Amp vs PA + Sub

[caballero59]

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

 

[GotGroove]

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.

I'm not going to start a debate on what frequency the 'bass should live at'. There's plenty of threads on that here and on other bass (and drum) sites. But the idea's not wrong. When 2 instruments compete for the same frequency, mud is generally the result. Since the kick isn't going through your amp, you'll hear a lot less of that mud. But try recording the room and you'll find that it's still there, minus any HPF filtering your amp may cut for you.

A HPF can definitely help with that without messing up your EQ or your sound. Where you cut off largely depends on the instrument you're playing, the type of music you make, the room, the frequency range of your amp/PA system and the frequency of said drum kick but I find 40Hz to be a good starting point.

Regardless of what frequency you end up on, dialing this in properly (either by you on your board or by the sound tech on the mixing desk) should be part of any soundcheck. In my humble opinion anyway.

-edit-
typos

 

[caballero59]

My RCF 705a sub is crossed at 80 hz. If I filter the bass at 90 or above, there is very little bass guitar in the sub. Now putting the kick in the sub is a huge improvement. I guess for now, haven't solved how to make bass guitar sound good at the lower frequencies in a full band mix. It's a great idea but it just doesn't seem to work for me. I've even heard of people attempting to use only a sub for the bass. That would put out some serious mud.

 

[Wasnex]

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:

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.

 

[TomB]

…and ridiculous expectations for low end out on the floor!

 

[dbsfgyd1]

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

Sounds like you need a super hero.. a HPF! Set it a 100 hz (per Bomamassa). This will stop the bass drum-bass conflict while maintaining your low mids that you need to provide that fullness you are looking for. Hope this helps.

 

[caballero59]

It is amazing how many problems are solved by just using the Markbass setup. Punch and no mud. However, this could be a problem with larger gigs, just relying on the bass amp.

 

[Zooberwerx]

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

How does the bass sound in the PA without the kick drum in-play? Conflicts do arise and there are a few work-arounds as already suggested.

Riis

 

[caballero59]

How does the bass sound in the PA without the kick drum in-play? Conflicts do arise and there are a few work-arounds as already suggested.

Riis

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

 

[Nuisance]

General rule of thumb:

Dial in th HPF until you hear it affecting (thinning) your sound. Then go a little more. You'll need to do this each time you play a different room. Then (and this is the important part), don't be afraid to crank the bass and/or low mids a bit. This will push the lower frequencies to increase warmth while the HPF is doing it's job on the sub frequencies.

 

[caballero59]

Won't this effectively keep the bass out of the PA sub?

 

[Zooberwerx]

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

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

 

[Zooberwerx]

Won't this effectively keep the bass out of the PA sub?

Not if the mains / subs are balanced-out correctly. Contrary to commonly held beliefs, the bass bins carry only a limited component of the sonic content....and crossovers don't create "brick walls".

Riis

 

[Pep]

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

HPF (high pass filter) between the Tech 21 VT the PA should solve your problem. Compression would help as well.

This is an easy fix if your soundman knows what he’s doing and that’s a big if. If he’s unable to fix this then you’ll either need to replace him or get a bigger rig to carve out your territory.

 

[caballero59]

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.

 

[Pep]

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.

First of all you want that HPF between the Tech 21 and the board.

Each of your parametric EQ knobs controls a wide range of frequencies. The HPF is a more tightly focused filter. It will tame some of those super deep frequencies and help allow you and the bass drum to coexist in the overall PA mix.

Do you use an HPF with your Mark Bass rig or does it have one built-in? I had never used one until I bought a Mesa Subway WD800. Once I started using it I was amazed at how much better my bass sounded. Tighter and more focused on the low end. It was so impressive that I bought a separate Broughton HPF to put on my pedalboard to use with other rigs that don’t have one.
That would be a huge step in cleaning up your sound in the PA.

 

[DaveParker39]

I hear ya. Frustratingly, despite the fact that it is the sound engineer's job to fix these sorts of problems, it is quite a rare luxury to find a good one, and to have a good soundcheck with proper troubleshooting. It's just a rarity in a lot of local music scenes.

When my band did our own sound we actually did sort of the opposite... we allocated one sub *just* for the kick drum. Worked pretty well

 

[erratick]

I hear ya. Frustratingly, despite the fact that it is the sound engineer's job to fix these sorts of problems, it is quite a rare luxury to find a good one, and to have a good soundcheck with proper troubleshooting. It's just a rarity in a lot of local music scenes.

When my band did our own sound we actually did sort of the opposite... we allocated one sub *just* for the kick drum. Worked pretty well

Agree it's hard to find a good sound engineer. Disagree it's his job. When we talk tone this is part of the job. Many people consider their instrument tone in isolation. And without thought to volume. No thought to how it fits in. I'd argue good tone is an compromise- how can I best be heard, yet allow others to be heard?

Guitarists- scooped sound- sounds great in a bedroom. Turn it up with a band? Mud city. And your solos disappear with the mids. Mid forward distortions help get that guitar out front for a reason.

The bassist parallel is round full tone (or super bright scoops also). Sounds like mud with a kick and conflicts with some guitar or indistinct with a keyboard player. HPF and add a little resonant peak or saturation so it's not all low end.

Listen to your bandmates, be able to talk frequencies with them. Hopefully they will also accommodate your frequencies (without blocking off the lower half of the key's players instruments). Also understand what happens as you turn up volume- that fletcher/munson curve kicks in and what was nice accentuated at low volumes is over blown at loud volumes.

Live can be challenging in some rooms, but it's usually better than trying to get good tones out of an iphone speaker.

 

[erratick]

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.

All good tips, have done most of these. Still like the Audix D6 because it's cheap and dependable. Side chain effects, I do on recordings all the time. Less live, but it's mainly because I don't usually have a compressor and send to dedicate. However, side chain compression can be it's own instrument- get that bass pumping.

Aux fed subs is my cheat move, but you have to be careful.

EQ and low passing aggressively live can help. Especially if you are working with bands who don't really know how to sound good in a room on their own. If you're fixing the sound inputs, it makes things really tough. Same thing with recording. There really isn't a good way to record a bad performance. You can only do so much.

 

[Wasnex]

EQ and low passing aggressively live can help.

If you mean high passing aggressively, I agree .