The pursuit of bass...

I would be more concerned about peak somewhere ocatve of half below or above that dip. i have instaled nearly half hundred rooms and in rooms with clear resosonse mode there is always (mostly in theese areas ) peak at 58-65Hz and dip either 80-100hz or (more common) 35-42hz. there is nothing can be done for preventing main room resonanse mode. even if it can be atenuated by digital eq corection ,its level just maches main spl level but resonanse stays(its just much lower in level)its very audible on recording where music piece exactly maches peak..

You need space for bass most loudspeaker designs are highly compromised in performance as to pas WAF allow hi profits ease of manufacturer shipment etc. Good sound while not the last thing most loudspeaker designs strive for but not near the top either profits are. Many have also been sold the line for years that little monitors with wee subs or slim towers are the better performing designs when its the complete opposite thats true. So you end up with most loudspeakers producing little to no infra bass. Or bloated subwoofer adding there drone. Bass response dynamic range and lack of thermo compression are critical to great sound but conventional designs mostly over look this.

My pursuit of a little more bass has me using equalizer. While using my music server I started to play around with iTunes and the equalizer in the program. The adjustments are made on the fly from my listening chair. I have to tell you I am really enjoying it.

Jax2, can you borrow a sub? Perferably one with a phase reversal switch. It can be a small sub that doesn't go very deep. Try it along the wall behind the speakers, with the phase reversed. I'm hoping that its response will "zig" where your main speakers "zag". Also try it along the wall behind the listening position, starting out with normal polarity. Having powered subs in your main speakers is a big advantage here, because in either of these cases you will probably need to adjust their level.

You said that your speakers were "solid", with "no boxes" - could you elaborate?

Thanks for the sub suggestion - Again I have such limited space that it becomes a real estate issue. I have had a sub in here several times before, though not with these speakers as no one would ever listen to these and think they need anything more in the low end. I can reverse phase on my preamp, but of course that would address both sub modules and do nothing like you suggest. I can also separately attenuate the sub sections (as well as the tweeter) on the speakers. I have tried that and the suckout remains unchanged, hovering around -10db while other regions do change. The point I was trying to make is that it's not the specific speakers, but the room that's causing it. Elviukai - there is indeed a peak just below the suckout dip, right at 50hz. Again, a consistent theme no matter what speakers are in place. So it sounds like the only real way to to address this is to alter the position of the system in the room, as Duke suggested from the start?

Duke, the current speakers are AudioMachina Pure System MkII. The body is solid aircraft aluminum (no box - just enough space for the drivers including the sub driver). The online information has not been updated to the Mk. II version, which has changed from Karl's dated website (I'm working with him on an updated site with new images). They are extraordinary speakers...quite unique...sound amazing; basically a full range driver with a subwoofer and supertweeter. If you have not heard them, check them out and introduce yourself to Karl at RMAF. You'd probably enjoy each other. They have attenuators on the sub and on the supertweeter.

The room's been a thorn in my side from the time I had to move my system there from my studio (which I gave up five years ago). I'll include it in this discussion only because it certainly does play a big roll in the pursuit of a full range sound. It is about 11+ feet wide by 24 feet long and the furthest 10 feet of that length opens up to about 16 feet wide with a cathedral ceiling and a 14 foot peak. The system is on the long wall at one end of this space furthest away from where it opens up larger. A big sacrifice I had to make is that the system had to go under the the higher part of the sloped ceiling (ideally I would have it the opposite way). So at the listening position the ceiling is 8 feet, and at the system/speaker it is 11 feet. Speakers are about 30inches off the back wall and listener about 7 feet from the speakers. It's a very challenging room. Hardwood floors with area rugs and lots of hard surfaces which make it very lively. Plants and room treatments are all I have going for me. That and being nearfield does obviate some of the room issues, while making bass a more challenging issue, as I understand it. The overall volume of the space is probably around 2000cf. Any WAF suggestions would be appreciated. Duke, if I do get the chance to borrow a small sub I will try what you suggest, but you're asking me to put it where the bass traps are (directly behind the speakers).

Jax2 asked: What is the difference between pink noise and white noise (noticed the recommendation for white noise in the Geddes reference)?

IIRC, white noise has equal SPL/Hz across the spectrum, whereas pink noise has equal SPL in each octave band. Pink noise is thought to be more relevant to the perception of sound. It's been nearly 50 years since I've had to know such stuff, so my recollection may be faulty, but the distinction is something along those lines. I'd be inclined to use pink noise unless Geddes has a well reasoned rationale for his preference, though white noise generators that meet specs may be easier to find in products aimed at the consumer market.

db