Tube vs Solid State

That’s an interesting point, Lalit. The sensitivity of our ears to deep bass frequencies, relative to their sensitivity to higher frequencies, will of course be less at relatively low volume levels than at higher volume levels, per the Fletcher-Munson effect.

Which leads me to wonder about the gains your amps provide when used in bridged mode vs. when used in a vertical biamp configuration. The gain of the amp is spec’d at 26 db, a typical number for a power amp, which I presume applies to the stereo mode that would be used when biamping. But I would suspect that their gain in bridged mode, which does not appear to be specified, may very well be (and probably is) 6 db higher. And if so, unless you took special measures to accurately compensate for the reduced gain when you tried vertical biamping the result might have been that you were listening at a somewhat lower volume in that mode, which might account for your perception of less weighty deep bass.

Don’t know about you guys, my room is 15’D x 30’W and 60db’s is plenty loud.

Although it’s not particularly relevant, I’ll mention that my room is 12W x 22D, opening to another room in the rear. My listening is mostly to classical music, and in many cases to recordings having very wide dynamic range. Average SPLs at my 11 or 12 foot listening distance are typically in the mid-70s or thereabouts, but I have at least a few orchestral recordings that were engineered with minimal or no compression, and produce SPLs that can vary between around 50 db and brief peaks of 105 db on the same recording!

Best regards,
-- Al

Al, you are spot on amp gain in bridge mode, it's 32db. I mostly listen to jazz and classical music. I think it's worth a second shot to  try vertical bi-ampimg again tomorrow and increase the volume upto 80db to compensate for -6db gain. 

George, good point. A loudness switch is what I need :-)

Thank you both for great feedback! 

You’re welcome! A minor correction to my previous post: The width of my room is 13.5 feet, not 12 feet.  Length is 22 feet as previously stated.

Best regards,
-- Al

Al - 

After a day of 85db plus listening, my ears were ringing all night long with musical passages :-)

In all seriousness, yes 800's and KWA150SE performed much better in vertical bi-amping at 85db plus. And I did appreciate the separation between low bass frequencies from mid's and high's. 

As others 800's owners have suggested in this thread, a higher wattage (600W -1000W) amp would be better suited for my listening preferences.  

May be a pairing of McIntosh MC601/MC301 with a tube preamp or McIntosh MC601/MC2301 with a MEN220 in front of MC2301 would just do the trick! 

Cheers!

I see that you have your Modwright KWA150SE up for sale.
Did you get a new amp already?