hwatkins Posted February 17, 2002 Share Posted February 17, 2002 One of my center trials is scheduled to be two heresy on their side with horns in the middle. Being neophyte, but willing to learn - I will be able to preamp the center, so what do I need after that to drive one signal to two 8 ohm speakers? ------------------ Hwatkins Quote Link to comment Share on other sites More sharing options...
Ninja Nate Z Posted February 20, 2002 Share Posted February 20, 2002 You need to run them in parallel, and use a high-current, preferrably toroidal transformer based power amp capable of pushing 4ohm loads w/out much distortion. If I read your post right, you are modifying 2 Heresy's into one enclosure using all the drivers from both, making one KICK-*** center channel, is this correct? Quote Link to comment Share on other sites More sharing options...
dsommerl Posted February 20, 2002 Share Posted February 20, 2002 Ninja I am also watching HW's experiment on this. I am pretty sure he is wanting to use two individual HeresyII's on their sides (with the horns of each abutting each other)---and is wanting to know how boyh can be driven-by the same C channel signal---don't think he's building one BIG ctr channel spkr---- Forgive me HW if I mis interpreted your MO on this. Dave Quote Link to comment Share on other sites More sharing options...
maxg Posted February 21, 2002 Share Posted February 21, 2002 First off I think you need to be careful with this one. You may well get cancellation of signal as both speakers will receive the same signal at the same time. The easiest way to tes this is to buy a Y-piece for the RCA's - plug it into the centre out of the source and then run both channels into the left and right channels of the pre. Just a thought - if you avoid cancellation it could be cool. ------------------ 2 * Heresy 2 (mains) 2 * Homemade horn speakers (rears) 1 * REL Strata 3 sub Accuphase E211 amp. Tube monoblocks with separate pre-amp (solid state). Marantz CD6000 player Sony NS900 SACD/DVD player Stax Headphones Humax 5400 digital satellite receiver Sharp Video 32" Sony flat screen 16:9 TV Mogami interconnects Silver Synergistic speaker cable Quote Link to comment Share on other sites More sharing options...
HornEd Posted February 21, 2002 Share Posted February 21, 2002 Hwatkins, what a grand experiment! It should go particularly well for HT. I don't remember the rest of your rig but your experiment should prove a winner, particularly since the Heresy is a sealed speaker and, therefore, better suited to dialogue. All you would need to complete the test, given the pre-amp signal would be a power amp supplying no more than 100 watts per Heresy... matching the 8 ohm requirements of the speakers, of course. For testing purpose an old stereo power amp would do with a "Y" connector sending the pre-amp out to both stereo inputs. If the test is to your liking, then you can upgrade the amp. As you may recall, I run a "horizontalized" KLF-30 as a center atop a 65" RPHD monitor with amazingly wonderful results for multi-channel music and incredible HT performance. I built a new motor board to be able to have the horns in the center flanked by the 12" woofers. By laying the Heresy's on their side with the horns side to the center, you will have the components in proper position. However, the horn array on a heresy is midrange 80°x30° and tweeter 90°x40°... and that potentially affects the size of the sweetspot... but with two sets of horns head-to-head you may be okay. New, mirror image motor boards could be fashioned to bring re-establish the horn orientation. Another area of concern would be clarity of dialogue... the whole concept of a tapered array came out of the concern of two speakers being slightly out of unison creating an intelligibility problem. In my KLF-30 center experiment, the intelligibility was better than the KLF-C7 that preceeded it. Given the multi-channel trend with higher emphasis on center channel performance... massive centers that timbre match the mains are the biggest step to a better sound experience. Be sure to use an A/B test of your trial center against a phantom center to check how well the twin Heresys are performing with the rest of the speakers. Oh, yeah, and make sure you fine tune your rig with an SPL meter BEFORE making your critical ear test. Who knows, perhaps Klipsch can figure out a way to market massive centers and create a whole new bottom line enhancer for the legacy of Mr. Paul... a pioneer of high end three channel sound! Be sure and let us all know how it goes. HornEd ------------------ "LEADING 8 LEGENDS INTO THE 6.1 GENERATION!" FOREGROUND SOUND STAGE: KLF 30's: Left Main, Center Main, Right Main KLF C7's: L & R Front Effects on 5' sand filled columns BACKGROUND SOUND STAGE: KLF 30's: Left Surround, Rear Effects, Right Surround LARGE MOUTH BASS: Twin SVS CS-Ultra SubTower, Samson Megawatt Amp KLIPSCH SPEAKER SUPPORT SYSTEMS: Bass friendly, oversized, glove-leather LazyBoy Recliners Mitsubishi RPHD1080i 65", Yamaha RX-V3000 Receiver Toshiba Pro Scan 6200, Toshiba Pro 6-head SVHS W808 in search of the Eternal Tweak! Music Respite Room: Vintage Cornwall's in Transition Klipsched Class "A" Motorhome: On the road testing This message has been edited by HornEd on 02-21-2002 at 06:17 AM Quote Link to comment Share on other sites More sharing options...
hwatkins Posted February 21, 2002 Author Share Posted February 21, 2002 Thanks all - that is the start I was looking for. Dave is right in what I will be initially testing - individual speakers together for Center. My pre-test, using my existing HK AVR-40 with one heresy for center on the floor, existing heresy for mains was clearly an improvement in tonal matching. HOWEVER, the experience moving around the room was very mixed - where it was good and clear I couldn't imagine it getting much better. But from various spots there seemed to be severe dialogue intelligablity (new word?) problems (and got worse with speaker on its side). I really did not spend enough time with the pre-test to tune and tweak - I was impassioned by how good it sounded in various sweet spots. This will take some time - I have the Denon avr3802 arriving today (according to our UPS friends), The next set of Heresy in about 10 days. I am going to run lamp cord in the ceiling to the rear center surrounds (to use my existing surround speakers for rear center) today and cable all existing components and manage output from Denon until speakers are all in place. A pair of heresy will go on the wall at ceiling where existing surrounds are. Now - mounting the Heresy is in the cool idea stage. I will be connecting four stranded wires to each Heresy (undetermined method at the momemt) and through small holes in the ceiling raise the speakers and then secure them to either roof rafters or ceiling joists - invisible suspension! I can't say that my wife finds this the most attractive part of me, but seems to overlook it for some other obscure good quality. She thinks she will eventually get an addition to the house out of this stuff and then I can have my own area that doesn't compromise the rest of the house. Henry's playroom. ------------------ Hwatkins Quote Link to comment Share on other sites More sharing options...
Guest BobG Posted February 21, 2002 Share Posted February 21, 2002 Do a search on this bulletin board for "using two center speakers". You'll find the topic has been covered a few times already. Basically, it's a bad idea. The only possible benefit is an added 3dB of volume (assuming your amp can maintain voltage into 4 ohms). You could get the same thing by turning up a single center by 3dB but even then, the center would not be properly balanced with the rest of the system. The downside? Severe interference between the two speakers reproducing the center channel information. If you are PERFECTLY equidistant from each of the speakers, there aren't many problems, but when you are not perfectly centered, there is a big penalty. This is true even when you move your head a bit to the right or left. Same thing as using a speaker too near a reflective wall, the reflections interfere with the primary output causing severe comb filtering of the information - particularly mids and highs. This is why you don't see speakers with multiple midrange drivers or mulitple tweeters. You either use one, or a whole line array (which has a totally different directional pattern). Multiple woofers do not suffer the same problem as they are typically mounted close together compared to the wavelengths they are producing. If the drivers are within 1/2 wavelength, they don't interfere. No harm in experimenting, but do listen for rougher mids and highs when you try this. Quote Link to comment Share on other sites More sharing options...
HornEd Posted February 21, 2002 Share Posted February 21, 2002 Thanks BobG... I suspected as much and so have never experimented with two sets of tweeters and mid-range horns. I tried to hint at it with the comment about tapered arrays being somewhat analogous. Your little forays onto the Reply end of this Forum are much appreciated for wit, history and tech advise. Oh, and thanks for encouraging experimentation... it sure has helped me to buy more Klipsch speakers! HornEd Quote Link to comment Share on other sites More sharing options...
dsommerl Posted February 21, 2002 Share Posted February 21, 2002 HW Being an STL local---can I come out and watch this install? "I will be connecting four stranded wires to each Heresy (undetermined method at the momemt) and through small holes in the ceiling raise the speakers and then secure them to either roof rafters or ceiling joists - invisible suspension!" Holy Cow! and I thought I had "gone over the top" Just teasing---my living room as morphed into a used Klipsch store---- Bet the folks at Klipsch reading this stuff--must FREAK OUT Keep up the great work out there in St Charlie, HW Dave Quote Link to comment Share on other sites More sharing options...
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