First off, thanks everyone for the responses. Having others chime in has helped me narrow this down a bit already. I really do apprecaite that!
I've been out sick for a few days, and I'm just catching up now.
Originally Posted by LTD02
yours is a little bit of a tricky one in that you don't have any bass management on the two channel system, correct?
how are you hoping to switch back and forth between the two systems? or, is that part of your question?
No bass management on the two channel system. At this point I'm really excited to even have DSP in the iNuke (which I took out of the box and plugged in on Wednesday night). I picked up the Crown 2502 because I thought the high sensitivity input would help with my Denon, and it sounds OK, but after dialing in the iNuke with about a 16hz highpass (using your guide LTD - thanks) and pegging the receiver at 0db on the sub, and the iNuke 3000 all the way up, the bass is closer to what I used to have with my Onkyo...and a little tighter with the ULF rolled off. That said, with the old setup I was 100db @ 10hz at seating position with my old Onkyo + EP2500 + 21" and only occasionally had it flub. Maybe my memory of the sound with my old receiver is off, but this just doesn't sound as house rattling as I remember. I've had friends pull up to my house during movie night, and when they came in they said my siding and soffets were rattling!
As for switching, all I have now is moving cables around. I'm OK with this for the time being - I'm more concerned about getting my system crushing souls again like it used to. If I build the pair of 18" HT D2 I might just leave them connected to the two channel system on the iNuke, and only add them to the HT system for movie nights with friends...leaving the big 21" to day to day HT use.
Originally Posted by LTD02
when you say "fill in the lowend" on the 2 channel rig, do you have some idea of where your mains are rolling off?what kind of music are you looking to enhance the lowend on and how loud are you shooting for?for some reason, when I first saw your setup, I was thinking an open baffle experiment might be interesting as that might provide maximum purity with those drivers, but open baffle doesn't really crush it on the very low end so maybe that would be the wrong direction.
I've actually got 5 pairs of speakers to choose from for two channel...well, 4 pairs and the Klipsch towers which are a garage sale find that actually work well for HT. I found my UMIK-1 and downloaded the calibration files - I'm hoping to find time this weekend to setup REW and read up on that. I've used it in the past when I built my 21", but only for basic frequency response measurements. Ultimately I'm going to use REW to measure my room and test my sound treatments I build. So I currently have good guesses as to where my two channel speakers roll off, but I'll have measurements soon.
As for filling in the bottom end...most of the high-efficiency "audiophile" speakers I have are pretty weak on the low end. They say 20hz-20khz, but that's not exactly true in the real world. I'm looking to fill in anything from say 15hz to 50hz probably. I listen to pretty much everything. Lately a lot of Folk Rock, blues, acoustic music (rock, jazz, classical acoustic music). Mostly because that's what my speakers excel at. But the bass doesn't have the presence that the rest of my audio spectrum does.
Also, funny you mention OB - I just picked up a pair of 95db efficient full range drivers that I heard at an audio show in October. I typically don't like OB speakers, but these really sounded good.....when filled in with a 15" OB woofer
. So your intuition is spot on - the trend of nice sounding full range OB with good boxed woofers is part of what is driving me to finally do something with this pair of 18" drivers.
Originally Posted by LTD02
as for the 21", input sensitivity on the ep2000 is around 1.15v, which shouldn't be a problem for most amps (though i don't what the voltage output of yours is in particular and for some reason the manual wasn't loading for me from denon). if in bridged mode, do you have the gain all the way up on channel one and all the way down on channel 2? ...and you thought you had all the questions. :-)
I'm starting to worry that there is an issue with the Denon. I just downloaded and re-read the manual, and one suggestion in there is to setup the sub for LFE+MAINS. It says the voltage is v1.1 on the Denon, but the Onkyo 805 manual doesn't have voltage listed at all. I remember a thread back in the day where someone measured it, and I thought it was above average.
I've tried the 21" from the subwoofer output of the Denon using all four of the amps listed in my OP (EP2500, Ashley, and now Crown and iNuke). So far the iNuke sounds the best and is closes to what I used to have. I re-ran Audyssey yesterday since I was home sick, and it didn't improve the sub at all, maybe helped the mains sound better, and it dialed down the rear channels a little. Distance measurements came out pretty close. Watched Flight of the Phoenix for the first time in a LONG time, and it sounded really good, just not as huge as with the Onkyo.
But, that's not really the focus of this thread - I was fishing for ideas for the SI 18" D2
I've been reading up on other peoples SI builds, and it seems everyone is gravitating towards the Marty builds. Since I have the house to myself, I can pretty much build anything I want...from IB to LLT or whatever. But I'm trying to avoid cluttering up the room too much more...I don't have an AT screen at this time (that's a few years off I think), so I can't just build a wall of subs like I want to.
So for now, I think I'm going to churn out a sealed box really quickly, just so I have something on the 2nd subwoofer output of the Denon, and I can play with that on my two channel setup while I decide which big ported box to build. If I recall correctly, a 24" cube is good to go with these SI 18HT, right? Then I could build some obnoxious big ported box and see which I like the sound of in my setup, sealed or ported. That will give me time to learn REW and see if my MiniDSP even works.
I'm fine with selling my EP2500 and Ashley amps and getting another iNuke, but I question if the newer class D amp is "better sounding" to an older A/B amp like the Ashley. Right now the DSP is making it easy to sound better, but with REW and some tweaking, a good amp could sound GREAT.
I think I almost have too many options right now. LOL But at least I have a project in my sights - I'll start with a sealed box for the 18" while research more and dial in my system more.