I've been testing speakers also and your observations are in-line with what theory predicts.
Basically the most important part of a piano's sound is the midrange. the is the few octaves on either side of middle C. So you want a system that handles midrange very well. this means
one (not two) of the drivers is optimized for this range. the worst thing would be for middle C to fall right on the frequency where two drivers are crossed over.
Also with sub woofers. They work because human ears can't locate the source of low frequency sound that is below 80 or 60 hz. We use the highs to locate the source.
What this means is that if the satellite speakers are so small that the sub needs to reproduce mids or even mid-bass we will know in a minute the sound is coming out of that corner where we placed the big sub woofer. With bigger left and right channel speakers with can cross the sub over at 60 or 50 Hz and then it sonically disappears and we could place it under the piano bench and our ears would never find it. The other problem with putting mids in the subwoffer is that those are taken out of the stereo image and the ears can no longer use location to pick out and isolate the sound.
Bottom line is you really need a 5" minimum speaker to reproduce the mid-bass. Without it, that range fall on the sub abd the illusion is busted and sound then seems to come from speakers and not the piano.
That small THX system is designed for movie sound tracks, these lack mid-bass, that areas below the make voice and above the car crash and explosion range so small satellite s and big sub woofers work perfectly for action films.
I've tried several different sets of speakers and have a couple more in the pipeline. I'm using a P155. Every time I try a pair I think "these are pretty good." and then I A/B test them with a switch. Usually it does not take much switch flipping to find the winner.
So when someone says "My brand XYZ Speakers sound pretty good" I'm never surprised because "good" is always relative" It does not take much to sound beter then the P155's internal speakers.
In my experiance so far I find that physical size really, does matter. Assuming a decent brand and reputation, size matters more then anything else including cost.
I think if you look at the CLP380 speakers, the 2.1 system and the p155 results match up pretty close to what the above predicts
So I finally got a set of Logitech Z-2300 speakers. I actually bought them for my P-155 but I don't have access to it for the next few weeks so for now, I've only tried them on my CLP-380.
The good:
- Consistent tone and clarity even at high volumes
- Powerful bass -- playing that low "D" in Bach's Toccatta and Fugue BWV 565 with the Pipe Organ Tutti sound and feeling the whole room shake is a lot of fun ;-)
- The satellites are fairly small and light, and look good on the piano
The bad:
- The subwoofer is huge and overkill for piano sounds (what's the point of that heavy box when you have to almost turn it off to avoid it from overpowering everything else?)
- The midrange in particular sounds a little artificial
- One clearly hears the sound coming from two speakers (of course this is an issue with any 2.1 speaker system). The internal speakers of the CLP-380 on the other hand, credibly create the illusion of an acoustic piano in the room.
Overall I am quite impressed and looking forward to the strong improvement the speakers will provide to my P-155. However, I would certainly not recommend them for a CLP-380 and I am quite puzzled that anyone would find them as good -- let alone better -- than the CLP-380's internal sound system. I would rate the sound as follows:
- P-155 internal speaker: 3/10
- Z-2300 on CLP 380: 7/10
- CLP-380 internal speakers (with enabled iAFC): 9/10
I should mention that I also tested my M-Audio Studiophile AV 40 speakers (which I use with my PC) for purposes of comparison (they cost approx. the same as the Z-2300). The AV 40s were excellent, particularly in the midrange (easily superior to the Z-2300s) but lacked power overall. I had to turn up the volume almost to max on both the piano and the speakers to get an acoustic piano volume, at which the speakers were clearly reaching their limit. It's a shame really, because with just a little more power they would have been clearly superior to the Z-2300s; as they are though, I can't really recommend them.
