Huge difference in tone between post-EQ feed to PA vs amp tone.

[agedhorse]

The real question is "does it even matter" in the bigger picture of the mix. Especially when each PA and each room sounds different anyway.

 

[micguy]

My amp is the CMD112p and when I feed a post-eq line out to the PA, the sub rumbles unacceptably. My thought is the 12" cab is simply not reproducing those frequencies so the PA feed and bass amp sound totally different. It appears the Markbass combo does not have a HPF.

Bass guitar cabinets that reproduce the fundamental of the Low E on a bass guitar are very rare. Those that reproduce the low B on a 5 string don't really exist. A PA with real tour grade subs will easily reproduce the low B of a 5 string.

In your opinion, what should the kick and bass be HPF'ed at?

The kick and bass can be high passed pretty low - at 30 Hz if you want. The problem with certain acts and bass isn't the frequency that the high pass filter is run at, it's the amount of power they want to use at low frequencies. Bass can be really extended and not be at all boomy or muddy. Contrary to popular opinion, mud is not created by having extended low frequency content. Mud is created when you put extended low frequency content through woofers that can't handle it cleanly - like pretty much all bass guitar cabinets.

 

[agedhorse]

Bass guitar cabinets that reproduce the fundamental of the Low E on a bass guitar are very rare. Those that reproduce the low B on a 5 string don't really exist. A PA with real tour grade subs will easily reproduce the low B of a 5 string.



The kick and bass can be high passed pretty low - at 30 Hz if you want. The problem with certain acts and bass isn't the frequency that the high pass filter is run at, it's the amount of power they want to use at low frequencies. Bass can be really extended and not be at all boomy or muddy. Contrary to popular opinion, mud is not created by having extended low frequency content. Mud is created when you put extended low frequency content through woofers that can't handle it cleanly - like pretty much all bass guitar cabinets.

It's also possible to put enough low frequency energy into the environment (and ears) to simply overwhelm everything else.

 

[micguy]

It's also possible to put enough low frequency energy into the environment (and ears) to simply overwhelm everything else.

Yes - too much power at low freq’s is absolutely an issue. It does take a lot, but some PA’s are capable of that.

 

[JimmyM]

I have an experiment for you to try. Put a mic in front of your cab of choice, record some playing. Tilt that mic slightly angled to the speaker, record some more. Reposition the mic to various points on the speaker, do the same. Now put the cab in a different location and repeat.

Tell me if they all sound identical, or if there's pretty significant differences in certain notes appearing and disappearing. If you notice that they're different- now imagine that instead of being in a home/studio environment, you're in a chaotic venue under a time crunch having to contend with many other sound sources that also need adjustment and limit where you can place your cab+mic due to the risk of bleed.

If this compromise is accepted and an imperfectly mic'd signal is used, an engineer can try to fix the note balance issues that appear with compression. A noise gate can shut out bleed from other sound sources. But in using them, they're altering the dynamics & the timbre/tone of the bass in a potentially undesirable way.

Live mic'ing presents challenges, these challenges can be overcome with effort & compromises. Why compromise, when you can consistently sound your absolute best with minimal headache? Seems like a win for all involved.

Except for me because I want a mic on my cab. Anyway, put a mic on a speaker, aim it for the center…done. If you want to make it brain surgery, you can spend all day aiming mics and whatever, but that’s your choice. Center always gives you a reliable choice that’s representative of the cab sound and all its glory. Adjust the tone for the room…that’s the worst of it. And…

The real question is "does it even matter" in the bigger picture of the mix. Especially when each PA and each room sounds different anyway.

…as Andy says, you have to adjust to the room no matter what.

 

[lyralain]

…as Andy says, you have to adjust to the room no matter what.

There's two distinct acts going on in mixing here- getting the timbre/tone you want, and adjusting for the room.

The OP is missing the timbre/tone of the cab in what comes through the PAs. One solution is to mic the cab, another is to use convolution with a cab IR. Both impart the flavor of a cab onto the bass.

But the key difference here is- what the flavor is will always be consistent with the cabsim no matter where you pull up, yet it will vary with a mic'd amp thanks to physics altering the frequency response & the addition of other sound sources bleeding in.

With both signals, you will need to make adjustments to them to make sure they play nicely through the PAs with the acoustics of the room. But with the mic'd signal, there's also the added complexity of ensuring the timbre/tone remains desirable, as the room imparts its affects not just on the PA's, but also what the mic is capturing from the cabinet.

If you want to pull up with your cab and mic it, and feel it's simple to get a sound that works without running into issues, keep at it. This thread began with somebody noticing their bass sounded different than through their cab, the solution of mic'ing was suggested, and I just pointed out some difficulties mic'ing faces as well as an alternative solution that yields a similar result with less challenges to overcome & points of failure. ¯\_(ツ)_/¯

 

[agedhorse]

Regards of the tone coming off the cabinet or the DI, it still needs to fit into the mix, be supportive of and appropriate to the genre of the music and the intent of the band.

 

[JimChjones]

From what I've seen doesn't the frequency response of most mics drop off considerably at the bottom end? And if this is the case doesn't it mean mikeing up the cab is a crude form of HPF?

 

[JimmyM]

From what I've seen doesn't the frequency response of most mics drop off considerably at the bottom end? And if this is the case doesn't it mean mikeing up the cab is a crude form of HPF?

Plenty of purpose built mics. Well not plenty but many mics are built with strong sub low response. They’re not all 57’s. But absolutely some can act as HPF’s.

@lyralain I’m just going to come out and ask if you ever tried micing a bass cab before. Because it sounds to me like you haven’t. Bet you miced plenty of drum sets , though. Do you insist on triggers, too?

 

[Stylee Mousse]

A SM57 rolls off pretty perfectly to high pass a bass guitar in many live situations. Definitely not ideal if you rely on very low frequencies. Also pretty closely matches the roll off of a 810 SVT cab.
As for axis, bleed etc. not a problem at all. A mic on a bass cab is going to hear the speaker 3 inches from it. I’ve miced bass on loud stages many times with no problems.
Vocal mics and drum overheads are quite a different story.
IR is fine if you have it and I definitely used many musician’s preferred input methods over the years although not always to the benefit of the mix. Post eq amp di is a good example of a dicey proposition, depending on the player and gear.

 

[Arjank]

Anyway, put a mic on a speaker, aim it for the center…done.

Works for guitar but less for bass cabs that tend to have a tweeter of some sorts.

Anyways, the reason I try to design the tonal goals of my cabs (except the Cyclops 115) towards "studio"-ish is to minimize the effect of what the OP is talking about. I send the post-eq signal to the FOH and most of the time the difference in sound is within what I find acceptable. The situations that are still problematic is when the FOH isn't calibrated, then the sound can be all over the place.

 

[GreyBeard]

Mic-ing is also a nightmare in terms of dealing with different room acoustics, the potential for feedback, and the potential for bleed from other instruments.

To get the cabinet sound without any of those problems, a cabinet Impulse Response (IR) used with convolution would work better. I'm a laptop-enjoyer, but a purpose made Cab-Sim pedal can do the trick.

I have never had any of those problems