This characteristic sound of piezo pickups has been discussed a lot here lately. I think in this great pickup comparison video you can really hear the quack/honk...
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Double Bass The piezo quack
- Thread starter elmer
- Start date
Yes, this is great! It's still good to keep in mind that in any live situation the point is not that the amplified signal sound exactly like your acoustic sound, but rather that it blend well with the acoustic sound you are already putting out.
That's a good analogy. To be fair, the gentleman in the video has no idea how to mount the Ehrlund EAP, as he's using the putty as if he were a brickmason. The DPA 4099 is pointed at the top close to the F hole.
We also have no way of knowing what the impedance load is on each of the pickups so the Shadow Nanoflex may have an advantage, because I believe the little preamp does that for the Nanoflex pickup.
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(Hmmm. Brand new anonymous user, no profile info, picking a 2-year old thread, in particular picking on a 2 year old, not-editable post from a highly respected TB/DB member. What does it mean???)
Perhaps more on-topic... From my simplistic newbie standpoint, maybe the quack -- or possibly aka: electric tone in general -- is one reason it is nice to be able to select to use either a piezo or a mic depending on the volume situation, or perhaps even mix the two signals together??? (Except for me, I'd really prefer to let a FOH do the mixing if at all possible.)
But realistically, for a DB being played by any less-than a famously superhuman DB player, in a combo including 2 to 6 other instruments and/or vocalists, is this quack really going to matter that much to a person running a FOH, or for that matter, to an audience? Maybe the important question is "how may DB players will be in the audience?"
To be fair, at the end there is a hint that the input impedance for all piezos is 1 MegOhms.
But for me it rather sounds like being between 330 KOhms (Polytone Mini-brute) or 500 KOhms (Markbass CMD121P). They might have used a DI box. As the exact chain from pickup to recording is not known, there might have been something that lowered the impedance from the 1 MegOhms.
And 1 MegOhms might still be a bit too low for some of the pickups.
I have at least four of these pickups and contact mics including the Nanoflex with the integrated impedance buffer, the Ehrlund and the AKG C411 and none of them sound even slightly similar or comparable to the others on my bass.
My biggest criticism is that the contact mics which sound highly depend on the position on the instrument are compared that way. They should have positioned at the same place or their best place, it but the only one positioned well is the Ehrlund.
The volume should have been adjusted, the air mics are too quiet for a sound comparison.
Also the presentation should have been grouped in bridge pickups, contact mics and air mics. Not mixed and/or mixed to best sound of the groups for a comparison what could be expected from which kind of pickup.
The old problem: if you do something for the first time there is almost always something wrong. Could be in planing or execution.
But for me it rather sounds like being between 330 KOhms (Polytone Mini-brute) or 500 KOhms (Markbass CMD121P). They might have used a DI box. As the exact chain from pickup to recording is not known, there might have been something that lowered the impedance from the 1 MegOhms.
And 1 MegOhms might still be a bit too low for some of the pickups.
I have at least four of these pickups and contact mics including the Nanoflex with the integrated impedance buffer, the Ehrlund and the AKG C411 and none of them sound even slightly similar or comparable to the others on my bass.
My biggest criticism is that the contact mics which sound highly depend on the position on the instrument are compared that way. They should have positioned at the same place or their best place, it but the only one positioned well is the Ehrlund.
The volume should have been adjusted, the air mics are too quiet for a sound comparison.
Also the presentation should have been grouped in bridge pickups, contact mics and air mics. Not mixed and/or mixed to best sound of the groups for a comparison what could be expected from which kind of pickup.
The old problem: if you do something for the first time there is almost always something wrong. Could be in planing or execution.
…not sure why anyone should edit perfectly legitimate and well-informed criticism.
There have been great comparisons of microphones like this one that are well done. I’ve done one in the past that’s buried somewhere in one of the Xlson microphone threads perhaps our new guest could search that one out while he’s doing a deep dive. Just my take of course 
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There have been great comparisons of microphones like this one that are well done. I’ve done one in the past that’s buried somewhere in one of the Xlson microphone threads perhaps our new guest could search that one out while he’s doing a deep dive. Just my take of course
Thank you, Rick.
I do not know why I appear as anonymous, becuase I have included my name in my profile. I am John R. H.
I landed on this thread in my search for demonstrations on Piezo Quack, for amplifying my classical guitar. The guitar pages did not really leave me knowing what it is, or sounds like, and were indeed full of opinions by people who do not know themselves, either. Also, they were all for acoustic guitar, not for classical guitar. But on this Talk Bass thread, I found the comparison of several different transducers, with some well-known microphones, whihc appeared to be a good effort . Like a well-designed experiment, it had the experimental subjects and the controls for comparison.
My reason for commenting on your post is that I felt that the man who prepared, executed and published his comparitive test was being denigrated as a person, in a rather insulting or dismissive fashion. It is better to acknowledge his efforts, and then to add one's own technical contribution, without referring to the author in any negative way.
I have read, reviewed and written a number of reasearch reports and engineering reports during my lifetime. In this process, we never belittle or criticise the person. We only address the technical content.
No doubt I was too hasty in writing my reaction to your post, and should have followed the draft - review - edit process myself this time.
Happy recording.
Regards,
John R. H.
I do not know why I appear as anonymous, becuase I have included my name in my profile. I am John R. H.
On this Talk Bass thread, I found the comparison of several different transducers, with some well-known microphones, whihc appeared to be a good effort . Like a well-designed experiment, it had the experimental subjects (the contack pick-ups) and the controls (actual micriphones - air mics) for comparison. The mics do not have 'piezo quack,' so they are the reference - essential for comparison.
I felt that the man who prepared, executed and published his comparitive test was being denigrated as a person, in a rather insulting or dismissive fashion. It is better to acknowledge his efforts, and then to add one's own technical contribution, without referring to the author in any negative way.
No doubt I was too hasty in posting my reaction to your post, and should have followed the draft - review - edit process myself this time.
Happy recording.
Regards,
John R. H.
There have been great comparisons of microphones like this one that are well done. I’ve done one in the past that’s buried somewhere in one of the Xlson microphone threads perhaps our new guest could search that one out while he’s doing a deep dive. Just my take of course
I haven't messed with a mic for decades. Too much got in the way of making music for me, and it's expensive. I gotta say this vid piqued my interest because #5, the prodipe, sounds good in the under the bridge position and it's cheap enough to take a flyer on. Anyone have anything to say about this mic?
Earl
Supporting Member
I bought one pretty cheap and like it a lot. At the moment though I am going through a 'simple' phase - Yamahiko or Krivo to amp, done.
I have one. Great little mic for the money. I'll try to do a quick video clip comparing it to my Xlson today.
This is actually from the other day, comparing the Prodipe to the AT2020. These are just the respective bass tracks. As expected, with the AT2020 about 2 feet from the bass there is more piano picked up (bleed), the Prodipe was under the bridge right against the table.
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And just for kicks here's my Shen Gemunder with the Xlson mic.
This makes me think I shouldn't sell the Shen. Anyway, two basses are better than one, right?
This makes me think I shouldn't sell the Shen. Anyway, two basses are better than one, right?
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IMHO here's what you need to know. Choose a suitably high input impedance to terminate the piezo. AFAIK this extends the low frequency response and also smooths at the response contour a bit. The appropriate load varies by pickup design and the physical size of the piezo element.
Keep in mind it's possible for the input impedance to be too high. It's not necessarily desirable to extend the low frequency response down to DC. Also, if the impedance is way too high, the pickup can become underdamped and ringy. This degrades sound quality and also lowers gain before feedback.
Although it's often touted as sort of the gold standard, AFAIK 10Meg is actually a bit too high for the vast majority of piezos. I believe the sweet spot typically falls somewhere between 2-5Meg. However the difference between 1Meg and 10Meg is often rather subtle. Also some pickups may benefit form 20Meg or higher...there is no gold standard.
A piezo with the optimum load is just the starting point. You also need to apply corrective EQ. The instrument, pickup, amp, and cab all work together to form an amalgam of an instrument. The combined frequency response of the different elements of this amalgam will be far from flat and possess resonances that modify the frequency response contour as gain is changed. The mechanism for this change is the feedback loop, which is completed in free air.
Most of the acoustic guitars I know of have a built-in preamp that buffers the pickup from the input impedance of your amp or DI. In other words, the built preamp provides a specific load to the pickup and prevents it from being loaded down by other devices. Active preamps are not typically super sensitive to variations in the input impedance they are driving.
Beyond that, FYI @Ric Vice is both well informed and extremely experienced in these matters, and IMHO his comments in post #5 are entirely relevant and appropriate for someone with his reputation and stature. IMHO he is a qualified expert, which is something you will quickly learn if you spend any significant time here. Rather than criticizing and attacking a highly respected member, I suggest that you actually try to understand what he said and why it matters.
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