Energy in music drops with increasing frequency so although you have a 4 ohm dip in the mids, your amp won't have to deliver as much power as they would at, say, 30Hz and 4 ohms. Give it a shot - I think you will have no problems at all. I biamp my speakers with tubes on top and they sound better than ever before. However, B&Ws are not the best suited for that arrangement since their lower crossover is kind of high at 350Hz. But it is still worth a try.
As Arthur notes, you should be able to do it. OTOH, 350Hz places you smack bang in the middle of the voices range, so most of yr tenors will come out of the "bass" amp and most of yr sopranos fm the triode (likewise with cellos and violins):)
Just check that your triodes of choice sort of maintains constant power between ~3,5ohm and ~8-10ohm.
Of course, you will test this before you buy, right?
Anyway, depending on how the triode behaves under test, you can guess at the end sonic result from an amplitude point of view.
Having owned several sets of b&w's, inc. M802's, & knowing how much power they require, I'm skeptical. But then, I never tried to bi-amp them. A more complete list of your system, power amp, etc., would help.....
Two different amp signatures crossing at 350hz does indeed sound terrible. I tried it and that's how I know. N802's will play fine with 55 tube watts, PHI110 in triode but I usually run the 110 watts in ultralinear.
I am going to make the plunge. Actually this is really a transitional stage for me anyway - I will be working system towards a biamped line array system (these can easily be made ultra-sensitive). I just didn't to leave myself high and dry in the meantime.
I will be using a BAT VK-55 on the top and Parasound JC1 on the bottom.
The key is that I can actively biamp and eliminate any overlap between amps. I will be using a DEQX that can do 100db/octave+ crossovers.
While I can't say I am speaking from personal biamping experience, I believe that the tonal differences between an aluminum tweeter, kevlar midrange and paper woofer are probably greater than tonal differences in amps - even tube vs ss.
I will be able to accurately compensate for gain differences with the DEQX also - bi/tri-amping is it's whole purpose.
Wish me luck
should work. On my 603's the top seems to do only tweeter while the lower terminals do mids and low end. Try urs to see if that is how urs is setup if so the tweeters need very little power
The key is that I can actively biamp and eliminate any overlap between amps. I will be using a DEQX that can do 100db/octave+ crossover
I strongly suggest you follow the characteristics of the passive x-overs (slope, freq, q, etc)
You will disconnect the spkrs' internal x-over of course.
I strongly suggest that you IGNORE the previous passive characteristics. Let the DEQX do what it does best. A lot of passive crossovers are designed with computer models , then tested and refined in an anechoic chamber and then further fine tuned in a given R&D room. This is to say- It ain't YOUR place.
In contrast, a DEQX has a mic input and full RTA functionality as it relates to YOUR personal listening room. Your room acoustics are taken into account when the DEQX puts the crossover together. That's a HUGE advantage. In addition to that- the DEQX qualifies each driver. What specs may be found for a given driver are done in proprietary labs with proprietary equipment boasting exaggerated results. The DEQX will see the driver for what it really is and make the appropriate compensations (if need be). Then when it's all said and done- the DEQX can put the EQ curve you prefer most on the final result. Most loudspeakers are designed with an end result in mind in terms of linearity. If you prefer a flat response from your speakers- you can get that. Rolled off highs? Inflated mids? Why settle for one? Most recordings benefit from some level of EQ on the playback end. It's all there for you to explore in the parametric EQ presets that can be flipped through on the fly from the remote.
To answer your first question- is 55 watts enough?
In a word "Yes".
remember that you should put some caps on the terminals to avoid any junk from your amp getting to the fragile HF drivers. Just because you are filtering the freq before the amp- the amp may be spitting out small amounts of low freq hum that is NOT being divided by the DEQX. It only takes a little to blow a tweeter. With a cap on the terminals for protection- you will be running them in a pseudo-passive/active configuration. So 55 watts active isn't entirely correct. OTOH, most db output ratings given for a driver are measured at the standard 1 watt/1 meter. A few watts is enough to run you out of the room if it's clean and fully active. 55 watts in your given scenario is enough to blow the cones/diaphragms out of the frame. Be carefull, and BEST of luck. Great piece of gear!
Thanks Tube lvr,
I appreciate your input.
I have sold the N802s so the question is somewhat moot now. I have bought drivers for a pretty big line array - 18 Seas W18E001 7" mag woofers plus 16 Fountek Neopro5i ribbon tweeters. The speakers are designed based on the line array principles laid out by J Griffin in his excellent line array white paper.
The amps are 2 Parasound JC1 for the low and a Bat VK55 for the hights.
The xover, as you know, will be handled by the DEQX.
Very big project for me. I am building the cabinets. Basically have to as the drivers themselves for this speaker are about $6,000! Can't wait to hear the huge soundstage, unlimited no distortion sound. Just have a huge learning curve to get there.
Thanks again and rock on!!!
Sounds like fun!
In the past- people have attempted to gather their allstar drivers and stick them in an enclosure and end up with expensive noise. Just like in sports- teams win consistantly when they learn to play together as a TEAM. This is the same with drivers. Put a bunch of allstart drivers together and they will usually cannabilize each other. It takes careful slection, and a refined crossover to get them to sound like proper loudspeakers.
The DEQX units excell at taking an already great loudspeaker and ignoring the passive crossover- thereby letting the DEQX "redesign" it from scratch. You are already using a great selection of drivers that are proven winners with respect to how they play together....as a team. Think of the DEQX as an upgrade in talent and coaching. ;-)
One caveat: it has to be fully utilized. Take the time to study the software and tap into its full potential. To your advantage- support is excellent. I think your biggest aspect of the 'learning curve' will be with the DEQX unit itself. Dial it in and you'll be in heaven, I'm sure.
Keep us posted on your results. I, for one, am very interested.
Hey just had to let everyone know that this ***hol* tube_lvr who posted right above me stole 1200.00 from me. He put an ad up for a cart and I sent him the money. He cashed the check and never sent me the cart and won't respond to phone calls or emails for 2 months now. Sorry just pissed me off when I read this thread and noticed he had contributed. Just wanted everyone on here to know what a piece of !@#$ this guy is.