greg928gts Posted June 6, 2003 Share Posted June 6, 2003 I thought I'd bring this topic back up and give you guys an update on how things are going. Just to review, I stumbled on a SET amp a couple of months ago, and really like the detailed sound through my Khorns. But not enough power for me, especially for the bass frequencies. I've been used to a McIntosh MC2205 on my Khorns for years. I surmised that bi-amping would give me the best of both of these amps. So I got a Rane active crossover and hooked up my SET amp to the horns of my Khorns, and my McIntosh MC2205 to the bass bins. I really took my time with the wiring and setup adjustments, but I realized after a few times listening to it, that I still had the bass bins up a tad too high. We're talking minor adjustments here. I worked on it some more today and listened for several hours, and I think I've got it now. I am definately still getting the wonderful detailed sound from the SET, but I also have the power of the McIntosh on the bass. When doing a bi-amp setup, the thing you have to guard against is setting the bass bins up too high. There's a tremendous amount of the sound coming from the bass bins, much more than just the low notes from kick drums and bass guitars that we normally associate with coming from the bass bins. The whole body of the midrange, vocals, guitar, drums, everything is really rounded out and defined through that bass bin. So turning it up to get more kick or extreme low end, also turns up these mid frequencies as well. It's amazing when I turn off the amp to the bass bins, how little sound is actually coming out of the mid horn and tweeter. I know that there's a very wide range of frequencies, many octaves, but in terms of the actual amount of sound that is produced with the horns, it's very little compared to what comes out of the bass bins. For this reason, I think I am giving up some of the quality, detailed sound that I was getting with JUST the SET amp in those lower mid frequencies. The crossover point is set at 400hz. From 400hz all the way down to about 150hz I would consider to be very important to the midrange, or body of the music. I think these frequencies are also very important to the overall sound quality that I was hearing with the SET amp, when I JUST had the SET on the Khorns. So, I still need more time with the bi-amp setup. I figure what I'll do is wait a couple of weeks and then switch back to just the SET to see if I get that same feeling that I got the first time I hooked it up. That feeling that I was hearing things that I had never heard before on my CD's. The feeling that there are spaces, split-second voids in the music that I was never aware of before. If that happens, then I know that the bi-amping is really not fully preserving the quality of the SET. I think either way, I would want a larger SET or a pair of Mono SET's, I can really hear it straining at higher volumes. Greg Quote Link to comment Share on other sites More sharing options...
djk Posted June 7, 2003 Share Posted June 7, 2003 The Rane AC 22 is a POS. Earlier ones don't even have a regulated supply, no power supply bypasses. They have ceramic caps in the signal path, and most of them have electrolytics in the 20hz filter. Did I mention the cheapest opamps money can buy? What are you doing for the mid-to-tweeter crossover? The best way to do bi-amping with an SET and Klipschorns is to get a nice 2µF cap and hook the K77 through it to the 16 ohm tap on the SET, then the K55 to the 8 ohm tap(also use the p-trap if you have the drivers that benefit from same). With 24dB/oct you can lower the crossover point to 300hz too. For off-the-shelf inexpensive units, the Goldsound, Madisound, Fender, TDM(all the preceeding built by TDM), and the Marchand models are the best. A DBX can be had dirt cheap and then hopped-up to sound as good or better than the above. A DIY unit is quite simple and would blow any ready built unit away. Quote Link to comment Share on other sites More sharing options...
Chris Robinson Posted June 7, 2003 Share Posted June 7, 2003 Greg, interesting experiment and good logic chain. Let us know how it goes! Quote Link to comment Share on other sites More sharing options...
horonzak Posted June 7, 2003 Share Posted June 7, 2003 Greg Good work. wait till you go 3 way. Dont muck it up with other junk in between drivers & amps. Quote Link to comment Share on other sites More sharing options...
NOSValves Posted June 7, 2003 Share Posted June 7, 2003 If my Audio journey ever made me start to look for the extra detail of SET I would follow the same path as you have. I have been doing some experimenting for the last few weeks and have come to the conclusion that although some of the members here may feel that 3 watts is enough in my mind this is impossible. I purchased a really nice watt meter (digital/Analog) and have been watching it while playing various artists and music type's when setting the sound level to a relative 1 watt steady state when heavy transients hit the peaks can often be near 15 watts that the amp is asked to deliver if 15 watts are not available the transient just doesn't seem live. For instance just to give everyone a idea the band I did a good bit of this testing with was Dire Straights with there first album. The only thing that makes me wonder about even the 3 watts for the top end is that the meters shows these peaks being delivered for higher frequencies also like high pitched guitars which happens often with Dire Straights ? I also have found that the more powerful the amps you use the louder 1 watts seems to sound and this proves true with a Db meter especially the peaks and dynamics just come thru more effortlessly and clear. Craig Quote Link to comment Share on other sites More sharing options...
greg928gts Posted June 7, 2003 Author Share Posted June 7, 2003 djk - You're suggestions sound interesting. I love the idea of lowering the crossover point, I feel as though the horns aren't doing anything close to what they're capable of. What about even lower than 300hz? Is that volume dependent? I suspected the Rane would not be the best sounding unit, but it was cheap, and a good first step to see if I even wanted to consider a better unit, which I do. I'm currently using a Audio Electronic Supply SE-1 which has no adjustments or options for impedence output to the speakers. I'm sending the signal out of that amp to the input on my stock AA Khorn crossovers to supply signal to the mids and tweets. The bass goes directly from the 8 ohm tappings on my McIntosh MC2205 to the woofers. I follow what your saying as far as putting a cap on the tweet. I assume that would roll off the lower frequencies at a certain point. What happens when you send all the frequencies above 300hz to the mids without rolling off the upper frequencies? I don't know what you mean by a P-trap. I would have the physical skills necessary to build my own electronic crossover, but not the know-how as far as design or where to get components or what components would be best. I think this may be beyond what I want to tackle. But I would very much like to get a higher quality unit. Maybe the home built unit is not as complicated as I think it might be. One thing I realize is that I don't need to have the sweep controls, or probably not even separate gain controls (my McIntosh has volume knobs)for high and low output. So, this might make the design and construction much easier, and the signal path less congested. I would appreciate any guidance you can provide. Would you be interested in building one for me? This is really fun. Next steps in my system will be better crossover stuff, experiment with a DAC or two, a pair of monobloc SET amps, maybe get back into vinyl, I have a MQ107 that I haven't even tried yet, Where does it all end? Greg Quote Link to comment Share on other sites More sharing options...
Daddy Dee Posted June 7, 2003 Share Posted June 7, 2003 Greg, Thanks for posting your experience so far on bi-amping the Khorns. I've been wondering, (just wondering and nowhere near checking it out) about bi-amping my La Scalas. Will be looking forward to your future posts when you check back to listen with the straight SET option again. Regards, Dee Quote Link to comment Share on other sites More sharing options...
j-malotky Posted June 7, 2003 Share Posted June 7, 2003 Greg Nice project. I too have been considering running MC for bass and SET for detailed mids and highs. Keep us posted. Pics would be nice too. JM Quote Link to comment Share on other sites More sharing options...
Chris Robinson Posted June 7, 2003 Share Posted June 7, 2003 Greg, I'm pretty sure you've talked with Mr. Klappenberger on this subject. If not, I would highly recommend some phone calls. He's very knowledgable on both Klipsch and crossovers. Skip the emails ... just call him. I have the number if you need it. Quote Link to comment Share on other sites More sharing options...
greg928gts Posted June 7, 2003 Author Share Posted June 7, 2003 Thanks Chris, could you please email it to me at glroberts@prexar.com. Greg Quote Link to comment Share on other sites More sharing options...
greg928gts Posted June 17, 2003 Author Share Posted June 17, 2003 O.k., time for an update. Over the last couple of weeks, I've noticed more and more, that I really was not happy with the sound quality from this biamp setup. I was still hearing that wonderful detail in the high end, but the bass had become muddy. I could make the bass stronger of course, but I had quality issues. Midrange was good on some cd's with decent soundstage, but others sounded harsh, or sometimes boxy sounding. The bass was the real problem though, and I have to think that this is a signal quality problem, and not the amp or speakers (McIntosh Mc2205 and Khorns). Muddy, not well defined. I was fooling myself at first, thinking that this was the answer. I thought that I had both detail in the high end and strong bass, but all I was really doing was mixing the bass up louder at the crossover. The more I listed to it, the more I realized that the stronger bass was not very good sounding. Overall, this biamp setup didn't work out. What to blame? The Rane would be an easy target, but there may be issues here with the WAY the Rane crosses the frequencies. I feel that my interconnects are in good order, my cd source, was until yesterday, a Denon with burr-brown chips, a decent unit, my preamp is a McIntosh, again, a decent unit. I dunno? I changed back to just the SET amp on the Khorns and all of a sudden the midrange was back!!! In a big way. What a difference. Just like I remember, big, airy, open sound, like you can walk into the song. So here I am, lovin this new MSB DAC and Denon 1650AR that I bought, listening to a wonderful SET amp on Khorns. It's the most satisfied I've ever been with my system from 150Hz and up. But not enough punch in the low end, not quite enough volume without hearing the amp straining. Just a few watts short. I don't know what my next step will be. Maybe a better active crossover? Maybe more powerful monobloc SET amps and bi-amping through the Khorn passive crossovers or ALK's? Maybe try a really nice pair of monobloc PP's and try pushing a lot more tube power? There's so many options that it makes this really difficult. I'm glad I've got a place to talk to other like-minded people about these things. Just wish I had more time to talk to you guys about this. Greg Quote Link to comment Share on other sites More sharing options...
j-malotky Posted June 17, 2003 Share Posted June 17, 2003 Greg What output tap are you using on your 2205? Since the K33 is something like 3 ohms you may want to try the 2 ohm tap. 4 max. Are you bypassing the crossover components on the inside of your bass bin cover? Make sure you have your woofer connected directly to the plugs. My '83 AK networks had a bunch of components on the back of the door. Just some suggestions. JM Quote Link to comment Share on other sites More sharing options...
greg928gts Posted June 17, 2003 Author Share Posted June 17, 2003 Thanks JM. I did have the woofers directly wired, not through the AA crossovers. I don't remember any components inside the woofer bin. I had the woofers hooked to the 8 ohm output on the Mac, but I can't imagine that would have any affect on sound quality. Power output, yes, but not sound quality. It's disapointing that the bi-amp setup didn't work out perfectly, but I have to tell you, I might be willing to live without the perfect bass to have the kind of sound quality I'm enjoying right now! I'm just saying that, I know that eventually I'll long for the feel of the Khorns moving air in the room again. This journey has to be enjoyed along the way. Greg Quote Link to comment Share on other sites More sharing options...
Audible Nectar Posted June 18, 2003 Share Posted June 18, 2003 "Thanks JM. I did have the woofers directly wired, not through the AA crossovers. I don't remember any components inside the woofer bin. I had the woofers hooked to the 8 ohm output on the Mac, but I can't imagine that would have any affect on sound quality. Power output, yes, but not sound quality." Before you give up on this, I highly recommend that you try this again, using the 4 ohm taps. You should be aware that the impedance drops in the lower frequencies (I thought I read on this board that the impedance is about 3.2 ohms on the k33). The Macs do sound a bit different in the finer details when switching taps - and the Mac should be better suited to drive the woofer at the lower impedance tap (4 ohms). I use the 4 ohm taps on my Macs to drive my klipsch. It does seem a bit more "controlled" at that tap vs. the 8 ohm tap. Of course, it could very well be that this combo just isn't viable, but I would try switching the taps before you give this up entirely. Quote Link to comment Share on other sites More sharing options...
j-malotky Posted June 18, 2003 Share Posted June 18, 2003 Greg DND and I are saying the same thing. In a nutshell, the great old McIntosh amps and there autoformer technology's only downfall is that they can not calculate the proper dampening factor and rely on us to select the proper load on the barrier strip. Like DND, I drive my 8 ohm Khorns on my 4 ohm MC taps. FYI - I did try the 8 ohm taps but found only the "up front" music sounded better. The 4 ohm sounded more flat and the subtile background sounds were much more defined. That is why I recomended you use the 4 or 2 ohm taps for your 3 ohm K33. Looks like Both DND and I think this may be your key. JM Quote Link to comment Share on other sites More sharing options...
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