Originally Posted by dominguez1
That's also another good test! 2 1200D's stacked on on top of another, but both perfectly 180 degress out of phase with one another. SPL should be very little, but PR
and TR should be higher: get rid of the boominess (minimize SPL), but keep all the slam (maximize PR
and TR). This would certainly work if they were the only two subs in your system...not sure what happens when you try and integrate that configuration with other subs...
Good idea on running two of the 1200D's stacked and 180 degrees perfectly out of phase with each other. I agree that would be a great test. Actually I forgot that I did that with the 180 degree phase switch on the 1200D. I mainly messed with the distance for phase tweak when I was trying to reduce the combined SPL a little and leave the gain alone on the 1200D to keep that increased mid bass slam without the bit of boominess that it added. When I flipped the phase switch to reverse, oddly enough my FR (overall and also the nearfeilds (bank of 3 sealed 18's and the farfield on there own) looked about the same (FR on the 1200D did change a bit though). But it didn't sound the same. TR felt the same but the overall bass was quite a bit thinner sounding. I guess I was experiencing what you guys were discussing earlier in this thread about out of phase - less SPL but still have the TR. I probably should have up'd the gain on all subs to see what kind of TR brutality I could get out of it. Problem is I don't think I have enough subs and headroom to increase the gain a substantial amount without putting to much stress on everything. Maybe if I went from 4 to 8 subs or more. As is right now with the 4 subs (3 of them nearfield right behind me and a pretty hefty LS filter to lift the bottom end) it seems to be fine at my listening levels between -10 to 0 MV and subs about 6db hot on most movies.
The crazy thing is, by switching the phase on the 1200D, even though the FR looked basically the same, about half the bass sound was gone. Some times this stuff is so hard for me to wrap my head around. About the time I think I got the whole FR, TR, PR
, nearfield and farfield stuff figured out, something like this happens. Dom, what you did with your 30hz peak reductions with the NF & FF subs with phase makes since to me. But what I was experiencing doesn't.
I've ran Audyssey XT32 several times over the last couple of months just playing around. Sometimes tweaking pre Audyssey with a miniDSP only using 1 Subout for all subs and also using 2 Subouts (farfield on one bank and the nearfields on the other bank). Both work very well and I'm usually quite pleased with the results. BUT, even though the overall FR and also the farfield and the nearfields FR by them selves look real similar, it usually always feels just a tiny bit different. I think some folks wouldn't notice it and might not even care, but I'm so used to certain demo scenes that I can always feel the minuet differences in TR. IMO I think that's one of the coolest things about the nearfield subs right behind the LP - whether its a true full range sub or an MBM, you can feel all the little nuances in the bass frequencies that they cover.
Originally Posted by dominguez1
What did you end up doing with the 1200D if not placed on top?
At the moment I dont have it hooked up at all, nor the FV15HP. I dont really feel like they add much if anything to what I already have running now, other than more headroom which is always good. I may play around with the 1200D and FV a bit more and try to integrate them into the mix a little better. I don't have the Cap any more.
Originally Posted by coolrda
As you stack subs or raise them you change your modal response, accentuating midbass frequencies.
Well it definitely changed my response in the midbass area by raising it a little and accentuated it, hence the increased SPL in the midbass frequencies. It did increase chest slam a little but accompanied by a little boominess as well.
One thing I found quite interesting a while back when messing with these nearfield subs and raising the drivers up higher, is the effect on the sound and TR when raised vs. on the ground. I used to run a JTR cap2400 directly behind my seat and loved it. I was curious what it would feel like if I raised it up off the floor to up behind my upper back area instead of the driver firing into my low back/butt. When I did this FR stayed pretty much identical, but felt and sounded different. Midbass chest slam was better but it didn't sound as big or feel as big in the lower frequencies.
The most brutal and severe HT bass experience I've ever had is when I stacked two full range subs right behind me to get the best of both worlds (the JTR cap2400 on bottom and the Rythmik FV15HP on top). They were EQed together close to flat and then ran about 6-8db hot on a handful of big bass movies. Mad Max Fury Road bass was brutal and seriously punishing, leaving me feeling beaten and tingly all over. Although almost to much, its was awesome!! Here's an old crappy cell phone pic of that set up about a year ago ...
While that temporary set up would never pass WAF in the living room, it was ridiculously fun! But these 3 smaller sealed 18's nearfield do Pass the WAF (thanks wife!) and they do look a lot better I have to admit, its still not quite as brutal, but very close. If I could get away with it and have my way, I'd stack one more sealed 18" (two high) on top of each 18 behind the 3 main seats. Actually if I had my way, I'd put one of the new JTR 4000ULF's behind each seat
I guess the wife has to draw the line somewhere LOL. Here's recent pic of the 3 sealed 18's behind the seats now ...
I gotta say, that as much as I love the really low ULF wobble sensation awesomeness and the gut punch 25-50hz stuff, I think I love the mid bass chest slam the most. IMO its just exhilarating and brings out the experience that much more. I'd hate to loose any of it though. Good times - I'm so glad I discovered this place and learned about nearfields, TT's, etc.