Big Red theater build 21' x 27' - Page 4

after a lot of listening tests i have decided what to do with speakers. for the fronts i will be doing a DIY design but using all active crossovers. i am building a variant of this design

http://htguide.com/forum/showpost.ph...&postcount=537


i am using the SEAS tweeter as it has a little more "air" to it. i am also building them in 2 pieces - one for the mtm and one for the 2 10". that is because for the center channel i will sit them side by side over the sub and for the right and left they will be stacked on the floor. The beauty of diy in this scenario is that i don't care what they look like. ugly old mdf is actually the best thing to build speakers out of but we make it harder by trying to cover that with nice veneers and such. since mine are behind the screen they will be flat black and UGLY.

for the surrounds i am using 2 axiom qs8 for each side


and 2 axiom m22s in the rear


greg

steve - i really like your mains. the curved sides are really beautiful. i really want to do a curved piece like that someday. i watched you building them and that gave me the confidence to build mine.

the m22's have about 2" behind them. that wall is insanely thick plus 1" of sheetrock. with a double driver m22 i seem to be getting all that i need from it. sometimes i wonder if we overthink the surround channels. i had a set of very elaborate designs for building all the surrounds then decided to just spend a few extra dollars and buy the axioms. i have more than enough to do.



g

ebr - yeah i wondered about that but i fired them up in 2 channel mode and didn't notice anything obnoxious. it wouldn't do for reference listening or anything but it makes a serious rear channel.

thanks,

greg

i got my LCR loaded up and running without the woofers. just the 7" and 1" drivers and i set the crossovers to run the 7" all the way down. it definitely needs the double 10" for my taste. vocals were thin and it seemed really obvious to me that there was a hole between the 7" midwoofs and the 15" ubbersub. i put the boxes for the 3 double 10's together today and will try to load them up tomorrow. i have one of the two ubbersubs running and i have to say it moves some air. the other one is on hold because i found i had a defect in one of my tc2000 drivers. i am happy to say that i called up tcsounds and they immediately offered to ship me a new driver. i would say they are first rate and kyle in tech support was very helpful. as soon as i get the fourth driver i will fire up the other sub.

btw, a trick question - what is the best interconnect you can use for the speaker wires where they go into the speakers?

this is a block diagram of the audio components.

greg

ebr!!!

10 awg wire out of the wall and into the sub. i am not moving that sub without a crane since i built it in place.

i went with active crossovers on my diy speakers for several reasons but one was that i like the control if gives. i have a friend with EASE who can bring his computer and reference microphone over and we can dial in the crossover, eq and any time delays that might be needed (i doubt). in case you have not worked with one a pa processor is a pretty handy piece of kit. in the olden days (when i used to own sound systems) you carried a house EQ, a few parametric EQ's for trouble spots, an electronic crossover for each channel and sometimes we inserted a compressor or time delay into the mains. now you get one giz called a pa processor which takes in several channels of sound and does an A-D conversion then does all the things i descrived above digitally. you can soft configure the components you want on each channel. i have used dbx driverack processors in the past but for the theater i decided to try these behringer units. they are cheap (around $300) and they have a nice RS232 interface that lets you configure them from your pc. you can even daisy chain them together so they only take on rs232 port. so far i am pretty happy with them. i should say that behringer is kind of a controversial company as they are known for taking the designs of popular products to china and having knock-offs built for less.

here is what the configuration utility looks like to set up the audio path. here i have the first input (red) routed to 3 outputs after passing through crossover, eq, etc. that is my center channel. i have the second input (yellow) going to the 4th output after passing through processing. this is my sub. here i will set the limiter at just below clipping so that if i ever do drive my subs beyond their limits the limiter will not allow the amplifier to clip.


this is another screenshot which shows the crossover setup.


http://www.behringer.com/DCX2496/index.cfm?lang=eng

greg

hi spizz. the lobby is not done but here is the current state. i will do the colomns around the door at the same time i do the rest of the columns. the movie one sheet frames are working but not fully loaded yet. my dad got these out of a theater that closed down and i had the contractor frame them into the wall. the bar/candy case is on the to do list but i have not had much time for building things lately.





greg

i have the cherry soffits in and ready to be stained. the white part of the ceiling will be a starfield. i know i will anger the soffit gods by not making mine out of fabric and treating them but ...

i really laugh at the fact that every incomplete theater in this forum has materials and tools spread around but in the middle of the room is always "the chair". like all the others, mine has had a definite productivity impact.







greg

thanks mike. ibtw, i LOVE your sconces.

greg

good eyes w00lly. we will refer to that as the subtemperate refreshment dispenser. it goes in the little room right behind the theater next to the microwave.

greg

yeah my wife thinks i'm having an affair with the UPS delivery lady since she shows up every day.

g

i now have sound coming out of all channels. i am still missing a sub from tc sounds to replace the defective one i got but i have one channel of the subwoofer up running 2 of the 15" drivers. the front mains are triamped and i dialed in the levels by ear (which means they are not even close ) coincidently WOTW was on directv last night so i recorded it. 20 min ago i gave it the first test. the dog pee'd. my wife almost pee'd. windows upstairs were rattling. the granite island was moving and pans were shaking in the cabinets. the low freq went through 2 sheets of drywall like they were not there. my wife went outside because she was concerned for the house (she is a little dramatic but i have to say it was pretty unreal). i ran pro sound for many years and have stood in front of 100K watt PA's that really kicked hard but i have never felt subsonic energy like that before.

all in all the test was a huge success. i can't wait to get the other sub running.