To Bi or not to Bi? That is the question

I have recently purchased a pair of Dahlquist CA2 and W2 speakers. These were/are a fabulous speaker designed to be bi-wired or bi-amped. For those not familiar, there are two cabinets, one for the highs (D'appollito array) and the other cabinet contains 2 6.5" woofers. The two cabinets stack one on top of the other and are bridged together. I currently am using the same amp I had to drive my old speakers which is a "modest" Hafler 9180 (105wpc). Needless to say, I'm not getting the best from my new speakers. What I am looking for help with is in the biamping process. I really like the 9180 which has that warm MOSFET sound and am thinking of keeping the amp to run the top cabinets. I would then like to get a stronger amp (looking at Hafler or Bryston)to drive the bass cabinets. I am a little concerned because I have read differing opinions on using two different powered amps in this configuration - some say they should be the same amp while others say a combo produces good results. What do you think? Also, my pre-amp only has only one set of outs for the mains, so a Y would be needed here - which brings me to another problem - where to fing a high quality Y (I am currently using AQ Opal to go to the main amp)? Thanks for the help in advance! BTW: I do not use an external crossover. Tony
Bi-amping with two different amps can be good or bad. It just depends on the synergy of your system. Make sure each amp is a good match for each cabinet. Personally, I have always used the same amplifiers to do it, but I can definitely see advantages to use two different amps. The best advice I can give is to experiment for yourself and see what configuration you like the best. I've never run across a decent "Y". I wish I had though.
Bi, I say. Since the choice is vast, I suggest you start with a few amps on loan -- if possible. Just to get an idea. As S7 said & and the resident EE's will confirm, it's useful to match the sound characteristics & phasing of the two amps.
How about a tube for the upper... assuming the Hafler can drive your woofs. Otherwise, you'll need a powerful machine for the woofs which may be faster (if recent model) than the Hafler -- thereby creating phase problems.
Not a problem; just fun in researching, if you can. Good luck, nice speakers!
Thanks for the responses. I guess the first step is to get hold of some good cable. I am running AQ Argent+ which I will use for the tops and am thinking AQ Midnight for the bass. That still leaves me with my quest to find high quality Y adaptors. Anyone have ideas there?
While i can't vouch for them personally, you might want to try looking at for either part number 263-754 or 263-588. Both are RCA splitters but of different configurations. I would opt for the one with a female at the end and on the side rather than the two on one side. Without looking at them in person, i'm guessing that they might be too close together if you used fancy cables with large barrelled RCA's on them. Hope this helps... Sean

PS... Once you take the plunge, the next step is active bi-amping. THAT is where the big gain is at. Sean
Just a note: It is very important to as closely match the gain of two dissimilar amps as is possible for this method to stand a chance of working correctly.
If one stereo amp is for the highs and another for the lows--it shouldn't matter assuming their of good quality. has an article all about biamping--and its not a hoky one, but not super technical. Click on articles and its the first one.
I foresee two problems for you:

1)The volume you get from each amp may be different, so you end up with too much or too little bass.

2) An amp designer I know calls this "fools bi-amp" and believes that driving an amp full frequency range and using only part of that frequency range causes audible problems, esp. for the tweeter amp as there is a lot of energy in the bass frequency - which the tweeter amp isn't getting rid of but IS trying to produce.

Get yourself an active crossover, even a cheap one for now - you can always upgrade it later - I REALLY recommend this as a major gain.
Worst case, a good car one can sound OK for now - I have seen one powered by a spare car battery that was re-charged every couple of weeks!
Do some homework about cross-over slopes, use the same slope (1st, 2nd, 3rd or 4th order, also sometines refered to in dB per octave) and crossover point as the crossover in your speakers.
You can also get different alignments, I would reccomend Linkwitz-Reilley.
Don't worry about mixing amps, as long as you think the sound character is simmilar at the point where they will cross over.
I use VTL 100 monoblocks (tube), crossed over at 400 Hz to New Zealand made mostfet 250 watt per channel then to a 215 wpc mosfet parasound in bridge mode at 80 Hz to drive the sub.
This is using an active crossover. Nobody has ever commented on the mixture of amps and some people into live and studio sound professionally have been unaware they were listening to a multi-amp set up - when told, they were not suprised as they thought it "sounded too good for a passive cross over".

Only in "hi-fi" do people seem to insist on using one amp full range.
Not only does it make an amps life hard, passive crossovers are a nightmare. Expensive (VERY) to do well, hard to drive and they consume a lot of power that never even gets to the speaker drivers!!!
I was looking for a high quality Y connector and the options seemed to be solid Y splitters, which effectively mean you have to buy 3 interconnects for each channel plus the solid Y, or getting one built. In my quest, however, said they can get a Kimber Kable Y connector with 2 6" male leads and a female RCA end for a fairly reasonable price. Because WBT doesn't make cable terminated female RCA connectors, they end up using a chassis mount RCA and heat shrink tubing. Apparently it isn't pretty, but you can get one built out of KCAG if you want.

I gather from my research at some point that there is some marginal benefit to "splitting" at the amp end rather than right out of the pre-amp.

Best of luck.
Thanks for all of the comments. I certainly have some experimentation ahead of me. I've thought about an active crossover but am trying to keep this simple as possible. In the end, however, that may be the route to go to get the best performance from the speakers. I'm still looking for suggestions for a good Y. You guys that are bi-amping now, do you have a pre with double outs or are you splitting the signal with a Y? If so, what are you using?? Sean, I'll look in to the partsexpress. Thanks everyone!
Tmcroy somehow I've become a bass freak realy believing that subharmonic bass freequencies drow the main line of a sound signature and imaging. I also have the same monos as you do and probably will be planning to acquire 200W/ch-ish SS amp that is probably specifically great for bass(I believe it could be McCormack DNA1). The speakers that I have are Totem Forest(a great value for the bass freaks). I will also look towards building an active crossover with Marchand parts since I also believe that there is no point using different amps in passive bi-amping.
It is OK to use amps of a same kind without active external crossover.

If you can wait and stretch you budget(not realy big) or even browse to find used models of Rogue 88(power amp) and Rogue Tempest(integrated) that are designed for biamping together, you'll never regret. I might mistake on model numbers which means there are Rogue amps ntegrated and power amp having the same output power and double outputs for bi-amplification i.e. do the research.

And finally, I've enjoyed reading such controversal responces although choose to stay with my position that is completely in sink with Tmcroy.
Hi Marakanetz,

My 100 monos are very early and offer ultralinear only, a sort of compromise between pentode (being EL34 type tubes)and triode.
Your ears will very soon tell you which is right, but if you are crossing over to a solid state amp (mosfets being slightly tube-like in sound make life easier than bi-polar transistors), then I would expect tetrode to be better.
Tetrode is closer to solid state in being less "lush" and edging both amps towards each other in sound helps. VTL's are good as they do not have a particularly "tubey" sound.

Anyway, trust your ears - you have to listen to the result and I have NEVER heard anything that sounded totally right - especially immediately after listening to live music!

One thing I have found usefull is (assuming you are male) finding a woman (preferably fairly young so the top end of her hearing hasn't gone - for that reason avoid party animals as well) prepared to sit down and listen to female vocals.
They have much more sensitive ears than men in the vocal range and everyone has a good live reference for the human voice.
I have found the acid test is their willingness to listen for long periods, assuming they have the time. This at least tells you that there are no significant nasties or annoying discontinuities in the sound that males can't quite hear - but are fatigued by.

I understand your love of good bass. If it is quick and clean it does provide a great foundation that adds to the pleasure of the music.

Best of luck and trust your ears.
I have found that you can have a LOT of fun if your wife and/or girlfrind are bi. Especially after some Xs and coke.

Johnnybravo, peace, love, overandout...