SIGNAL PROCESSING

[Marc.]

OK - I play at home and have many custom sets sounding totally awesome thru my headphones or the stereo. I am learning that this is not how my V's will sound in a "live" setting, i.e. direct amplification to a loudspeaker. This is not a good thing.

So now we must purchase additional h/w to process the V's signals in order to reproduce the great sound I hear thru the phones? Not only that, but I must also create a duplicate set of my kits and alter all the settings for a "live" environment? I think the term was to deliver as "dry" a signal as possible. This too is not a good thing.

I have no problem buying an amp & speaker for "live" playing. That's a given. I am learning that we need to purchase the actual h/w versions of the TD's on-board effects to get that same "sound" I delicately crafted on the brain?

I can understand vocals and acoustic instruments requiring signal processing, in that the only device capturing their sound is the mic. What I don't understand is why the v's electronic signal (or any e-instrument for that matter) is not faithfully reproduced. IOW, what exactly happens to that great sounding signal that I hear via my headphones that causes it to sound different "live". Do I need a course in quantum mechanics or string theory.

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[Jimmy C]

I can understand how processing already processed/manipulated sounds can create some problems - but I also don't quite grasp why it can sound so different (good) when sent thru headphones. Something to do with the jacks as suggested by others? I dunno.

[puttenvr]

Marc., this is indeed a difficult theory, perhaps other members can answer the questions better than I can.

But what I learned from playing the units is that the headphones out uses a give more controlled signals than the 'normal' outputs which you connect to a sound system. Perhaps this has something to do with the small amplifier which runs the headphones out while the other outputs give more rough signals. The problem of hot spots in general also only excists when you play the e-drums live, not with the headphones on. I noticed even a differences when the e-drum sounds are triggered by the internal demo songs and when you play them with drum pads. When played by the demo songs or internal sequencer also the MIDI dynamics are not a problem. When played live, they are...

In another thread members already wrote that you do need signal processing for playing the V's live. I wait for a technician to explain why.

[Marc.]

Thanks Rob, an interesting thought. It's easy for me to understand analog-to-digital-to-analog, which I equate to, say, capturing an acoustic/vocal sound, sending it through all the gear and hearing the end result via the speakers. But my problem is I cannot grasp why a signal that starts out digital needs to be further d-i-g-i-t-i-z-e-d !
If it is being degraded by the output circuitry of the TD, I would definitely be lighting up fires over at Roland and demanding that this "problem" be fixed.

ERGO, what would be the result if the amp/speakers were connected to the headphone outputs? Would a warp-core breach ensue? I'm not trying to be funny here, just trying to get some schooling as I ponder returning to live playing.

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[Boingo]

Originally posted by Marc.:
ERGO, what would be the result if the amp/speakers were connected to the headphone outputs? Would a warp-core breach ensue? I'm not trying to be funny here, just trying to get some schooling as I ponder returning to live playing.

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I think a couple of the guys have written about running the headphone out to a monitor amp. I recall them saying it worked fine however I don't recall them saying it was better.

Frankly, I am not quite so surprised at this phenomenon. You are taking two (rather small) speakers and putting them directly to your ear. You can hear every little echo, high and low, (depending on speaker quality), etc. Why is everyone so surprised to the have this detail lost in the amp. Some amps produce better sounds than others and my guess is just about all of them color the sound - some quite a bit. Add to that room acoustics and the plot thickens. It's no wonder to me you need to either change settings drastically or get better processing equipment.

I have found that I can get very close to the sound of most of my kits on my amp with a lot of tweaking of TD settings as well as the EQ on my amp. However, I am playing at a rather low volume in a basement. I have taken the same kits and copied them to a Church setting and seen a drastic change in sound. Different amp, different TD, different room, yada yada...

[Marc.]

Good points Boingo. So perhaps I won't need to go pyro on the Big R. It's beginning to sound as though the environment acoustic phenomena are the major players here. If this is indeed true then everything would require processing. However, I have read that signal processing is also required for studio work. What???!!! This seems to me a different can of worms! The confusion mounts ...

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[szvook]

It’s actually quite simple. A digital signal is a processed signal that has been sampled for optimum control of the signals perimeters. Unlike the analog signal, which is raw and wider in comparison to the digital signal. Hence the reason the sound engineers use very good outboard gates for acoustic drums. A digital signal lacks the warmth and width and punch of an analog signal. An analog signal must be processed heavily in order to contain it unlike the digital signal, which is contained already. A digital signal will be thin and will stay thin if played live through a good size PA, unless you send the signal through outboard equipment that will enhance the dynamics of a digital signal and push it out through a PA to be noticed. EVERY DIGITAL PEASE OF GEAR needs to be enhanced this way to be used efficiently and productively – that is why in studios, the sound engineers use professional outboard gear to bring out the dynamics and punch from the digital equipment – that includes any keyboard or drum modules.
With analog gear, the outboard equipment is used to tame the analog signals first then compress them and feed them out.

The digital signal needs a strong dynamic boost first and then it can be compressed OK. Although the digital signal is compressed already, it lacks the punch through a PA, but it does sound good through the headphones or small speakers – it’s always that way and it has been always. That is one issue with digital signals that are known and has to be acknowledged when crossing over to the digital realm.

Also. A digital signal is always boosted/dynamically enhanced/EQ’d then compressed and maybe EQ’d once again with shelving filters to give it professional punch for live or recording applications. And it will not sound like it’s over processed at all – unfortunately professional outboard equipment can make that noticeable and not the internal effects of the drum modules by them self’s. This logic applies to ANY professional musical application from any musical instrument, be it analog or digital – that is the way it is!

If any of you were sold on the idea that the TD’s internal effects are professional effects that could be used in a professional application – I’ am sorry to burst your bubble.



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szvook

[Jimmy C]

.......(pop!)

[puttenvr]

szvook, you're head of the technician departement right now.

Ouff... wish I've learned more on school...

[gingerbaker]

Szvook,

I'm no engineer, but....

Are you saying that the actual output from the TD-? is a digital signal? I don't think that is the case.

And, isn't the signal to the headphones as processed as that to the different outs? I would think that your argument would predict sound as crappy to the headphones as one would (does) get from the direct outs.

Additionally, unlike Puttenvr, I am quite aware of hotspots when I listen through the headphones. Again, if the headphone circuit was extra-processed, wouldn't it sound worse than the direct outs, not better?

It's almost as if the sound from the single powered monitor using direct outs is compressed compared to the headphones. (perhaps this is a characteristic of the amps in these systems, designed to prevent overload?)

I think the difference in speaker sizes and impedence across frequencies is why the V's sound great through headphones (also perhaps a hotter signal?) than through a single monitor, like a JBL or Mackie.

I know that there is a huge difference in sound when I use either the single powered monitor, or go thru our P.A. which uses a powered crossover, and a subwoofer and front-of-house mains each having their own amplifier channel.

In other words, with the higher quality speakers and amps in the P.A., the sound of the V's is very much like what I hear in the headphones. And the onboard effects sound fine through the P.A., while they seem a bit much through the single monitor.

And, no our P.A. has just a compressor,limiter barely running and our reverb is not used for the drums.

So, it seems to me that the output of the V's can be amplified wuth excellent reproduction compared to the headphone sound (our defacto "reference" sound) but only using multiple cabinets and lots of power.

I guess my question is, why do the single powered speakers, like the JBL G2, or the Mackie sound like crap compared to either headphones or a P.A.?

And, more importantly, what is the best way, short of carrying a real P.A. around with you, to maximize the sonic quality of a single powered speaker?

[Boingo]

Thanks for the response szvook. That shed some light on things. I understand what your're saying, it makes sense and I have no arguments with any of it.

I would like to point out to people that there's a difference between totally unacceptable sound, acceptable sound and great sound. Personnally, I think the V's are an excellent alternative to those with limited monetary units and you can get a good (not professional) live sound. I play at a Church with ~350 in attendance. It's a good sized room. We can't afford "professional" equipment. The V's allowed us to have controlled, good sound quality. I'm sure many bands fall into this category. While no where in these posts has anyone said the V's fall into the unacceptable category, I can see people possibly interpreting it that way. Some may disagree, but that's how I see (hear) it.

Marc: you can go the Dave Weckl route if you have the resourses and that's what it takes to satisfy your needs. You have to be the judge.

[szvook]

First things first. The TD’s signal is a digital signal that has been processed and compressed prior to being sampled and stored within the TD’s. All drum machines/modules that are in the market to day are the same in that respect. Drum machines/modules are basically the same as keyboard/synthesizers that rely on sampled internal sounds, which have been digitally recorded and stored. The analog modules that were used before (and still do now) always were known to have the sounds act up from time to time and required additional tweaking in order to maintain the stability of the sounds – at times just leaving an analog piece of gear turned on for a while would result in the sound degrading for no reason, or turning the analog gear off and on a day later would result in the programmed sounds to change. The digital equipment were a big relief to many musicians because the sounds and the settings were always the same no mater how long the gear was left on or how many times a musician would tear down their rigs and set them up again from gig to gig.

Some manufacturers out there right now claim that their digital equipment can reproduce analog affects by incorporating analog LFO filter within the equipment and by sweeping through these filters an analog type of effect can be applied to the digital signal to beef it up. If this was applied the TD’s or any other drum modules/machines, then the digital signal could be tweaked a bit through an analog filters resulting in a stronger dynamic output.


The headphones output does run through an internal amplification component within the TD’s and the signal is not as hot as it is from the outputs of the TD’s. It is more contained because it is being used in a very closed environment and will not go beyond that. So the internal amplification for the headphones is a lot different then the individual outputs.

Single powered speakers just can’t handle the load at high SPL’s. For a PA, there are many combinations that would make a difference in the output and unfortunately the TD’s will need to be tweaked further as you go from your PA to a venue PA. The right impedence between the amp and speakers is vital in order to have the frequencies match up for a better output and that is where some problems can arise and the TD’s could stand to take the blame, yet they are not the reason for lack of appeal. Most amplifiers run best at 4 ohms. Some are stable at 2 ohms but for longevity and to avoid overheating 4 or 8 is best. Speakers have an impedence. The speaker impedence is what the amplifier sees as the load. It’s always better to have the amp impedence match the speaker’s impedence for optimum frequencies respond and output. Each time a digital signal is fed through a larger sound system, the frequencies need to be adjusted accordingly based on the PA size and what ohms are being used with the speakers and amp.


The higher the SPL rating of the cabinet, the more efficient it is. If you have a cabinet with an SPL rating of 100db, you can achieve much louder sound with less power.

103db=2 watts
106db=4 watts
109db=8 watts
112db=16 watts
115db=32 watts
118db=64 watts
121db=128 watts
124db=256 watts
127db=512 watts


During a gig, an acoustic drummer usually hears the drums differently then the audience does. If a sound engineer knows what he (or she) is doing while your set is going on, the signal from your microphones to the main board is going through a good rack of outboard gear, processed than fed out to the house PA for the audience. The sound the audience hears is not the same sound that you will. Your drums are not processed and they will not be as crisp, unless you are in the audience and you can hear the difference fast. Some acoustic drummers incorporate stage monitors to hear the drums playback signal after they are fed through signal processors first and then out to the stage reference monitors for them to hear what the audience hears. Dave Weckl is one of the drummers that like to hear his drums processed through signal processors and fed out to his stage reference monitors.

This is a digital world right now and digital signals are more stable than analog could ever hope to be. That is why they are chosen and used more often than analog, but they can’t cover the frequency range that analog could and need to be used in conjunction with outboard gear for professional application – for any other application the digital gear can suffice and be used with good results.

I hope some of this shed some more light.

Peace

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szvook

[This message has been edited by szvook (edited March 24, 2001).]

[puttenvr]

Okay, so far I understoud what people say (i always lie )

Two more questions:
- why do keyboards and guitar systems also sound a bit different on headphones than on a sound systems, but is the difference not that large? I play some keyboards myself and I never have to tweak the sounds that much. Is it something with the trancients (sounds without a real tone like snare buzzing and the attack from a drumstick on a drumhead). I heard people complain about their Vsnare sound in live situations. Such a snare drum has two trancients (buzzing and attack). Do sound systems have problems with the spikes in a drum sound and small headphone speakers not? Why does the V-guitar system from my band-mate sound much better than my Vdrums ever did? Same company ... ehhh, so there must be something with drum sounds?

- on the other hand, szvook, you found out yourself that the ddrums sound good on a small sound system without any outboard gear as well. This is not meant to be a thread "Vdrums against ddrums" but I wonder why this difference? Is it the processed V-drum sound who needs an extra powerfull system? Or the 18 bits D/A converters on the d?

I agree on the SPL rating/decibel theory. I play a 130 watt combo myself and you may think it isn't loud enough. But it is ...

[szvook]

To honest, I don’t think the TD’s were made for professional applications to begin with.
I think the ddrums were made after the first TD hit the market and I bet the ddrum people listened to the Roland TD module and tried it for them self’s to get an idea of what they can do. As far as the keyboards and guitars go. The need for good Roland equipment to be used in conjunction with these instruments was much higher then the need to have good edrums. The edrums were a novelty idea that has evolved but it has a lot of ground to make up compared to the guitars and keyboards that were being used much more frequently and were in demand compared to the edrums. Some of the top musicians in all musical forms were in need of a new type of gear to use with their guitars and keyboards (actually new digital keyboards in general were the demand) and Roland wanted to have some thing for the musicians to push their music further.

So in my opinion, the market for edrums has evolved and the demand is HERE AND NOW, but the modules might need to evolve a bit more to be used in a professional application without pissing off the drummers that are looking to use them for all type of professional applications.

But I still like the TD’s and I have found how to use them in professional applications, live & recordings and I have to use outboard gear with my TD-8 to get what I want form them – but I’ am very happy that at least there are edrum modules that I can use and although they are not as predominant as the V-guitar for example, I can still get by with a little additional help, for now. Maybe the next wave of edrums might raise the bar higher and we might be happy after all.


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szvook

[Marc.]

Originally posted by szvook:
...If any of you were sold on the idea that the TD’s internal effects are professional effects that could be used in a professional application – I’ am sorry to burst your bubble.

No, not me. Very good data szvook. However, gingerbaker has made a valid argument also. Bottomline seems to be what one hears and the degree of satisfaction at what is heard, professional or not!

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