On Yamaha keyboards, as well as many other keyboard makes/models, many sounds rely heavily on special stereo efx processing to give them their impressive sound quality. Unfortunately, when the sound is mixed together to a single channel mono output (L/L+R), not only do you lose the stereo effect, but phase canceling results, and a severely degraded (thin)sound quality occurs as well. I particularly notice this on the 'live' Grand Piano instrument voice as well other voices which rely on efx processing.

In light of this, I decided to follow in Beakybird's (Larry Levin) footsteps and pre-ordered (with a 30 day risk free trial) from our forum buddy Dan O'Neil (at the Piano Man), a "Motion Sound" model KP-100S 'all in one unit' stereo speaker amp which claims to addresses the very problem I outlined above, as it contains 2 stereo speaker inputs in a single lightweight PA cabinet. It also includes a special 'stereo image enhancer' feature which accentuates the stereo field so the audience hears the effect of stereo yet I'll only need to take ONE relatively lightweight (38 lb) PA box. I had considered getting the larger (55 lb) KP-200S (which the Pro owns), but would prefer the lighter weight KP-100S to be used for smaller venues. For med-larger affairs, I would continue to take the two EV SxA100's, and perhaps augment them with the Motion Sound KP-100S as well.

The KP-100S won't be available for release till April, but because I pre-ordered I expect to get mine (along with Beakybird's) in the first shipment.

I'm interested in getting detailed feedback from 'the Pro' and others who have experience with Motion-Sound keyboard speakers. How large room (and number of people) do you think the Motion Sound KP-100S vs the KP-200S will handle? Do you think the KP-100S will be adequate for smaller venues (up to 40 people)? The KP-100S also allows you to add a sub woofer. Do you think the KP-100S has enough powere/punch w/o adding a sub woofer for the more acoustic jazz gigs?

I also heard that the Motion Sound KP-200S recently recieved a good review in Keyboard Player (Feb 2003 issue). Here's a link to Motion Sound's website:
http://motion-sound.com

Feedback & comments appreciated.

Scott

Scotty,

I'm so glad you brought up this topic. Not to start another long winded debate regarding stereo vs. mono, but I've been using a Stereo Keyboard amp for about a year now doing about 60 gigs and I'll never go back to playing through a MONO system. I hear the difference, the crowd hears the difference, and the band hears the difference.

With that said, I have had terrific experiences using this Fender Keyboard Amp - SFX 200 http://www.musiciansnews.com/piano/64/sfx_200_keyboard_amplifier.shtml

I don't know why Fender killed it (Sales probably), but for me this amp is rugged, lightweight, has wheels, great effects for Vocals, and great stereo imaging.

A freind of mine told me to check out the new CARVIN stereo keyboard amps. I might consider getting one as a backup in case of an emergency. They can be viewed at : http://www.carvin.com/cgi-bin/Isearch.exe?P1=KBA

The friendly neighborhood keyboard salesman is trying to talk me into getting (2) JBL G2 Eon's for all around stereo high amplification with a clean sound. I have not tried them yet in a keyboard situation,but I am familiar with them in vocal situations and they sound clean and pure.

I did have a Motion Sound Pro3T Leslie simulator amp that I used for 1 gig and sold on Ebay. I didn't like it at all since the rotor effect was only pronounced at very high volume levels.

Good luck with your persuit, I hope any of this information helps.

Al




[This message has been edited by kbrkr (edited 02-25-2003).]

I played the 200 alot when it first came out, and I didn't like the bass response. Now remember, I play mostly left hand, maunal bass parts, and I think they may put more strain on the overall sound than a processed, automatic style part, so ..... maybe I ask more than the amp wants to deliver. All I remember is that ..... the bass got "splatty" too often for my liking. I imagine the 100 will have even less bass "umpfh".

Playing the bass manually really does add a lot of extra expression to the (already)dominant drum section, so maybe it will not be trouble for you arranger type players, but I advise you to really test these babys out with your own gear before you commit to any long term aggreement.

I never ordered anything I didn't hear until the 1st PA80 came out. I was so excited about the "supposed" features, and I trusted the name so I took a shot. The original O/S wasn't nearly ready and I HATED it. It took 3 revisions to make it work for me, so "Buyer's Beware !"

I owned the Pro Leslie sim and that was a killer machine. The quality of the unit was great. I am very leary of a spacial expander that affects the voice ......... I think it might make you sound like you're in a fish bowl.

Al: I followed all your links above and did not find any information about stereo keyboard amps. The Carvins were all mono and the link to Musicians News went nowhere. I'm very curious about stereo keyboard amps from other companies so please repost the links if you have info. Also, I have a pair of EON G2 10's that I still use with my keyboard rig and they do sound great, but really they sound best with a mixer/preamp of some sort, not just with the keyboard alone run direct into them. I did several gigs with my 9000 Pro and the EON's alone and they didn't have the warmth and punch I wanted. I wound up adding a mixer. The KP-200s has the mixer/preamp built-in with active EQ and stereo enhancement in a package that weighs the same as my EON's together do. The bonus is that I can easily use my EON's as extensions to the KP-200s.

Scott: I've probably ranted too much already about how much I like my Motion Sound KP-200s. To answer your thoughts, I'm uncertain about how well the KP-100s will do since it has two 8" speakers instead of the two 10" in the KP-200s and the specs show a corresponding drop in bass frequency response. That's not to say that it may not work for your application of 40 people - it may work fine. Sure, you can add a subwoofer but the point in my mind was not have to carry additional amplification - I really wanted a one-piece unit that would carry most if not all of my gigs, and the KP-200s does that. In other discussion groups there are several people who have preordered the KP-100s for the same reasons and applications you have so I think it's going to be a very popular amp and I look forward to your review. I don't see how you can lose since you can return it if you don't like it, but I wish you could compare the 100s and the 200s side-by-side and see if the freq's of the bass speakers make a difference. Personally I wanted the power of the KP-200s and the amp is still quite small and at 55 lbs it's not overly heavy either. The stereo enhancement effect is uncanny and it will change your mix somewhat so expect some surprises. I'll bet you're going to love your new amp.

Also worth noting: Motion Sound's website refers you to a company called Le Cover for ordering custom amp covers should you decide to keep your KP-series amp. I just got my padded cover from "Larry" at Le Cover yesterday and it is great - fits like a glove and feels like a quality product inside and out. The front of the KP amps seems like it could be damaged easily so I think getting the padded cover is a good idea.

Sorry Al - I should have looke closer at the Carvin amps although I'm still uncertain if they are true stereo amps or not. They say that they have controls for "Amp1 and Amp2" and a crossover for bi-amping but there's only one horn and two 10" speakers in their "stereo" 1010 model so they only thing that'll be in true stereo with their amps is the bass?!? The Motion Sound amps go out of their way to emphasize the stereo imaging: not only are there two horns and two 10" speakers in the KP-200s but the speakers are mounted at an angle away from one another and there is a phase adjuster that spreads the image even further.

That stereo imaging facet of these amps doesnt sit good with me. Reminds me of that awfull Acoustic Phase feature on the Technics Kn5k etc. Very fake, sounding like your in a tunnel. I could be wrong but I would take a serious test run on
"Your Equipment" with these type of stereo all in one's to make sure it gives off the sound I want and need vs a two speaker stereo setup.

I fixed the link in my earlier post they should work correctly now. Damn periods, who needs 'em!!!!

Al

[This message has been edited by kbrkr (edited 02-25-2003).]

Be sure to check the Carvin - it looks like they are using a stereo-capable amplifier (see the last line indicating that it is 2 rack spaces high) built into a mono cabinet.

Also, 84 lbs is quite a bit of weight.

Interesting, especially because Fender claimed that they could create realistic stereo keyboard imaging from a strange-looking amp with one 12' speaker, one 10", one horn and two 80-watt amps with their SFX 200. This has been discontinued so it must not have been wildly popular and now Fender no longer makes keyboard amps at all.

Yes and ditto. In fact, the Motion Sound amps employ something similar and if you overuse it then you do get the "tunnel effect". What it's doing is reversing the phase of the speakers so what's panned to the middle is reversed and diminished somewhat, same as what "vocal eliminators" do, leaving the reverb. Since the Motion Sound uses a true discrete stereo amp, both in terms of actual amplification and speaker setup, I think it probably sounds better than the quasi-stereo amp offerings. Turning it's stereo enhancement knob up really does make the sound expand all around you in a very obvious manner and the effect to your mix is similar to compression, except that it doesn't affect the tonality. I find it works best for me set at about 5-6 on a scale of 10. There really is only one way to know if it works for you or not...

Jim (the Pro): Do you feed both vocals as well as the keyboard mix thru your KP-200? If so, what 'stereo expander' setting do you find the best for this situation? I assume it's also possible to turn OFF (bypass) the stereo enchancer feature completely, right?

Scott

Scott: Hmmm... let's qualify my answer: I don't sing ! So my mic, which is for announcing only, is hooked up to the mic input of the 9000 Pro and then the sum stereo signal from both the keyboard and mic goes into one channel of the KP-200s. The amp has two stereo channels (each channel has it's own pair of L/R inputs) and Channel #2 controls a lo-z mic input (on the back of the amp) so it can be used as a dedicated vocal channel. Each channel also has it's own stereo enhancer control, which is a knob from 0-10, so you can turn the effect completely off and just have normal stereo - you'll find normal stereo to be a little dull in comparison though.

I don't think the enhancer will have any effect on your main vocal but it probably will affect the sound of your harmonized backing vocals if they are spread in a stereo field (it might make them sound better!). The enhancer doesn't do anything with mono sources, only stereo ones.

BTW: earlier I said that the stereo enhancer reversed the phase of the speakers - to be more precise, it changes the phase of the stereo SIGNAL, not the speakers themselves.

I know what you mean....when I originally test drove this amp at my local music store, I was dumbfounded when I heard it was discontinued. It sounded great, and still does. That 10 inch speaker which is transversed to the right is actually the right channel of the stereo image. I play on the left side of the stage all the time and I can play around with the deflection by pointing the face of the amp at the band and the traversed speaker at the crowd.

You can find these amps on Ebay from time to time, but they sell for quite a premium now. I've been looking for the matching sub-woofer for a while now without luck. There is a separate sub output on the back which would be kind of fun.

I must say, you guys have me curious about the Motion Sound amp. I may have to toddle off to the music store this weekend to check it out (if they have it).

Al