulchor

Your demonstration doesn't disprove it or address the property.

The idea of this property has been around longer than the bass guitar, and is one of the facts that led to and supported the belief that ear/brain works like a filter bank in processing frequency/pitch.

Present a complex waveform. The theory is that the ear/brain does something comparable to a Fourier transform. Remove the fundamental. There is still ALL the information in the harmonics.

In practice, consider the times you've talked to a man or low-voiced woman on a telephone. Could you hear them? Did they sound like themselves? But phones work with very reduced bandwidth, both high and low freqs are dropped. We never miss the lows.

I think people on the phone sound like people on the phone. There is no bass (or even low-mids). Ever hear someone simulate a phone call on a recording? It's cutting out the bass and punching up the "sensitive" frequencies.

[mellowgerman]

At first glance I thought you were talking about Pennsylvania

[walterw]

Originally Posted by Execut1ve

well, the sub turns out to be 2 15's which the sound guy estimates run around 800W, although I'm certain he runs it at much lower volumes. He promises to email me more detailed specs when he can find them.

if he's running it right it's probably shelved off at like 40Hz anyway, not reproducing anything below that.

your bass will sound like it sounds anyway, as it actually produces little below that range (as has been pointed out, it's mostly harmonics of those lower pitches). don't give it a second thought.

[rbonner]

Originally Posted by mulchor

Your demonstration doesn't disprove it or address the property.

The idea of this property has been around longer than the bass guitar, and is one of the facts that led to and supported the belief that ear/brain works like a filter bank in processing frequency/pitch.

Present a complex waveform. The theory is that the ear/brain does something comparable to a Fourier transform. Remove the fundamental. There is still ALL the information in the harmonics.

In practice, consider the times you've talked to a man or low-voiced woman on a telephone. Could you hear them? Did they sound like themselves? But phones work with very reduced bandwidth, both high and low freqs are dropped. We never miss the lows.

We never miss the lows... Hardly.

You miss read my humorous line, of the old wives. That fundamental is not necessary. While in the strickest sense information is passed, the actual quality of the information is marginal. This is completely not applicable when it comes to musical instrument reproduction where you don't want your brain working to understand the material.

I used to use high bandwidth phone lines in radio station links. 8K bandwidth lines; and you should have heard what a radio station sounded like when they installed the wrong phone line.... Yeah it worked, but it sounded like POOP through the proverbial fan....

I'm very familar with phone systems. Spent the last 30 years pushing data through them.

Now with digital telephone they have once again expanded the bandwidth. That same radio station connection would now have a T-1 passing the data. But that's not what we're talking about here.

Charlie E, was doing some tests in a different thread, but in all cases the fundamental was always present to some extent and the files were being reporduced on a computer speaker.

My point was, just because your brain is able to tell what notes are being played, they sound like CRAP without the fundamental in there.

By boosting 30Hz you get more bass, by boosting 6K you get more treble.

As you are bonking away on your 3 1/2" speaker there still is 31.87 Hz still finding its way even if it is down 30DB... Your little speaker will sound poor and a whomping 810 cab with a lot of power behind it will sound great. Even if it is down 12DB at 31.87Hz. It is still reproducing the fundamental.

You would have some pretty nasty sounding bass guitar if it didn't.

Sure the main blast is in the mid frequencies, but that's just the nature of things. You adjust the tone for shape and your desired sound.

You best reread what I typed. If you still are not convinced that music needs the full spectrum of reproduction to sound full; set up the gear yourself and rerun the test. Or get on a plane and come here and I will rerun the test just for you...

When the fundamental is completely removed the note is there but its character is mutated. The same goes for having only fundamental and no harmonics reproduced electronically.

If this was not the case, high end stereo and audiophiles wouldn't even exist... I think they'd tell you where to jump if you started babbling about "fundmentals are not required in musical reporduction."

They've been making serious sub bass since the late 50's... EV would have never bothered with their 30" drivers and 74 Cubic foot bass cabinets if the low stuff wasn't part of the equasion.

DO NOT CONFUSE, reduced with not needed; and I don't date girls with deep voices.

BOB