I was going to start a new thread about this, then realized I'd already started this one and had only to revive it . . .
A set of
Bose 901 Series V did finally make their way into my house, along with a
NAD 304 integrated amp and a
NAD 2200 power amp (thank you, un-named Pelican!). I also bought a
miniDSP 901 EQ (a DSP with the 901 equalization curves pre-programmed) and a cheap set of cocktail tables with pedestals that raise/lower and swivel to set the speakers on.
Initially, I ran the 901s from the NAD 304 (signal went from the 304 pre-amp out, to the miniDSP, then the 304 power-amp in, then the 304 speaker outputs to the 901s). They didn't sound that great. Disappointing.
Then I ran the 901s from the NAD 2200 (signal went from the 304 pre-amp out, via Y-cable to the 304 power-amp in AND the miniDSP, from the miniDSP to the 2200 power-amp in, then the 2200 speaker outputs to the 901s). The speakers sounded
a lot better. I mean, the difference was very obvious.
After a week fiddling with location and orientation - how far from speaker to rear wall? how far between speakers? how high the cocktail tables, what direction speakers face? - I concluded that the speakers sounded best with:
- a solid wall surface behind them, to the extent possible (my brick fireplace surround)
- the tables as high possible (about 32" from floor)
- the speakers pointed at the room (I also tried them facing the rear wall).
But they still lacked high end - cymbals and hi-hats sounded muffled and dull, like Sonny Rollins is blowing in my room but Elvin Jones is doing his drums in another room. Lack shimmer, brilliance, etc.
This got me testing my hearing, which resulted in the other thread about hearing loss, and also looking at frequencies in music, which led me to conclude that since I can still hear to 10kHz-13KHz, I should be able to perceive
some of the shimmer of cymbals. Although, hardly all of it:
https://www.head-fi.org/threads/what-general-frequency-range-are-cymbals.98473/
As confirmation, my 21 and 25 y/o kids with their young ears also thought the speakers sounded dull, and my son's GF who is 21 y/o and a musician, agreed.
So I went looking for a tweeter that is omni-directional to add to the 901s. Found some cheap Radio Shack
Optimus LX5 speakers on eBay - before you laugh, these are a two-way bookshelf speaker that were semi-famous for having the
"Linaeum" tweeter that was considered pretty good back in the day and radiates in a omni (actually dipole) pattern rather than beaming. I simply connected them to the 304 speaker outputs and placed them behind the 901s (i.e., between the 901s and the rear wall, out of sight). So the 901s are driven by the 2200 and the LX5s by the 304, and only the 901s are getting the miniDSP EQ.
The difference was remarkable, everyone from old decrepit me to young kids/GFs agreed. More brightness, shimmer, brilliance, whatever you want to call it. No harm to the sound of the 901s. Except, the mid range was now a little too loud, due to the unwanted contribution of the LX5's "woofer", but this was just a quick-and-dirty test.
Next step is to remove the Linaeum tweeters from the LX5 speakers, place the tweeters on top of the 901s (right now the line-of-sight from tweeter to listener is blocked by the 901 cabinet), use a capacitor to pass only high frequencies to the Linaeums (I'm thinking around 8kHz or 1 uF), and figure out some sort of volume control on the tweeters (right now the 304's volume knob controls both the 901s and the LX5s), and get it all looking decent instead of the hot mess I have now.