hwatkins Posted January 30, 2003 Share Posted January 30, 2003 The attached pic shows my unfinished center channel. Some of you have been aware of my efforts - so I wanted to update with this first look. Here are the specifics: Klipsch K-77 Tweeter, Klipsh K-55 Squawker w/700 (Heresy model) lens, Type 'E' crossover and two Fostex FE168S. I did not make any changes to the Xover and have the Fostex wired in parallel. After testing for three weeks I am going with a sealed design - the best sounding of the bunch. The box is screwed together to get me through testing configurations. As you can see it is set up for a set top (RPTV) installation (meets WAF requirements). This evening I will dismantle and prime the exterior. Then I will paint (semi-gloss Black),secure air leaks around any speaker, glue the box and build a grille for final use. I plan on leaving the back as a screw attached in case of future changes. The sound - blown away good. It is very smooth and mixes extraordinarily well with the front main Heresy and the side heresy. I had quite a few conversations about the Fostex with some box builders that led me to believe that I may have been making a mistake, but the design simulations kept coming out OK so I got bull headed and plowed on (especially since I needed the efficiency of the Fostex). While the Fostex is sold as a full range, it performs well in this box with a crossover that limits its upper freqs. The rollover/transition to the squawker is, to my ear, indistinguishable from the Heresy. The LF to the sub is managed at the amp to 80hz. The woofers have a 6db drop at 75hz - listening to discrete speakers you can notice the difference (this doesn't happen with the Heresy), however, this box performs better than any other speaker attempted as center except an inverted Heresy - and it does give the Heresy a run for its money by providing better debth (My words - It seems much fuller than the Heresy, excluding that 3db or so difference near the transition point to the sub). I tested venting to 50, 60, 70hz tuning and all were a tad too boomy (that is why I am leaving the back attached by screws - I may change the woofers some day)for my taste. The whole family (who are generally disinterested in my over the top passions) felt the sealed version was best and that it is a wonderful improvement to the Home theater. It is also amazing when added to the stereo image - PWK was on target talking about a center for music. All said - It is a wonderful addition. Smoother, clearer center with the timbre match I was looking for. When the finish is applied I will send pictures of it in place as well. This first project was cool and the results surpassed my expectations. I will be looking to build more speakers (maybe start looking at VOT projects as I get better). Just what I need - another variation on this passion..... Quote Link to comment Share on other sites More sharing options...
hwatkins Posted January 30, 2003 Author Share Posted January 30, 2003 Side view of above Quote Link to comment Share on other sites More sharing options...
michael hurd Posted January 30, 2003 Share Posted January 30, 2003 Looks nice ! Having a center that is spouse-approved will definately help matters. BTW, I wonder what some have said about the 42 lb rc7.... But honey, it's not as cute as that little _____ center at best buy ! LOL. Quote Link to comment Share on other sites More sharing options...
j-malotky Posted January 30, 2003 Share Posted January 30, 2003 Looks good. Nice all purpose sizeing. Very versitile. I like it! Nice Job. JM Quote Link to comment Share on other sites More sharing options...
hwatkins Posted January 31, 2003 Author Share Posted January 31, 2003 Michael - this baby is not light - I can't tell the difference in wieght from the Heresy, but I did get kudos from significant other on the profile. J - Thanks for the kind words - also thanks for you words of help early on in this project - your information was invaluable in filling in some gaps. Trey (Mr. Klipsch tech support) - thank you, thank you. The T/S on the K-22 was the piece of information that let me determine how the woofers would compare (and therefore the Xover effect) to a standard Heresy. With this info I completely understood any compromise made and what I should expect to hear. For a first project I am surprised at how close I was to optimum - something that tested near what design said would happen. After some time with this I will probably look to baffle changes and maybe other woofers to get even closer. I am scared that my addiction has taken on a new level - just so you know, this speaker was more expensive than buying a single Heresy (but It left me with parts to sell to other Klipschers to finish their projects). Cheers Quote Link to comment Share on other sites More sharing options...
EJH Posted February 1, 2003 Share Posted February 1, 2003 Great idea! Beats waiting for an Academy to come around and costs less too! How did you do the shielding? Quote Link to comment Share on other sites More sharing options...
hwatkins Posted February 1, 2003 Author Share Posted February 1, 2003 Shielding isn't needed - this is on a Rear Projection TV. All the magnetically influenced parts are housed in the bottom of TV cabinet -easily 24 - 36 inches away from the speaker which will sit on set top. Several box builder sites give info on shielding the box (which gives you freedom on choosing speakers that do what you want - the shielded speaker world is not as prolific as the unshielded). Bear in mind that if you persue this type of project most DIY loudspeaker folks are very much into two channel setups and getting advice for a center is sparse - and sometimes caustic. Just remember that is the norm for on line conversations and be patient in weeding out the good advice. The separate camps are also entertaining - The full range speaker folks, line arrays, the horn folks, the two way speaker folks and the three way speaker folks (mine's bigger than yours, is not, is too, is not, etc.). I do recommend two pieces of software - BoxPlot and Unibox - that you can get for free or at a reasonable shareware cost that seem very accurate in modeling the results (at least they were for me). Just try those words in your search engine. Quote Link to comment Share on other sites More sharing options...
EJH Posted February 1, 2003 Share Posted February 1, 2003 Henry - Thanks for the info. LOL! Please post a picture when you're finished. Quote Link to comment Share on other sites More sharing options...
j-malotky Posted February 2, 2003 Share Posted February 2, 2003 ---------------- On 2/1/2003 12:38:27 AM EJH wrote: Great idea! Beats waiting for an Academy to come around and costs less too! How did you do the shielding? ---------------- If I was a betting man. I would put money on, that this center speaker hwatkins built goes a lot better with Heritage than an Academy since he is using the K700 and K77 combination. If you were using a LAS or Khorns for mains, would probably want a bigger midrange horn, like the K500 or K400. JM Quote Link to comment Share on other sites More sharing options...
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