orangeblood Posted March 17, 2023 Share Posted March 17, 2023 hello - first post but Klipsch owner since 1981 i recently acquired 2 Crown D75 amps, I am considering running each in bi-amp mono mode and feeding my gen 1 heresys at a small outdoor gathering. aside from putting each amp in mono mode and correctly wiring the setup - is there something i should be aware of or avoid? i've never done this before and have pro audio experience. Just looking for coaching thanks 1 Quote Link to comment Share on other sites More sharing options...
billybob Posted March 17, 2023 Share Posted March 17, 2023 Hello, If one or both of the Crown is in decent shape, would just hook the one Crown. It should be enough without getting into and understanding what you are doing well enough to not damage your equipment. Not certain that if anything can be gained by the complexity of the hookup significant enough for the doing. One and done IMHO... Welcome @orangeblood 2 Quote Link to comment Share on other sites More sharing options...
billybob Posted March 17, 2023 Share Posted March 17, 2023 Not saying that it cannot be done btw. Quote Link to comment Share on other sites More sharing options...
orangeblood Posted March 17, 2023 Author Share Posted March 17, 2023 billybob - thanks for the reply / coaching i posed the question for the reason you allude to ...i dont want to damage my gear. both amps have been serviced. i'll go with a 1 amp solution as you suggest, but i am curious about the complexity you mention. from my read of the crown d75 user manual, running the amps in mono mode is simply a matter of jumping the speaker posts and flipping the mono switch on back. what could go wrong? (just hoping to learn) 1 Quote Link to comment Share on other sites More sharing options...
billybob Posted March 17, 2023 Share Posted March 17, 2023 14 minutes ago, orangeblood said: billybob - thanks for the reply / coaching i posed the question for the reason you allude to ...i dont want to damage my gear. both amps have been serviced. i'll go with a 1 amp solution as you suggest, but i am curious about the complexity you mention. from my read of the crown d75 user manual, running the amps in mono mode is simply a matter of jumping the speaker posts and flipping the mono switch on back. what could go wrong? (just hoping to learn) What source will you be using for music? Some amps use either a left channel or right for mono. Not always both. A signal from the source must be supplied to both of course. Also, usually a preamp is used so that only one volume control is being used. Other but, drinking coffee atm. If you have the time and the cables required before the gig, and the patience, you could go for it. A certain amount of tweaking and you are there. If using phono for records both must be connected unless you use one as preamp and then you are back to just the power of one to both speakers. If you have considered this still, would proceed with caution. Others here may give you guidance as to what is possible without hitches involved. This close to showtime only you can answer. Quote Link to comment Share on other sites More sharing options...
billybob Posted March 17, 2023 Share Posted March 17, 2023 When you have a good working Crown, it should work well, and certainly just a pair of Heresy driven, would be adequate in stereo. Biamping btw is something else we need not go into as defined. Quote Link to comment Share on other sites More sharing options...
orangeblood Posted March 17, 2023 Author Share Posted March 17, 2023 again, thanks. i'll take the advice and go with one amp. i had planned to use a rockville preamp with a bluetooth interface. it has separate R/L left TRS inputs and outputs. i had planned to send one output/channel to each amp (running in mono mode) i'll admit that most of the energy behind this plan was the enjoyment of seeing and hearing two 40+ year old classic Crown amps driving a pair of one-owner 40+ year old Hersey gen 1s. i have collected a vintage rack mount case, preamp, power supply and EQ. the set up looks super retro, but since i had no experience with amping each channel separately i thought i had better get some coaching (....yeah, i know...old guy stuff...guilty as charged) 3 Quote Link to comment Share on other sites More sharing options...
JohnJ Posted March 17, 2023 Share Posted March 17, 2023 You would probably need a preamp to get the signal through both amps. I did something similar with good results but with only one receiver. Used the A speakers output for the HF and the B for the Low Frequency on a single set of Fortes. Easy to hear the improvement in the bass then other frequencies and soundstage. If those output 55WPC using them as monos (if you don't crank them to "10") seems possible. My Heresy IIs took 125 wpc for decades, needed recapping but otherwise handled it very well! 1 Quote Link to comment Share on other sites More sharing options...
JohnJ Posted March 17, 2023 Share Posted March 17, 2023 Saw that you posted while I'm getting my go-juice. Welcome! Have fun, Measure Twice & Cut Once! 1 Quote Link to comment Share on other sites More sharing options...
billybob Posted March 17, 2023 Share Posted March 17, 2023 6 minutes ago, orangeblood said: again, thanks. i'll take the advice and go with one amp. i had planned to use a rockville preamp with a bluetooth interface. it has separate R/L left TRS inputs and outputs. i had planned to send one output/channel to each amp (running in mono mode) i'll admit that most of the energy behind this plan was the enjoyment of seeing and hearing two 40+ year old classic Crown amps driving a pair of one-owner 40+ year old Hersey gen 1s. i have collected a vintage rack mount case, preamp, power supply and EQ. the set up looks super retro, but since i had no experience with amping each channel separately i thought i had better get some coaching (....yeah, i know...old guy stuff...guilty as charged) Sounds nice and may as well pursue this when you have time and the focus. Hope all goes well! Yes, not a spring chicken here. Since a member now, let us know how it goes and, others with more experience than I are here. Cool... 1 Quote Link to comment Share on other sites More sharing options...
The Dude Posted March 17, 2023 Share Posted March 17, 2023 Sonds like a fun project, I bet those Crowns with Heresy's are going to sound great. Quote Link to comment Share on other sites More sharing options...
Ceptorman Posted March 17, 2023 Share Posted March 17, 2023 Give it a try but be careful with the volume knob. Quote Link to comment Share on other sites More sharing options...
billybob Posted March 17, 2023 Share Posted March 17, 2023 Yes, your having a preamp wasn't mentioned at first. Changes the complexion somewhat. Still, proceed with caution. Quote Link to comment Share on other sites More sharing options...
Toz Posted March 17, 2023 Share Posted March 17, 2023 What you propose is simply bridging each D75 to mono for increased power and headroom. There is no mystery or trouble. It's a good idea to eliminate the chance of clipping for your outdoor gig. Quote Link to comment Share on other sites More sharing options...
OO1 Posted March 17, 2023 Share Posted March 17, 2023 rent a set of powered outdoor or cheap PA speakers ......, crank em up , blast away for hours .leave the Heresy at home or sell them Heresy 1 is not a PA speaker , it's a HIFI speaker with + 40 year old parts , EV replacement diaphragms for the k-77 are no longer available , take good care of these tweeters . Quote Link to comment Share on other sites More sharing options...
orangeblood Posted March 17, 2023 Author Share Posted March 17, 2023 001 - thanks for the words of caution i dont intend to blast the volume. just some background tunes for a group of 13 guys at a brangus ranch in the texas hill country that will dig the vintage set up and sounds outdoors. they wont be volume abused. no way i'll ever sell my heresys. they are literally the first speakers i ever bought. $700+ in 1981 1 Quote Link to comment Share on other sites More sharing options...
Ceptorman Posted March 17, 2023 Share Posted March 17, 2023 34 minutes ago, orangeblood said: 001 - thanks for the words of caution i dont intend to blast the volume. just some background tunes for a group of 13 guys at a brangus ranch in the texas hill country that will dig the vintage set up and sounds outdoors. they wont be volume abused. no way i'll ever sell my heresys. they are literally the first speakers i ever bought. $700+ in 1981 If you crank it, I might hear it, I'm in New Braunfels. Quote Link to comment Share on other sites More sharing options...
JohnA Posted March 17, 2023 Share Posted March 17, 2023 There is little to be gained by biamping Heresies. Modifying the cabinets and crossovers to separate the the woofer from the HF would stop me. However, if bridged for mono, their approximately 100 watts each will be a perfect match for your vintage Heresies. Heresies protect their tweeters very well. Dinna fash a whit about your tweeters. I'll recommend placing the speakers in or near a corner to boost the bass output so you're not tempted to turn up the bass knob and put your woofers at some risk. Quote Link to comment Share on other sites More sharing options...
orangeblood Posted March 18, 2023 Author Share Posted March 18, 2023 11 hours ago, JohnA said: There is little to be gained by biamping Heresies. Modifying the cabinets and crossovers to separate the the woofer from the HF would stop me. However, if bridged for mono, their approximately 100 watts each will be a perfect match for your vintage Heresies. Heresies protect their tweeters very well. Dinna fash a whit about your tweeters. I'll recommend placing the speakers in or near a corner to boost the bass output so you're not tempted to turn up the bass knob and put your woofers at some risk. my mistaken use of the term bi-amp. as you correctly write i plan to bridge for mono two Crown D-75 amps and feed each heresy with a dedicated ~100 watts. Ceptorman - i hope you dont hear them, they'll be in bandera county, but ping me if you do and i'll turn them down Quote Link to comment Share on other sites More sharing options...
Coytee Posted March 18, 2023 Share Posted March 18, 2023 23 hours ago, Toz said: What you propose is simply bridging each D75 to mono for increased power and headroom. There is no mystery or trouble. It's a good idea to eliminate the chance of clipping for your outdoor gig. yep... not biamping, though there are two amps involved Quote Link to comment Share on other sites More sharing options...
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