Piano re-amping trick - man, I wish I'd thought of this....

[Dave Bryce]

I had lunch with my friend Ronan Chris Murphy today. Great guy, killer ears, always a pleasure to see the brother and hopefully get to learn some things from him...

 

I was asking what he did to record piano - I had noticed he had an older upright in his studio that, while tuned, definitely sounded like an upright. I asked if he was using that much, and he told me he had come up with and interesting "re-amping" idea of sorts - he put a sandbag on the sustain pedal, and then hooked up a Roland digital piano they have, putting the speakers he was running it through (small two-way KRKs, 8" woofers) right up to the back of the upright's sound board....then, he miked the whole thing.

 

He tracked a direct feed from the digital piano as well as splitting off a separate stereo feed to the speakers....and the sound coming out of the speakers caused the upright's harp and soundboard to ring sympathetically, giving him a really nice ambient feed that he blended in as well.

 

He only told me about it - I didn't hear the result - but I give the man deep props for thinking of it!

 

dB

 

 

 

[mate stubb]

Great trick. Whenever I use my Nord EPs in the studio, I always run them through a guitar amp as well as direct out.

 

I have heard of this speaker reamp trick used on drums a lot too. Speaker sits behind a kick drum, mic picks up the resonance of the drum.

[Allister]

i've always called it piano reverb (not sure if its the correct term though), has some cool effects when you use it on other instruments too. i'm lucky enough that my university has steinways in the studios i can play around with ill get some samples uploaded if i can find them.

 

definitely great studio technique and can give really nice results, i personally had never thought about using it for a digital piano though. sometimes the answers right in front of you i guess.

[Theo Verelst]

Maybe he could also run the chords or notes played seperately, I mean not as the whole track at once, but per piece, allowing the resonance to die out and start afresh for the new chord,of course you'd preferably program a sequencer and recorder do that automatically!

 

T

 

[Bridog6996]

Yeah, that's a cool technique. I've haven't actually done it with a piano sound, but I've used that effect with other instruments, like having a trumpet player play with the bell of the horn stuck down into the piano, for example. An upright works great for that, because of the way the sound board is enclosed. It allows the sound to bounce around quite a bit. I believe there's also a software reverb that attempts to recreate this particular effect as well.

[Joe P]

That's inventive. I would love to hear it.

 

Even in my home recording experience, I've found direct + mic'd-amp to be prudent, especially with bass guitar and even electric guitar. Blend to taste...

[The Real MC]

So if I play my DP through an amp and point the amp at a banjo, will it sound like a banjo?!?

[Bridog6996]

I've been racking my brain to remember the name of the software reverb I mentioned above, and it's called, obviously enough, PianoVerb. Yep, facepalm moment. I've never used this plug-in. Just remembered hearing about it at one point. It's free, apparently, so I might just give it a try.

[kanker.]

I've done a bit of reamping - this is a whole new thought process. Thanks for posting it dB!

[Tusker]

Thanks DB. Very cool idea.

 

He's got the string resonance as well as the sound board resonance going. Still, it makes you wonder if smaller resonances (like an acoustic guitar without strings) might be handy to make other samples more interesting.

[wmp]

It's nice to see you were only fooling about too many piano and organ threads.

 

It's nice to have a piano again too. I just lifted the damper and knocked on the key slip, just to read some of that resonance. I've never done the digital piano reamping as you call it. But I have used same thing on other sounds with a speaker facing up under a grand soundboard and the piano mic'd from above. I called it string rever and used it mostly on drums and vocals. It's hard not to use some on the drums if your drummer is set up next to the piano.

 

I can see where this would work great on a digital piano. The lack of sympathetic resonance is why a sampled piano starts to sound artificial as it decays. A couple of the Kurzweil PC3 pianos have a resonance layer, but it's just a drone of the entire piano and not sympathetic with what's being played. I hope I get to try this out sometime soon.

 

[JeffLearman]

Thanks DB. Very cool idea.

 

He's got the string resonance as well as the sound board resonance going. Still, it makes you wonder if smaller resonances (like an acoustic guitar without strings) might be handy to make other samples more interesting.

Well, I put mutes in the strings of the guitars hanging on my wall to avoid that, because I find it annoying. You only get resonance at the fundamentals and harmonics of the 6 strings. It's not really a pretty sound, though I'm sure there's an application for it somewhere (and of course, tuning the guitar for the desired effect).

 

In general, though, the resonance of a guitar sitting in a room is only a little less annoying than drummers who walk away from their kits and leave the snare engaged. (I've tried but failed to ever get any drummer to learn how annoying this is. Instead, I just walk over and flip the lever. Turns out to be a lot less work than trying to enlighten the drummers!)

[JeffLearman]

No doubt I'll have to duck after posting this, but I bet there's a good way to get most of the benefit inside the DAW, digially, using a convolution reverb like SIR.

 

Mic the piano however you want (ideally, lots of different ways). Whack the piano with a hammer and record it -- not sure where the best place would be, but the idea is to imitate a "step input" to the system, just as we'd use a gunshot in Carnegie Hall (to get a convolution reverb to sound like Carnegie Hall).

 

Use the recording as the filter kernel (aka "impulse") in a convolution reverb. Once you've collected a set of impulses and found a few you like the sound of, it's a lot quicker to try them all and see, and if it's not mixed in at a very high level, it might be indistinguishable from the real thing.

 

This works to the extent that the "piano reverb" is a linear system. The fact that keyboard makers use convolutions for resonance is an indication that it might be pretty close.

 

Yeah, I know, it kinda takes the wood out of the picture, and way less fun. A lot more convenient, though. It also avoids whatever unwanted violence the speaker may be doing to the signal. Of course, sometimes violence is exactly what we want.

 

(On an aside: convolutions are used to do speaker modeling, and IMHO speaker models are useful but lame compared to the real thing. Speakers are far from linear, even though the ideal PA speakers would be! My father once deposed a guy, a laser expert, who invented speakers that were measurably linear to a very high precision over a very wide frequency range. Audiophiles didn't like how they sounded.)

[Joe Muscara]

Whack the piano with a hammer

I hope you mean with a rubber mallet or something that wouldn't damage it...

[Theo Verelst]

...This works to the extent that the "piano reverb" is a linear system. The fact that keyboard makers use convolutions for resonance is an indication that it might be pretty close.

 

You cast some doubt on it yourself. It isn't right to call reverb spaces and piano frame-soundboard-strings linear in the system theory sense. First of all a lot of effects that are fun to listen to are not completely linear (for which the human hearing easily has more discerning quality than CD accuracy), or for instance exhibit an amount of Frequency Modulation, or slight non-multipicative non-linearity which creates hugely audible, but technically small distortion components.

 

But, more importantly, which I feel is essential in these subjects, the system theory on which the impulse response science corner (*extremely* well known in the 2st years of EE (university at least) is based also requires the system to remain stationary, or have only the actually recorded poles and zeros as "memory" or in yet more general language: the system's initial conditions must be known/zero. That condition is generally the reason why imitation reverbs with inoulses are fun but by nature of thus errors sounds by itself dull and repeatable for any listener in a small amount of time. Their still fun to play with, of course.

 

T

[JeffLearman]

And yet they're useful as hell. Of course, many digital pianos already have them built in. In any case, it'd be a fun experiment, and I bet it'd be very useful in the studio. It'd be interesting to compare using impulses with actual re-amping. Of course it would sound different, if for no other reason than the speakers, but it might even sound better.

 

The initial conditions should be silence. My understanding is that the biggest compromise is that the input (hammer blow or pistol shot) is not an instantaneous step from 0 to 1 as the theory requires, but is a pulse (0 to 1 to 0, and even then, only very approximately, and not instantaneous).

[JeffLearman]

Whack the piano with a hammer

I hope you mean with a rubber mallet or something that wouldn't damage it...

I would probably place a 2x4 against the soundboard under the middle of the bridge, and give it a nice firm controlled whack. I'd probably use a 16-oz claw hammer, but I'd also try a hand sledge (*very* carefully).

 

I'd look for other places to try whacking it, without doing damage.

[Threadslayer]

....and the sound coming out of the speakers caused the upright's harp and soundboard to ring sympathetically, giving him a really nice ambient feed that he blended in as well.

 

Very cool idea. The only potential problem I see is that once the soundboard starts to vibrate sympathetically, what's to prevent the piano's strings from doing the same thing? It seems like once the strings got to resonating across the spectrum undamped, the sound would get pretty muddy. You might need to damp the strings with a felt strip like piano tuners use or something.

[Sparky2]

Gosh, I need to step away: I'm actually understanding a conversation between Theo and Jeff! (No insult intended. Carry on....)

 

Mark

[zoooombiex]

Interesting idea to warm up a DP recording. I've done similar things but more for experimental purposes - e.g., play a trumpet (or other acoustic sound source) right up against a guitar and then record the output of the guitar pickups. You can get some interesting sounds, especially depending on how you tune the guitar to control the main harmonics you'll hear.

[Theo Verelst]

The design of a rock sound stage with drums and well done bass and a heavy and capable enough PA will get you a WHOLE LOT of sympathetic resonance. Making sense out of that, harmonically too, and in many instances stopping the resonances is a hard pro problem...