I have built and owned the Pi 3 high efficiency for a year now. It sounded pretty exciting at first, but honestly I cannot listen to it for a long time. And I have to switch back to the Merlin TSM after a few weeks of listening and the excitement has died off. I would use it every now and then and it is still great for watching movie (this is one area that the Pi beats the Merlins), I found the high a bit to edgy.
Recently, I bought a cheap class T amp kit Amp6 from 41Hz.com (under $100). Class T or digital amps never interested me in the past. But for less than $100? I reckon it would be a fun little project and a good back up amp when my valves fail (as it has happened recently). It took me about two evening to build it and install it. I will talk about this amp later, but what happened was the Pi sounded even worse with this amp (as expected thinner midrange and less bass). I got a bit frustrated so just pushed the speakers all the way into the corners. Then I remember the recommended speaker placement from Wayne (the designer) and I thought, why now give it a go? So I toe them in at 45degree and move couch a few feet forward. Now the sound is much much fuller and has more weight, no more thin midrange and the highs are way less edgy and shouty. The tonal balance is more natural and the sound has more ‘body’. The soundstage depth is not great though, so I move the Pi slightly out of the corners (about 1 feet fromt the backwall, but still very close to the side walls) and get a little bit more depth (still not the best but acceptable).
With this placement, the tweeter horns no longer points to the listening position. Instead, the axis-crossing point is 2-3 feet in front of the listener. This is a lot of toe-in, way more than anything that I have tried or seen in the past. This placement method is actually recommended by Wayne Parham (the designer) and have been discussed alot in his forum, but for some reasons, I never really tried it in the past. The large toe-in minimizes early side wall reflections and allows a much wider ‘sweet spot’. At the same time it reduces the high frequency energy and make the highs less in your face. The corner placement also helps increasing bass weight.
Now, I can listen to the Pi for a longer time without fatigue, and it is still a pretty ‘exciting’ speaker to listen to. I am really amazed with how good it sounds with a $100 12W class T amp. I really look forward to drive the Pi with the quicksilver valve amp again (I am waiting for some new tubes as the old ones have failed. BTW, although the JJ KT77 sounds great, they are NOT reliable, do a search on www.audioasylum.com).
Next time I will talk more about Amp6 kit.
