Double Bass Directional amplification

[JBarz]

Hey gang,
I know enough about studio subwoofer placement to know that I know very little in terms of voicing a room.

I am seeking consistency in a sea of variables when it comes to amp placement. I prefer acoustic playing - having to hear my sound come from a box across the bandstand is irksome to me.

I know a lot comes down to experiment and trial and error in different spaces, but can we distill our collective wisdom to any easy to remember axioms?
(ie, “never in a corner”, “at least 6’ away from bass drum”, etc)

I keep going in and out of love with my (very directional) Phil Jones Amp gear (cub or suitcase, older style), but every once in a while I’ll hit that sweet spot in the bar where it doesn’t feel amplified but I can hear myself in the mix without dominating.

I’m intrigued by the upfiring AI gear, but also know that gear lust and GAS is a trap and am not letting myself indulge, but I am considering modifying my PJB cub to be down firing, I don’t know - has anyone experimented with this kind of thing? I couldn’t find much info in the search.

Help a novice out - where do ya’ll tend to put your amps in the context of a small jazz quartet in awkward shaped bars/bandstands?

 

[AGCurry]

Hey gang,
I know enough about studio subwoofer placement to know that I know very little in terms of voicing a room.

I am seeking consistency in a sea of variables when it comes to amp placement. I prefer acoustic playing - having to hear my sound come from a box across the bandstand is irksome to me.

I know a lot comes down to experiment and trial and error in different spaces, but can we distill our collective wisdom to any easy to remember axioms?
(ie, “never in a corner”, “at least 6’ away from bass drum”, etc)

I keep going in and out of love with my (very directional) Phil Jones Amp gear (cub or suitcase, older style), but every once in a while I’ll hit that sweet spot in the bar where it doesn’t feel amplified but I can hear myself in the mix without dominating.

I’m intrigued by the upfiring AI gear, but also know that gear lust and GAS is a trap and am not letting myself indulge, but I am considering modifying my PJB cub to be down firing, I don’t know - has anyone experimented with this kind of thing? I couldn’t find much info in the search.

Help a novice out - where do ya’ll tend to put your amps in the context of a small jazz quartet in awkward shaped bars/bandstands?

In my experience with "awkward shaped bars/bandstands," the decision of where to put my amp has very little to do with sound and much to do with where it can fit.

 

[JBarz]

Yeah, that’s kind of the blessing/curse of this tiny PJB Cub amp - it can fit in anywhere and works great in low-volume situations, but really seems to change characteristics in the mix depending on where I physically put it. I’m probably overthinking the whole thing.

 

[AGCurry]

Low frequencies are inherently less directional than higher ones, so when you're calling your speaker "very directional" you're probably referring to overtones.

Conventional wisdom applies - pointing at your ears more than your feet, away from walls, etc.. Some rooms are great, others aren't. It's impossible to do accurate sound checks without an audience, and you can't really interrupt the gig to move your stuff around, so you just have to arrange as best you can, using conventional wisdom, and have faith.

Moreover, I find that my happiness with a room is influenced by how well I hear and accept what I'm hearing... in other words, I have to stop fighting it.

 

[brianrost]

To get truly directional at a given frequency requires a stack of speakers roughly as tall as the wavelength of the lowest frequency. The wavelength of the open E string is about 25 feet. The open C (with an extension) is about 36 feet. So no normal amp is going to be directional at the low fundamentals.

While not used for DB amplification, here's one audacious solution that was abandoned due to the expense of hauling it around. The reason for so many speakers is that each instrument and microphone had it's own set of speakers and did not required monitors, either. Supposedly it could project for a quarter mile (1320 feet) before wind interference started reducing the sound quality.

Today's downsized equivalent is the Bose L series, which was intended to be used as a set of columns, one per performer. Few people actually use the Bose systems that way except for solo performers. Because the Bose colums are not 30 feet tall, subwoofers are added for instruments like bass or drums. I've played my DB with a Full Circle and Baggs preamp through a Bose system and liked the sound, but it's not very practical as a gigging amp.

 

[Greg Clinkingbeard]

I setup wherever it makes sense from a comfort and visual sense. It’s very important to be able to maintain eye contact with everyone on the bandstand. I prefer to be on the Hi Hat side of the drummer, although that is negotiable.
With those considerations in mind, I put the amp on my left so I can adjust the volume and eq to the room. Before amplification, it is said that bassists chose their spot based on how the riser or stage resonated and helped them project. Thankfully, we’ve moved on from that.

 

[AGCurry]

... here's one audacious solution that was abandoned due to the expense of hauling it around.
View attachment 4335470

Ya think?

 

[Wasnex]

I keep going in and out of love with my (very directional) Phil Jones Amp gear (cub or suitcase, older style), but every once in a while I’ll hit that sweet spot in the bar where it doesn’t feel amplified but I can hear myself in the mix without dominating.

I used a setup that was intended to make it easier for me to hear my bass while minimizing my stage volume. We generally had full audio support, so the PA distributed my sound to the audience and other musicians, and my amp served primarily as my personal monitor.

I toured, so my cab was in a flight case with wheels. I used the flight case as a speaker stand. This put the bottom of the cab about 3' off the ground. Additionally I wedged an extra DI under the front of the cab, so it tilted back and pointed up at my head. I did this because low frequencies are omni-directional, and speakers only develop pattern control as the frequency goes higher. This changing dispersion pattern is due to the relationship between the wavelength of the sound and the size of the radiating surface provide by the speaker. A bigger radiating surface will control the dispersion to a lower frequency, but it also tends to get beamy at a lower frequency as well. The relevant point is if the cab is not aimed at your ears, you probably won't hear it full frequency response unless you are far enough from it to get into the dispersion pattern for all frequencies.

Even worse, with a cab that uses several of the same type of driver, you get destructive interference off axis, that can be described as comb filtering or lobing. The result is you hear a frequency response with peaks and dips instead of being nice and flat.

Elevating the cab reduces the lows and also introduces a notch in the low mids that is determined by distance from the cab to the reflective surface. You get cancellation where the distance is equal to 1/4 wavelength. With the cab elevated to 3', I believe the cancellation occurs centered in the low to mid 90hz range. I personally like this sounds.

The other benefit of elevating and tilting the cab is less energy is directed in the the basses body. In my experience this reduces the interaction between the bass and amp so the sound is more natural and there is less chance of feedback.

One final aspect is I generally had the amp really close to my back. To me, playing through an amp makes me feel disconnected from the instrument to some degree, as if there is a percieved delay between when I pluck and the sound reaching my ears. Keeping the amp as close to your ears as possible seems to help with this sensation somewhat. Hearing the higher frequencies more clearly also seems to help.

Getting the amp close to your ears also changes the balance between the direct and indirect sound Frequently there is a build up of low frequencies in the reverberant field. If the reverberant field is too strong it can mask your direct sound, so you only hear an unfocused, incoherent mess, instead of a nice focused tone.

I really like this approach as I prefer to hear the lows, mids, and highs as naturally balanced as possible. Many do not like this approach because they want to feel surrounded in a nice warm, deep, thumpy sound, rather than hearing a clear and focused tone. Perhaps the secret is each person should experiment with this setup and learn to find the balance they prefer. The only problem is each performance hall will have its own unique acoustic problems, so you can't use the exact some setup and adjustments for each gig. Rather, you need to assess each situation and adapt.

Good luck!

 

[jthisdell]

While not used for DB amplification, here's one audacious solution that was abandoned due to the expense of hauling it around. The reason for so many speakers is that each instrument and microphone had it's own set of speakers and did not required monitors, either. Supposedly it could project for a quarter mile (1320 feet) before wind interference started reducing the sound quality.

To take it to extreme, each string of Phil Lesch's bass went through a separate set of amps and a separate stack of speakers. I have a hard time seeing the benefit of that but that was how it worked.

 

[Wasnex]

To take it to extreme, each string of Phil Lesch's bass went through a separate set of amps and a separate stack of speakers. I have a hard time seeing the benefit of that but that was how it worked.

IMHO, beneficial yes, practical no.

My last touring rig typically used an Eden D210XLT powered by about 250W. I also had a D410XLT and a stereo power amp so I could run both. I didn't really feel the larger cab provided enough benefit to bother. When I did run both, it was usually to satisfy someone else's needs.

After I retired from gigging, I assembled this rig, which was inspired by the Wall of Sound. This was just for fun, and I doubt I will ever gig the stack. I does sound pretty darn awesome though.

Way smaller than Phil's part of the Wall of Sound, and IMHO still totally impractical. Per the spec sheet, height is 7'8" and weight is 232lbs.

The cabs are Genz Benz Uber Quad (1288T-UQ). I don't really like the way one by itself sounds, but two is way more than I would ever need. Three offers a fairly significant improvement in tone, but the difference when you add the fourth cab is actually pretty small. Mainly adding a fourth cab moves the ghost image of the sound source a bit higher.

(Note) To my surprise the ghost image seems to emanate from the center of a straight array, and I had the same observation with Bose L1s.

It would be fun to see how high I could stack the array before I stopped noting any perceived change, but it seems silly to continue dropping cash into something I never plan to use.

Of course this is only working as a line source in the mids. It is too short to function as a line source down low, and 8" mid drivers are too big to integrate into a line source up high. Also if you move your head up and down, you can hear the gap between the 8s in each cab.

 

[JBarz]

I’ve actually got one of those L1 Bose vocal amps I use for solo guitar/vox gigs - I should try bringing it out for bass - hadn’t thought of that yet.

Here to fore, I’ve thinking about trying to be less directional - maybe even pointing the amp at the back wall - trying to catch the current of the room, so to speak, so the amp fills the space with minimum “effort” … but now ya’ll have me rethinking that approach. Thanks for giving me some food for thought. I’m going mess around with these ideas for the next couple months and let you know if anything works out particularly well. I appreciate your help and guidance as always.​

 

[Chris Fitzgerald]

I use a PJB Super Flightcase. It has two upfiring speakers and 4 front firing. I set it right by my left foot so that I can hear the upfiring sound, and forward enough that the front firing sound goes past my bass and toward the audience. This setup has worked well for years.

I have a CUB as well, and find that it sounds OK...until suddenly, it doesn’t. I think they made the cabinet and ports too small for optimal sound in the interest of size. Past a certain volume point, it sounds like a muffled shoebox. I never take it on gigs any more because it’s a crapshoot as to whether the gig will require the volume to be turned up past the muddy shoebox threshold.

 

[JBarz]

I’m with you about the Cub. It seems to work best with gut strings and Realist pickups (opposed to steel and full circle), but still only does the business 1/2 the time in any given room, even at low volumes. I’m going to stop bringing it out and relegate it to a practice/travel amp for my EUB… I would love it if my old-school first gen PJB suitcase had a couple upfiring speakers! That was a super clever re-design on their part and I might see if I can just trade up for one or an AI upfiring combo if I can’t find some compromise with the gear I’ve already got. Although I loathe the idea of carrying more stuff to the gig, maybe the suitcase + the cub as a monitor/“ear box” kinda deal is the solution- we’ll see)… Appreciate the wisdom!

 

[Marty Forrer]

In recent times I have gone from 2 1x10 Barefaced cabs on the floor to just one mounted on a pole at ear height. I run a line from the DI on my amp head to the PA desk. This lets me hear what I'm playing with the benefit of also going through 2 1x12 tops and 2 1x15 subs. Very pleased with it so far.

 

[kerrycares]

Welcome to one of the worlds largest rabbit holes!
Recently I have been smitten by the Acoustic Image Doubleshot and as soon as the world opens back up I’ll get one.

 

[N. Kentucky Bass]

The best of both worlds works for me. Two speakers firing straight out, and two up. Thanks Phil!

 

[JBarz]

Those barefaced cabs look awesome - looks kinda like the old GK cabs!

Here’s what I’m going to try this week. The cushion gives it up to 8 inches of angled lift — My intention is to stand 6’ in front of the amp with my ears directly in the “line of fire”, and simply make fine adjustments to the volume via my fdeckv3. Simple and elegant - but I’ll let you know how effective…

 

[DaveAceofBass]

I use a Barefaced Super Midget on a pole mount behind me, along with either Acoustic Image or Aguilar heads. I often use a One 10 somewhere on the floor angled up towards me as well if I need more sound.

 

[Chris Fitzgerald]

Those barefaced cabs look awesome - looks kinda like the old GK cabs!

Here’s what I’m going to try this week. The cushion gives it up to 8 inches of angled lift — My intention is to stand 6’ in front of the amp with my ears directly in the “line of fire”, and simply make fine adjustments to the volume via my fdeckv3. Simple and elegant - but I’ll let you know how effective…

View attachment 4340172

Years ago, I used a simple tilt back mechanism on my cabs - just a small flat piece of wood to tilt the cab back onto, and a strap with velcro to attach it to the bottom of the cab. It worked well, and was simple enough that even I could build it.

 

[N. Kentucky Bass]

I use this to angle a cab. Fits in a gig bag. Works great!