Double Bass electric bass amp with upright?

[fdeck]

I have no idea what this means. If you are referring to loudness countours (ala Fletcher and Munson), it is not relevant as those curves flatten well below the levels that typify amplified instruments.

I was indeed referring to loudness contours. Thanks for clearing up my misconception!

All of this speaks, once again, for the ideal of choosing components with reasonable flat response within the range of the spectrum you wish to reproduce. Choosing otherwise is what is likely to result in hit-or-miss affairs because you are hoping that the errors compensate for each other. That's tricky business.

In principle, I agree. For my day job, I design scientific instrumentation, and we always try for the flattest possible response function before adding corrections that basically amount to equalization. And I would do this with music gear unless faced with an extenuating circumstance.

The extenuating circumstance is that a speaker with flat response down to 40 Hz is going to be big and/or inefficient, but a lot of bassists seem to be happy with speakers that have a cutoff frequency well above 40 Hz. Equalizing the speaker, rather than the electronics, to have this cutoff, results in a speaker that is smaller and more efficient -- the proverbial free lunch.

For better or worse, the point of departure for most bass speakers is not a flat response function, and like you say, it does add to the guesswork. But the gain in portability is worth the trouble, and it seems to be a workable compromise for most bassists.

 

[Doug Ring]

I think an open E-string is 43Hz, so it would seem you'd need a speaker that goes down to 40 Hz, yes.

But just last night I was playing my bass guitar through a digital sound desk that has very steep high-pass filters. The monitoring in this studio has a sub woofer, so I could be confident about what I was hearing. Starting off with no filtering, the bass sound was deep, boomy and ... hideous. Filtering below 40 Hz made no difference. In fact, I had to turn the filter up to 50 Hz before there was a noticeable difference, and the sound cleaned up and became much more presentable right up to 55Hz. After that it started to sound thin.

My point is that there's no need for speakers that go very low for a 4-string bass to do its job musically. The ear seems to put the fundamental back in the correct proportion, and that's why you can often get away with or even prefer the sound of an 8" or 10" speaker. Don't forget too that a lot of speaker measurements are done in anechoic chambers, not real rooms. Because a lot of rooms will have resonances around the low notes of our instrument, you get "free" amplification of those notes and don't need to put out full power down there.

 

[drurb]

I was indeed referring to loudness contours. Thanks for clearing up my misconception!

In principle, I agree. For my day job, I design scientific instrumentation, and we always try for the flattest possible response function before adding corrections that basically amount to equalization. And I would do this with music gear unless faced with an extenuating circumstance.

The extenuating circumstance is that a speaker with flat response down to 40 Hz is going to be big and/or inefficient, but a lot of bassists seem to be happy with speakers that have a cutoff frequency well above 40 Hz. Equalizing the speaker, rather than the electronics, to have this cutoff, results in a speaker that is smaller and more efficient -- the proverbial free lunch.

For better or worse, the point of departure for most bass speakers is not a flat response function, and like you say, it does add to the guesswork. But the gain in portability is worth the trouble, and it seems to be a workable compromise for most bassists.

Agreed, except for the efficiency part. There is a long-standing engineering axiom. You can only have two of the following three:

1) Small cabinet

2) Extended bass response

3) High sensitivity

For a small cabinet to have extended bass response, it will be most "inefficient." When one uses heavy equalization of small cabinets to achieve good low-end response, it is at the expense of sensitivity/efficiency.

Some, like Paul Klipsch, have argued that much more is sacrificed. That's more of a hi-fi concern and would take this post way off track.

 

[drurb]

I think an open E-string is 43Hz, so it would seem you'd need a speaker that goes down to 40 Hz, yes.

But just last night I was playing my bass guitar through a digital sound desk that has very steep high-pass filters. The monitoring in this studio has a sub woofer, so I could be confident about what I was hearing. Starting off with no filtering, the bass sound was deep, boomy and ... hideous. Filtering below 40 Hz made no difference. In fact, I had to turn the filter up to 50 Hz before there was a noticeable difference, and the sound cleaned up and became much more presentable right up to 55Hz. After that it started to sound thin.

My point is that there's no need for speakers that go very low for a 4-string bass to do its job musically. The ear seems to put the fundamental back in the correct proportion, and that's why you can often get away with or even prefer the sound of an 8" or 10" speaker. Don't forget too that a lot of speaker measurements are done in anechoic chambers, not real rooms. Because a lot of rooms will have resonances around the low notes of our instrument, you get "free" amplification of those notes and don't need to put out full power down there.

You are mostly correct. I have been making a similar argument in these threads regarding the high-frequency cutoff. That is, if there is no appreciable energy there, one does not need to have a system that will reproduce it. Thank you for reinforcing this point with regard to the low end as well. One should be aware, however, that manufacturers often use the 3-dB down point as the lower cutoff. Unscrupulous manufacturers will spec the lower cutoff substantially lower.

The ear does not restore the fundamental in proper "proportion." What the auditory system (not the ear, per se) does do is restore the pitch of the fundamental. That's why you hear correct bass pitch even with a little AM radio! The pitch is restored via the partials that are resolved along the basilar membrane of the cochlea. I could go on about this but I'll stop there. The point is that you cannot restore the power and "feeling" of the fundamental. When it is missing, it is easily discriminable from when it is there. Your filtering experiences make perfect sense.

 

[TroyK]

That's more of a hi-fi concern and would take this post way off track.

THAT would take this post way off track?

When I saw the original question posted which was something like "hey I need to amplify my double bass for the first time, will the amp I use for my electric bass work?" I smiled, because I knew what he was in for.

The answer is: "Yes it will work, but you may find that you're not satisfied with the sound and start chasing true neutral doublebass amplification, which is elusive and expensive, but by all means start with the amp you have and go from there."

I knew that those of us who have already fallen off the deep end pursuing "the sound" wouldn't be able to leave it at that and although, I think we've lost track of the original question, I've been facinated by the analysis from you guys. Nothing but respect for your knowledge and attention to detail and I'm grateful for this forum so that I can reference this type of info, but I had to jump in on "..that would take this post off track."

Nothin' but love for you brothers!

Troy

 

[Ric Vice]

I think an open E-string is 43Hz, so it would seem you'd need a speaker that goes down to 40 Hz, yes.

Because a lot of rooms will have resonances around the low notes of our instrument, you get "free" amplification of those notes and don't need to put out full power down there.

Doug,
That must be why my bass sounds so good in the corner
of my practice room. Wooden floors.

 

[Dan in NJ]

Great stuff! FWIW I'm with Troy, play whatcha got--it's useful to learn how to make a less than ideal amp work for a gig, right?
The pursuit of getting "the" sound will keep us going and going, because it's so cool to sit inside a beautiful sound--
so yeah Troy I agree--the definitive answer is yes and no--

haha!

 

[Doug Ring]

Doug,
That must be why my bass sounds so good in the corner
of my practice room. Wooden floors.

Yep, Ric: A floor helps, a floor next to a wall helps more, and a floor and two walls - a corner - helps even more!

 

[Doug Ring]

What the auditory system (not the ear, per se) does do is restore the pitch of the fundamental. That's why you hear correct bass pitch even with a little AM radio!

Man, you don't let nobody off with nothing

You're quite right of course. You can't perceive more energy than was originally there. I should have chosen my words more carefully.

 

[drurb]

Man, you don't let nobody off with nothing

You're quite right of course. You can't perceive more energy than was originally there. I should have chosen my words more carefully.

Well, by th icon you included, I am reasonably confident that you accepted my comment in the spirit in which it was offered. The phenomenon of the perception of the "missing fundamental" is one of the oldest in pyschoacoustics. I just wanted to be sure that readers knew what it was about.