Hi Scott,
I followed a link posted on S-Z over to the Bose forum and found this comment on stereo sampled sound:
http://bose.infopop.cc/eve/ubb.x?a=tpc&s=8206048934&f=4806048934&m=7456092785

I don't care much about this person's critique on stereo sampled sound, but his comment on what your audience actually hear. Would your audience hear the difference sitting in the listening area?

I took my PAS to the extreme yesterday by playing my music for the church choir. They had 4 condenser mounted high above the singer, plus two Sennheiser handheld for solos, all mics went in my mixer with my two keyboards and send the mixer's L/R outs to ch1 and ch2 of the PAS. We had a little trouble at first because of the sensitive condenser mics, and ended up had the PAS about 8 feet directly to the right of the choir. Things went great from there. It was pretty amazing that what the choir heard was what the congregation heard!

Uncle Dave was absolutely right when he talked about the comments he received from his audience. In my case, it was the same.

..rb

This whole mono vs. stereo discussion has deteriorated. Here is a link to another person from Bose who thinks stereo amplification is best for singles and duos, but really he is pushing the idea of an individual PAS system for each member of a band: http://bose.infopop.cc/eve/ubb.x?a=tpc&s=8206048934&f=4286020764&m=8896074194
Get the picture? What Bose is doing is trying to sell PAS units. If you are single or duo then two units is fine - if you're in a band then one for each member is fine. And they'll drum up whatever psycho-acoustic information you need to justify their sales. So forget stereo - at least a half a dozen PAS units for your church group is what Bose really thinks you should have.

So far, I haven't seen where any amount of facts about acoustics has made any difference to anyone who already had decided what they were going to do with their sound setup.

[This message has been edited by The Pro (edited 03-15-2004).]

It seems you are on fire again, Jim Although your reasoning MAY BE correct it seems to suffer from a logical fallacy, the one of "hasty generalization". Yes, we should keep our eyes and ears open to the possibility that their speech is a strategy to increase sales, but what they say makes sense to me (and beside that, don't they have a money back guarantee?): a single system is not well adapted to work with effect tuned sounds (like stereo piano sounds). Of course their choice of words to explain the issue is kind of hard (the other guys are guilty), but that's understandeable and does not allow me to draw any quick conclusions about their official speech strategy. I'm really badly anxious to have the opportunity to audition and A/B test it with my current PA, in Europe. That'll be the final judgement. BTW, I have asked myself (before this discussion was brought up) about the reason my Kurzweil synth has mono piano samples when the stereo samples sound so good on a stereo system...

-- José.

I'm hardly "on fire" about this issue - it's more like I'm bored to death with it. It was bad enough when few stereo sound system options existed, so whether to amplify keyboards in stereo really wasn't a question once. Now that stereo options exist some people want to switch the debate to why keyboards have stereo samples and/or outputs in the first place. Maybe we should debate whether we need two ears instead of one...

There shouldn't be too much debate about this. We don't "need" two ears, but the fact that we have two instead of one adds the ability to localize the sound source. There is also an improvement on clarity and fine distintions between sounds.

Given that Bose accepts that their mono system isn't able to reproduce some stereo samples with the same quality than stereo systems do, the test I would like to perform is to compare the quality of a (true) mono sample on their system with a stereo sample through a stereo system. No other comparison seems fair to me, but it will never be possible in some keyboards (namely on my Tyros Stereo Grand Pianos). That would help me to estimate if the investment is worthwhile or not.

-- José.

Jose,

Your comparison would be correct if the piano was the only sound emanating from your keyboard, but for most of us arranger keyboard players the whole point is to simulate playing as a band. We do need separation for realistic sound. Unless you envision all the band members piled up one on top of another, a single speaker will not cut it. I want to have separation between individual instrument sounds - I think we all do. Our outputs HAVE to be stereo, unless we have instruments with individual outputs for each solo and accompaniment track, and have a dozen PASes connected in (though I am sure Bose would like us to do that).

In addition, a piano is a "stereo" instrument by its nature, especially when you are playing it - the base is emanating from the left, and the treble tones/harmonics from the right. This is part and parcel of a realistic piano reproduction.

Regards,
Alex

Ok - sorry I stirred up the stereo debate. Here's a different topic for a change:

What is the power rating of the System?
The system delivers 750 Watts continuous power, broken down into 3x250 Watt. Each of the two sections of the Cylindrical Radiator™ loudspeaker handle 250 Watts and another 250 Watts are delivered into up to two B1 bass modules. This is both the power rating of the power amplifiers and the loudspeakers. Each rating has been established individually through industry standard measurements. These ratings do NOT reflect the actual power that is typically produced by the power amplifier and consumed by the loudspeaker. We also would like to point out that the power amplifiers, loudspeakers and internal limiters are exactly matched. This makes it virtually impossible to overdrive the loudspeaker and to clip or overload amplifiers while at the same time using all available resources very efficiently. (from Bose, of course)

..rb

The only thing that sounds bad in a Bose PA is a bad input source. If you can't get a good mono sound from your sample, than the sample is at fault, not the system.

Stereo is fluff, and while I LIKE fluff, it's not the end all. Most rooms do NOT benifit from stereo and this is easy to prove. I happen to own a pair so I can utilize stereo when it's going to be effective ....... most times, I just use the single tower.

Remember, my kb puts out 66 watts of stereo power as well, so the Bose is auxilary amplification. Right in MY corner of the stage ..... it's VERY stereo. That's where it ends ..... the crowd loves the new system. It's the best I've ever sounded. Mono OR stereo - is not the issue. I use what's best for each venue.

Maybe the room doesn't benefit from Stereo but Keyboards sure do! Stereo samples need stereo speakers to sound optimum, period. Even if you're pleased with your results that is only half of the equation. The other half is the audience that is listening to you. If you can still pack em' in with one PAS then more power to you UD. Of course if your playing in Bars you realize that most of the patrons are probably tanked and couldn't tell the difference anyway, having their audio perception off kilter because of their being plastered. Plus you could sing to them with a Radio Shack year end clearance 75% off Microphone (real cheapie) and they'd probably still think you sounded every bit as good as Michael McDonald. That's just Bars though. If your playing in other venues then that would be the true test in keeping them coming back with one PAS or not. Plus if you're not using auto-accompaniment I could see where your sound wouldn't be that big of a deal except your piano samples that are in stereo. If you've got mono sampled piano[s] on the KN7K and you're not using auto-accompaniment then you're in like Flynn and the sound emanating from the PAS should suffice. Plus like you said the KN7K has "Stereo" speakers too that put out quite a bit of volume that your audience no doubts hears also.

Best regards,
Mike



[This message has been edited by keybplayer (edited 03-15-2004).]

Alex,

I agree with you... in theory. A relevant fact is that part of "real audiences" in "real rooms" do not "feel" the stereo field effectively, as many have mentioned. I find intriguing that although the PAS is mono, many consider it sounds very good, dispersing the sound in a very effective manner. Until now, the big complaint has been the way stereo samples (concieved to be played through a stereo sound system) sound deceiving with the PAS. Given that the efforts in the development of effects has been done taking advantage of the possibilities that stereo sound system open, I want to give the PAS a fair possibility of comparison. I'll be the first to recognize that it's a step back or a mere good marketing campaign, if that's the result of my evaluation. Does anybody know when it will be possible to audition the PAS in Europe?

-- José.

The "bars" I play are upscale resteraunts. Very few patrons are "tanked", but there is booze-a-flowin'.
All that said ....... my audience has come to expect a certain excellence from me and they all noticed a change for the better since the Bose. It's drastic. The comments are coming in like crazy.

The sound from my kb is definatly a factor in the overall package, but the way this PAS fills a room is better and fuller than anything else I've had....and I've been in stereo for 20+ years. It's wonderful, it really is.
As for the samples ....... you can debate all day long about what sounds best, but in a crowded room with extraineous noise - mono/stereo is a non factor.

Until you all USE this tower, you really can't comment on the coverage. It's unlike anything I've ever dealt with, and it IS an improvement. As long as the sound going IN is excellent, the sound coming out will be the same!

Fine UD: you want to be the "High Priest of Mono" then that's your choice, but everything you said about mono ain't the gospel truth. The engineers at Bose at trying Yamaha P250's on their mono Bose PAS systems and are finding that summing the mono signal causes phase problems. Forget how crowded the room is or isn't - phase problems will cancel part of the sound BEFORE it ever gets to your audience. They actually think you should use the mono XG piano samples instead of the signature stereo sounds of the P250, or buy two PAS systems of course, to avoid this. But they only invented your PAS system so what do they know?

Read their comments here

Hmmm, a bit testy today Jim?
C'mon - you know I love stereo as much as the next guy. My point is not "mono is best" ... but rather: Sometimes, stereo doesn't MATTER.
I repeat - the problem with a stereo sample that sounds bad in mono is the sample, itself, not the system, so don't fault the PAS for lousy Yamaha samples.
Stereo effects have been a large part of the "sizzle" in sounds since the very "average" M1 of old.

All I'm sayin' is ...... for the road warrier who sets up and tears down more than he plays ..... the PAS has been a GOD send. Everything we do involves compromise. This is one area where the mono aspect is minscule compared to the studio quality, even sound that fills the room.

My advise to you all is to stop reading about this system, and PLAY one. On YOUR gear. Tweak it, experiment with it, and make your mind up. For me, the choice was easy. The improvement I get in sound with the Bose has been far greater than the loss I get from a mono sound. It's such a small deal really ...... the rest of the package has so many advantages - I could never go backwards. Remember, I also have a second tower for those times when stereo can be effective. I want it all, and I have no desire to entertain the priesthood.

Agreed with UD: Listen to the system, pack it, unpack it, then decide for yourself.

On a different topic, my pastor called me last night and asked me to setup the PAS for the Passion play next month. This church always play some sort of the Passion on Good Friday. This pastor has been here for 8 years and he requested this year to use the PAS instead of the regular audio system that the church had been using for the last 6 years. I'm pretty sure he like the sound from the PAS.

..rb

UD: what's testy about what I said? You've been hammering this 'go mono for the sake of PAS' thing over and over for weeks... give it a rest already. The PAS and/or running mono isn't the only convenient way to do a gig. If Bose engineers found that running a stereo Yamaha piano in mono produced phasing cancellation (why ignore that?) and you're willing to live with that - it's your music. But a lot of your generalities like "stereo doesn't MATTER" and "the problem is the sample, not the system" are speculation and nothing more. You're asking for faith, Father Dave of the PAS.

Jim,
The name calling is uncalled for. We're just talkin' here. That's what I mean by testy.
My observations on stereo in a large room are not speculation - they are researched, tested responses from many different areas of application.

I agree - there are MANY fine systems available, and I have used almost all of them, but I'm trying to share a breakthrough with an uneducated buyers group here. This is a whole new ball game, and I think it's exciting. The stereo sample issue is further punctuated by my original rule of thumb - KB's NEED to have speakers on board. That way, the original tone comes through in the performers face. How you make it louder for a larger area is still loaded with options. The Bose is just one of the newest, coolest options that needs a better understanding before it's accepted.

I don't know if you'll find this interesting or not but here goes....

I threw together some samples of the Tyros piano and Korg PA1X piano taken from the excellent demos provided by Dirk Baert (notlos). First up is the Tyros, a short clip played in stereo, 128 Kbs, mp3. No edits, same as the original. Then comes just the right channel, then the left, then the sum of both channels to mono.

Tyros Piano Stereo

Tyros Piano R. Ch.

Tyros Piano L. Ch.

Tyros Piano Summed Mono

No doubt about it, you lose a lot of good sound.

Here's the Korg's PA1X piano demo, again from Dirk's demos.

PA1X Piano Stereo

PA1X Piano R. Ch.

PA1X Piano L. Ch.

PA1X Piano Summed Mono

Kind of sounds like this piano patch will suffer the same fate as the Tyros when summing.

So here's my dumb question...Why? Why do the manufacturers do this? I understand why they play with the phase for ambience or spatial effects. But why play with the phase of the actual piano sound?

Tyros owners...When playing your stereo piano samples thru a stereo PA at your venues, how does it sound back in the far corners or way in the back of the room, out away from where the stereo field exists?

mike

I'm confused about you folks using the Motion Sound amps. Aren't these amps basically mono? Don't they reproduce a simulated stereo. Do they have two discrete output channels? All the specs that I've found say that they have two input channels. I've read nothing about two output channels.

Tom

[This message has been edited by Tom Cavanaugh (edited 03-17-2004).]

Hi Tom,

The Motion Sound KP200S is STEREO! Two double stereo inputs and an additional microphone (mono) input. There is also a stereo L/R output (2 x XLR) in case you want to connect another PA. There is even a very effective stereo enhancer on each of the two input channels. This a unique feature of these stereo amps.

-- José.

Here's a hunch. By now, other brands should be having their eyes and ears on the new PAS concept. Maybe they will come up with a clone of it, and who knows, cheaper and already taking in consideration our "stereo needs". That would be great wouldn't it?

-- José.

I also lose respect for people who insult those who have a different outlook.

My gut feeling is that Uncle Dave has pretty good ears and that many in his audience have good ears too. He doesn't make a living playing in Alzheimer units like I often do. I think his enthusiasm for the Bose unit is more than a materialistic rush with a new toy.

The KP100S is stereo too. The power output is rather anemic however, even for 100 watts. The sound quality is very good though, especially after I changed the woofers.

You know, before I played the KP100s and used a JBL Eon10 G2 for my gigs, I wasn't that annoyed by the phase cancellation. I mean, I noticed it, but with an arranger, and all those other voices, it wasn't a big deal. A lot of the reason I got the KP100S was for the novelty of the thing. I am happy with it.

I think that if Uncle Dave can get rid of some of the phase cancellation by doing two different eqs, you might have to look at the whole picture. I get the impression that the Bose system is something incredible. You might have a slight problem with phase cancellation, but if the sound quality is that excellent, perhaps the Bose system does deserve some examination - for those who can afford it.

Dave, do you hear any phase cancellation when you play mono?

Beakybird

Hi Beakybird (Larry), I'm not sure what keyboard Uncle Dave is currently playing, but I sort of doubt if he's tried this on a Yamaha Tyros or PSR2000/2100, because in my tests with my Yamaha Tyros, I was not able to satifactory alleviate the phase cancellation problem even after making several PAS EQ setting adjustments. The phase cancellation problem remains an issue (for me) on the Bose PAS. See this thread for my more in depth opinion after trying out the PAS on two sepearate occasions & venues: http://www.synthzone.com/ubbs/Forum37/HTML/008658.html


- Scott

I'm using the kn7000, and I have no complaints about the mono sound. Of course, where I sit, I hear the stereo signal through the 66 watt internal amp. That's a significant addition to the room sound.
The acoustic piano on the Tyros didn't light my fire at all, so comparisons to stereo/mono are wasted on my ears. From the posted demo's of the stereo/mono samples ... I agree, the Yamaha sounds pretty lame in mono. That's yamaha's fault.

I don't want to get in any shouting matches about this PAS. I only want to try and educate those who have no idea about just how cool this new approach can be. It's a different concept. A different sound, and IMO a very large improvement over what we were used to in the past.
ie:
Last night was pretty crowded for St Patty's Day (even though I was in an Italian Resteraunt)and some friends came in late and sat RIGHT in front of the tower. I mean, RIGHT IN FRONT. Maybe 3 feet direct dead center of it. I watched their body language all night and listened to their conversations ....... there were NO harsh, peircing tones making them lean in to hear each other. There was no "loud spot" in front of the perfomance area, and the entire room still had an excellent coverage. There were people dancing in the back room even.

Short conclusion:
This has been said before, but is worth saying again:
If the signal you put INTO the Bose is excellent, then the signal you hear OUT of the Bose will be excellent. If your kb sounds like crap in mono ... it will sound like crap, only louder in the PAS.
It's a "garbage in-garbage out" theory that is being proven again, and again.

Don't fault the system for inadequate sound. If you put somethig wonderful in to it .... you'll get something wonderful out of it.

OK, I guess the rest is up to you to try for yourself. I won't try to sway your opinions. Gary Diamond is going to audition my setup tonight. He's a writer and maybe he can give you another unbiased opinion.

Unbiased? What if he gets scared with all mighty UD? (Just kiding, Gary!)

Seriously, I understand what you're saying, UD, although I'd hardly put it in the terms you use. I think that at this point, testing the PAS in fair terms, would require using true mono samples, or at least sounds that do not lose quality when the L and R signals are simply summed up (that doesn't seem to be the case of Tyros pianos, and other Yamaha pianos, for example).

I look forward for a clone system of this PAS that addresses the stereo issues (something that doesn't force us to double our expenses, at least!), and maintaining the intrinsic qualities of this concept. If they really exist and are more than a "more transportable system", then it's a matter of time until we see something that suits the needs of us, "stereo guys"

-- José.

[This message has been edited by Route 66 (edited 03-18-2004).]

Mike:

Good test and some nice music too. Thanks for trying to provide an objective demonstration of the phase cancellation phenomena. I honestly am not convinced that this is a fault of Yamaha or Korg, or at least it may not be something that they accounted for. Phase cancellation happens when two signals meet each other that are out of phase. It's easy to make this happen and Korg and Yamaha probably didn't think that a lot of people would listen to their PA1XPro, Tyros or P250 or any of their stereo instruments in summed mono... that would be like blaming Sony if your home stereo didn't sound good in mono - they probably didn't think you'd use it that way. Some keyboard manufacturers have accounted for this and provided a mono output (and mono samples?), some haven't. I don't think there's anything that can be done about it, at least until newer models come out and only if customer demand for a mono output forces the issue.

Here's a good quote from UD: "If your kb sounds like crap in mono ... it will sound like crap, only louder in the PAS." Let's say we buy that theory because it may well be correct. That means that you really have to shop for a mono-compatible keyboard if you plan on going with just one of the PAS units, unless you find phase-cancelled sound acceptable. If you go with stereo then you are free to choose any keyboard on the market. Hmmm, this could be an interesting discussion after all...

Hey Pro,

I understand what you are saying about the manufacture(s) possibly not accounting for it. They were simpy trying to create a realistic or believable representation of the listening experience of that instrument.

Here's what sparked my question although I realize it's not the same thing but I'll share it with you none the less. I'm in my car driving home listening to a far away FM radio station and the "Stereo" light on my Alpine unit is turning on and off. I'm losing the stereo signal. What do I hear from the speakers. I lose the spatial-ness or directivity of the sounds. But I don't lose any specific frequencies, bass notes are still there, so are the mids, and so on. Stereo light comes back on, stereo signal processed and I'm back in the hall.

I get home, head straight for the stereo unit, cued up a CD and start playing with the Stereo/Mono button. Same results, lose the sense of space, don't lose the actual notes.

I know...It's not the same thing, I wasn't summing signals. But I couldn't help but wonder, "What's up with keyboards?"

Want some more reading? Try these:

http://www.anstendig.org/Stereo.html

I thought this was little biased since the author never really explained "why".

http://www.dogstar.dantimax.dk/acoustic/acoust-1.htm

I thought this was interesting since I previouly read an article about how we have two ears for creating two individual signals to feed to the brain (for directionality purposes), but that the brain processes these signals into one source (mono). We HEAR in mono, stereo is a man-made concept.

I'm not saying that, the article is. I don't know what to say (or think) at this point but I sure do enjoy the reading and learning.

mike

Mike:

UD commented on this in another thread with the correct answer I think: unlike all keyboard manufacturers, recording engineers realize their music will be heard in both stereo and mono and use phase adjustment tools so their sound is acceptable if heard in either format. My guess is that keyboard manufacturers who provide a true mono output in addition to a stereo output also use some sort of phase adjustment tool on their samples. In fact, just such as device may be the answer to using a stereo keyboard with a mono PAS system:
http://www.littlelabs.com/ibpjr.html



[This message has been edited by The Pro (edited 03-18-2004).]

After having auditioned the PAS myself in an actual gig venue, I concur that the PAS's 'claim to fame' would have to be its even 'coverage' throughout a large room, especially suitable for background music. Unfortunately, for a solo arranger keyboard concert with a sit down audience in a quieter setting, I definitely prefer going stereo. With the Bose PAS, the deep sub (thumpy) bass sounds very impressive, but I find the 'mid-low' frequencies sorely missing, giving bass notes a thumpy quality lacking pitch clarity and definition. Though I can feel the bass notes, it's difficult to her their actual pitch. - Scott

I have owned Bose Hi-Fi speakers (model 901) for many years; the concept behind these speakers was to recreate the sound of a concert hall (small or large) where -according to dr. Amar Bose- the sound that reaches our ears is only 30% direct and 70% reflected (by walls, ceiling, floor, etc). I have always thought that, albeit these speakers lacked the frequency response of direct systems, their spaciousness and their realism were unbelievable.
This is to say that dr. Amar Bose has always been a pioneer in the study of the so called "psycho-acoustic" and I have no doubt that even these PAS are revolutionary, in their own way.
I have tried to follow all the discussion that is going on these days on this stereo/mono issue on different Forums (including Harmony Central) and think that the PAS have brought to the general attention a problem which will change the way manufacturers like Yamaha, Roland, Korg, etc make their keyboards.
Basically I think that we all can agree that when we are listening to a group of musicians performing live cannot just think in terms of "left and right", because there is also a "up and down", a "front and behind" and all the intermediate degrees between them, and this is exactly the reason why, after listening to one of those home theater systems (5+1 or -even better- 7+1) nobody can go back to a simple stereo system without feeling a sense of deep insatisfaction.
So, like Mike asked, why are the people at Yamaha, Roland, Korg, etc selling keyboards with sounds sampled in stereo? Well, maybe because they sound more spectacular than a sound sampled in mono, at least until somebody comes up, even in the PA field, with a revolution comparable with what the surround systems have represented for the home listeners.
At this point, on the basis of the keyboards and samplers currently available, I have another question: what happens if I sample a piano sound in mono and then pan it according to the key played (bass notes on the left, mid notes on left + right, high notes on the right)? What's the difference with a sound originally sampled in stereo? In both cases, when I play a note, the sound that reaches my left ear is different from the sound that reaches the right ear. So, is it possible that -aside from saving 50% of the internal memory- sampling a sound like a piano in mono will give a more natural result, maybe because sampling the same piano in stereo can introduce artifacts, and the phase cancelation problem is just one of them?
I would like to know if anyone here has ever tried to play a monophonic piano multi-sample, panned according to the key and routed through a good digital reverb: what's the difference with a stereo multi-sample? Is the former less spacious or less natural?
I have a feeling that the people at Bose have just opened a BIG can of worms...

I get the feeling that people do not understand the phase cancellation problem when summing stereo audio signals to mono, though it's been explained in many ways.

I'll try again: the problem only occurs when the same sound occurs with itself but out of phase. A sound wave has an up and down cycle... now if you take two of the same sound and they occur simultaneously - nothing happens, but if one of those sounds is delayed by an incredibly small amount, then the "up" cycle of one wave will occur at the "down" cycle of itself, thus cancelling each other out. This is phase cancellation.

The problem occurs for keyboardists when you sum the left and right signals of a stereo signal like a piano into mono, and because of many possible factors then some of the tones wind up cancelling each other. The result is a "phasey" tone that seems to be missing some of it's mid-range (although all of the frequencies can be affected to some degree, while other frequenciess may not be affected at all, depending on which up & down cycles collide and when). The exact tones that are affected vary widely depending on keyboard and sound system.

You can do a search for "audio phase cancellation" and get much more detailed explanations, theories and diagrams.