TasDom Posted July 8, 2013 Share Posted July 8, 2013 I recently added an additional XPA-5 amp as I was upgrading from a 5.2 set up to possibly a 9.2 I decided that 7.2 was sufficient for now so I now have 3 channels unused.I was thinking about bi-amping my mains (Klipsch RF7II's) and wondering if there is any sonic benefit in doing this. I know the best way to find out is to try it and listen but wanted to get some opinions from the forum...... Thanks in advance for any opinions! Quote Link to comment Share on other sites More sharing options...
Zen Traveler Posted July 8, 2013 Share Posted July 8, 2013 Hi Tasdom, I would leave the jumpers in place and run one set of wires...Fwiw, I don't think you would gain anything unless you were going to change to an external/different crossover. Quote Link to comment Share on other sites More sharing options...
derrickdj1 Posted July 8, 2013 Share Posted July 8, 2013 Hi Tasdom, I would leave the jumpers in place and run one set of wires...Fwiw, I don't think you would gain anything unless you were going to change to an external/different crossover. What he said! I tried the horizontal, vertical and bi-wiring, I thought it work right after I did it but over a peroid of time seen that it did not make any real difference. It did not make things worse, just not better. Quote Link to comment Share on other sites More sharing options...
moray james Posted July 9, 2013 Share Posted July 9, 2013 Tasdom: I do not have RF7 ll but I have biamped vertically with two very nice very modified Quad 405 amplifiers on a pair of modified H3 and a pair of modified KLF20 and a pair of modfied CF3 and I cannot imagine going back to a single amp set up ever. As they say YMMV and you guessed it there is only one way for you to know for yourself. Have some fun and experience what you are wondering about. Best regards Moray James. Quote Link to comment Share on other sites More sharing options...
TasDom Posted July 9, 2013 Author Share Posted July 9, 2013 Thanks all. I'll try it in the coming days as I have extra wire and cables so no out of pocket expenses. Worth a try to satisfy my own curiosity. Quote Link to comment Share on other sites More sharing options...
jtubbs6117 Posted July 12, 2013 Share Posted July 12, 2013 Tas this is something I wrote a while backt that will support your thought. I havechanged a few things in the setup My NAD now powers the HF and my B&K powers the LF on the RF7s. Very nice Much more impact than only running one amp. Just thought you might like another opinion. The more clean power you can run the better. I don't like the idea of distortion creeping up just to try and get close to the RMS power. Guys I have the RF7's like a lot of members. I think people should look at the spec sheet for this large floor standing monsters. The spec sheets states 250watts RMS, this is an understatement. I am running 375 to each one of mine and they will take way more on the LF side. The way I have found to get the best performance from mine is to Bi amp. Running them this way really makes everything flat and nice!. The problem I had with my Mac only on the RF7's it would sound great at low volumes but when turned up the horn would over power the LF to the point it seemed obvious to me. If think about electricity following the path of least resistance or the sensitivity after the power hits the crossover the horn will be louder every time. Using two channels of amplification on each you have two separate sources so the horn does not rob from the LF drivers, or when the LF drivers ohm dips the horn is not affected. Let me explain the 375 Mac MC250 (250x2) runs the HF on the RF7s and NAD 925 (130x5 give or take) runs the LF. This has given me such a good result I don’t normally have my Paradigm Servos turned on. This is just what has worked best for me I really want to get another amp to run the LF side that is a better match for the MAC something that will put out closer to 250 so everything will be equal. Feed the monsters!!!!!!LOL Quote Link to comment Share on other sites More sharing options...
moray james Posted July 12, 2013 Share Posted July 12, 2013 horizontal biamping has it disadvantages and is further complicated if you are using different amps as is very often the case. That in itself shoud be obvious in that they will not sound the same. If you use a stereo amp to drive the left and right woofers then you are asking the supply of that amp to deliver the bulk of its power to both channels at the same time which maximizes the draw on the supply. When you use two identical amps the gain is identical and the sound is identical. If you biamp vertically then only one channel of each amp is asked to deliver peak power to the woofer section while the other channel is doing next to nothing driving the horn section. This then frees up available supply to the channe driving the woofers if it should be necessary. The only thing better than a stereo amp with a common supply to do this job is a stereo amp which is in fact a dual mono amp in one chassis or mono blocks. I agree that once you have fully experienced biamping especially vertical mode biamping You are not likely going to be interested in switching back to a single stereo amp again. Best regards Moray James. Quote Link to comment Share on other sites More sharing options...
derrickdj1 Posted July 12, 2013 Share Posted July 12, 2013 I wish I could be in the room with my RF 7's near RMS. I have never seen mines go past 60-80 watts on the Yamaha M 80 or M 70 meters, or the power console. As far as power distribution, around 300 Hz the power to the HF and LF is pretty even but the HF is not working at that low a level in the RF 7/7II. Most of the time the horm is using less than 10% and closer to maybe 5% of the power. Without the active XO, most of the power from passive biamping is dissapated in the xo network. At higher volume, the horn can be louder due to due to power consumption by the woofer making the HF 3-5 db louder than the woofer. At best, yymv with passive biamping. I wonder if it is not wattage but, current that causes part of the HF/LF mismatch? Passive biamping may help with xo performance according to avr makers. I do run my RF 7's full range since the Yaqin integrated tube amp has no bass management and is for 2 channel. But, I still find myself listening to 2.1 for a lot of things because the subs are the best bass producers in the system. On my power console the highest watt read was around 850 hitting 120 db in the room with some intense LFE going . I had the Yamaha M 70, M 80, Carver amp, avr, BDP, TV app going. Most of this power usage was the subs, the Dayton amp on the subs did not work after this, lol. Quote Link to comment Share on other sites More sharing options...
Kev the ironworker Posted December 10, 2013 Share Posted December 10, 2013 hi, I know that this post is a bit old (6 months) but I have to toss in my 2 cents....I got the biamping bug and spent a lot of money on it....a pair of bryston 7 b-st monoblocks, an audio research vt-50 tube amp for my horns, a luxman a-2003 tube crossover (and $ 1000 worth of upgrades on it) a Richard grey power conditioner, a monster voltage regulator and another conditioner....antique sound lab tube preamp....jolida tube cd player...new rf-7ii's, rc-64 center, a sw-115 sub and my back speakers are rf-82's...(that are powered by a Yamaha m-85 ....sever overkill)... for movies, all this is powered from a cheaper onkyo ht-rc 370 through it's preout jacks. for music everything goes only through the tube pre....does it sound good ? you bet ! would I ever do it again ? no way !...lol....at low volumes there really isn't a noticeable difference in biamping....but every time I turn it up I have to take a step back and smile...the luxman lets you adjust the low, med and high octave range (the horns are almost not even on) but what it's done is now the speakers aren't at all bright....beautiful sounding and powerful.....detailed....I listen mostly to r&r and some female singers as well ....all I need now is a better preamp (looking for an audio research sp-11 if anyone has 1.....) and a much bigger house too...if anyone is interested I have a luxman a-2002 (2 way) tube crossover for any reasonable offer....to sum it all up...I think biamping does make a difference in sound but it's expensive... Quote Link to comment Share on other sites More sharing options...
TasDom Posted December 10, 2013 Author Share Posted December 10, 2013 Glad to hear you noticed a difference. I wound up buying some RS7's and never did try to bi-amp mine. I actually forgot about this post but maybe some day I will give it a try. For now tho, I'm quite content as is. Quote Link to comment Share on other sites More sharing options...
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