My Quad 2905s have a pair of extra panels over the usual arrangement of the 63 and later models. They aren't bad at bass, but it is rather polite. Fine for classical music, but not really authentic for good recordings of small ensembles. My fix for it will horrify those with more money to throw at it: I have a powered subwoofer, made by Axiom in Canada, and bought very cheaply to go with a basement movie room in my old house. My pre-amp has two sets of outputs, one for my Quad II/forty amps, and the other goes to a Musical Fidelity X-Can V3 for headphones. The X-Can has a pass-through function, so I can use its output jacks to go to the powered subwoofer. It has its own volume control and crossover adjustment. I do use Y-connectors to make the X-Can work in mono (you'll see why below) and to feed a mono signal on to the subwoofer.
The subwoofer blends in nicely with the Quad ESLs and it doesn't seem at all disjointed to me. I may have two advantages here: the new house has a large open plan main floor, and in the centre of it is a fireplace and chimney breast which rises up to the post and beam rafters. My Quads sit on either side of the fireplace, the monoblocks are at the side of the fireplace, and the turntables etc sit on an old oak chest at the rear of the chimney breast. The subwoofer sits beside the chest. No one sitting on the sofas in front of the speakers has any idea where the bass is coming from, and it only sounds odd if you go back to the turntables and discover the bass is pretty strong back there. However, no one listens back there as the area is a large curved staircase well down into the basement. My secret weapon though, is that I have only one functional ear, so I just don't do directional hearing at all! I'd like to hear stereo, but never have since I lost my left ear aged eight, and I can't say I miss it as I have no memory of what it was like. That's why I make my headphones play in mono. So it all works for me and makes me happy. My old neighbour from the last house was a concert pianist and when she visits I play her all sorts of piano pieces, and she often comments on how it sounds like there is an actual piano in the room. She should know: she has a baby grand in her house!