• TalkBass has been independent since 1998. Add your voice.
    Create a free account to reply to discussions, view embedded media, and browse with fewer display ads.
    Join free Log in
    Want zero display ads or expanded classifieds tools? Compare plans.

Hey, I thought active basses were louder than passive basses???

shaginwagin

shaginwagin

Apr 2, 2012
421
36
Arizona
#1
Hey everybody,

So I was practicing the other day and decided to switch from my P knock off (passive) to my ESP LTD B104 (active). I immediately noticed the difference in volume. I assumed the battery was getting tired in the esp so I replaced it... no change. The passive P is much louder!

Why?
 
#3
I kind of notice the same thing. I have an Ibanez GSR200 (which everyone says has active pickups - it has a 9-volt powering it) and my Acoustic B450 amp has inputs for Passive and Active. If I plug in to the Passive input, it's nice and loud. If I plug in to the Active input, the volume is noticeably lower.

Perhaps I'm misunderstanding the whole Active/Passive thing.
 
#5
I think it depends on the electronics package and how it's set up. I've had a couple of cheaper basses that you would have to crank the bass and treble pretty hard to get them to the output level of a passive P.

The better active basses I have, when set flat, tend to be of similar output to a P.
 
#6
does your amp have an input for active and passive? If you use the same one for both (assuming they are both there or a switch exists) I'm not surprised about the volume spike. I have some passive basses with serious output. Your preamp may have something that allows you to add/subtract from the active output.
 
#8
P pickups can be loud or soft depending on how they are made. Active basses might mean active preamp with passive pickups which would not be noticeably louder then straight passive.
 
#9
That's fairly common. Some passive basses are super loud. I've owned active basses that were fairly low output, but when all of the controls were boosted, got pretty loud.

The inputs (passive/active) really only vary in that the "active" input brings the gain down a little bit. It's basically like you lowered the gain knob when you plug into the active input.
 
#11
Hmm, ok. So the P pickups are pretty hot across the board then. I wasn't aware of that.

And yeah, I would figure being a cheaper bass, the esp probably has a low output active preamp. With both bass and treble boosted its louder, but sounds crappy. I only ever boost the treble.

Thanks everybody! I appreciate the help!
 
#15
bronsonelliott said:
I kind of notice the same thing. I have an Ibanez GSR200 (which everyone says has active pickups - it has a 9-volt powering it) and my Acoustic B450 amp has inputs for Passive and Active. If I plug in to the Passive input, it's nice and loud. If I plug in to the Active input, the volume is noticeably lower.

Perhaps I'm misunderstanding the whole Active/Passive thing.
Click to expand...
Generally, Active inputs on amps are padded (meaning their gain is reduced in comparison to the Passive input) to reduce the possibility of distortion with high-output active basses. I know that's counterintuitive, because the Passive input will be louder for a given gain setting. Also Active/Passive inputs may have different input impedances but that isn't something you need to really be concerned about.

A P-bass pickup is a 2-coil humbucker wired in series, which gives it a high output with lots of midrange. Many active basses use either single-coil pickups (like a Jazz bass) or parallel-wired humbuckers, which tend to have a lower output than series wiring.

From Seymour Duncan's website:
Series and parallel wiring usually refers to two separated but related issues. The most common usage refers to how two coils in a humbucking pick up are connected to each other. With series wiring the individual coils are connected end to end. Current flows first through one coil and then the other. This is the way most humbucking pickups are wired. With parallel wiring the individual coils are connected to each other at both ends and current flows through both coils at the same time. Pickups wired in parallel are brighter sounding and have considerably less output than an identical pickup wired in series.

The terms series and parallel are also used to describe the way in which separate pickups are connected to each other in the guitar by the pick up selector switch. In the vast majority of guitars the pickups are connected to each other in parallel. The same rules apply to pick ups wired in series and parallel as a humbuckers coils wired in series and parallel. Two pickups wired in series will have higher output and a fuller tone.
Click to expand...
 
#16
So, this might get technical...
Active circuits could boost voltage, amperage, or both. I think the primary advantage of a small, onboard amp would be to provide amperage that a passive pickup cannot provide. Just because it can does not mean it will. Amperage is a measure of electron flow where voltage is the force that causes the electrons to flow. The third element in the equation is resistance. The equation is known as Ohms law and looks like I=V/R, I being amperage or current, V being voltage and R being resistance. This isn't the whole story because we're dealing w/ alternating current, but it's close enough.
So, if a passive bass has a certain output voltage level(determined by the magnets and coils in the pickup) and the amp has a certain input resistance, then I is the ratio of those. If the input resistance of the amp is very low, then I becomes very high. The pickups may not be able to generate sufficient I, the pickups become loaded and you get distortion. By adding an active circuit in there(specifically a voltage buffer which does not boost voltage, but does give current gain), the current required by the amp is provided by the battery, not the pickups themselves, you alleviate that distortion. This is probably how most active basses are built.
However, that's not the only reason for an onboard preamp. Long cable runs introduce resistance and capacitance into the circuit. This is also detrimental to the sound in a variety of ways. Put simply, you want to "overpower" that resistance and provide a higher signal to the noise in the cable(ie increase signal to noise ratio).
Going back to Ohm's law, a longer cable will have a higher R(in conjunction with the amp). If V does not increase, I will be lower and may not be sufficient to drive the amp cleanly. So an output stage to increase voltage may be part of the preamp.
If R doesn't change(same cable, same amp) this should increase the volume. However, it's entirely possible that your amp, as overpower protection attenuates the incoming signal to a certain level before feeding to it's preamp or power amp sections. Thus you wouldn't hear any significant difference in volume in the end. If the active electronics in the bass are good, it wouldn't surprise me if it sounded better, just not louder. On the other hand, if you don't have a long cable run, and your amp and passive bass are well matched, the passive bass could sound better because it doesn't have limitations of some active circuits.
 
#17
bronsonelliott said:
Perhaps I'm misunderstanding the whole Active/Passive thing.
Click to expand...

I think most people do. Active is a completely generic electronic term, when you say a device is active it simply means that electrical power is required to operate the device. In a bass that power almost always comes from 9V batteries. It implies nothing about anything that most people on TB are deeply concerned with. If you want to know those details you have to read the advertising very carefully and even then you will often go unrewarded.

In most cases an active bass will have a lower output impedance than a passive bass and that is an advantage for a variety of technical reasons. But a low output impedance can be provided at any output level so there is no firm relationship between output level and active circuitry. In fact the true value of active circuitry is that it enables one to break all the "rules" that passive basses have to abide by. Anything is possible. But that means that any assumptions the consumer might make about how an active bass will operate are all potentially invalid. The result you get from an active bass is the result the designer was trying to achieve so you cannot assume anything.

In many cases active basses have one, two, three, or more band equalizers. In many cases if you set all bands to max you will have a ton of output. But set them all to min and you will get a whisper. And a perfectly good active EQ could be set up to have less output than a passive bass even when everything is boosted to the max. You will have more headroom in the EQ that way.

If you want to know how an active bass will operate you must study the advertising, ask questions of those who know (if you can find any!), and try before you buy

Ken
 
#18
BobaFret said:
does your amp have an input for active and passive? If you use the same one for both (assuming they are both there or a switch exists) I'm not surprised about the volume spike. I have some passive basses with serious output. Your preamp may have something that allows you to add/subtract from the active output.
Click to expand...

Pretty sure its the same situation with either amp input... ill check that out too.

Thanks!
 
#19
So, is it possible that if I had a cable run that was say 50 ft would the passive be quieter than the active because of the added resistance of the cable? And the actives ability to overcome said resistance?

My cable now is only about 10 ft.
 
#20
The resistance, though measurable, is so low as to be irrelevant at typical cable lengths. We're talking maybe 5 ohms for a 50' cable. The volume pot on a typical passive bass is 250 to 500 thousand ohms. What matters is the capacitance, which (with a passive bass, not an active one) rolls off the high frequencies. The longer the cable, the more highs are lost.

Active devices (preamps, buffers) can have positive gain (be louder), negative gain (quieter), or unity gain (same volume). It is NEVER safe to assume an active bass will be louder.
 

Latest posts

Top Bottom
Back