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.