Everything I always wanted to know about Bass EQ but was afraid to ask!

[Lorenzop]

So, my question:
If pickup translates a frequency to voltage, and we can't change that ( at input so to speak, ie what it "picks up") then:

Is adding an active preamp (active bass eq), or a pedal with parametric eq, or going straight into an amp head and twiddling it's eqs, basically the same thing?

In other words: no matter where you put it, but a EQ that cuts and boosts is basically the same (albeit EQ circuitry) regardless of wether in bass, in a pedal, or head?

If YES:

My second question then:
on a passive bass, isnt putting a cut/boost EQ after the bass output basically turning the bass into an Active Bass ??

And if YES

Then what's the point of active eq circuitry inside the bass??
I mean can such a small EQ circuit as those found inside active bass really stand up to say dedicated studio EQ 19" rack units 50 times it's size?? Or even mixer channel eq?? and I don't just mean bigger is better, I'm sure there are better onboard preamps than some cheaper pedals or dreadful racks but I mean, is it even theoretically possible that such a small eq circuit really can be a GREAT eq in comparison to outboard eq?

Don't get me wrong I have active basses and like to twiddle directly on it as well as on amp head, but I gotta get my head around the signal path once and for all!!

[tabdog]

If pickup translates a frequency to voltage

You are starting out with a misconception. A
pickup is not a frequency to anything, and it
picks up more than a mere frequency.

Tabdog

[Lorenzop]

Mmmmm k .... What then??

A pickup just picks up the vibration of string, which induces a Voltage in the coil/magnets right?

I suppose the vibration of the wood also - just like tapping on it- will also change its magnetic field and force it to Induce a V is that what you mean??

Anyways back to OP!! I wanna know about EQ!!!

[bassist4dalord]

I had a Boss GEB-7 7-Band bass equalizer for a short time. I ran it with a passive Squier P-Bass, and then an Ibanez GSR200 (which has built-in EQ). I found that it boosted the signal, much like a built-in preamp would. Mostly, the GEB-7 is used for restoring low-end for multiple effects users.

Great pedal, for what it is.

[Lorenzop]

Ok any other comments?

[nukes_da_bass]

Yeah- passive circuitry isn't cut/boost as you claim. Your theorem of a passive bass being active, without the added voltage of at least a battery, is faulty as well.

[Wallace320]

Originally Posted by bassist4dalord

I had a Boss GEB-7 7-Band bass equalizer for a short time. I ran it with a passive Squier P-Bass, and then an Ibanez GSR200 (which has built-in EQ). I found that it boosted the signal, much like a built-in preamp would. Mostly, the GEB-7 is used for restoring low-end for multiple effects users.

Great pedal, for what it is.

I'm not usin' it anymore for I've a full pedalboard (actually two)
which's in turn fully tweaked/adjusted in its (mine) parameters.

Take a look at my profile
It's not enough...

I got different heads n'cabs for different pourposes (being'em stage sets with cover band, stage sets with my thrash metal band, or studio recording)

In the studio (yet it's no dogmatic) passive basses are better, but, especially live, I put on three cooperatin' equalizations:
I start up from a flat onboard settin' (I mean, on my bass), this signal goes to the input of the head; the head have its equalizer settings; then it receives my pedalboard equalizer settings in its send/return circuit; this goes thru the cab

If I need "more power" (think about Star Trek's Enterprise Captain James Kirk askin' for it to engine officer "Scottie")
the bass it's the Enterprise, I'm Captain Kirk and the onboard active preamp is Scottie: I really think you can get my point.

Cheers,
Wallace

[Emibass]

Active circuitry works as a buffer too and this way the signal travels better through the cable.
My perspective. It´s not the same to boost/cut on the bass onboard eq than on an exteranl 19" rack eq. It´s just different. Even though studio eqs like on Neve, SSL, API desks or outboard like Avalon, Massenburg are any other brand are incredibily good (IME) but sometimes you need that pre on your bass to achive a more modern sound. But it´s true engineers tend to like a passive bass and than use a high quality DI/Pre/Eq or whatever depending on the sound they want to achive.

[Lorenzop]

Ok why exactly ate passive preferred in studio? Because if noise?

Also for the signal chain is it better then to put : bass - amp head eq (preamp) - effects send (compression)
Or where would you put an extra eq / compression?

[Meddle]

[quote=bassist4dalord;13755405]Mostly, the GEB-7 is used for restoring low-end for multiple effects users.[quote]

And raising the overall noise floor of your signal chain, if that is your fancy.

[Emibass]

Originally Posted by Lorenzop

Ok why exactly ate passive preferred in studio? Because if noise?

IMO, engineers want the shortest/best signal posible and a passive bass is basicaly pick-ups going straight to studio board or DI. And belive me, if you bring an active bass with mid quality electronics the signal may suffer, in this case doesn´t matter what hi-end equipment the studio has, the bottle neck would be the poor electronics of the bass.

[Wallace320]

Originally Posted by Lorenzop

Ok why exactly ate passive preferred in studio? Because if noise?

Also for the signal chain is it better then to put : bass - amp head eq (preamp) - effects send (compression)
Or where would you put an extra eq / compression?

For the reason that they cut thru way better in a crowded, thick wall of sound, they're simpler to manage for a sound engineer in a recordin' environment

Usually bass guitar requires a mono, plain track (summed up from both an amp/mic line and a direct input line) so... the simpler the better for a tech

Live you may need a "quid plus", whenever you feel not at home with house setting, overall output and so on, that's where onboard preamp walks in

Talkin' about the correct chain, it's more rigid, in a way, down to stomp positionin', yet absolutely subjective in an equalization perpective

For example, in my setup of choice (I mean: amp is mine, cab is mine as well) I place pedalboard or multifx into send/return
channel, for I selected the amp (and cab, but it comes after) for its equalizer, its "sound"
If I'm out on a venue where I'm lucky enough not being forced to bring my gear with me 'cause there's a respectable resident
setup, which I don't really know characteristics of and simply ain't "mine", I can run my bass directly into my pedalboard or multifx, and it into resident head input to have my sound and settings maintained, nearly excludin' what's comin after them.

Cheers,
Wallace

[swedbass]

The point of an active onboard pre is to change the impedance thus reducing signal (mostly high frequencies) loss in the cable. But unless the pre is very high quality, it will probably do more harm than good. In studio you are better off with a passive bass and short high quality cable (e.g. Tara Labs) going into a studio grade preamp (I use an Avalon sp737). Most effects pedals will degrade the sound, so unless you really need them for the performance, it's better to add e.g chorus or reverbwhen mixing

[MCS4]

One of the other "points" to active circuitry is the modification of very specific frequency ranges. Any EQ, whether onboard, in a pedal, or on your rack, only modifies a limited range of frequencies. For example, the "mid" knob or knobs on your amp most likely affects a different frequency/frequencies than the "mid" knob(s) on your bass. In a quality piece of gear, these frequencies were selected by someone who believed them to be the most likely to produce a pleasing effect to your sound. Having multiple EQ sources means you have more options on this front.

To give a real world example, my basic sound is relatively full-range but with a slight boost in both low mids and hi mids. I tend to accomplish this by using amp EQ, because I usually prefer their sound to the mid boosts on my basses. This also means that I can dial in a slight mid boost for all basses via the amp, rather than by setting each individually. *However*, my main bass is just a hair short on lows, so I prefer to give it a slight boost via its active circuit -- which I also think gives a better-sounding bass boost than my amps.

P.S. My main Carvin LB70 has a standard Carvin active preamp and Aero pickups, and the last two engineers I recorded with had only great things to say about its tone and ease of recording.

[darkstorm]

Various sections of my processor have their own tone control. I use them for little tweaks for best sound even though I also use the processors seperate eq section. On the bass, I use both the 3band eq and pup balance to adjust tone. I generally prefer small adjsutments to the 3band eq on the bass. The final tone section for Pa is more about tailoring sound to the venue. The signal arriving at the mixer is the ready for recording sound. The mixer and monitor eq is for adjusting to the room rather then creating ready for recording sound to me. Though drum machine and synthesizer get some tone tweaking at the mixer for best sound. In the end, the signal coming out the mixer is the final in the mix ready for recording one for the instruments. If I go from a well carpeted room to all hard surfaces room, Id want to tame parts of the treble etc for better sound in the room. As example of using your bass amps eq for similiar purpose. If you dont use a bass processor you may also need to use bass amps eq in part for voice shaping. And adjust that again as needed for a given room.

[spiritbass]

Originally Posted by Emibass

Active circuitry works as a buffer too and this way the signal travels better through the cable.

To me, this is the biggest advantage. All signal cables have a capacitive value which will remove a bit of the high frequencies from the signal from a passive, high-impedance pickup/tone circuit. The buffering of an onboard preamp lowers the output impedance of your instrument and helps to pass the full frequency band to the input stage of your amplifier. Also, with an onboard preamp/buffer, you can turn down the volume without altering the frequencies you are passing to the amplifier. When you turn down the volume on a passive instrument, you are also altering what frequencies (tone!) you are passing to the amplifier.

[khutch]

Actually most basses are active. The passive ones become active as soon as you plug them into any kind of an amp. The location of the active components in the system does have some secondary effects but to a large extent it doesn't matter in many cases. EQ controls are more convenient to use if they are located right on the bass, active basses do drive long cables better, very low noise and distortion preamps draw a lot of current and quickly eat batteries, etc. So there are reasons to put or not put the preamp in the bass that may be very important in certain situations or to certain individuals.

Passive basses are a known quantity. Recording engineers like dealing with known quantities. An active bass can do and be almost anything. That scares the poor recording engineer. The only real reason to prefer a passive bass for recording is that active basses use low current circuits that tend to be a little noisy for certain kinds of music depending on how you adjust the knobs.

It is not entirely wrong to say that a pickup converts a frequency to a voltage. It would be better to say that a pickup produces a voltage that replicates the frequency and other characteristics of the string vibration.

Ken

[Emibass]

Originally Posted by khutch

Passive basses are a known quantity. Recording engineers like dealing with known quantities. An active bass can do and be almost anything. That scares the poor recording engineer. The only real reason to prefer a passive bass for recording is that active basses use low current circuits that tend to be a little noisy for certain kinds of music depending on how you adjust the knobs.


Ken

I don´t think it´s a matter of scaring the "poor" recording engineer. I´ve been in the place of the recording engineer and can´t tell how many bassist came with super dooper active basses and when plugged in sounded like anything else but a bass and not to tell about buzz and noise problems.
But I also recoreded bassists with good active basses with no troubles.

[hrodbert696]

Originally Posted by khutch

Actually most basses are active. The passive ones become active as soon as you plug them into any kind of an amp. The location of the active components in the system does have some secondary effects but to a large extent it doesn't matter in many cases. EQ controls are more convenient to use if they are located right on the bass, active basses do drive long cables better, very low noise and distortion preamps draw a lot of current and quickly eat batteries, etc. So there are reasons to put or not put the preamp in the bass that may be very important in certain situations or to certain individuals.

I think this is what the OP was getting at. To restate his question: If a preamp with EQ can exist on the bass, in a pedal, or in the amp, what difference does it make where in the signal chain it is? What's the difference between an active bass vs. a passive one running through an EQ pedal? I'm actually kinda curious about this myself.

[bongomania]

The answer is really simple. The difference is in whether the cable affects the tone.

With a passive bass, the capacitance of the cable you use to connect to the amp (or to any outboard EQ, whether pedal, rack, or iPhone) interacts with the pickups to form a filter that alters the tone. To various degrees, a long cable will turn down the highs a bit, and create a resonant bump (slight boost) in the mids just below the point where the highs start to roll off.

If you put a buffer in the bass, and any active pickup, preamp, or EQ is a buffer, then the cable capacitance is taken out of the equation! No filter affecting the tone.

This is just the broadest general case--of course there are individual cases where the onboard EQ may sound like crap, or the preamp may be hissy, etc., but those specific cases don't apply across the board.