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Stgdz's QSCinema build

21K views 52 replies 19 participants last post by  kgveteran 
#1 ·
5/19/New subs


Old subs


5/3/11 All pics rehosted at AVS

4/15/11 pics are not working will update to new host

I'm proof positive you shouldn't buy a projector before your walls are up


So about a year ago Chucky's QSC 2150 clone thread I had built up a set of D3's, unicc's and D2's and I replaced my dual sealed sub setup with a THT. While the THT was really awesome I started to notice then my speakers would distort a bit when pushed hard and I had been looking for a little bit more so I purchased a bunch of waveguides




At this point though I deviated from what the original QSC-2150's were built to for two reasons,

1)I didn't see much of an advantage to a ported design since these things could extend down to 80hz at 97db according to winISD. As pointed out in MK's thread by LT there isn't much advantage to ported with an 80hz crossover(I believe he said something to that extent)

2)more importantly I didn't have a AT screen so that will come in later.


So sealed vs ported


Not seeing much of an advantage at 80hz, only 3 db down from the ported with a max of about -6db at 60hz.


So I decided to built sealed speakers but I was uncertain about shelling the 1500-1600 for all three speakers so I built a center channel in a horizontal WTMW configuration and ordered the parts. I figured that since it was a three way designed crossover would be sound fairly close in a horizontal and vertical configuration, it may not be ideal but I figured the waveguide would make up for any issue that I may hear. So I built it up and it sounded absolutely amazing, I couldn't believe the amount of detail that I was hearing in a lot of listening spots. The next day I ordered the remaining parts and a couple of days later the biggest package I saw arrived on my doorstep. I couldn't believe how big it was




So I built the boxes with arauco ply because it was so much easier to deal with compared to MDF and added a horizontal brace in the middle. I was taking a risk using the arauco vs the MDF but I figured the brace would make up for the lower density of the arauco. When I was done with them they passed the knuckle test


Crossover installed


I stuffed these with some r25 insulation. I am still reading through the stuffing thread but I cut the insulation to about 14-16" long for each cavity.


These things were huge, and you can see my unpainted center channel in the back.






So I was pretty happy at this point and I sit down to slowly start these in and my heart just drops at the next point....




They sound like absolute crap. The highs were all muted and the mids just sounded tinny.



I checked the exterior connections, everything was tight and looked rite but I couldn't figure it out. So I pm'd chucky to ask if he had run into this issue and his suggestion was to recheck everything so I checked the center channel and the speakon connector.




I then go to check the left and right connections only to find this


And it should look like this


bonus terminal plate shot



After that they sounded absolutely wonderfull, I couldn't believe how much detail I was now hearing. I could hear Cash plucking the strings during folsom prison, individual mechanical noises during transformers, and the horns, horns just sounded so much better. It feels like there is just one giant speaker in front of me now when I toed them in.



I realize I haven't put rock up or even put a border on my screen but I am just enjoying my theater way to much. Also since I have two extra waveguides I am going to build some surrounds with them.


 
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#27 ·
alpha niner, as you are already way ahead of the game, you'd probably have to go to a large format horn for an upgrade. at your level, you might be eyeballing a 2"/4" be tad on a 3 foot wide horn crossed at 500hz/woofer side and 10khz/super tweeter side.
 
#28 ·
So tonights little adventure was in gain control


My parasound has gain control knobs on the back of the amp and it is currently set to THX level and it buzzes the high and mid range like no other. I can reduce the buzz by setting the dial to about half but then I have to raise the input level at my source. Well I went through that and recalibrated the speakers using soho54's dvd. After I got it recalibrated the speakers sounded pretty good on an action DVD until the action hit and then the sound went to absolute ridiculous levels and it felt like it was much louder than before.


I didn't have a mic and just used my ears but man was it loud. Is that the gain control does? I figured the gain control works similar to the input level on my source.


oh hear is the paint I used and the texture that turned out from the roller




 
#29 ·
Nice build!


I was torn between these and the ewaves/no quarters. Went with the ewaves. I know that Ill want to build something new in no time. Dont we all get like that.
 
#30 ·

Quote:
Originally Posted by LTD02 /forum/post/18962160


alpha niner, as you are already way ahead of the game, you'd probably have to go to a large format horn for an upgrade. at your level, you might be eyeballing a 2"/4" be tad on a 3 foot wide horn crossed at 500hz/woofer side and 10khz/super tweeter side.

I know you're referencing the JBL K9800 and D66000 and I have referred to the engineering guides many times for ideas, but ultimately I want to go a different path.


I've got a whole bunch of 2445/2446 with original Ti phrams and Radian Al replacements as well as the BMS4590 (since just after it was released) and Emilar EC320's. Tried them all on custom round tractrix, vintage JBL radials incl modified 2345/2350 and stock 2360, Yuichi Arai A290 and E300, Emilar EH500 and some large 90x40 and 120x40 EV units whose model numbers elude memory at the moment. Not interested in the TADs due to cost and same with the TrueXtent Be JBL replacements so far. Not using any of them now and I've got the Unitys for the mains and don't see anything better on the horizon.


I was thinking of the QSC for one of two large 4 way bedroom speakers I've (roughly) sketched out as a 2011 project and apart from the WG's and 6.5" drivers I have all the parts on hand for either version. Just want to build either for the fun of it and the most likely candidate in my take on a classic design using modern drivers.
 
#31 ·
So here is what i was thinking of aiming with my waveguides for a surround

JBL 8340A
http://www.jblpro.com/catalog/suppor...pe=3&docid=638


But I am going to use the econowaveguide delta 10e and substitute the deltalite woofer with the dayton 10" pro.

Econowave Bom http://techtalk.parts-express.com/sh...89#post1647589

Dayton 10" woofer pro http://www.parts-express.com/pe/show...number=295-030

I realize the woofer isn't a delta lite but it is somewhat close in specs and response.



So here is the winISD plot comparing the front woofers to the surrounds



With the room configured the way it is I was thinking of angling the baffle about 30 degrees. I have some values that I can upload tomorrow with and a basic outline of the box but the over all dimensions are 18" baffle width, 18" depth at the top, 9" depth at the bottom, a baffle height of 22", and an overall height of 15.75."


Seems like kinda a large box compared to the JBL though and that JBL is ported.
 
#33 ·

Quote:
Originally Posted by stgdz /forum/post/18991049


But I am going to use the econowaveguide delta 10e and substitute the deltalite woofer with the dayton 10" pro.

Econowave Bom http://techtalk.parts-express.com/sh...89#post1647589

Dayton 10" woofer pro http://www.parts-express.com/pe/show...number=295-030

I realize the woofer isn't a delta lite but it is somewhat close in specs and response.

There's been some interesting measurements done of this type of design with some artifacts relative to your proposed design, considering the surround placement. The long distance from the drivers individual centers create multiple vertical nulls which may create significant problems with a surround placed high on a wall relative to the seated listener/viewer. For a speaker on the horizontal plane of the listener..fine....if not.....not so good! Zaph's own WG designed TMM is afflicted to the point where standing while listening isn't an option....and that's only a 6.5" guide.
 
#34 ·

Quote:
Originally Posted by mayhem13 /forum/post/18991362


There's been some interesting measurements done of this type of design with some artifacts relative to your proposed design, considering the surround placement. The long distance from the drivers individual centers create multiple vertical nulls which may create significant problems with a surround placed high on a wall relative to the seated listener/viewer. For a speaker on the horizontal plane of the listener..fine....if not.....not so good! Zaph's own WG designed TMM is afflicted to the point where standing while listening isn't an option....and that's only a 6.5" guide.

How does the JBL 8340a address these concerns?
 
#35 ·
Mayhem,

I am guessing this is the article you are talking about
http://zaphaudio.com/Waveguidetmm.html


I am using the waveguide from HPR series(econo deluxe) and not the round elliptical waveguide that the 10e build uses. I thought the HPR waveguide offered a superior vertical response to other waveguides. I have thought about the elliptical though but I had the HPR available.


By my calculations though, a 30 degree angle should be sufficient in aiming the speakers at the middle of the room and middle of the front and second riser. I figured the waveguide would end up doings its job for for the rest of the seating positions. QSC does offer some waveguide surrounds also too http://www.qscaudio.com/products/spe..._surrounds.php
 
#37 ·

Quote:
Originally Posted by stgdz /forum/post/18992111


Mayhem,

I am guessing this is the article you are talking about
http://zaphaudio.com/Waveguidetmm.html


I am using the waveguide from HPR series(econo deluxe) and not the round elliptical waveguide that the 10e build uses. I thought the HPR waveguide offered a superior vertical response to other waveguides. I have thought about the elliptical though but I had the HPR available.


By my calculations though, a 30 degree angle should be sufficient in aiming the speakers at the middle of the room and middle of the front and second riser. I figured the waveguide would end up doings its job for for the rest of the seating positions. QSC does offer some waveguide surrounds also too http://www.qscaudio.com/products/spe..._surrounds.php

So your crossover is based on the delta 10e, your horn is from the deluxe, and your driver will be a dayton pro? This sounds like a frankenstein! Let us know how it sounds!
 
#38 ·
Run tom cruise run!




By accident I ordered two copies of WoW so I figured I would build an additional THT but this time it woulld be a 12" driver version.


All done



Don't have any REW measurements but it compliments the other THT fairly well. Also I made significant progress on the surrounds this weekend. I have to order some stuff from PE though, one terminal jack and some foam plus a splitter. Doesn't quite qualify for free shipping so what else should I order?


 
#39 ·
So I finished these late last night with Zilch's help on my crossovers. I had some caps reversed. They are also tilted back a bit in this photo.




They sound pretty good and will work extremely well for surrounds, I played around with some Johnny Cash music last night and the bass is exactly what I wanted. They lack a little bit in the mid range vocals compared to my big three ways but I think many people would be happy with this two way combo.



Now onto mounting these things, I was thinking of using some of my scrap 3/4" wood and making a french cleat out of them.
 
#40 ·
How wide is your room and how far will they be placed from the LP? Are you doing sides only or sides/rears? Will be interested to hear your opinions on localisation and panning with these CD designs in use.
 
#41 ·
The room is about 15ft wide, so with the speakers about 6 ft above the lp my fuzzy math equates the distance to around 10ft.
 
#42 ·
Got them hung up tonight



Yes they are level!




They sound really good, and I mean really good. Just moving around tonight and every thing just seemed balanced where the sound wouldn't change. Details are there, bass is there, a little bit lacking in mids. They just complement the fronts so well.


Also I got the zilch sign of approval over on TT
Quote:
Originally Posted by Zilch /forum/post/1666059


COOL!

[Good to see you got the priorities right -- speakers get built before the walls go up....
]


 
#45 ·

Quote:
Originally Posted by greg_mitch /forum/post/19107791


Are these things....

"THINGS?"


[You mean "precision-crafted EconoWave variants," of course....
]
 
#46 ·
Well I got the opportunity to run them at full throttle last night and for a surround speaker they work exceptionally well. When the action hits its like one big speaker, sound comes from every where and it really enveloped me last night. The localization is still there but its not like it was with my old direct radiating speakers where I could tell where the sound was coming from all the time.


Its similar to how my three front speakers act as one speaker, the localization is still there with the fronts but it just sounds like a big speaker. Waveguide people will probably know what I am talking about.
 
#48 ·

Quote:
Originally Posted by greg_mitch /forum/post/19113496


Let's come up with a real name so I can reference them correctly!

How about stgdz surround



Got them painted this weekend and the other THT subwoofer.




I flipped the sides so the port is facing towards the screen now.



I am going to need to get a complete picture sometime in the future.


 
#49 ·
Was at the local audio king today and I saw that they had the Klipsch THX system setup in on their rooms, also had dual klipsch's thx subs. Decided to try it out with the superman bluray intro at -10dB.


I really wasn't that impressed. Ok it sounded good but my QSC system sounded so much better to the ears. The only way I can describe it is that the sound was much bigger from the speakers, MKT has made that statement many a times but I never understood what it was till today.



Also my dual THT's absolutely blew away the klipsch subs, I got a little rumble in the chairs from the opening scene with the klipsch's. The THT's just had way more impact and shook the couch even more at my place.



I have no measurements on the room but it was smaller then my crappy room as it is now but I am so happy with these speakers and sub setup.
 
#50 ·
After visiting the KRIX factory I was convincing myself that I needed to build a clone of their Cinema stuff. (PIX and others) BUT after seeing the price of things I decided to build BFM SLA's for my L/R.


Now after pushing the volume on my budget system I dont have enough. SO I am starting to think more along the lines of what you built.


I am wondering though how did you choose a loudspeaker design?


I am wondering just because how do you choose how low you want the mains to go when you have a sub?


I have many more questions but for now I will just stick with these.
 
#51 ·
Well as I stated in the OP I build these because I didn't have a transparent screen and wanted a center channel.



I started a pretty big thread about what point does bass become omnidirectional, and from what I gathered it was 80hz so there wasn't an advantage to me in building a ported design for this system.
 
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