Double Bass Best 1x12 for the $$$$$

[bribass]

I think the magnetic pickup does not produce infrasonics because the signal it receives is processed by a nearly ideal bandpass filter -- the strings. If my hypothesis is correct, then the subharmonic thump is caused by the attack on the string effectively beating on the body of the bass like a drum. And the drum is tuned to produce that thump.

The electric bass incorporates the same ideal filter, but also has no body to make the thump.

Naturally, a real acoustics expert could either put the above into proper technical terms, or tell me that I am wacko.

I get a lot less thump with my mag pup.

I'm no acoustics expert nor do I play one on TV, but this is what I'm saying about the Realist. Isn't that the pu that picks up the most subharmonic thump since it is placed on the body of "the drum"?

BG

 

[drurb]

I think the magnetic pickup does not produce infrasonics because the signal it receives is processed by a nearly ideal bandpass filter -- the strings. If my hypothesis is correct, then the subharmonic thump is caused by the attack on the string effectively beating on the body of the bass like a drum. And the drum is tuned to produce that thump.

The electric bass incorporates the same ideal filter, but also has no body to make the thump.

Naturally, a real acoustics expert could either put the above into proper technical terms, or tell me that I am wacko.

I get a lot less thump with my mag pup.

I think the ideal bandpass filter is the inductor of the magnetic pickup. It will not pass DC or anything near it. I agree that SOME of the infrasonic response could be caused by the "thump" through the body-- but not much. Here's why. First, the offending infrasonics can be in the region of 10-15 Hz or so. The wooden body of a bass, double bass or EB, is not going to transmit those frequencies very well, if at all. It, too, acts like a bandpass filter.

Second, the infrasonic response via a piezo can be demonstrated without any transient attack at all. As I mentioned in another post, with such a setup, all one need do is wiggle the E-string back and forth and you can see the cone of a ported cabinet (like the Wizzy) dance back and forth in step. You can do this at about 5-10 Hz!!!

BTW, does being honored as a Fellow of the Acoustical Society of America qualify me as "a real acoustics expert?"

Finally, you are NOT wacko. Quite the contrary, my fiend. As far as I'm concerned, you are one of the more cherished "thinkers" here on TB.

 

[drurb]

I'm no acoustics expert nor do I play one on TV, but this is what I'm saying about the Realist. Isn't that the pu that picks up the most subharmonic thump since it is placed on the body of "the drum"?

BG

Do we know whether the Realist even produces the "infrasonic problem" at all? Try the "wiggle" test.

 

[bribass]

Well I'll try the wiggle test w/ the Realist. Played in a darker room tonite so I couldn't see the cones that well.
But I have to say about engaging the hi pass filter all the time. W/ my Prescott it seems that the hp can cut out some of the girthy fequencies that I want in the signal. Especially at lower volumes in rooms w/ better acoustics. I was ABing the hp on and off tonite during a very pleasant piano, bs, drm trio gig in a beautiful sounding room in an old colonial inn. It's hard to make this bass sound bad thru any rig, but it was definately warmer, a bit bigger and not as dry w/o it engaged.
As the volume goes up in worse sounding rooms the hp can be invaluable to be sure, to focus and clarify the sound in a bad mix, but even w/ the filter knob all the way to the left sometimes it just sounds better w/out it to me. This is at least true w/ the Prescott thru my Focus 2R III which was NOT sent back to AI to have the hp filter's functionality enhanced like I know some TB Focus owners have done.
But I think it's also a function of a better instrument having less erent or undesirable frequencies (ie. standing waves, wolfs, out of tune resonances, bad subsonics etc.) floating around and and more good tone to be amplified. For example I think the hp filter helps my plywood w/ this rig more than the Prescott. This ofcourse is IMHO from observation in the field w/ my equipment thru a M-line Wizzy or a Aguilar GS 112 (did ya notice that attempt at staying on thread topic there) in a wide variety of situations.

BG

 

[bribass]

So, all you hi pass filter fans.
Would you agree about better basses needing hp filters less?

BG

 

[Uncletoad]

I have tried to like HP filters on my bass sound and have used a bunch of different structures and EQ points. For me I must say I just don't like them. I'm a big fan of ass. In my bass tone too. No matter how I've used those HP filters I loose that ass.

Maybe the Focus HP filter could be tweaked to just kill stuff below 15hz or something. The real speaker killers. I don't like that HP filter either.

I use it as a notch filter turned all the way down in the pickup channel because I have to have phase reversal. Sounds better to me than the HP filter turned all the way down. That always kills my beloved ass.

I'd rather not have any filters at all but nobody makes an Uncletoad signature series amp yet.

Oh yea. 12's are cool.

I don't have any.

 

[bribass]

I have tried to like HP filters on my bass sound and have used a bunch of different structures and EQ points. For me I must say I just don't like them. I'm a big fan of ass. In my bass tone too. No matter how I've used those HP filters I loose that ass.

Maybe the Focus HP filter could be tweaked to just kill stuff below 15hz or something. The real speaker killers. I don't like that HP filter either.

I use it as a notch filter turned all the way down in the pickup channel because I have to have phase reversal. Sounds better to me than the HP filter turned all the way down. That always kills my beloved ass.

Oh yea. 12's are cool.

I don't have any.

Phil, Do you mean w/ the HP filter AND the notch buttons depressed w/ the knob turned all the way to the left?

That does sound better to than the HP alone to me as well, but at low volumes both of them off sounds best.
More "ass" is right.

I really like 12's. Faster than 15's and less brittle and brash than 10's, but I'm sure there are some great 10's out there (ie:EA) that I've never tried.
On loud gigs for years I've been using a 15 on the bottom w/ a 12 on top for "ass" AND definition. Best of both worlds. I must try this w/ the M-line Wizzy stacked on my EV 15, but two M-line 12's are killin'.

BG

 

[Uncletoad]

Phil, Do you mean w/ the HP filter AND the notch buttons depressed w/ the knob turned all the way to the left?

The way I understand it if the upper switch is pushed in it's a 12 DB per octave high pass filter with the frequency starting where you set it on the adjacent knob.

When the upper switch is out it's a notch filter with an 18db sharp cut at the frequency the adjacent knob is set at.

I want phase reversal but no low pass or notch but that's not an option. To me using the notch or the upper switch out and the knob all the way to the left at 30hz sounds better than the low cut/high pass when the switch is in.

Either is assuming the lower switch is pressed in.

So I like lower switch in, upper switch out knob all the way to the left.

...or as you mention the whole damn thing off at a reasonable volume. Best sound of all.

 

[Ric Vice]

T

I want phase reversal but no low pass or notch but that's not an option. To me using the notch or the upper switch out and the knob all the way to the left at 30hz sounds better than the low cut/high pass when the switch is in.


...or as you mention the whole damn thing off at a reasonable volume. Best sound of all.

Phil,
As we have discussed (moaned, complained, etc.) The older Walter Woods had a phase switch and "it worked". Why no one will put one on the newer amps (including Walter himself). is the mystery for the ages.

 

[Uncletoad]

...or as you mention the whole damn thing off at a reasonable volume. Best sound of all.

And one could take that to mean the whole amp turned off and left in the truck. The best sound of all.

 

[drurb]

Well I'll try the wiggle test w/ the Realist. Played in a darker room tonite so I couldn't see the cones that well.
But I have to say about engaging the hi pass filter all the time. W/ my Prescott it seems that the hp can cut out some of the girthy fequencies that I want in the signal. Especially at lower volumes in rooms w/ better acoustics. I was ABing the hp on and off tonite during a very pleasant piano, bs, drm trio gig in a beautiful sounding room in an old colonial inn. It's hard to make this bass sound bad thru any rig, but it was definately warmer, a bit bigger and not as dry w/o it engaged.
As the volume goes up in worse sounding rooms the hp can be invaluable to be sure, to focus and clarify the sound in a bad mix, but even w/ the filter knob all the way to the left sometimes it just sounds better w/out it to me. This is at least true w/ the Prescott thru my Focus 2R III which was NOT sent back to AI to have the hp filter's functionality enhanced like I know some TB Focus owners have done.
But I think it's also a function of a better instrument having less erent or undesirable frequencies (ie. standing waves, wolfs, out of tune resonances, bad subsonics etc.) floating around and and more good tone to be amplified. For example I think the hp filter helps my plywood w/ this rig more than the Prescott. This ofcourse is IMHO from observation in the field w/ my equipment thru a M-line Wizzy or a Aguilar GS 112 (did ya notice that attempt at staying on thread topic there) in a wide variety of situations.

BG

Well, I'm afraid this does not square with physical acoustics. Assuming your Prescott is a four-stringer tuned in the customary fashion, there is nothing really being produced by the instrument acoustically below 43 Hz or so. If your HP filter reduces the very low end, then the HP filter has its corner frequency set too high. I do not believe that better instruments have less errant low frequencies.

The use of a HP filter that I have advocated is to get rid of the anomalous and artifactual infrasonics that can be produced by piezo pickups.

 

[drurb]

So, all you hi pass filter fans.
Would you agree about better basses needing hp filters less?

BG

NO!

 

[drurb]

I have tried to like HP filters on my bass sound and have used a bunch of different structures and EQ points. For me I must say I just don't like them. I'm a big fan of ass. In my bass tone too. No matter how I've used those HP filters I loose that ass.

Maybe the Focus HP filter could be tweaked to just kill stuff below 15hz or something. The real speaker killers. I don't like that HP filter either.

I use it as a notch filter turned all the way down in the pickup channel because I have to have phase reversal. Sounds better to me than the HP filter turned all the way down. That always kills my beloved ass.

I'd rather not have any filters at all but nobody makes an Uncletoad signature series amp yet.

Oh yea. 12's are cool.

I don't have any.

Once again, if you find that the HP filter alters your sound by removing low-end, then the filter's corner frequency is too high. This is not magic. If you are using a four-stringer tuned conventionally then the lowest fundamental is 43 Hz. Neither your bass nor mine produces anything desirable that is lower in frequency.

 

[drurb]

Phil,
As we have discussed (moaned, complained, etc.) The older Walter Woods had a phase switch and "it worked". Why no one will put one on the newer amps (including Walter himself). is the mystery for the ages.

Now, why is it that you guys think that absolute phase with a single driver matters?

 

[Uncletoad]

Once again, if you find that the HP filter alters your sound by removing low-end, then the filter's corner frequency is too high. This is not magic. If you are using a four-stringer tuned conventionally then the lowest fundamental is 43 Hz. Neither your bass nor mine produces anything desirable that is lower in frequency.

So are you saying that these high pass filters start at a frequency higher than 43hz even though the knob says 30hz?

Hard to convince me that nothing is going on under 43 hz cause I can feel it in the bandstand every time I play a gig.

Maybe its coming from some part of the electrical signal rather than the acoustic signal I don't know but my experience with high pass filters tells me something is going on down there. Otherwise I wouldn't notice when it was gone.

Now, why is it that you guys think that absolute phase with a single driver matters?

Explain.

 

[drurb]

So are you saying that these high pass filters start at a frequency higher than 43hz even though the knob says 30hz?

Oh, this is quite possible. I'd have to measure one to tell you for sure.

Hard to convince me that nothing is going on under 43 hz cause I can feel it in the bandstand every time I play a gig.

What is it that you feel? You likely feel the "thump" that is defined by the relatively broadband transient created as you pull the string and then you feel the note produced by the string itself. The fundamental of the low E is about 43 Hz. You're not going lower than that. Higher-- yes, lower-- no.

Maybe its coming from some part of the electrical signal rather than the acoustic signal...

If it were, then it would not be anything you want.

I don't know but my experience with high pass filters tells me something is going on down there. Otherwise I wouldn't notice when it was gone.

Down where? Below 40 Hz? I don't think so. If you are missing desirable signal, then your HPF is cutting into the passband up into the 40-50 Hz region.

Explain.

With regard to polarity, if you have a single amplifier and a single loudspeaker cabinet, then changing polarity, which affects only the absolute phase of the signal, will produce absolutely no audible effects. This question has been settled for decades. There is nothing to debate, it is not open to interpretation, and any differences reported to be heard are the result of biases and faulty auditory memory. Now, if you are talking about the relative phase between signals emanating from two different systems that is another matter entirely. That is because the relative phases will determine the degree to which constructive or destructive interference occurs. In English, whether the waveforms reinforce or cancel each other. Edit: A double bass and its amplifying rig can be considered two such systems. In this case, changing the polarity of the amplifying system can reduce acoustic cancellation between the speaker system and the bass itself. Differences in relative phase (or more properly, timing differences) are also crucial across your two ears. That's a fundamental cue for the localization of sound but that's another chapter entirely.

 

[Uncletoad]

With the acoustic bass when the speaker signal is out of phase with the movement of the top it sounds tighter and gets less feedback. Phase reversal on a fender bass is useless. On my Double Bass it is crucial past the normal low volume spots. I prefer phase reversal at the source rather than switching the speaker cables because PA's speakers need the same relationship to my bass as the amp does or it howls like a pig at concert levels.

The low pass filters I have used in the past have had cutoff points at 20hz, 40hz, and a variable from 30 to 120. In each case including the lowest setting on the variable filter the low end rumbling around the bandstand was reduced and my band mates were less satisfied. I can't explain where that sound is coming from but I'm quite sure it's there.

You are suggesting that all those filters are kicking in above 43hz. Perhaps that is the case. I think more likely that there are lower partials that exist in a bass string note that are present in the same way upper partials are. 43hz may be a fundamental note but I think I feel stuff lower than that frequency that the low pass filters scrub out when in use.

I don't have any empirical or documented stuff to prove that. I could be dead wrong. I'd like to see the scope of a bass string note that emanates from the fundamental up only. That would be interesting.

 

[shwashwa]

i have to say that i'm addicted to my high pass filter, but i think you need to use it in conjunction with your volume control. at low volumes i dont use it at all, in fact at low volumes i'm boosting the bass like crazy because i still want to feel the bass. i think its like the "loudness" control on a stereo system , or the "enhance" knob on the swr amps. at low volumes it's good to enhance the sound by adding lows (and highs). at higher volumes the low end doesnt need much enhancing for me. there's plenty to go around, so much so at those volumes that i think some of it (probably the infrasonics created by the piezo, not the bass itself) clouds my tone and actually starts to bother my ears after a while. what i do with the fishman is boost the bass slider all the way, then dial the hp filter till i hear just the right amount of tightening in the sound that i want. i can still get plenty enough bottom to feel the bass, but it cuts out the stuff that just makes mud. guys on the bandstand have commented that they like it on better in those loud situations, but just enough tighten up a little. so in other words, i think the overall volume is a big factor in deciding if you want to use one or not... just my $.02

 

[bribass]

Now, why is it that you guys think that absolute phase with a single driver matters?

So it does matter if you are using a two speaker system?

Also i have to agree w/ what Uncletood describes on the bandstand. Too much girthy lows get cut out. Initially we're both talking about the HP's on the Focus 2R III which is the only HP I have exprience w/,but Phil has says he experiences this w/ other HP's as well. Can they all be set higher than they say?
BG

 

[drurb]

With the acoustic bass when the speaker signal is out of phase with the movement of the top it sounds tighter and gets less feedback. Phase reversal on a fender bass is useless. On my Double Bass it is crucial past the normal low volume spots. I prefer phase reversal at the source rather than switching the speaker cables because PA's speakers need the same relationship to my bass as the amp does or it howls like a pig at concert levels.

Okay, I see. Yes, indeed, the relative phase between your bass and the speaker may be quite important. It ends up being the "two system" case I discussed. I had not considered that effect. Sorry. For years (and it still goes on) there were nut-cases who argued that they could hear "absolute phase" in hi-fi systems. When you mentioned polarity, I got sucked down that old road.

...I think more likely that there are lower partials that exist in a bass string note that are present in the same way upper partials are. 43hz may be a fundamental note but I think I feel stuff lower than that frequency that the low pass filters scrub out when in use.

Well, when a string vibrates, the fundamental is the lowest partial. That's why is referred to as f0. Now, the only way I can imagine you can get lower frequencies out is if the pickup transduces the percussion of your fingers hitting the string. I seriously doubt that percussion would produce appreciable energy below 40 Hz. I do know this. Such energy would never be transmitted acoustically by the bass. Thus, if you were to mike a bass, you'd never get any of it. This puts us back where I started-- holding that any of those very low frequencies are artifacts of the pickup system. You may very well find them desirable. To each his own and enjoy!