Axiom Home Page Forums General Discussion Advice from Axiom Owners SPL Help

Michael, you might possibly reach over and do sub settings by "braille" as I do after backing my EP500 tightly into a corner. Because of the sensitivity of my fingers, I've determined that the level setting I arrived at(with the receiver sub trim at +2dB)was about 7:38:23. Don't overlook the significance of the trim control which Peter mentions, especially if your room isn't very large. In my particular combination of room size and sub location in a corner, I found that the "full" trim setting gave smooth yet still very strong results in combination with my M22s.

Can you tell me where your listening position is in relation to the front (sub) wall and back wall? I'm guessing that your seated in a location that has a room null. The ideal location is 38% from the front wall, followed by 38% from the rear wall. These locations are best for flattest response. 50% is not great, and the worst is being up against the back wall.

My listening position is about 10 feet from the sub which sits about 2 feet from the back wall and 1 foot from the side wall, there is virtually no back wall behind the couch since my setup runs at an angle and the room is open to another room that's at a slightly lower level, the nearest wall in direct line with the front of the sub would be around 40ft away.
I think you are right about me sitting in a fairly null area, as John and Peter suggested I'll try adjusting the trim settings to see if that helps.
Of course I can manually adjust everything so it sounds great in my sweet spot, but like most folks that get into this darn hobby it bothers me that I can't get it optomized throughout the room, and the fact that my Denons autosetup will drop the sub 10db's.

Good Luck...The newer Denon's have the latest technology from Audysseywhich takes measurements from 8 (depends on model) different locations and then applies filters to even out the frequency and get the best response from all locations. Reviews have been very positive from many reputible online websites.

I know you don't want to get a new AVR.

Oh I want that Audyssey But I'm starting to think I just may be one of the lucky ones in the group who's rooms suck.

Welcome Home, My Brother.

One thing I noticed about the suggestions in this thread is that you are using a range of 70 db and push the needle up to +5 to get 75 db (if I understand correctly). I have a very similar SPL meter (different brand but looks exactly the same) and the manual says that if the needle goes above ~+2 or 3 you should switch to a higher range. Reason being is that if you do the battery test its basically pushing the needle as high as it can go with full voltage applied, and if your batteries are low (say +2 during batt test) then there's no way to get a consistent reading at +5. It would only ever get there due to fluctions in the bass frequencies that cause the needle to 'swing' past the +2 up to the +5 for a short time before it drops back down. This could explain why your sub needs to be so loud, to get lots of these fluctuations to keep the needle close to the +5 position. If this is the case, I'm not sure why the other speakers are able to be calibrated at +5, possibly because they use higher frequencies and the fluctuations happen much more often.

My suggestions is to calibrate at a different level, such as 70 or 80 db, to overcome this limitation of the analog device. This way you will be able to see fluctuations both above and below the reference point and will not be depending on the battery level.

Thanks Jason, I'll try the 80db setting and see what happens, I've done some searches and have read about other people having similar problems in trying to get the db's on their subs high enough, I may be just dealing with odd room acoustics.

Michael, I think Jason's suggestion is good, as are your observations about nulls. You might try a inverse sub crawl; leave the sub doing something relevant where it is and walk around - even to the adjoining rooms. I was very surprised to find a big peak in the kitchen when I did this. I'm sorry that I haven't been following your story very closely, but if there is a way to experiment with sub placement, I'd strongly suggest it.