Axiom Home Page Forums General Discussion Home Theater BFD & 600s All Set Up

Much thanks goes to Doug, Peter,Adam, and Lee for spending over 5 hours here today on calibrating and adjusting the BFD and the twin 600s. There is a VERY noticeable differance with having the two subs, and also with the BFD in the system., as the graph below shows. Blue is without the BFD and pink is with the BFD added, in my opinion, the BFD was worth the extra investement and time. Had it not been for above people, I would have been here for weeks getting it set up on my own.

WOW! That is a pretty nice final graph.

Wow... that's mighty nice for "in room" response.

Did you tell them where MarkSJohnson lived ?

Yeah man that looks really good.I wish I could hear those bad boys .

Only wished Mark was close enoguh to get the kind of help I did, I'm very lucky to have such kind offers of assistance.

Thanks again for having us over, Dennis, it was a lot of fun!

I've never heard a system sound so effortless at such high volumes - I played the 2nd movement of Beethoven's 7th symphony after we'd done a basic speaker and sub level calibration, and was amazed. There's simply no dynamic restraints! For those of you familiar with the piece, it starts off fairly quiet and builds to a nice fortissimo, and during the quiet passages it was probably around 85db or so. I'm used to hearing a little strain from anything I turn up that loud, but the fortissimos were as effortless as the pianissimos. Impressive! Although, it becomes very apparent (or should I say, painful) which cds were mastered hot at those levels. Stick on a bright cd and you're left wincing at every cymbal crash or "s" sound from the singer. Stick on a good cd, and man, what a treat!

After we'd spent a good couple hours measuring room response and calibrating the BFD, the system was really something else. The subs took the most time to calibrate and really get a smooth response, but once that was done, the sound was just awesome. Smooth, clean, in your face and right in your chest. From Darla (Finding Nemo) to depth charges (U-571) to rockets (Incredibles) to music from Beethoven to A Perfect Circle and everything in between - this system is MIGHTY impressive. I don't think I could listen at the levels Dennis usually listens to for long, but I could understand the temptation to when it sounds so effortless.

In reply to:

---

...I played the 2nd movement of Beethoven's 7th symphony...

---

Hey! That's on my mix cd that Tharkun will likely receive tomorrow!

Yup - when I looked at the track listing on your mix, I noticed it and smiled. I think that's my favorite movement out of all of Beethoven's symphonies. Maybe even all his work, period.

The kiddo is down for the night and my wife has gone to bed (and the dishes are even washed!), so I can now concentrate on an official report of the latest visit to Haxiom Theater.

The main event today was calibrating the subs and tweaking their in-room response with the Behringer Feedback Destroyer. Doug (dougmcbride), having the most experience calibrating subs, manned the command post and directed the calibration efforts. My brother Adam (AdamP88) and I manned the Denon 2900 and Parasound C2 remotes. I also did the button-pushing on the BFD. Lee (koiman) lent his ears and brain to assist in calibration decisions. Lee brought his wife (whom he referred to as "his navigator"), who valiantly tolerated the high levels of geekery oozing from the rest of us who were engrossed in the calibration process. When they arrived, she saw the SPL meter on the tripod and said "I know what THAT thing is! That means there's going to be loud noises."

After we took the initial readings (the blue line in the graph above), Doug broke out an online tutorial for configuring the BFD as a bass response "smoother-outer". All of us were expecting it to be a bitch and a half to set it up, but it actually went quite smoothly. It helped that the tutorial was pretty good and that I'm really great with buttons.

The great thing about the BFD is that it allows you to precisely specify which frequency you want to correct, and the bandwidth to the left and right of that frequency point you want to be affected. We ended up using 6 of the available 12 frequency filters. The results speak for themselves.

Prior to calibrating, we watched the U-571 depth charge scene. Doug noted that it sounded a bit anemic. Post-calibration, that same scene produced the chest reverberating sensation Doug was looking for. Most impressive!

I would highly recommend a BFD to anyone as a cost-effective (only $108) way of dialing in sub room response. You could easily spend more than that amount on room treatment and bass traps and not come close to the results we achieved withthe BFD.

Of course, it always helps to start with great equipment.

Peter, excellent results with the 600s and BFD. Unless I've lost it in some post I've missed(been doing tax returns; finished!!),there hasn't been any discussion of how the 600s were located for the blue line readings or whether alternate locations were tested before the BFD did its thing. One of the interesting papers on the Harman site tested a bunch of alternate locations for single or multiple subs.