Boomy Amp Issues

[dazza14]

Hi all, I'm looking for a little advice with my amp setup.

I have a Mark Bass combo amp, it's a single 12" speaker, which was lovely for my old Squier Jazz bass when I played rock stuff, but now I play a double bass and the amp seems a bit too much for the task.

I have the volume set to around 2 on the dial and even then the bass is boomy on certain notes which disrupts the overall balance of sound that my jazz band produces.

I've tried turning down the bass and upping the mid and treble but it's still booming and I wonder if I would be better off using a smaller speaker size, say a 8"...?

 

Does anyone have any advice?

 

I've tried sitting the amp higher, on a stool or stand, and I keep the amp away from the cavity of the double bass so I don't get echo/reverb.

I use a pickup that sits beneath the bass bridge. I get no feedback from it.

[Jakester]

You say it's not feedback, but are you sure? If it suddenly sounds boomy on certain notes it could be resonance-induced feedback on particular frequencies. 

 

I have the same amp and an under-bridge pickup and I do get some feedback if too close to the amp on certain notes/frequencies. 

 

I recently posted a thread about feedback on hollow-raised stages and it was suggested I get a HPF - perhaps that might help you? 

 

Or perhaps try using multiband eq to identify the particular frequency and cut it?

[Bloopdad1]

You need a High Pass Filter. 

You don't mention what pickup you're using of if you're going through a preamp. It often helps if you can switch the phasing 180° but unless you have that facility then get yourself a HPF to cut all the mud/boominess below your "boom" threshold. 

 

[songofthewind]

I have just acquired one of these amps, and I find it is boomier than my MarkBass 2x10 combo.

I spent this morning experimenting with the parametric EQ in my Helix HX Effects to good effect. I set a couple of parametric to cut various frequencies below 40hz. I am going to try this at various volumes, but initial results are very promising. Everything just sounds higher and more focussed.

[jrixn1]

1 hour ago, dazza14 said:

the bass is boomy on certain notes

 

Continual low booming on all notes, I would say HPF.  But boomy only on some notes - which ones?  For me it was A/Bb on the G string, and a wolf tone eliminator helped e.g. https://musicalsuppliesdirect.co.uk/product/double-bass-wolf-note-eliminator/ 

 

It goes on the afterlength and alters or dampens its resonant frequency (or something like that).

[dazza14]

Morning all, the pickup I use is a Realist Copperhead.

The note that booms the most is B on the A string, I watched an organist play in the same venue and his bass pedals boomed at the same note, I'm wondering if some of the issue is the room, maybe the hard surfaces resonate...

 

I think I'll look at HPF's but I was wondering if the amp is just too much for the size of room because I use a practice amp at practice, a 30W guitar amp with a 8" speaker and there is no problem.

[Clarky]

Even if its the room, an HPF would be a good long term investment. While its difficult to get hold of an fdeck (the US manufacturer won't ship overseas), there is an fdeck clone made by Rafferty in the UK which sells for £90 https://www.ebay.co.uk/itm/125014998206

[Beer of the Bass]

Apologies if this is an overly dumb question, but how are you setting the VLE and VPF filter controls on the Markbass? The "off" setting on those knobs is fully anti-clockwise, and I've seen a few people not realise that and start with them at 12 o'clock.

Edited August 11, 2022 by Beer of the Bass

[dazza14]

15 hours ago, Beer of the Bass said:

Apologies if this is an overly dumb question, but how are you setting the VLE and VPF filter controls on the Markbass? The "off" setting on those knobs is fully anti-clockwise, and I've seen a few people not realise that and start with them at 12 o'clock.

I'll have to have a look. I think some time fiddling with the settings would be a good start and then looking at HPF's.

[tinyd]

I have a GK amp (12") and a Realist pickup and it definitely requires spending time with the amp's EQ to get rid of those nasty frequencies, especially as they can be a lot more "specific" than on BG.

[Maude]

A HPF is a really good thing to have with doublebass even if you don't think you have a problem. 

I use a PJB Suitcase with a 4b extension cab with my doublebass. 

Without the fdeck HPF it sounded fine but my speakers were moving back and forth a long way. 

Occasionally things got slightly boomy so I got the fdeck. 

With it the occasional booniness was sorted but two added bonuses occurred. 1, the speakers now hardly move at the same volumes where they were leaping around before and 2, the whole band just sounds cleaner and better. 

The amp/speakers were obviously spending a lot of energy trying to produce inaudible low notes, and all that subsonic mush was having a detrimental effect on the rest of the bands sound. 

I now use it even at low volumes just to clean up the whole bands sound. 

 

[NickA]

Spec sheet for my pjb flightcase says it has a 40Hz hpf built in. 

 

This thread reckons all modern amps do, so an external hpf might not help.

 

When I've had " boomyness" it's fixed by standing to the side of the speakers and careful placement / tightening of the pickup (a realist sound clamp) piezos don't like being squeezed too hard.

[Dan Dare]

Amplifying acoustic instruments is always a compromise. You have a big hollow box full of air that vibrates in sympathy with what is happening in the air around it. The resonant frequency/frequencies of the instrument itself usually need to be tamed. If you're playing on a hollow or resonant stage or surface (being a double bass, the instrument will make physical contact with it) that can exacerbate the problems. Feedback doesn't have to manifest itself overtly (i.e. through actual howling and squealing) to be an issue.

 

When I use a pickup on my fiddle, I find notes around D always cause trouble.

 

A decent parametric eq can be very helpful. A HPF can be a bit of a blunt instrument, in that it gets rid of a lot of things from the sound that you ideally want to keep.

[NickA]

9 hours ago, Dan Dare said:

A decent parametric eq

Indeed.  There's a great you tube video of John Patitucci playing with a sound clip pickup and demonstrating how to remove unwanted frequencies using eq.  It helped my double bass sound ok through my old trace 1x15" (though getting a 10x 5" pjb worked even better!)

 

https://m.youtube.com/watch?v=sNQclaAmyX8

 

I was at Clark Tracey gig last year and the bass sounded awful, some notes disappeared and some too loud.  Even the pros get it wrong!

[Dan Dare]

On 22/08/2022 at 22:19, NickA said:

Indeed.  There's a great you tube video of John Patitucci playing with a sound clip pickup and demonstrating how to remove unwanted frequencies using eq.  It helped my double bass sound ok through my old trace 1x15" (though getting a 10x 5" pjb worked even better!)

 

https://m.youtube.com/watch?v=sNQclaAmyX8

 

I was at Clark Tracey gig last year and the bass sounded awful, some notes disappeared and some too loud.  Even the pros get it wrong!

 

PJB are my speakers of choice, too, for electric as well as DB (and my fiddle, for which they work nicely - no tweeters to accentuate the harsh high frequencies that you can get when using a bow). I have five of his 5x4 cabs and use as many as the occasion demands. They're also great when you want that foam-under-the-strings P bass thump. 

[Downunderwonder]

On 11/08/2022 at 20:03, dazza14 said:

30W guitar amp with a 8" speaker and there is no problem

No problem because it won't be making any fundamental of that B.

 

100% the room is tuned somewhere around 60hz or 120hz.

[Marty Forrer]

Another point is that piezo pickups like a minimum 1 meg ohm load. Many bass guitar amps have an impedance much less than this because magnetic pickups don't care. Not sure about Markbass, but my Acoustic Image Clarus head has 1 meg and 10 meg inputs. My Genzler Magellan head has a 1 meg input. Both sound great with a piezo. Also I agree with Downunderwonder, sounds like the room has those annoying troublespots. An amp with a semi-parametric eq section would allow you to find that frequency and dial it out. Now I think about it, I once had two Markbass heads and they sounded OK for bass guitar, but I got rid of them because I'm a doubler and couldn't get a decent double bass sound from them. Just my experience.

Edited August 30, 2022 by Marty Forrer

[dazza14]

Reading the responses and it becomes beautifully technical and scientific. Brilliant! 

I spent a few hours with my MarkBass amp and fiddled with the settings, I have now got a nice warm tone that I am happy with - for the practice room at least - I had to reduce the Gain and I toyed with the knob called VPF which after a few attempts did the trick.

The rest was simple EQ stuff which was surprisingly responsive.

[pete.young]

VPF is effectively a mid-range cut.

[Downunderwonder]

On 07/09/2022 at 22:11, dazza14 said:

Reading the responses and it becomes beautifully technical and scientific. Brilliant! 

I spent a few hours with my MarkBass amp and fiddled with the settings, I have now got a nice warm tone that I am happy with - for the practice room at least - I had to reduce the Gain and I toyed with the knob called VPF which after a few attempts did the trick.

The rest was simple EQ stuff which was surprisingly responsive.

The VPF cut indicates you have a ~120hz resonance.

[Japhet]

I'd be tempted to try a Behringer FBQ1502. It's a full graphic equalizer (15 band I think). If it detects feedback at any frequency an LED on that slider flashes which makes it dead easy to cut out trouble on a narrow frequency band. Have used the bigger FBQ3102 a lot (for PA duties) and it's a good bit of kit. Usually cheap as chips on Ebay too.

[Paddy Morris]

I thought I'd ask this here, instead of starting yet another amp thread.

 

Does anyone have experience of using GK amps for upright bass? Positive or negative?  I have a little PJ two-four which is great. Also I have a brute of a 15" TC Electronics amp. This TC can sound great under ideal circumstances.  Very clean, and I don't come remotely close to clipping ever.  But it is just very prone to boominess, and I have to mess about with graphics and placing it on chairs and away from corners in most indoor venues, just to get it to sound acceptable.

 

Someone on this thread said that a physically smaller amp might be better.  And I'm looking at a 12" GK combo on ebay.  I know they are very tailored to a certain type of electric bass sound, but was just wondering if anyone had tried one for upright?

[Jakester]

1 hour ago, Paddy Morris said:

I thought I'd ask this here, instead of starting yet another amp thread.

 

Does anyone have experience of using GK amps for upright bass? Positive or negative?  I have a little PJ two-four which is great. Also I have a brute of a 15" TC Electronics amp. This TC can sound great under ideal circumstances.  Very clean, and I don't come remotely close to clipping ever.  But it is just very prone to boominess, and I have to mess about with graphics and placing it on chairs and away from corners in most indoor venues, just to get it to sound acceptable.

 

Someone on this thread said that a physically smaller amp might be better.  And I'm looking at a 12" GK combo on ebay.  I know they are very tailored to a certain type of electric bass sound, but was just wondering if anyone had tried one for upright?

The GK MB combos were really 'the' big DB combo for years, before PJB and Mark Bass came along with their more powerful combos. 

 

https://www.gallien-krueger.com/microbass-combos

 

The MB150 has a low cut filter which works well with DB: https://www.gallien-krueger.com/mb-150s112-specs

 

But I think these days if you're looking for lots of volume it's probably not the one.

[tinyd]

22 hours ago, Paddy Morris said:

I thought I'd ask this here, instead of starting yet another amp thread.

 

Does anyone have experience of using GK amps for upright bass? Positive or negative?  I have a little PJ two-four which is great. Also I have a brute of a 15" TC Electronics amp. This TC can sound great under ideal circumstances.  Very clean, and I don't come remotely close to clipping ever.  But it is just very prone to boominess, and I have to mess about with graphics and placing it on chairs and away from corners in most indoor venues, just to get it to sound acceptable.

 

Someone on this thread said that a physically smaller amp might be better.  And I'm looking at a 12" GK combo on ebay.  I know they are very tailored to a certain type of electric bass sound, but was just wondering if anyone had tried one for upright?

I have a MB150E - it's old and I'm sure that there are better small amps for DB out there, but I'm not convinced that there will be enough of an advantage to justify spending a load of cash. I use mine on upright all the time and I like it - it's loud enough for jazz gigs and a three piece rockabilly gig. I have a preamp, but I never use it because I can usually get the sound I want by tweaking the GK's EQ. One criticism I'd have is that it can sound a bit "boxy" but with EQ work I can usually get this to go away. I really also like the portability - there's a lot in there for such a small amp.

The general impression I have is that it used to be "the" small combo for upright bass players but lots of competitors have come along since. Not sure what budget you have but if you can get the GK at a good price then I don't think it'll be a bad investment.

[jrixn1]

On 18/10/2022 at 12:39, Paddy Morris said:

I thought I'd ask this here, instead of starting yet another amp thread.

 

Does anyone have experience of using GK amps for upright bass? Positive or negative?  I have a little PJ two-four which is great. Also I have a brute of a 15" TC Electronics amp. This TC can sound great under ideal circumstances.  Very clean, and I don't come remotely close to clipping ever.  But it is just very prone to boominess, and I have to mess about with graphics and placing it on chairs and away from corners in most indoor venues, just to get it to sound acceptable.

 

Someone on this thread said that a physically smaller amp might be better.  And I'm looking at a 12" GK combo on ebay.  I know they are very tailored to a certain type of electric bass sound, but was just wondering if anyone had tried one for upright?

 

I also had an MB150 back in the day, and agree they do go relatively loud for their small size but that there are better options these days.

 

But you only said '12" GK combo' - of which MB150 is just one.  Gallien Krueger also make the MB 112, Fusion 112, and Legacy 112 (based on RB) combos.  I had an MB 210 combo and RB head years ago, which were fine - but as you allude, not typically the first choice for upright.  (I was doubling.)  When RB is mentioned, I think of Flea!  Although Dave Holland is also a GK endorser.  Anyway - my MB combo was absolutely blown away by Barefaced.  And since you're after more volume, I'd need convincing that the MB 112 was the way to go.

 

Not sure about this idea mentioned that you need a physically smaller amp.  I've used 8x10 on jazz quartet gigs without any boominess (it was turned down quite low).  Actually it sounded great!

 

If you're happy with Phil Jones but just need more volume, he makes larger ones than the Double Four.  However the ultimate in flat amplification, which is what I use myself, is an active PA speaker.  Additionally, it will be cheaper than PJ, and likely louder per kg.  Look at RCF, Yamaha, QSC.  You could use your Double Four into it as a preamp.

 

But returning to your initial complaint of boominess - the very first thing to ask is have you tried a variable HPF?  Essential piece of kit, whatever amplification comes after it.