Driver size for upright sound

[funkyjazz]

In my quest for the sound of my acoustic bass guitar which in fact sounds much more like an upright I tested the cabs I have and found the following

Tecamp 1x12

I had to exclude the tweeter immediately to avoid feedback from microphone.

The sound was good but a bit towards the low mids and not as dry as I wish for an upright sound.

 

PJB C4

much more the sound I want. Unfortunately the 5" speakers tended to feed a bit more than the 12" alone so some care was needed. I had to engage a notch filter on my Headway EDB2-HE preamp and keep the speaker high at ear level. Whereas I could play with the bass right in front of the 12" speaker almost no problem.

 

Now my question.

Are there 12" speakers which can sound a bit more dry than the one I have maybe with an additional 6" driver as the FMC ones or should I just stay below the 10"?

 

[Phil Starr]

With any acoustic instrument the problem is down to resonances. There are frequencies at which the body of the bass is going to resonate and other frequencies at which the air inside will also resonate. It's what makes an acoustic instrument sound different from a solid bass. If your amplification also has peaks at those frequencies you'll get feedback earlier as you turn the volume up.

 

Your speaker will have frequency peaks and yes, some speakers are flatter than others but largely that isn't due to the diameter of the speaker.

 

A lot of those frequencies are affected by distance, starting with the mic. Have a look at You Tube for videos on how to mic an acoustic guitar, the positioning of the mic is crucial to getting a good sound and avoiding feedback. I'm assuming you are using a vocal mic? That may have built in frequency boosts to enhance the human voice. Ultimately you might need to look at buying a new mic or going for a fitted pickup. Worth also visiting the UB section of BassChat and asking there.

 

Don't go rushing out and buying stuff though, try and get the best out of what you have and study how other people are doing this. I remember from my PA days back in the early 70's the nightmare of mic'ing up acoustic guitars and the joy of semi acoustics with built in pickups when they first appeared. There's a learning curve I'm afraid. Good Luck

[funkyjazz]

Just for clarity. I have a piezo pickup and as mic a DPA 4099 for double bass. I have worked at the sound in headphones and now I am happy with it. I am just trying to find the right cabinet for my taste. The PJB C4 is already a good one. But I tend to look at other opportunities to get a better sound all the time

[Frank Blank]

I was on exactly this quest as I wanted my Rob Allen Mouse to sound as much like an upright bass as possible for some songs. I found the best sounding to me was to use a QSC K12.2, even without a preamp, just bass straight in, it sounds great and very upright like.

[Beer of the Bass]

Putting a microphone through backline is always tricky for feedback, and I only see people having success with it on very low volume gigs. A lot of double bassists using a mic for larger shows are running only pickup signal into their backline amp, and the mic goes to the FOH.

[Dan Dare]

1 hour ago, Beer of the Bass said:

Putting a microphone through backline is always tricky for feedback, and I only see people having success with it on very low volume gigs. A lot of double bassists using a mic for larger shows are running only pickup signal into their backline amp, and the mic goes to the FOH.

 This. A mic' into your backline, combined with a naturally resonant instrument like an acoustic bass guitar or double bass, is almost inevitably going to suffer feedback and require some sort of notch filtering at anything other than low volume. Pickup into backline and mic to FOH is usually the best compromise. It means you won't hear exactly the sound you like from your backline, but it's workable practically.

 

Driver size is not relevant. I use several C4s and/or 4Bs for electric bass and they have plenty of bottom end and are not "dry" unless I eq the amp to be so. 

Edited August 8, 2023 by Dan Dare

[Phil Starr]

4 hours ago, Frank Blank said:

I was on exactly this quest as I wanted my Rob Allen Mouse to sound as much like an upright bass as possible for some songs. I found the best sounding to me was to use a QSC K12.2, even without a preamp, just bass straight in, it sounds great and very upright like.

Great advice above.

 

OK you only mentioned a mic, a mix of the piezo and a mic like that is a great way to go. Your original post also implied both bass feedback and problems with mids and top end so I was trying to address both.

 

The QSC is a great speaker, I was going to suggest that a PA speaker would be a way to go, the flatter the response the less chance of hitting those resonances. Few dedicated bass speakers or amps are truly flat response and the whole point of PA speakers is to only reproduce what they are sent.

 

We've been looking at speakers for DB recently and a restricted bass response helps a lot. We had good results with a 'shelving response' where the inherent characteristic of the speaker starts to cut the bass fairly high up but then sees it fall slowly down to cover most of the fundamental frequencies. 

[Bill Fitzmaurice]

If I was to have a speaker for upright use only I'd load it with an eight inch. The upright low frequency limit is much higher than electric bass, so there's no need for the lower response or low frequency output capability of larger than an eight. An eight will go high enough to make a midrange and/or tweeter unnecessary, and will have 1.5 times the midrange dispersion angle of a twelve. For higher output requirements I'd use a stacked pair.

 

On the low frequency limit, the two instruments do have the same fundamental frequencies, but the main content lies in the harmonics, not the fundamentals. When an open E is played on electric most of the content is at 82Hz and higher, when played on an upright most of the content is at 123Hz and higher.

[JPJ]

18 minutes ago, Bill Fitzmaurice said:

If I was to have a speaker for upright use only I'd load it with an eight inch. The upright low frequency limit is much higher than electric bass, so there's no need for the lower response or low frequency output capability of larger than an eight. An eight will go high enough to make a midrange and/or tweeter unnecessary, and will have 1.5 times the midrange dispersion angle of a twelve. For higher output requirements I'd use a stacked pair.

 

On the low frequency limit, the two instruments do have the same fundamental frequencies, but the main content lies in the harmonics, not the fundamentals. When an open E is played on electric most of the content is at 82Hz and higher, when played on an upright most of the content is at 123Hz and higher.

^ and this is the technical answer to why my NS EUB ‘sounds’ best through my TC BG250 208 combo. 

[Frank Blank]

3 minutes ago, JPJ said:

^ and this is the technical answer to why my NS EUB ‘sounds’ best through my TC BG250 208 combo. 

 

 ...and why a lot of upright players use AER amps. I used to have the AER Basic Performer, lovely amp but it didn't sound as good as the QSC.

[tauzero]

Have you got a sound cover in the bass soundhole? https://rockguitaruniverse.com/guitarists-cover-the-soundhole/

 

It should at least help suppress the feedback.

[funkyjazz]

It is more of a hiss (mic picked up by the driver).

btw I have some custom f holes so there won’t be a solution (if that would have helped) other than blowing 2 balloons inside the body