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Discussion Starter #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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Discussion Starter #2
So I took some measurements of the fronts, I did it at 1m using my Ratshack meter and REW(1/3 octave applied).
something I know that could replicate a aneorchoric chamber but I was generally curious as to what would the response would be like

So I measured the woofers first since I wanted to know how the sealed box would perform


Then I decided to do the HF and MF


And the full front and all the drivers




I talked to curtc about an issue I was having with the center channel, I got a lot of distortion coming from the woofers and I figured it was due to the crossover. So I took the crossover out and figured out how it worked and what components it used. Curt suggested that we add a zobel with a 4ohm resistor an 47uf(I believe) to the woofer. I ordered the parts from PE but then I remembered that I never lined the chambers because I got so excited once the parts came, after lining the chambers the same way I did the fronts and the distortion went away.


I will have to measure the center but I would like to see what sort of an affect it has though.


 

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Discussion Starter #3

Here is what I plotted out for the surrounds




I went with a ported because I figured it would mix well with my THT. The dimension will be posted later.


I flipped the speakers around so the port is now facing towards the screen







The speakers sound excellent at any point in the room



 
 

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Nice build.


I understand the PJ bit. It should always be done last, or things never seem to get done.



Do not read any stuffing threads.
Do it the easy way and add 1lb per sq ft, or if you have impedance measurement gear, keep stuffing until the impedance peak begins to move up in frequency. Take the last bit added back out, and you are done.
 

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Stgdz,


Those are some great looking speakers, I need a set, I like the way they stradle the screen, just put another woofer or two in those boxes, add an another speaker to put on top of your sceen and that can be your screen border
. Is it like the commercial, where you set in the chair and it puts you back in your seat?


BTW, what did you finish those with?


Wem
 

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Stgdz,


Congrats on a great successful build!!! That center looks really nice. What are you're plans for the rear? I see that you mentioned that you have 2 extra waveguides and a reserved posting.


FYI... I run mine full range off of the Sony STR-DG1000 (120w x 7) receiver with no issues at all at any volume. I'm still looking into the resistor that you PM'ed me and referenced above and may just order them to see if anything improves.


Question... now that you're gone pro audio for the theater, can you go back to consumer speakers again? I know that I cannot!!!



Again, GREAT JOB and CONGRATS on the build!!!
 

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Welcome to the world of Waveguides!!!! I like the look. Very clean and I agree with Chucky That center looks great.


I was looking but did you buy all the drivers through QSC? What models are they.


I have those waveguides, CD and mid woofer for them but I have been waiting to findout about the woofers. This will be a build for a friend in 2011.
 

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Really a nice job on this build. More details, please. What is the H x W x D of the speakers? Did you buy the crossover for the mid & highs from QSC as well? What is the size of just the bass bin? The finish turned out nice as well, what did you use? Glad you are enjoying them!
 

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cool build stgdz!


normally a wtmw center is a fail because of off axis comb filter interference, but with what you have the crossover point is likely low enough to mitigate that.


what is your crossover point from the mid/high unit to the woofers?


could you create a full list of components including crossover so we can know what you have there?


also, looks like you are picking up some good room gain on the bottom end (flat past 80 vs. -6db or so in winisd model). with an 80hz cross, dual 15's should be clean at any level that you play them at. you will be pushing 120db with only 1-2mm of linear cone motion. hehehe...


now, what subs do you have that will keep up with these monster mains?


again awesome work!
 

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"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)"


it depends on the driver, the enclosure, and the room gain. ideally, if using an 80hz crossover, you want the mains to have a second order rolloff and -3db point of 80hz, as that is what is assumed by the electronics in thx systems. if you are higher or lower, you can always eq to taste. for many 15's in medium to large enclosures, there is not much benefit provided by going to ported if using an 80hz cross. of course, not everybody uses an 80hz thx-type setup, so its not like there is only one solution that will produce amazing results.
 

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He has a THT. I guess that is why he built the mains, so they would keep up with the sub.



I wonder how a single 15" woofer would sound with that config.
 

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Damn! Now I have horn envy!


Awesome job!


What are you using to power these?


Wasn't there some fear that QSC would pull their parts website if we started to rob their spare parts? I know we are paying...but they would essentially be supporting the well documented practice of getting their speakers for well less than the MSRP if you are willing to put in some elbow grease.


Either way...I want to get these now!
 

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So far so good with the QSC online parts order BUT recently the link right on the HPR-152i page for ordering HPR-152i parts disappeared. I had to go through the general parts ordering link and I had to know the part number to order.


I think they decided to make it "tougher" to order.


FWIW, I sent that 6.5" woofer and waveguide off to Brandon for measuring. It wasnt all that pretty but for its price tag its probably okay and the QSC XO probably makes it all fine. There is a fine line between worrying about how a measurement looks back to just enjoying the sound.
 

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Discussion Starter #15
Thanks guys for the compliments, the finishing took for ever on these but it was three coats of primer and three coats of flat black. I used a roller on both the primer and the black and it actually turned out really well. There is a slight texture to it and I really like it. I can post the paint and the primer that I used but the primer got rid of all the wood grain and it go the wife approval



The box size is something like 36x18x14.50 I can't recall what it was I just plugged the driver info into winISD and then it spit out the optimum box volume. They are powered by a parasound 1205 I think they have broken maybe 5watts. They sound really good and I get so many details that I haven't heard before compared to my classic dayton driver speakers. The mid mixes really well with the tweeter though, I bounced back and forth between the Econo deluxe and a 2150 but I went with the 2150 because I figured I could use the standard QSC crossover with a better result then a WTW econo deluxe. The deluxe is configured for a TW config and I gathered the second Woofer wouldn't mix very well compared to WTMW config since all the distances would be same except for the woofers. It was some rationalization on my part but with the results that chucky got with his surrounds I risk'd it and built the center channel first because if it didn't work then i could use the crossover for the fronts.


My comment about hearing all the new detail has it drawbacks, I hear everything now with speakers and all the little inconsistencies are coming out with them. Its like moving from DVD to bluray, I have piles and piles of DVD's but I only watch my blurays now because the PQ is so good. I still enjoy my master and commander DVD though but I blew one of my 2 channel parasounds watching it. Also another problem is that I am getting a hell of a buzz from the speakers. At first I thought I had a ground loop issue but when I disconnected all the inputs from the amp I still had a little bit of a buzz, I guess high efficiency speakers really amplify everything. I am going to give the gainclone a try this week and see if I get a buzz.


I used all the info to order the stuff from chucky's thread http://www.avsforum.com/avs-vb/showt...8#post17439168 but I am building different surrounds and will post what I am going to do when I get a scan of my napkin drawing.


 

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the dudes at qsc should note that for every diy build there are a hundred buys, so the diy guys are really just helping to pump the qsc marketing machine. all the chatter about qsc will get more folks aware of them and their great products too. kind of like audioheritage does for jbl. now, can we just get a diy version of the meyer sound acheron studios? ;-)
 

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Quote:
They are powered by a parasound 1205 I think they have broken maybe 5watts. They sound really good and I get so many details that I haven't heard before compared to my classic dayton driver speakers. The mid mixes really well with the tweeter though

Very cool, do you have a SPL meter?


I have been looking at the parasound amps and if you are driving the tweeter with them could you place the SPL meter up to the tweeter mouth with just the amp on and tell me the SPL reading. I would like to know the "Hiss" level.


I 100% agree about the details vs the Dayton drivers.
 

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"I am getting a hell of a buzz from the speakers..."


don't worry, this is not 'normal' for high efficiency speakers. high efficiency just makes such problems more apparent. when you get it figured out, it will be dead silent. well, you might be able to hear a little something if you put your ear right up to the tweeter, but that is it. dead silent at the listening position.
 

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Nice work!


You really got me thinking now.


Doing the math, A pair of these (just electronic parts) will only cost $885.


Pretty good value IMHO.


My only problem is I need a shorter version, maybe with just a single woofer per cab?

 
Item QSC Part # Celestion Part # Location Quantity Locations Cost Total Cost
Waveguide PL-000447-GP Main 1 2 $29.94 $59.88
Crossover PA-000210-00 Main 1 2 $65 $130
Terminal Plate WP-002157-00 Main 1 2 $60 $120
Compression Driver SP-000086-GP CDX1-1425 Main 1 2 $60.68 $121.36
Midrange Driver SP-000085-GP TF0615 MR Main 1 2 $28.8 $57.6
Woofer SP-000084-GP TF1530 Main 2 2 $99.25 $397
$885.84
 

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Discussion Starter #20

Quote:
Originally Posted by mynym /forum/post/18958260


Nice work!


You really got me thinking now.


Doing the math, A pair of these (just electronic parts) will only cost $885.


Pretty good value IMHO.


My only problem is I need a shorter version, maybe with just a single woofer per cab?

 
Item QSC Part # Celestion Part # Location Quantity Locations Cost Total Cost
Waveguide PL-000447-GP Main 1 2 $29.94 $59.88
Crossover PA-000210-00 Main 1 2 $65 $130
Terminal Plate WP-002157-00 Main 1 2 $60 $120
Compression Driver SP-000086-GP CDX1-1425 Main 1 2 $60.68 $121.36
Midrange Driver SP-000085-GP TF0615 MR Main 1 2 $28.8 $57.6
Woofer SP-000084-GP TF1530 Main 2 2 $99.25 $397
$885.84

You have to order these brackets also for the speaker

HF/MF Mounting Plate (HPR-153i): CH-000574-GP

Price: $1.45ea (at the time)


You will need two of these brackets per speaker (in your case 4) but they connect the mid to the tweeter that is shown in my thumbs up thumbs down pictures and you will need a 4 pole speakon connector.



Also penn, the parasound is the issue, I plugged one of the fronts into my A500 and the buzz wasn't there as much in the midrange. It was slightly there in the tweeter but not as much. I couldn't measure it reliably though but it looked like around 55dB was what is was reading but the mic could have been picking that up from other sources. The dayton set I built I would consider very good and almost everyone would be happy with it, they can easily compete with some of the definitives and polks that best buy sells but they cost about a quarter of the price. They are placed in my main viewing area while the QSC's are in the theater.


I wanted just a little bit more so I went in the direction of the deep end, the artsy, or the wine and cheese crowd. Its like any other hobby that is out there, once you get to a certain area the minor details will start to crop out and I guess that is why MKtheater has been on the upgrade path like he has. You may notice a difference where others may not, this happens with guns and 1911's especially the high end ones. People would like the feel of a blued baer, the tightness of a wilson, or the snake skin of a ed brown. Some people may like the econo deluxes, the jbl pro speakers, or the danley horns.



I'm really happy with these speakers, the tweeters balance really well with the mids, the mids balance really well with the woofers, and the woofers balance extremely well with the THT. I may still put in the zobel network because I can hear the breakup if put my head rite up by the speaker but who listens to speakers at 1m.



like I said wine and cheese



 
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