Bose 901 VI flat?

Man I don't think I ever heard the Bose 901 sound good, maybe passable in some situations but if there was ever a mediocre speaker that was one. 

Thanks for backing me up guys but I wanted to say for the OP to use the Bose equalizer first, it won’t cost anything and you’ll have something to listen to. You can hook it up between your source and receiver as a test. 

That's right, USE the equalizer and see if you like it. If so, great, and find a way to implement the equalize. If you don't like it, cut bait and look for something else

They only sound "decent" with the Bose EQ- in your case probably in the tape loop. I think the EQ adds up to 18 db of gain in both bass and treble...you really have to use it.

I have to weigh in.  I had 901 vi’s with 100 wpc and they were a disappointment and I sold them.  I now have them again, but now in a large and difficult room, with a 10” Martin Logan sub, powered by 650 wpc mono’s.  They are astonishing in that room.  As good as anything I’ve ever owned and my go-to system.  

Nobody is more surprised than me.  In the right situation, they are more than they were ever cracked up to be.  From my experience, they need lots of power first.  Next, a sub to round out the low end.  Last, the right room.  

You must run the equalizer, which is old enough now to need re-capping.  The drivers on these are bulletproof and will last a very long time.  I’m so impressed with these, KEF Ref 5’s are being sold and I’m eyeing my new La Scala’s too.