Amp vs PA + Sub

[Nebadon2000]

Good suggestions so far: most of my thousands of gigs 1975 to 2023
My amp carried Venue and times had FOH for Bass worked out fine having both Quality PA and Sound Techs

With my Original Band 2002 to 2009
we started out using IEM and no stage Amps with me doing double duty as Bassist and Sound Tech which was new to me

I had same problem was using Mackie Powered 15's with Cerwin Vega Powered Subs with Allen Heath Mix Wizard

Spent boatload of time researching how to work sound and efforts at rehearsal understanding how things work so to speak

OK point being I could not get Bass to even sound close to a good bass amp no problem getting kick drum great

This most likely won't help but what I did was use my SWR preamp and Peavey Poweramp and put 4x10 Goliath in between PA in Front of Stage in line had preamp mounted on modified mic stand on stage for me next to mixer

Sounded great

Yes I tried many of suggestions here including HPF on mixer, compression etc. But either our PA and subs were not adequate or I wasn’t

 

[MrWolf14]

Reality: IME it's really hard to get great lows in most live settings. This is due to poor acoustics, a PA system with inadequate pattern control, or poor implementation of an adequate PA.

I agree with the final comment: too often the guy behind the mixer is responsible.
It happened to me a couple of times: I arrive at a gig, I bring my stuff to the room and in the meantime I hear the soundguy testing the PA with some music.
And I know already: this night my bass will sound like crap.
I listen to known songs, let's say AC/DC, which I know should sound well. But the guy is pumping the basses like crazy.
The room is not capable of absorbing such massive low-end-energy.
Everything becomes muddy ... and I look at the face of the "sound engineer": he is happy like a kid with his new toy.
Don't even try to explain him that you would like your audience to be able to distinguish what is happening in your music: it's a lost cause.
Just bite the bullet: resistance is futile.
Whatever you'll do, he'll fight back and he'll manage to bring back all the "mud" he wants to hear.
Hey; he spent a lot of bucks on his sub-woofer system! Now he wants to hear it.

Sorry for the long rant.
As I wrote, been there myself several times.
It's terrible.
I am so much happier when my amp can carry the room (a Markbass as well, I love their sound).

 

[Jack]

I think I can hpf on the bass channel in the PA. But really, I'm curious why I can't duplicate the sound of the Markbass in the PA. It is only frequencies after all and my Allen Heath CQ18T has a multi-band parametric EQ.

It shouldn't be a problem. In theory the PA (assuming decent tops and subs) should go lower, higher and louder than a decent bass amp, so in theory all of the sound is there it's just about removing what you don't need and enhancing what you do. Now, there's more to speakers than just frequency response, so your amp might just have different characteristics than the pa (you'd hope so actually, the point of an amp is to make your bass sound good, the point of a pa is to make something sound louder) but it should work.

If you like the sound of the amp have you tried micing the amp?

 

[SC Bassboy]

Do you mean mud out front or mud on stage?

Mud on stage:

Low frequencies tend to be omnidirectional, so they wrap around the subs and go in all directions. As the frequency goes higher, the wavelength gets shorter. This eventually allows the speakers to develop pattern control and force more of the sound forward. As a result, you tend to get a lot of bleed off the back of the subs but not a lot of bleed for mids and highs.

The bleed from the subs will frequently fight with the sound coming from your amp. Sometimes turning up helps. Sometimes a better solution is to turn down your amp or reduce the lows. If your DI has a polarity switch, sometimes flipping the polarity can help a bit as well.

Mud in the house:

A common strategy is frequency slotting. Basically a notch is carved out of the bass and a peak is dialed in to the bass drum. The peak for the bass drum should match the tuning of the drum. The bass live mostly in the low mids and usually there is a big scoop in the low mids for the bass drum. Most bass drum specific mics have this sort of curve baked in.

Audix D6 Bass Drum Mic Response:
View attachment 7454335
This is a very popular bass drum mic because it's very easy to get a good bass drum sound. Caveat...it's not necessarily easy to get a more natural/organic bass drum sound with this mic.


Another approach to clear up the low end is to use side-chain compression on the bass. The sidechain is triggered by the bass drum. So basically the bass is dipped with each drum hit. This is pretty common in the studio. AFAIK it's not common for live work, but it's possible.

Tuning of the PA is also a significant factor. A lot of people really like to hype the subs. This represents more concern with quantity than quality IMHO. Hyped subs can be appropriate for some styles of music, but in generally I find it distasteful.

Some audio techs use a technique called Aux Fed Subs. Basically the low frequency instruments are fed to an aux that drives the subs. These instruments are dual assigned to the mains. Higher frequency sound sources are not assigned to the subs. This approach can help clear up a mix, but it tends to be abused. A lot of audio techs use the Aux as sort of a tone control. If they want more bass, they boost the level of the aux.

If the subs and mains are properly aligned and tuned, bumping the subs can degrade the overall sound because it shifts the crossover frequency and causes phase errors between the subs and mains. Ideally once the system is tuned, the relative volume between subs and mains should be maintained. If more or less lows are desired, the change should be done on individual channel strips; for example turn up the entire bass channel, or dial in more lows using the EQ on the bass channel.


Reality: IME it's really hard to get great lows in most live settings. This is due to poor acoustics, a PA system with inadequate pattern control, or poor implementation of an adequate PA.

What they said. Sadly, I had never heard of frequency slotting the bass/kick until I got a DAW and started recording. That was a revelation. The low end tracks on my recordings went from mud to concrete.

 

[JazznFunk]

I seem to have a problem that is not common with others players. When I run a P-bass direct into the PA with the Tech 21 VT bass, the bass in the sub competes with the kick drum and causes mud.

EQ out the kick drum. Usually the kick is too loud/boomy and the subs are usually too loud/flabby as well. You may very well be sending a usable tone which is getting masked by the usual culprit(s) of bad sound and flabby FOH bass tone these days.

 

[bebass]

Who's your sound guy? Tell him to fix it....I'll assume he has a whole array of gizmos at his disposal. This is "Live Sound 101". I have a few simple tricks up my sleeve but it requires a modicum of cooperation on the part of the drummer and sound guy. OTOH, if they think it sounds good when, in fact, it a pile of **** or otherwise resistant to change, you're stuck-like-Chuck.

PA carries the room...no reason it can't sound great. Can't change the world but you can sweep-up your own little corner. I always use a HPF and compressor to rein-in the dynamic range. Here's the downside: you can polish your sonic footprint but you have no control (...maybe you do?!?) over the signal once it hits the board. Add the mis-EQ'd kick and maladjusted mixer / crossover / filters and you're right back where you started.

Riis

“…requires a modicum of cooperation on the part of the drummer…”
This is a thing ? Haha

 

[Zooberwerx]

I think I can hpf on the bass channel in the PA. But really, I'm curious why I can't duplicate the sound of the Markbass in the PA. It is only frequencies after all and my Allen Heath CQ18T has a multi-band parametric EQ.

To clarify:

*It's your board and you're the sound guy.

*The VT DI doesn't sound like what the MarkBass DI may impart. Have you run the MarkBass thru the A&H and, if so, does it cop the desired vibe / character?

*Each mic channel has a high pass filter. The boards are fairly complex and there are feature sets which have yet to be discovered.

*What are you using for a crossover / speaker-power management?

Riis

 

[2thAche]

I haven't been able to get a tone I can accept through our PA (2 mains, 2 subs). Full volume backline was overpowering our in-ears. For a while now I put the two F112 cabs next to our subs, and it's the best sound we've had. We run a little bass through the PA so someone can balance if needed. The trade-off is that a sound guy can't tweak the bass like he/she might want.

I'm sure there are people who know what they're doing with EQ and crossover who could get a better bass tone from the PA, and it would be a hell of alot easier to set up, but we haven't been able to, and the sound from my cabs is far superior to the PA.

 

[bucephylus]

I seem to have a problem that is not common with others players. When I run a P-bass direct into the PA with the Tech 21 VT bass, the bass in the sub competes with the kick drum and causes mud. If I EQ out the mud, it becomes thin. In practice, I much prefer the sound of the Markbass CMD 121+ New York 121 to that of the PA, regardless of how I EQ the bass in the PA. It doesn't have the mud and is more punchy. Maybe I just like the Markbass sound? I remember that Joe Bonamassa said that the bass should live at about 100 hz or above with the kick in the lower sub bass frequencies. Any enlightenment on this would be appreciated, thanks.

Also, different topic here. Would there be a market for an empty CMD 121 cab. I'm thinking of running the head plus two New York cabs instead of the combo but would like to use the empty (no head or speaker) combo cab as trade-in stock.

Scott

No offense intended; but, you are possibly falling into the same trap many of us have encountered. We start with some kind of backline setup, which sounds good to us, and then struggle to get that sound into the PA.

I have found this to be backwards logic. And, trust me, I did the same thing for only about 30 years or so. I would find some backline amp that suited my “tone” prefs; and then just plug in a DI cable or amp mic for the board, figuring the “tone” was the Sound Engineer’s problem. Bad idea.

PA systems generally produce the sound that the Audience hears. They are not specifically designed for Bass Guitar; but, the better ones do have controls for the channels, which are appropriate for Bass: HPF etc. An experienced Sound Engineer will take a DI feed of whatever you send them, and do the best they can with it. But, the DI Send does not always track with whatever the backline rig is doing.

A far better approach, IME, is to tailor your DI Send first; and then figure out how to monitor that on the stage, either on the backline or using monitors. Your stage sound is less important than your PA sound, as long as it is reasonable and not distracting. And, I have found monitoring a tailored DI Send on the stage to be far easier than reworking a backline amp’s DI Send. Plus you are hearing something close to what the audience is hearing.

There are now a vast, if somewhat murky, array of preamp/DI’s available. There are some VERY good ones. My first epiphany was understanding which of those the Sound Engineers generally prefer working with, at least as a starting point. But, there are also some newer ones that allow control of the DI feed. You will know by whether the SE smiles and gives a thumbs up at sound check.

The component of bass in the PA subs is dependent on the SE understanding Bass Guitar. Most do. Though one hobby band I gigged with ran their own sound, and would from time to time only send my signal to the bins; which produces a pretty hilariously dysfunctional result. Primary bass guitar content should be projected form the mains, with reasonable crossover and HPF limiting the reinforcement in the bins.

As for kick drums, most dance material swings off the 2 and 4. Emphasizing the 1 and 3 with overpowering kick projection creates more of a March rather than something that swings. But, some SE’s will do that nonetheless. Snare on the backbeat fills the dance floor. But, I suppose that mix choice depends on whether you are trying to fill a dance floor or not. Most Classic Top 40 fare emphasizes the backbeat for dancing; but, that may or may not be an objective. In any case, a properly applied HPF, found on the board channel should separate what the kick is doing from the bass reinforcement; IME / FWIW.

 

[caballero59]

Some interesting ideas here. Micing the amp to get "that tone". I haven't tried that. We all have our own taste but for me, when I finally bought a Markbass, to my ears, the mud went away. Listening to recorded music with headphones may tilt toward a different tone but in a live mix, the MB is good. DI'ing out of the amp (post preamp) didn't help because much of the tone (I believe) is in the cab. The problem isn't the mix either. I've set up the amp and PA side by side with only bass fed by a looper and could not get the PA close to the amp tone (no other instruments involved). What I'm finally doing (I'm super non-pro level) is run the bass into the PA and then feed the Markbass from an aux send with the Markbass sitting in front of the stage next to the sub which now only carries the kick. Clearly this wouldn't work at a pro level but I'm not pro. Sufficient bass is then fed to the wedges on other aux channels. I think what I'm learning is useable bass in a live mix lives at a higher hz then I used to think it would. Finding a sound man that can sculpt frequencies as suggested in my small town probably ain't happening.

 

[JazznFunk]

Some interesting ideas here. Micing the amp to get "that tone". I haven't tried that. We all have our own taste but for me, when I finally bought a Markbass, to my ears, the mud went away. Listening to recorded music with headphones may tilt toward a different tone but in a live mix, the MB is good. DI'ing out of the amp (post preamp) didn't help because much of the tone (I believe) is in the cab. The problem isn't the mix either. I've set up the amp and PA side by side with only bass fed by a looper and could not get the PA close to the amp tone (no other instruments involved). What I'm finally doing (I'm super non-pro level) is run the bass into the PA and then feed the Markbass from an aux send with the Markbass sitting in front of the stage next to the sub which now only carries the kick. Clearly this wouldn't work at a pro level but I'm not pro. Sufficient bass is then fed to the wedges on other aux channels. I think what I'm learning is useable bass in a live mix lives at a higher hz then I used to think it would. Finding a sound man that can sculpt frequencies as suggested in my small town probably ain't happening.

IMHO, having used a VT Bass pedal both direct and as part of my signal chain into my amp (and also into the FOH), you're chasing 2 different flavors of tone, and possibly overthinking it. In referencing very old threads and materials from when I used a VT Bass a lot, it seems to have only a modest high-pass effect.... this thread might be useful: VT Bass HPF Effect

Bass cabinets are voiced for bass. A PA (and subs) is/are voiced for more than bass. It's why using a powered speaker (like a JBL or something of that nature) sounds very different than a bespoke bass cabinet. It's going to respond and feel different. From personal experience, the VT Bass introduces a completely different voicing and color to your tone than what MarkBass's amps and cabinets produce, because the VT Bass is designed to emulate an Ampeg SVT/B-15, etc. ESPECIALLY if you have the speaker sim engaged. You could try disengaging the speaker sim to see if that helps, or makes a pleasant difference for you.... it used to change the tone dramatically on my VT Bass V2 pedal. I wouldn't dare say that the Ampeg tone is 'muddy', but the coloration of your sound and signal is a world apart from what you hear out of a MarkBass amp, without the VT Bass in the picture.

 

[psychovox]

Just get a Broughton RFE

 

[Pep]

I used a small Acme Low B2 (2-10j cab for a number of years in my Chicago Tribute band. I used the Tech 21 VT Bass Deluxe and sent the signal to both my amp/cab and the FOH. I was wireless and was able to go out in front of the stage and listen to what the soundman had dialed in and it was always perfect, clear, punchy and never muddy, and it complimented the kick drum.
Doing what you did with your MB amp should not need to be done. You should be able to tighten up the sound from the kick drum and shelve you bass to work amicably with it.
You’ve received a lot of good advice here and I would put it to good use instead of just compromising your sound to accommodate everything else. That’s not the way it should work. You need to set-up the PA with your rig and the drums, then you and the drummer need to work on it.
Set up just one sub and main, and aim it back towards you two, then start tweaking. You can get there.

 

[Zooberwerx]

Some interesting ideas here. Micing the amp to get "that tone". I haven't tried that. We all have our own taste but for me, when I finally bought a Markbass, to my ears, the mud went away. Listening to recorded music with headphones may tilt toward a different tone but in a live mix, the MB is good. DI'ing out of the amp (post preamp) didn't help because much of the tone (I believe) is in the cab. The problem isn't the mix either. I've set up the amp and PA side by side with only bass fed by a looper and could not get the PA close to the amp tone (no other instruments involved). What I'm finally doing (I'm super non-pro level) is run the bass into the PA and then feed the Markbass from an aux send with the Markbass sitting in front of the stage next to the sub which now only carries the kick. Clearly this wouldn't work at a pro level but I'm not pro. Sufficient bass is then fed to the wedges on other aux channels. I think what I'm learning is useable bass in a live mix lives at a higher hz then I used to think it would. Finding a sound man that can sculpt frequencies as suggested in my small town probably ain't happening.

Nothing wrong with mic'ing-up your bass rig and foregoing the DI. Older tech & approach but done for eons and, when done correctly, providing some stellar results. That's the charm behind the BDDI philosophy: supposed to sound like a full-blown mic'd SVT rig. Highly arguable among the purists but you get the idea. I had to re-read your post above a couple times...it's a veritable Rube Goldberg. FWIW, the PA enclosure array will never sound like a backline cab.

Riis

 

[el murdoque]

remember that Joe Bonamassa said that the bass should live at about 100 hz or above with the kick in the lower sub bass frequencies.

Another of those Bonamassa utterings that .... let's just say he should play one of his 12000 vintage guitars through one of his 12000 vintage amps, and turn it up so loud that no one can hear his voice any more.


It IS a good idea to separate bass and kick for a live mix. And it is a good idea to use a high pass filter on the bass.

It is important to understand how a high pass filter works, though. When reading what it does, one could get to the assumption that you set a frequency, let's say 50Hz, and nothing below that frequency passes the filter. This is not how they work.

A first order high pass filter (the most common ones) does -6dB per octave.
Since filters work a bit weird (usually the corner frequency on the filter is the point where you already have -3dB), you'd have -6dB on the fundamental of the low E when you set it to somewhere just above 70Hz.

Also, when playing the low E, the first harmonic is a lot more important than the root frequency.

When I set my high pass, I usually do it by ear. I hit the low B on my six string and then turn the filter up. It'll cut out unwanted rumble at first, but when turned far enough, it'll cut into the meat, the stuff I actually want to keep - so I dial back a little. That's usually somewhere between 65 and 75 Hz, which is much higher than I would have thought.

 

[erratick]

If you mean high passing aggressively, I agree .

Yeah. My bad.

The other fun thing about live sound- the empty room sounds different than when it is filled with people. People absorb an odd range of sounds. And how many people makes a big difference. So what sounds good at sound check, may sound thin with an audience. Speaker height and dispersion becomes important. You can just blast people out of there, but I prefer to have a more reasonable volume with better sound.

 

[JamesGrant]

I don't like it. It's too big. The amp is much more focused and punchy.

Bass (and kick) Probably needs HPF in the front of house, EQ, and compression to get it to sit within a desirable dynamic range.

A lot of front of house set ups will EQ the sub for the room but won’t account for the efficiency difference between sub and tops relative to the level range and relative to efficiency at different frequencies. Many subs (like mine….(RCF AS2 705 Mk2) are unruly and need to have careful ‘fine grained’ EQ (narrow bands and wide bands) and compression on the sub to keep it well married to the tops across the range of volumes and frequencies.

A lot of times sound techs torture audio sources to compensate for poorly set up sound systems that have wildly different overall frequency responses at different output volumes.

A lot of of pro sound engineers are fantastic. A lot of people paid to do sound are not pro sound engineers!

 

[caballero59]

I know it is a bit strange to run a bass amp from the mixer but I noticed on this thread that maybe three other people were having trouble getting good bass tone from the PA so they went with amps. Running the bass amp off an aux is unconventional but really no different in principle from using an aux to drive the sub and it gives me a HPF as well as compression before the signal hits the amp. I run the aux and mains from one DCA.

 

[JamesGrant]

I know it is a bit strange to run a bass amp from the mixer but I noticed on this thread that maybe three other people were having trouble getting good bass tone from the PA so they went with amps. Running the bass amp off an aux is unconventional but really no different in principle from using an aux to drive the sub and it gives me a HPF as well as compression before the signal hits the amp. I run the aux and mains from one DCA.

Sounds like making things more complicated than they need be, too many things in source->output chain and crosses domain boundaries - (bass player depends on sound engineer for everything, and sound engineer depends on bass player for everything).

When the bass isn’t coming out of any speakers, bass player looks accusingly at sound engineer, sound engineer looks accusingly at bass player.

I guess in your case bassPlayer=soundEngineer

I like to have a bass guitar signal chain that’s portable between venues and between PA systems, even if the venue is taking a feed from our digital brain. If my bass needs compression or EQ/HPF to sound good through my cab, then it’s done at my pedalboard before it goes off to the amp and FoH

 

[JazznFunk]

I know it is a bit strange to run a bass amp from the mixer but I noticed on this thread that maybe three other people were having trouble getting good bass tone from the PA so they went with amps. Running the bass amp off an aux is unconventional but really no different in principle from using an aux to drive the sub and it gives me a HPF as well as compression before the signal hits the amp. I run the aux and mains from one DCA.

Yeah, I don't understand this approach. If you are really wanting to micromanage it to that degree, you could literally split your signal from your bass, before you go to your amp OR to the FOH, using a solid, quality A/B/Y box (like a Radial or something like that). Whatever processing boxes you want to send to the FOH (HPF, VT Bass, etc) could feed one signal chain into a DI to the FOH, while you send your 'dry' signal to the amp, to manage discretely there. Using an aux send to come back to an amp is going around your elbow to get to your... well... you know.