I'll try to make this as short as possible...here's my question. I have three Harman/Kardon receivers in my "stable" of equipment. A 20 year old 680I, an AVM 20II and an AVM 35. The 680I and the AVM 20II both have on the reciever a "loudness" button, whereas the AVM 35 does not. The only system in which I have a Subwoofer is hooked up to the AVM 35. The others are for bedroom systems. I'm making a move to separates and started by purchasing an Anthem MCA 5 amp. Waiting on the Outlaw 950 to complete the combo. Seeing as the AVM 35 doesn't have pre-outs, the amp was basically collecting dust waiting on Outlaw. However, I got impatient recently and hooked the Anthem directly up to a 10 year old Yamaha CDP-91 5 disk changer. The Yamaha has variable output control, so I could control volume from the changer. My speakers are Paradigm Studio Reference 40's. Here's my problem. When I hook the 40's up to the 680I and engage the "loudness" button, I like the way it sounds. Very full, lots of punch...just nice. It seems a little "thin" on the bottom end without this feature. When I hooked the 40's directly up to the Anthem I noticed that the sound just exploded. Mids and hi's were incredible and the soundstage and clarity was amazing. Where the sound lacked was in the bottom end. It had that "thin" sound to it. Bass was very tight and clean, but didn't have that full bodied sound. In the Harmon manual, it states that LOUDNESS BUTTON - Press this button to compensate for the response of the human ear at low listening levels (known as the Fletcher-Munson hearing curve). The high and low frequencies are automatically boosted when this button is pushed in. In the OFF position the frequency response is flat at all volume levels. This button does not work at high volume levels. So, seeing as I've heard the 40's sound very full bodied when using this feature and that effect lacking when running the player directly into the amp, does this mean that the 40's NEED a subwoofer (which I have in another system and haven't hooked up) or are my ears just used to the "artificial" effect this feature brings. I loved everything about the sound of the amp except the missing (perceved?) low end. I've switched out cables and really wonder why the low frequencies aren't as prominent when played this way. Sorry for the long tirade, but this is confusing me. Thanks.