Is the sound of the cab replicated when mic'ing?

[211dave112]

Hello,

Not sure if this topic was best placed in here or the recording forum, it's relevant to both really.

To get to the point, you get a really good cab that sounds great in the practice room/at home. You come to play live or record and you want that sound to be the one through the PA or on record, so you mic your cab.

Is the sound that you get the sound of your cab or, as you're mic'ing the speaker, is it the sound of the speaker?

I've always assumed that a cab will sound the way it does due to a combination of factors, the speaker, porting (or sealed), where the listener is stood in relation to the cab, where the cab is placed in a room (?) and so on. But mic'ing the speaker relatively closely seems to reduce the influence of other factors and place most of the importance on the speaker itself.

I have absolutely no reason for asking this question (i'm not in this situation at all) other than it just interested me!!!

[stingrayPete1977]

The only time I would mic a bass cab would be when the set uses lots of effects, the sound man can have a clean DI from your bass then use an effects loop just to your amp/cabs, FOH can then have a suitable blend of actual bass guitar with an appropriate blend of your effected sound.

[charic]

I think it mostly comes down to the mic/s used and the positioning.

In the studio the best sound I've had from a bass amp was a combination of factors:
-AKG D112 < 6" from the cone slightly off centre of the cone
-Neumann U87 > 6' from the cab more or less directly infront but I don't think it has a lot of effect at this distance iirc

A mix between these two gave me a fairly accurate recreation to what I heard in the room.

In a live situation close mic'ing is the only plausible way of mic'ing and I would expect as you say that you will get more the sound of your amp + speaker + some cab rather than amp + speaker + cab.

Really it all comes down to mic'ing technique tbh.







Imo

[Kiwi]

In a word, no. The mic placement has a significant influence on the tone that is recorded.

[chris_b]

[size=4][color=#222222][font=Arial]A cab that sounds good at home won't necessarily sound good at volume, but you are right, close miking a cab on a gig won't capture what the audience hears, so mike the cab in the usual way or DI. The audience will probably only hear the PA cabs anyway and the FOH engineer has more powerful EQ available so it's more important to talk to him in order to get the sound you want. [/font][/color][/size][color=#222222][font=Arial][size=1][/size][/font][/color]
[size=4][color=#222222][font=Arial] [/font][/color][/size][color=#222222][font=Arial][size=1][/size][/font][/color]
[size=4][color=#222222][font=Arial]If you live in studios or use FOH support I'd suggest you get the best sounding bass you can and DI it.[/font][/color][/size][color=#222222][font=Arial][size=1][/size][/font][/color]
[size=4][color=#222222][font=Arial] [/font][/color][/size][color=#222222][font=Arial][size=1][/size][/font][/color]
[size=4][color=#222222][font=Arial]I don't use effects and go for a clean sound anyway so a post EQ DI does the job for me.[/font][/color][/size][color=#222222][font=Arial][size=1][/size][/font][/color]
[size=4][font=Arial] [/font][/size][font=Arial][size=2][/size][/font]

[Monckyman]

I use a D.I (box not amp output)and a beta52 on an Ampeg 810+Svt amp and mix the two. The D.I is useful for clean solid bottom end which can be nicely compressed,but the bassist in front of the 810 wants to hear those valves working, so the D.I is not what he wants to hear in his wedge or the FOH.
We can take the amps own D.I signal,which would catch any valve breakup but it really doesn`t sound the same as the cab breathing and responding to the amps output.
So IMO if you use valves or as above FX which you want the FOH man to be able to blend seperately,use a mic and a D.I

[51m0n]

A mic will output what it does based upon where it is placed (including the angle of placement), its ability to cope with the SPL and its own frequency response.

The PA/recording device will get a sum of this and the characteristics of the mic pre being used.

The biggest factors here are the polacement of the mic and its frequency response (on and off axis depending on what angle the mic is at to the source). Lets not worry about mic pres at this point!

SPL drops at a rate based upon the root mean square of the distance from the source.

So, if you put the mic very close to a speaker a couple of things happen, you get almost no meaningful spill from other sources (ie the drum kit and guitarist) and you get pretty much nothing but the speaker's output, so nothing that comes from the port or the tweeter of the cab (or any of the other drivers).

In order to get the sound of the cabinet as a whole you need to move the mic back several feet off the speaker grill. The trouble is that you are then fighting for your life against the spill from any other instruments and the potential horrors of the room acoustic. The result will sound further back in the mix, and much more in a space - because you have picked up a lot of information relating to the space in the way of reflections of the boundaries of the room.

As with all things in recording its a compromise.

One of the reasons I hate and strongly advise against the use of kick mics on bass cabs is they are massively eq'ed, they will cut up to 20dB of mids out of your sound (AKGD112 for example) which is hopeless if what you are trying to do is capture the sound of your bass. These mics are used in the belief that only they can handle the SPL up close - which is a nonsense, lots of dynamic mics can cope up close to a bass cab, and SM57 is happy as can be right in there. They give the initial sense of deeper bass, which is a lie, its not deeper there is just more of it at about 100Hz compared to what is available at 350Hz ([url="http://www.akg.com/mediendatenbank2/psfile/datei/38/D1124055c25c068d6.pdf"]pdf datasheet[/url]). Bass is all the way down to 40Hz though.

So, what to do? Well if you dont use loads of effects or rely on the sound of your amp overdriving to get your tone use a DI and you're golden, the simple fact is that in most cases live its the most complete signal you can give to the engineer and he is best placed to tailor that output to the PA, which will have a completely different frequency response to your cab and so should be pre-eq if at all possible (otherwise he will be fighting your amp eq set up for your cab which wont suit his PA speakers as well).

If you really need that mic'ed cab your best possible outcome live IME is something like a Heil PR40 and a DI, failing that a Heil PR20, Sure SM58 or 57, Audix D4, Sennheiser E835 or E845 are all fine. That mic is compromised due to close micing, its there to get all the interesting mid range information from the speaker, its not there to get the bass end of the spectrum or the absolute top end, thats where the DI comes in. The two signals are filtered and or eq'ed and mixed together to create a single glorious entirety.

Point to note, you absolutely must get the two signals in phase from the mic and DI, in practicale terms that means moving the mic until the output form it is in phase with the DI, which is no where near as hard as it sounds. They are in phase wheh the output is hottest.

Using multiple mics on a cab is perfectly possible (and I've done it often) when recording to get more of the room/cab, but you have to be very very confident of your ability to get everything phase aligned. It is not really suitable for live IMO.

Edited November 4, 2011 by 51m0n

[Bill Fitzmaurice]

[quote name='211dave112' timestamp='1320391937' post='1426146']

Is the sound that you get the sound of your cab or, as you're mic'ing the speaker, is it the sound of the speaker?

[/quote]The two are inseparable. The point of close micing is to take the room out of the equation.

[Guest bassman7755]

[quote name='211dave112' timestamp='1320391937' post='1426146']
Hello,

Not sure if this topic was best placed in here or the recording forum, it's relevant to both really.

To get to the point, you get a really good cab that sounds great in the practice room/at home. You come to play live or record and you want that sound to be the one through the PA or on record, so you mic your cab.

Is the sound that you get the sound of your cab or, as you're mic'ing the speaker, is it the sound of the speaker?

[/quote]

The thing about miking a bass cab is that by the time your audience hears it they are getting the sound processed by two sets of speakers (the actual cab and the PA) and a microphone. Generally your better off DI-ing with appropriate EQ (say to remove the highs is you dont use a full range bass cab).

[Bankai]

If you want the sound of a cab when recording, you'd use two microphones.

A Beta 52, D112 or my personal favourite a e602. This is placed right next to one of the speakers (usually top left).

Once you have that microphone in place to capture your fundamental tones, you then add the second one. The type of microphone which would be best for this would be a large diaphragm condenser. Something like an AKG C414. Placed between a foot and 2 foot in front of the cab.


Mix the two and you'll have the perfect replication (or as close as can be) to the sound of your amp and cab.

[charic]

[quote name='Bankai' timestamp='1320412707' post='1426530']
If you want the sound of a cab when recording, you'd use two microphones.

A Beta 52, D112 or my personal favourite a e602. This is placed right next to one of the speakers (usually top left).

Once you have that microphone in place to capture your fundamental tones, you then add the second one. The type of microphone which would be best for this would be a large diaphragm condenser. Something like an AKG C414. Placed between a foot and 2 foot in front of the cab.


Mix the two and you'll have the perfect replication (or as close as can be) to the sound of your amp and cab.
[/quote]

Sounds familiar

[51m0n]

[quote name='Bill Fitzmaurice' timestamp='1320409709' post='1426444']
The two are inseparable. The point of close micing is to take the room out of the equation.
[/quote]

I'd beg to differ here Bill.

If you close mic a couple of inches off the speaker you get none of the benfit of the cab port producing the low end.

So by close micing you tend to take at least some aspect of the cab out of the equation as well as the room.

[51m0n]

[quote name='bassman7755' timestamp='1320410802' post='1426475']

The thing about miking a bass cab is that by the time your audience hears it they are getting the sound processed by two sets of speakers (the actual cab and the PA) and a microphone. Generally your better off DI-ing with appropriate EQ (say to remove the highs is you dont use a full range bass cab).
[/quote]

Depends entirely on the sound of your cab and the amount of your sound that is derivived from your amp after the DI (can anyone say Power amp tube overdrive?).

WHat you say suggests that guitarists ought to DI too, and we know that isnt right...

Edited November 4, 2011 by 51m0n

[Guest bassman7755]

[quote name='51m0n' timestamp='1320416288' post='1426624']

Depends entirely on the sound of your cab and the amount of your sound that is derivived from your amp after the DI (can anyone say Power amp tube overdrive?).

WHat you say suggests that guitarists ought to DI too, and we know that isnt right...
[/quote]

For guitarists (I happen to be one of those as well ...) the power amp/speaker are generally much more a key part of the final sound. As you say, IF those things are key to your bass sound then you can be better off micing up but it seems to me that the majority of bass players, especially many on here who use solid state power amp and "boutique" speakers generally want those latter stages of the signal chain to add as little colour as possible. Also I think generally is much more difficult to get good reproduction of the extended lows from bass by micing up than it is when dealing with a more middly guitar sound.

[Bill Fitzmaurice]

[quote name='51m0n' timestamp='1320416219' post='1426620']

I'd beg to differ here Bill.

If you close mic a couple of inches off the speaker you get none of the benfit of the cab port producing the low end.

So by close micing you tend to take at least some aspect of the cab out of the equation as well as the room.
[/quote]
At a couple of inches off the driver the difference would be minimal; remember that port output is omni-directional. And there's also baffle proximity effect, which enhances the low end. True close micing to separate the driver and port outputs is done from more like a half-inch away.

[51m0n]

[quote name='Bill Fitzmaurice' timestamp='1320417621' post='1426650']
At a couple of inches off the driver the difference would be minimal; remember that port output is omni-directional. And there's also baffle proximity effect, which enhances the low end. True close micing to separate the driver and port outputs is done from more like a half-inch away.
[/quote]

Strange, thats not been my experience.

Is the port the true origin of the extended octave or so of bass? Certainly seems like it to me.

If so is it not possible that a combination of phase and off axis rejection from the mic would cause the mic to be significantly less bassy when micing from a couple of inches off the cone? Especially a cone a long way from the port?

Just IME getting that lower octave from a mic close to a speaker cone just doesnt happen.

Edited November 4, 2011 by 51m0n

[51m0n]

[quote name='bassman7755' timestamp='1320417195' post='1426639']

For guitarists (I happen to be one of those as well ...) the power amp/speaker are generally much more a key part of the final sound. As you say, IF those things are key to your bass sound then you can be better off micing up but it seems to me that the majority of bass players, especially many on here who use solid state power amp and "boutique" speakers generally want those latter stages of the signal chain to add as little colour as possible. Also I think generally is much more difficult to get good reproduction of the extended lows from bass by micing up than it is when dealing with a more middly guitar sound.
[/quote]

Agreed, except for anyone out there running a big Ampeg svt into a fridge. Or some clone of that tone.

As for the low end, thats where the DI comes in.

[Mattslouch]

[quote name='211dave112' timestamp='1320391937' post='1426146']
To get to the point, you get a really good cab that sounds great in the practice room/at home. You come to play live or record and you want that sound to be the one through the PA or on record, so you mic your cab.
[/quote]

Here's the point (or a point), you aren't just hearing your cab, you're hearing the room too. So you'll never get that sound unless you take the room with you!

Edited November 4, 2011 by Mattslouch

[charic]

I kinda cheat, I just use the Post EQ on my RH450 live and in the studio. Sounds great to me

[Bill Fitzmaurice]

[quote name='51m0n' timestamp='1320418058' post='1426658']

If so is it not possible that a combination of phase and off axis rejection from the mic would cause the mic to be significantly less bassy when micing from a couple of inches off the cone? Especially a cone a long way from the port?
[/quote]Anything's possible, as every scenario is different. That's why definitive cab measurements are made outdoors (assuming you don't have an anechoic chamber handy) with the mic at least two meters, preferably more, from the cab.

[51m0n]

[quote name='Bill Fitzmaurice' timestamp='1320423304' post='1426758']
Anything's possible, as every scenario is different. That's why definitive cab measurements are made outdoors (assuming you don't have an anechoic chamber handy) with the mic at least two meters, preferably more, from the cab.
[/quote]

Yeah true, I've had long chats with Alex about the lengths he has to go to when measuring his cabs to get some idea of their frequency response - not a trivial undertaking at all!

[stingrayPete1977]

If it sounds good FOH and you can hear yourself onstage it's FTW If people want to hear a more precise version of our music it's available on iTunes in the linky below

[Bill Fitzmaurice]

[quote name='51m0n' timestamp='1320423838' post='1426762']

Yeah true, I've had long chats with Alex about the lengths he has to go to when measuring his cabs to get some idea of their frequency response - not a trivial undertaking at all!
[/quote]
It's actually easy if you have the right gear, and an open space to do the job. You measure ground plane, the mic literally an inch off the ground, for a half-space result below the baffle step frequency. Then you put the cab on its back and suspend the mic above it to get a half-space result above the baffle step. Splice the two together and you're done. If you want to do off-axis you do that with the cab on its back only, as below the baffle step axial and off-axis are the same. The gear used to be silly expensive, but today the software is free, and the hardware is less than a hundred dollars here. You can do the entire job, including off-axis plots, in about fifteen minutes.

[51m0n]

[quote name='Bill Fitzmaurice' timestamp='1320435446' post='1426958']
It's actually easy if you have the right gear, and an open space to do the job. You measure ground plane, the mic literally an inch off the ground, for a half-space result below the baffle step frequency. Then you put the cab on its back and suspend the mic above it to get a half-space result above the baffle step. Splice the two together and you're done. If you want to do off-axis you do that with the cab on its back only, as below the baffle step axial and off-axis are the same. The gear used to be silly expensive, but today the software is free, and the hardware is less than a hundred dollars here. You can do the entire job, including off-axis plots, in about fifteen minutes.
[/quote]

You havent seen how small his back yard was

[charic]

Can't you just map the frequency response of a room? Not exactly simple but it's not rocket science either, just time consuming. Then it's a constant for all future tests?