Magnetic Pickups - Why Aren't We All Using Them?

Discussion in 'Amps, Mics & Pickups [DB]' started by SteveFreides, Jan 29, 2014.


  1. SteveFreides

    SteveFreides

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    I'm having a very interesting conversation on the subject of amplifying pianos with someone who makes a magnetic piano pickup, and I also grew up a guitar player in wide variety of styles played on a wide variety of instruments - I've owned piezo-pickup-ed classical guitars, full size and slim body archtops, and solid body electric guitars.

    It's the archtop electric guitar model that interests me as a double bass player. If, as I believe is the case, the sound of the wood and the sound of the acoustic instrument is, somehow or other, actually in the magnetic signal - as I understand it, the strings vibrate the wood, the wood vibrates the strings, and the wood's "input" to the strings is reflected in the magnetic pickup signal - then why aren't we all using magnetic pickups on our basses?

    I'm sure the answer is "they don't sound as good as piezo transducers and microphones." Far be it from me to argue with that, but I'd like to understand the situation better, and in particular, I'd like to understand, naieve as it might sound, why an upright bass isn't like a piano. The classical guitar has a mechanical argument - it's got nylon strings and thus can't use a magnetic pickup. But the bass doesn't - unless you're playing on gut strings and, since I'm not, this doesn't matter to me.

    Thanks in advance for what I hope is an interesting discussion.

    -S-
     
  2. kirkm24

    kirkm24

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    I'm interested in this topic as well. I am losing sleep at night debating between piezo and magnetic. The Krivo looks impressive but if it just sounds like a bass guitar why get it? On the other hand, I will likely use my bass in higher volume settings where feedback could be an issue...

    I would be very interested to hear people chime in on this topic. As I am torn between piezo and magnetic.
     
  3. hdiddy

    hdiddy Official Forum Flunkee Supporting Member

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    Because the sound your hear doesn't come from the strings alone. The bass is a big drum and the sound emanates from the top, back, sides, as well as the strings. Some components more than others. At these frequencies, it also takes a short distance for the sound to develop.

    If this weren't the case, close-miking any instrument would be sufficient for all applications. Even for a steel string acoustic guitar, a humbucking pickup doens't sound the same as if you mic it.

    Piano's don't have sound posts. They don't have long and wide surfaces to help project the sound.

    I think the same argument could be made for violins. Why do most players use mics and not magnetic pickups? It's probably the same answer.

    With Piezos at least the sound has be transferred through some amount of wood. Even then you end up with a result that is at best similar to close miking. Put a mic a certain distance away from the instrument and you get it in all it's glory but you also start to fight with feedback and bleed from other instruments.
     
  4. JeffKissell

    JeffKissell Supporting Member

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    I have used all three types for electrical amplification and played quite a bit acoustically as well. My take is that most of the signal to a magnetic pick up is from string vibration. Depending on where the piezo is applied to the bass, the signal gets more string or more wood/body signal. Mics are the most true to the sound of the actual instrument, with piezos under the bridge foot next, then bridge wing/above the heart attachments, then mags. A HUGE variable in all of this is how your bass sounds acoustically when you play it and what you expect it to sound like coming out of a speaker.
    In my experience high amplified volume is inverse to the natural, unamplified sound of the bass. The best way to get high volume in the house is to have a low stage volume and have a quality PA provide the muscle. If your intension is to compete with loud amplifiers and drums on stage then you WILL sacrifice the natural sound of the instrument to some extent. All of the artifacts and subtle sounds and qualities that make a double bass sound like a double bass are too fragile to compete with what comes out of amps, drums and horns. In other words, the sonic space is "overwritten" if you will, by the other instruments. Also keep in mind, modern drums and amplified guitars occupy a much greater frequency range which leaves even less space for those fragile artifacts. The best way to insure that your bass sounds like a double bass is to play with musicians who give you the room to let the instrument be heard.
    FWIW, I currently use a mic for amplification.
    This is just my $.02 and YMMV, etc.
    -Jeff
     
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  6. Mike Arnopol

    Mike Arnopol Supporting Member

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    I thought the same thing.

    I was in France a few years ago and a top sound company had just come out with a magnetic piano pickup. I was shocked. It sounded unbelievable.

    I've tries many versions of magnetic pickups on upright. Bartolini even made me a 4 pickup version. One small magnetic pickup on each string. Sounded really nice---like a nice fretless P Bass---not like a double bass. It's laying around in my parts drawer. If anyone wants to putz around with it I'll give it away.

    The guys in France were making a magnetic DB pickup. I'll have to contact them---they swear that it sounds like an acoustic bass. I'm dubious but I didn't think a magnetic p'up on a piano would sound good. It did.
     
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  7. Mike Arnopol

    Mike Arnopol Supporting Member

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    I've spent soooo much time trying to get a good sound at loud volumes---I believe that I do. Even at loud fusion levels I've been told that it really sounds like my bass. I've found out--at least in my experience that the speaker was the biggest problem. Bass and setup next---and then the pickup.
     
  8. JeffKissell

    JeffKissell Supporting Member

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    Mike you have an amazing sound as well as the fortitude and perseverance to make it happen under all kinds of circumstances. In no way am I saying it's not possible only that's not that easy and that I personally don't have the patience to figure it all out.

    Also I think people often have conflicting expectations when they're in the thick of navigating putting together a rig and sometimes the main premise, playing bass and communicating in the language of music, gets lost.
    -Jeff
     
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  9. SteveFreides

    SteveFreides

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    A couple of points/questions, and my thanks to everyone who's replied so far:

    The next question that comes to my mind is how is a piano different acoustically - how it works - than a double bass? This comes to mind after hearing Mike say, "a top sound company had just come out with a magnetic piano pickup. I was shocked. It sounded unbelievable."

    The whole guitar/upright bass/violin spectrum of instruments rely, I suspect, on a basically different model than a piano. A bass and its cousins are built with an eye towards keeping the wood and anything that vibrates as light as possible to get the job reliably accomplished. The cast iron sound board of a piano, OTOH, just by the fact that it's cast iron, must be a different beast altogether, and the way the wood functions in a piano must also be different.

    Another thing this makes me think of is "acoustic" instruments that sound better via a magnetic pickup than they do acoustically - archtop electric guitars come to mind. While I've heard some people rave about the unamplified sound of their Gibson 175 or similar guitar (full-size archtop), that sound has never made a favorable impression on me. The instrument's sound does get back into the strings but that seems to be it - you're still getting the strings' sound, not the sound that an instrument like an classical guitar or a double bass was designed to produce in the listener's ear.

    The thing that got me thinking about all this, a magnetic piano pickup, might actually be worth exploring for the piano. The whole thing started for me because an annual community fund-raiser I work on has its productions coming up. I'm playing double bass for one number but mostly playing piano, and I've been lamenting the fact that I have to switch to an electronic keyboard for the performances just to keep up with the volume produced by the rest of our pit band which includes two trumpets, a drum kit, and electric guitar and electric bass.

    I guess it's all about musical instrument acoustics in the end, and I need to understand more about how a piano works acoustically in order to understand why a magnetic pickup might work well there even though it doesn't work well for double bass and most of the other instruments with which I'm familiar.

    -S-
     
  10. Mark Gollihur

    Mark Gollihur Supporting Member

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    An interesting point. I'd think that "sound better" is a very subjective point, however. I believe that the "good sound" that we commonly associate with archtop guitars, at least in the modern perspective, is the sound of it with a magnetic pickup. So it's natural that "that sound" is considered to be the "best sound." It might be a matter of the cart having led the horse, so to speak. As an extreme example, a Stratocaster sounds way better plugged in than it does "acoustically" - the archtop just happens to have an acoustic body.

    Whereas, the "ultimate" amplified tone most of us would love to hear from the upright? What it sounds like, acoustically, when we stand a few feet away. Which is why the mic is the holy grail of amplification, if it weren't so darned complicated to make the bass loud without feeding back, or picking up the ride cymbal, or bumping the mic and drastically changing the sound, et al.

    As someone else mentioned earlier in the thread, my impression is also that -- with a mag pickup -- you're getting almost all of the "sonic information" directly from the string. There's very little interaction of the giant bass body that you dragged along, bought a large car to transport, and made a separate trip to bring into the venue.

    As such, I've always generally considered magnetic pickups to be a pickup of last resort; if you're in a loud/crowded/feedback happy environment, it may be the only way to get the upright bass in the mix without insane howling and much gnashing of teeth. Though, for some genres of music, that more "direct" sonic vibe that the mag pickup provides has become "acceptable" or even "preferred" (much like the archtop mentioned earlier)... so for some players, it's the perfect solution.

    As for specific magnetic pickups, I've heard several - The Schaller, the Moses Graphite (no longer available that I know of), a couple of cobbled-together contraptions with electric bass P-Style split humbuckers mounted in them, and the Krivo.

    Of the mag pickups, I like the Krivo the best, so far. It strays the furthest from "giant P-Bass" tone, IMO. The maker claims the use of "intentional microphonics" in the wood casing of the pickup have a lot to do with this more natural sound. I don't know whether that's what does it, but -- again, IMO -- something does, because I think that it has a natural tone heretofore unheard from a magnetic pickup.

    Just my $.02 (though it reads more like a nickel or so). ;)
     
  11. LowG

    LowG

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    Interesting discussion. I think a good part of the "why" is starting to be explained in the responses. I'll add a small bit: I've used a Pierre Joseph String Charger magnetic pickup on one of my instruments for about 15 years. It should be noted that the arco volume that gets "picked up" is far less than the pizz volume. This is clearly due to what has been highlighted earlier: the magnetic pickup only responds to the wood's interaction with the strings. For pizz it seems like the body and the string vibrate in a generally parallel way, meaning the attack/decay are generally "together". But arco: the string itself vibrates fairly little, but the energy is going into driving the top to vibrate. Hence why you'll never see violinists using magnetic pickups: they rarely play pizz. Also why a piano magnetic pickup has a better chance of sounding good. I do suspect that a magnetic pickup on a cheap piano may do better justice that a fine one. Not that I'm a piano expert, but I'd suppose the soundboard (which is in fact wood, not iron) of a fine piano imparts more tone than on a cheap piano.
    I'd certainly take Mike up on the offer for the magnetic pickup: I'll pm you.

    In the end, the bass is like a wooden speaker/amplifier. You could mic a guitar amp speaker with a magnetic pickup and get an accurate representation of the movement of the magnet. But that's not "all" of the tone, the box and cone have a lot in shaping the sound.
     
  12. drurb

    drurb Oracle, Ancient Order of Rass Hattur; Mem. #1, EPC Supporting Member

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    In addition and consistent with the other responses here, a big part of the problem is that, for a DB, the above is not true.
     
  13. SteveFreides

    SteveFreides

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    Please expand on that a little.

    Thanks.

    -S-
     
  14. MR PC

    MR PC

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    Some magnetic pickups are more microphonic than others. Usually the cheap ones, or ones that have gone defective somehow. On electric guitars this is generally thought of as a negative, yet great players such as Ry Cooder have managed to use it to great effect. He gets a pure acoustic sound from his electric guitar when he wants it. The acoustic sound of his electric guitar. Sounds like the inventors of this piano pickup have done the same.
     
  15. Mike Arnopol

    Mike Arnopol Supporting Member

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    I disagree---to a point.

    The string is forced into vibration--it then excites the wood of the bass. That information is transmitted back to the string.There is an ongoing communication with the string and the body While I think that pursuing magnetic pickups is something I don't have the time/interest in right now, I think that none of us has scratched the surface of what one can do. Where the pickup sees the string is CRITICAL---I haven't messed with that enough. Biggest problem with a mag p'up is the envelope--the front end of the note doesn't have the "thump" and the rear portion doesn't decay in the same way as the bass. The thump is more of a physical than pitch sound. If you're playing through a piezo---watch your speaker cone. It will move almost as much at the point of attack on the G string as the E string. That mechanical vibration is a very low pitch. It's a critical part of our sound which doesn't seem to be picked up by mag p'ups.

    Tons of information from the body of the bass is transmitted back and picked up by the string. That's why two identical electric basses (solid body) where the only difference is the type of wood yield very different sounds through the pickup. Even the weight of the wood---you'll hear it.

    BTW---the comments about a piano are really incorrect. The metal part is the harp which is the structural basis. The soundboard is spruce just like a bass. There is no reason why a piano would work with a mag p'up and a bass wouldn't.
     
  16. SteveFreides

    SteveFreides

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    I guess that makes the next question whether a piezo on the actual soundboard of a piano is a viable thing. But what I really want to know is why a magnetic pickup on a piano seems to sound good. I guess the first thing I'll have to do is try one myself.

    -S-
     
  17. LowG

    LowG

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    I have the Barcus Berry 4000 system (a piezo piano pickup) on the soundboard of my piano at home. It is just as finicky as any DB piezo pickup. Every inch you move or rotate it changes the sound, as does pressure... and there's quite a bit of wood available for experimentation.

    I have yet to find the "great" place for it, but with plenty of eq I can make it sound usable for what I use it for (mild reinforcement in a live setting, or wild effects-box integration).

    In regards to the interplay between wood/string/magnetic pickup: There's quite a debate on the EBG side of the forum on how much interplay there really is. There are many who claim wood matters a lot, many who claim wood does not matter at all. I have no idea the actual extent of the interaction.
     
  18. LowG

    LowG

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    Except for the unique ways the strings are energized. If acro is considered then it certainly complicates matters. I think magnetic pickups are more suited to pizz playing (and thus also piano).
     
  19. drurb

    drurb Oracle, Ancient Order of Rass Hattur; Mem. #1, EPC Supporting Member

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    Nice to have the attack/decay profile information echoed back at me. :)

    My point was that even if one can count on the influence of the harp, sounding board, etc. of a piano influencing the string enough for a magnetic pickup to mimic decently the acoustic response of a piano, one cannot count on that for a double bass. I stand by that statement and you have largely made the case for me. Specifically, a pickup at the string does not transduce the transient and steady-state characteristics of the temporal waveform that would be measured acoustically in front of the bass and which are very much a function of the vibrating plates.

    The interplay between the string and the wood of the bass is, as a matter of physics, highly asymmetric and results, in part, from a classic impedance mismatch. You can drive the wood with the string. You cannot so easily drive the string with the wood. So, the influence of the body is not as evident in the string as is the influence of the string in the body. The same applies to those wonderful speaker cabinets you build. They make really lousy microphones. :) The amp can drive the cone in the cabinet. The cone in the cabinet does not so easily drive the amp (which applies the forcing function-- as does the string). The pickup at the string is akin to a "pickup" (measuring device) placed at the electrical input to the speaker cab. The signal you measure will be dominated by the amp and will be influenced relatively little by (the "back EMF" of) the speaker cab.

    Now, considering that a piano is not a bass, it seems quite likely that there truly is a reason (or many reasons) why a piano would work with a mag p'up and a bass wouldn't. It's a matter of the specific impedance mismatches and mechano-acoustic transduction. I have no idea what are the characteristics for a piano as compared to those for a double bass but I can sure envision why they would, in fact, be radically different.

    A mag pickup might work as well, better, or worse with a piano than with a DB. What I do know is that a mag pickup, as you seem to agree, doesn't work all that well with a DB. That is, if you want to capture the temporal profile that is so much a part of what characterizes the sound of any instrument.

    See above. :)
     
  20. All Three

    All Three

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    I recall that for a couple of years in the '70s that Yamaha produced an "Electric Grand" piano. It was a huge step up in terms of sounding more like a piano than the commonly used Rhodes, etc. keyboards that used metal tines. It was used for the brief time before the introduction of modern keyboards.
    Does anyone know if the pickup for that was magnetic?
     
  21. Ric Vice

    Ric Vice Supporting Member

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    When I had my Clevenger EUB built, Martin actually offered a pair of Bartolini pickups mounted under the fingerboard as an upgrade, in combination with his Diamond Sonance pickup that has a bridge, mounded above a resonator.
    Those magnetic's were specially designed to work with a bow, since the strings excursion is different, than arco. When I decided to change over to Evah Parazzi Weich's I discovered that the Bart's would not pickup the Evahs' because the have a composite synthetic core. So for the present even if you did have a the greatest magnetic pickup in the world, you couldn't use it with gut strings, metal wrapped gut, or metal wrapped composite. It limits you to metal strings.

    Ric
     

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