:-) (Long time lurker though, hehe)
First a little backstory:
About 7 years ago I bought a house. The End. J/K
Wanting to set-up the living room with a decent movie viewing set-up, I purchased a LG PK750 50" plasma based on reviews on this forum and others. Needing an audio solution and the fact my bank account was hemorrhaging money at the time I opted for an Onkyo 7.1 channel HTIB as the receiver was well regarded and could be used with upgraded speakers at some point. Less than a year later I decided it was time to upgrade L/C/R and opted for Polk Monitor 70s with CS2 center. I didn't want to spend a grip since I was planning on building some custom speakers in the future and had to get a few projects off my plate before attacking them with gusto. Honestly, for the money spent, they sounded good enough to have kept them for 6+ years. Fast forward to about 9 months ago. The PK750 developed a vertical line of death that kept getting worse until I couldn't stand it anymore and started the research for a new TV.
With plasmas having gone the way of the dinosaur the only acceptable substitution was OLED. So I found a good deal on an OLED65B6, bought it, used Citi price rewind to get some money back, and was happy with the change. However, bass had always been subpar with the Onkyo HTIB 10 inch subwoofer, and I decided I needed to build a subwoofer. My living room lacks width, so I opted for a lilmike Cinema F20 with a Dayton RSS390HF-4 for raw output and semi small footprint. I paired it with a Dayton SPA250, but ultimately changed the amp to a Crown XLS 1502 (driving it with one channel only at this point). The room is large, as the dining room and kitchen are both open to the living room, but the hallway to the bedrooms almost cuts it in half and I am using the only wall possible for the media center. The Cinema F20 does quite well but now it overshadows the Polks by a good margin so I am building speakers to fulfill my quest for never wanting to go to a movie theater again, lol.
That's actually quite funny, since a good bit of discussion around here talks about cinema reference levels, and yet, I have NEVER been to a theater where I have been impressed with the audio. Even at the IMAX I felt the volume was too low and it lacked dynamics. In high school (longer ago than I care to admit), I remember watching Star Wars Episode 1 (well the cat's out of the bag on my age now) and actually leaving the theater to ask if they could turn up the volume. They didn't...
Anyway, so I am building L/C/R speakers and started getting into the passive crossover design when I decided to instead run them active. I've built crossovers with my brother and dad before. My brother is an EE and my dad was a systems analyst for Lockheed for 30 years. I'm just a lowly ME, but no stranger to the technical aspects of crossover design. What has always sort of bothered me about passive crossovers is the inability to change things and tweak the XO without buying more and more components and spending the time swapping them out. My dad is an audiophile purist so I haven't told him yet I am planning on running the crossovers through DSP. I plan on building them and demoing for him without telling him it is a digital crossover, just to see if he is as unimpressed as he would lead you to believe. We've had that conversation before. :-)
The L/R speakers will be 3-way, and the center 2-way. For the L/R I'll be running an SEOS-8 waveguide with a Transducer Lab carbon fiber dome tweeter (6 Ohm impedance) for highs, (2) Eminence Alpha 6A in parallel (4 ohm impedance) for mids, and (3) Eminence 8" DVC 'subwoofers' in series-parallel (6 ohm impedance) for the low end. I have the box designed and modeled in Bass Box. The low end is tuned for an F3 of 32Hz but will play down to 20Hz with decent authority, and I will cross them over to the mids around 400-450Hz around the baffle step frequency. I don't have room in this set-up for another F20, so I am hoping I can augment the low end with the towers. My girlfriend thinks I am nuts for wanting more bass, but I told her I haven't started cracking drywall yet so there is room for more. She puts up little resistance to my insane ideas, so I'm lucky in that regard. Then I showed her BTH's, Scott Simonian's, MKtheater's, and several other's set-ups and she thought I was a little less crazy. I'm really just desensitizing her now for what I have planned for the basement.
The center will be the same as the mids and highs from the towers but I will run the Alphas down to their useable low end, right around 80hz.
So, why is this in the MiniDSP thread again? Well, I am going to use an 8x8 for crossovers. I will be running a QSC CX168 for all 8 channels. The only decision left to make is how to add sub control into the equation. Ideally I would like 2 more channels of balanced analog output on the 8x8, but MiniDSP makes it stupid difficult to expand their products with analog I/O.
I have a question on the MDSP forums regarding the use of a DA-FP with the 8x8 and how the 10x10 plugin will handle routing, but have not heard back yet. I PM'd DS-21 on the MDSP forums (I assume it's the same DS-21 as on here) since he had originally asked if the DA-FP was compatible with the 8x8. The devteam response was yes it is compatible, but the thread ended and no discussion was had on how exactly the DA-FP works with the 8x8. I would like to run the LFE channel into the 8x8 and mix it into the lows of the towers as well as EQ the subwoofer output and send it to the 2 XLR jacks on the DA-FP. That way if I determine the towers are best crossed over to the sub at 60Hz (i.e., the FLH and (6) ported 8 inchers do not play well together) then I will have the option of adding some nearfield love behind the couch instead.
Will this work?
Or would it be better to spend a little more money and add in a balanced 2x4 in for sub duty? I have (2) LFE preamp outs I can run if I still want to mix the LFE into the towers.
Thanks for reading my novel, and any help is much appreciated!