Tuning the B4+. Man, I love this thing.

Gabriel_Lam · 03-22-2004, 01:46 AM

I've finally gotten the chance to play with my B4+ a little. I tell you, the wife has a baby, and everything changes.

A little background:

I'm in an 18x22 room (about there), with an 8' ceiling, with a big archway on one corner and corner placement. I just redid much of the room, and I think I'm going to stop for now, so that I can actually enjoy it for a bit.

Here's the front (click for bigger picture):

The center channel speaker is behind the bottom blackdrop area in the screen.

When I ordered the B4+, I was unsure of what color to get until I found out they can custom colormatch. No question, this is definitely the way to go.

I sent them one of my surround speakers (Aurum Cantus Leisure 2 Deluxe in Rosewood), and they sent me some samples of what they did. You really have to see it in person to appreciate what a piece of work that subwoofer is. The colormatching was excellent.

Again, click for full sized picture:

Here is the equipment rack, near the archway (click):

From top to bottom:

Gefen 4x1 DVI switcher, hidden (from our good friends at BetterCables, a HTF sponsor)
Voom HDTV box
Lexicon MC-8 Balanced
Vinc Bravo D1 DVD player with DVI output
LiteOn 5001 DVD+R/RW burner
Behringer Feedback Destroyer (now has 1" feet for some extra room off of the K2)
Crown K2 Amplifier
Panamax 4400 20-amp power distribution unit
Panamax 4400 20-amp power distribution unit
Panamax 5300 power filter
Adcom GFA-7807 7-channel amp

The K2 & BFD finally came and I started tuning. I started with 3 plugs in, but settled on 2 plugs.

I'm a COMPLETELY n00b at tuning this thing, but after hours of fiddling (and frantic icq messages to a friend), I arrived at this:

It sounds INCREDIBLE. I can't believe what a sub this B4+ is.

I know there's still more to tune out of it, so if you have suggestions, please chime in! I'd greatly appreciate it.

I think I have to start strapping stuff down...

Mitch Stevens · 03-22-2004, 05:20 AM

Damn!

I can't wait to get my B4+ which should arrive here either today or tomorrow. I'm going to have so much fun tuning it, just as you are now.

I have a question though. I thought it only came with TWO port plugs. In the picture, I see 3.

I thought, that if you plug one port, it tunes it down to 20hz, and another port plugged, it tunes it down to 16hz. A third one, and you should be getting 12hz, but I wasn't aware that the B4+ could go that low.

Gabriel_Lam · 03-22-2004, 05:35 AM

Hmm, it comes with 3, or at least mine did.

They don't mention what the tune is with 3 ports plugged, in the manual. I'm guessing you're right though, since it does say about 4hz per plug.

You know... my sub is missing the little SVS emblem! I just noticed that.

Mitch Stevens · 03-22-2004, 06:33 AM

I have a quick question, Gabriel,

It seems by your chart that you are only getting 100 dB at 16hz. Now, don't get me wrong, that's a lot, but looking at the online B4+ manual, it clearly states that with 2,500 watts (such as the K2 amp that you're using to power it) that it can hit 122 dB at 16hz.

JohnSmith · 03-22-2004, 07:02 AM

The above graph is used for frequency response chart- not extreme SPL's during use.

Sine wave are used to plot the graph. You don't want to playback sinewaves at loud levels.

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qualen · 03-22-2004, 12:16 PM

beautiful sub!

Dustin B · 03-22-2004, 11:26 PM

I typed this and decided not to post it twice already. Sort of picking an arguement, but I just don't get it.

Why do so many people buy the mighty B4+ and then cripple it by plugging the ports?

The B4 is underported with no ports plugged (granted the output four 4" ports can produce is sufficient that it simply doesn't matter for 99% of users). However, plugging 2-3 ports basically limits your sub to the output of a PB2+ in the last octave (with the exception of the very bottom of the last octave). I can justifying plugging one port, maybe, but that's it.

A 25hz tune is sufficient for ~95% of movies. A 20hz tune is sufficient for all movies. A 16hz stock tune is nice for ~1% of movies and some specific music pieces. A 12hz tune has no benefits with any source material I'm aware of.

Allen Marshall · 03-23-2004, 01:02 AM

howd you make/get that chart. Im startin to get jealious with all these waterfall and frequency charts up down and all around, there cool.

Edward J M · 03-23-2004, 04:38 AM

Quote:

A 25hz tune is sufficient for ~95% of movies. A 20hz tune is sufficient for all movies. A 16hz stock tune is nice for ~1% of movies and some specific music pieces. A 12hz tune has no benefits with any source material I'm aware of.

Dustin = the voice of reason once again. I agree 100%. Plugging one port on the PB2 series is all I ever needed, and that was for organ music with genuine 16-17 Hz content. Otherwise, let the sub breathe deep.