Bi-amping Question?


I am and amature to highend audio and am trying to get into it by first messing around with low-end eqiupment and learn concepts. Quick question. I have a pair of Wharfedale Diamond 8.4 (rated at 150W-RMS 6ohm impendence). Additionally I have a ROTEL RB985 (5 channel at @ 100W per channel at 8 ohm.) Could I bi-wire/bi-amp the Diamond 8.4s using two outputs for each speaker from the amp (i.e. Use Left Front to power Low Frequency of the Left Speaker and Left Rear to power the High Frequency of the Left Speaker and use similar setting for the right speaker). Since the Stereo pre-amp I have has two outputs for each channel, I was planning to connect Left out to Left Front and Left Rear and Right out to Right front and Right Rear on the Rotel amp. Would this actually make a sonic difference? Putting 100W in High Frequency and 100W in Low Frequency = The speaker being powered with 200W or is it still effectively 100W? Any ideas-under the assumption I am buying no additional equipment?
dkalsi
IMO, it will make a small difference. You can always try it both ways is see for yourself.
Yes it would work fine, more cables however. But you will have a left over channel doing nothing. Beyond that it may or may not be better sound, test it and see if there are any benefits to it and decide from there, just use cables that you have or borrow to see what happens. Something to remember though is that the woofer section generally dictates the overall impeadance, so the 6 ohm will probably drop more when you are driving the speakers, and will probably be only an 8 ohm load or something on the midrange and tweeter half, this is fine, but could heat up 2 of the channels and barely pull much from the others if that makes sense, this could be benificial if you are looking for more bass and to tame the treble and mids however. Trying it and hearing for yourself will be the key, but it is safe to do it so its up to you.
Bi-amping usually has only a small benefit.
The only thing I would be concerned about is that some (few) preamps have two outputs with one being a high gain and the other being low gain. Chances are this would not hurt anythingif it were the case, but it would sound terrible.
Try it anyway.
Then you too can tell people from personal experience that bi-amping gives you only a small improvement.

Have fun!
1. Wiring inputs and outputs that way will work just finely.
2. You may or may not hear a difference. If you don't have to buy more speakercable, TRY IT!
3. You will be driving your speakers with 400 Watts of rated-maximum power, and the sound should be more dynamic unless you listen at quite-low volumes. Actually, with 6-Ohm speakers, your amp channels could drive more maximum power, say, 150 Watts each, which is around the maximum-rated power of your speakers, so be careful--if you're a headbanger, you may be blowing drivers soon.
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My friend set up has bi-amp his B&W 801 with 2 ML333s, the initial improvement seems to be small but we both agreed that once we heard the bi-amp set up for awhile that we can't go back to single amp set up any more. We found the sound does not strain during the loud passages with bi-amp set up to yield more natural sound, much closer to life as I heard in the concert hall. The sound stage is also much stable with bi-amp set. I guess bi-amp set up is depending on the system resolution and power handling of the speakers. In our case, it was better match with bi-amp. Happy listening!!
Dkalsi, I would qualify the difference you WILL hear as huge. If as Tinman agrees, you can't go back, and you won't, that's huge. But wait, it gets better! The amp you are using has one power supply, upgrade to a true bi-amp setup and the difference will be HUGE. Enjoy. Z.
You still need to have a crossover between the preamp and the amplifier. If you don't, then you risk of destroying the drivers (and seriously degrading the sound). Alternatively if you leave the speaker crossovers in circuit then you are simply running bridged pairs of channels to each speaker, not biamping. Unfortunately biamping isn't possible when "buying no additional equipment". Biamping is also not "connect and play". You will need to tune the electronic or digital crossover to exactly match the speaker crossovers, or better still account for room resonances.
"...if you leave the speaker crossovers in circuit then you are simply running bridged pairs of channels to each speaker, not biamping."

Nope, you're wrong. The 'bi' in 'biamp' has to do with using at least 2 channels of amplification PER SPEAKER. 'Bridging' channels of an amp is completely different and has nothing to do with how you're driving the speaker.
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Yeah very wrong, you can infact run Passive crossover bi-amping by simply dumping the jumpers between your 2 sets of binding posts on each speaker... You will still have a dedicated crossover on each section don't worry.. Also, one of the real benefits to the biamping with the 4 channels out of the 5 on your amp opposed to 2 channel is the Higher current delivery to the woofer section without sharing to the upper range of the speaker, so say your amp peaks at 20-25 amps of current per channel, well now you will probably get about 10 to 15% more current to your lower bass drivers, this can tighten up things and have better head room for power, however it is not a guarantee in depending on the equipment and speakers reaction.. its all about synergy, so single channels in some cases could sound just as good or better as well.. bottom line try it and see what you think.
Apologies - I did not know that running pairs of amplifiers through the passive crossover was also referred to as bi-amping. I tried this years ago and was disappointed.
Recently I managed to get the right equipment together for actively biamping my Tannoy D900s. While not a trivial job, the result was well worth while. Besides slightly greater realism, it was particularly helpful on the louder passages when voices stand out better against the instruments. Much better for rock music for the same reasons. Another advantage is less distortion in the very high frequencies resulting in better cymbals on those recordings that have the information in the frst place.
I also have a pair of Wharfedales (1.6 Modus) and have one amp running the highs and a twin running the lows. Imo it sounds better at moderate/high to high volumes. It also sounds clearer on "complicated" tracks. Now Ravel's Bolero and Orff's Carmina Burana O fortuna is stunning instead of ok.