Single, Bi-Wire, Bi-Amp ... Latest Opinions

[oldflame]

Many educated replies. It seems that most responders have gone bi in one way or the other. 20 years ago when I got new speakers, I bi-wired because they have two separate crossovers. The buzz at the time seemed to support the logic of that method so I tried it and liked it. It could be that a different, single, cable may sound better than bi-wiring, but my large speakers and heavy amp are difficult to move and access the terminals. Because I may have gotten lucky that the system sounds good to me, and I haven't the funds or time necessary for experimentation, I'll stick with what I have.

Should Ed McMahon ever drop that big bag o' cash on my porch, then I'll hire others for daily chores and home maintenance and dive into bi or tri amping with new amps and speakers. The feedback to this post, from experienced AK members, leads me to believe that my old 1970's dream of multi-amping/electronic crossovers is a viable route to great sound.

The different methods of multi-amped systems, from highly sophisticated to almost easy, was educational reading about. It sounds like great fun, pursuing an ultimate system, but I'm fortunate to be happy for now. Thanks for the detailed information.

 

[Powertech]

There are some other relevant points I would like to raise, both plus and minus points.

With a fully passive crossover you can tailor the filter response to specifically suit the driver characteristics. With active systems this is difficult. Full digital response management is an option, but is complex and expensive. I wanted the crossovers to remain in the analogue domain so I chose my drivers very carefully. The bass and mid drivers are both from Peerless and use very similar motor assemblies. They have a very even response across the desired crossover region and very similar efficiencies. The tweeter (a VIFA unit) was specifically chosen because it has ferrofluid and is horn loaded. This gives an even response at the lower end of it's range and dispersion characteristics which are similar to the upper end of the mid range driver around the crossover region with the intention of a near seamless transition between the two drivers. Add cabinet and room responses into teh mix and what you have is a very involved and time consuming process to get it right.

If an amplifier in a passive setup goes into clipping from a short bass transient it usually goes unheard, but will be heard in the mid and treble frequencies because the whole music signal is affected. In an active system the short bass clip is again unheard, but the rest of the frequency spectrum is completely unaffected because it uses different amplifiers. In any case, active system amps are only handling a small part of the audio spectrum anyway, so the bass signal passing trough the bass amp does not have higher frequencies superimposed on top of it. What this means is that each amplifier has greater headroom than the single amplifiers in a passive system have. They are less likely to clip in the first place.

The points made about mixing amplifiers has many issues. I think it is best to have matching amps throughout the system at least to start with. That way all amps have the same amount to gain and will behave the same way. This removes a whle set of variables when setting the system up. Personally I have kept to this philosophy, but if you want to have different amps for bass and mid/treble at least you always have a standard you can go back to for comparison. I if also believe that you are better off having horizontal amp matching rather than vertical matching. This goes back to the clipping point I made above. If an amp is split vertically and it has a common PSU, a bass clipping event could pull the PSU down which is also being shared by the mid/top amplifier. With horizontal splitting this doesn't occur.

Just my thoughts.

 

[Poultrygeist]

I try and avoid passive crossovers when possible but they often become a necessary evil.
An active solution can be less expensive and more flexible but it too can add its own sonic
signature especially with highly resolving tube gear.

 

[Buanadha]

I've done Vertical, Passive, Bi-Amping. My experience is positive, but maybe not so positive that I'd recommend going out and spending a ton of money to get another amp that's identical to what someone is running now. I first tried it with a set of NAD 7150's, but now have it running in two places in the house:

- Living room - With 2 NAD 7100x amplifiers to run out to 2 KEF 103/4 speakers
- Basement - With 2 NAD amplifiers (C270 and C370) also running to 2 KEF 103/4 speakers

The simplicity and low cost of this approach appealed to me as both amps are identical and it's one amp per speaker. Once you have the amps, the only real cost for the setup is equal length/identical interconnects to split, and equal length/identical speaker cables.

One can certainly push things further than this, but this is a relatively simple way to add some value. Having the amps was more about setting up different systems in the house and wanting some redundancy, and then ending up with multiples -- I went on an NAD 7100 binge and got them at a very good price and had 2 around that I could apply to this, and accidently got the C270 to pair with the C370. I didn't dive way into the deep end to try to match different amplifiers or to try to manage a crossover myself, etc.

I like the results enough to keep them as they are. I don't blast things to test the amps at their limits to see if they'd clip when pushed and if I can go louder/clearer this way, but sound state is nicely wide and noticeable, IMO, on things like "Icarus" by the Staves, or "Oh My Sweet Carolina" by Ryan Adams (with Emmylou Harris providing vocals as well)

 

[oldflame]

Soooo ... Buanadha, you have me LOLing about your C270 "accident". Beautiful! Doubt that excuse would have a universal WAF. You accidently came home with WHAT?!?! Waddabout that new kitchen floor you promised last year? Hopefully a WAF isn't involved in your case or, like in mine, the little waf also enjoys the musical fruits of our stereo(s).

All the replies seem to suggest that my first sentence may be correct in that almost anything can be combined to work well -- from the simplest full-range driver with a single amp, to six amps for a pair of 3-way speakers ... and maybe a sub or four with complex DSP. Then we've got those who prefer a mono stereo - hey, don't call me an oxymoron - to a many multi channeled set-up. As the ol' cliché goes: "it's all good". And I'll ad my: sometimes.

 

[Buanadha]

Soooo ... Buanadha, you have me LOLing about your C270 "accident". Beautiful! Doubt that excuse would have a universal WAF. You accidently came home with WHAT?!?! Waddabout that new kitchen floor you promised last year? Hopefully a WAF isn't involved in your case or, like in mine, the little waf also enjoys the musical fruits of our stereo(s).

All the replies seem to suggest that my first sentence may be correct in that almost anything can be combined to work well -- from the simplest full-range driver with a single amp, to six amps for a pair of 3-way speakers ... and maybe a sub or four with complex DSP. Then we've got those who prefer a mono stereo - hey, don't call me an oxymoron - to a many multi channeled set-up. As the ol' cliché goes: "it's all good". And I'll ad my: sometimes.

LOL, yes, the things we tell ourselves so that we try to justify it to our spouses

She's pretty tolerant of the hobby at least. She appreciates the music and I try to spread things out and not go too crazy!

To be fair, I wasn't ACTIVELY looking for another amplifier, but it came up locally and when the guy dropped the price it was 200 less than the last sold one on ebay and 300 less than one that's there now! that's kind of "accidentally"

Lots of interesting ideas and approaches in this thread! I know that I definitely don't have the skills for some of them, though. It's cool to see so many approaches to getting a setup that makes the owner happy!

 

[Dr. Ears]

I bi-amped my Infinity Kappa 200's using the A and B terminals of my Sansui's receiver.
I noticed an overall improvement , so I continue to have them wired that way.
It made most frequencies sound better to my ears.

 

[oldflame]

Good Dr. you may indeed be experiencing better sound, but isn't your hook-up actually bi-wiring? Are you using the same or different cables for the "top" & "bottom"? I use similar cables: the top is the old AQ Type 4, and the bottom is AQ Type 8 - not exactly the same but real close.

 

[Dr. Ears]

Good Dr. you may indeed be experiencing better sound, but isn't your hook-up actually bi-wiring? Are you using the same or different cables for the "top" & "bottom"? I use similar cables: the top is the old AQ Type 4, and the bottom is AQ Type 8 - not exactly the same but real close.

I not really sure, you maybe right.
I use simple 16 gauge lamp cord and they serve as rear/quad speakers.
They sound better than they did with a single wires and the jumpers in.
My reference Green Mountain Audio towers are wired with a Dueland four nines silver ribbon wire embedded with oil at high pressure, both internally and externally.
The price difference is a huge mismatch, I have $15,000 in the towers and $500 in the Infinity Kappa 200's, yet the 200's add something to the overall sound.
I have inexpensive tube buffers feeding both sets, loaded with a few Philips, Holland tubes, which give me something close to the tubed integrated pictured an my avatar.
A Sansui SS integrated, the AU-7700 drives the towers, while a Sansui Quad receiver, the QRX 6500 synthesizes and drives the rear/quads.
I went from a dozen tubes in my setup down to 3 and don't miss them.
If, you can afford them, Philips, Mini-Watt, Holland tubes are magical in all types I have tried including their metal base GZ-34's and their EL-34's.