My system-
Opera turntable with RS Labs RS-A1 tonearm and Miyajima Shilabe cartridge
Wright Sound Silver Top phono stage
47 labs Shigaraki cd transport
Hagerman Chime DAC
Supratek Cabernet Dual with 6h30 outputs and 101d outputs
tweeter amp Decware SE34I.2
bass amps two SE84CS series strapped into mono
speakers Sonist Concerto 4's
all wired up with mostly 1'st generation Stage III Concepts
Sounds really good to me with the EL34 tubes for the highs being pushed with a 101D
and EL84 tubes being pushed with a 6H30
I think it is system dependent and there are no fast and sure rules!
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lonemountain
"Passive Bi-Amping
Passive bi-amping is what you typically see when bi-amping is discussed. It’s the most common. With Passive bi-amping, you are still using the crossover parts of your speaker to send the correct frequencies to each speaker driver."
this is for speakers whose crossover is designed to alternately accept bi-amp via a removable jumper, as the AR-2ax crossover is.
"Bi-Amping with an Active System
You can also bi-amp with an active system. This is not very common and only available with a limited number of brands. With an active system, you actually have a separate electronic crossover in front of your two or three amps. It gives each amp the correct set of frequencies and you remove the crossover from the speakers."
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@elliottbnewcombjr : You are using the word Bi amp in such a way as to cconfuse us more.
There is only one explanation for biamp. Bi-amp requires an external [line level] crossover BEFORE the amplifiers. The example above is a bi wire set up, with or without jumpers, as a passive [speaker level] crossover is AFTER the amplifiers. One of the side effects in the bi wire set up is the amps are still running full range and do not specialize in one band: the crossover after them is filtering part of the full range amplfier output out. Electronic crossover bi-amp divides the preamp output into two, LF and HF, sending only HF to one amp, only LF to the other amp per the instructions from the crossover. Now you can have the large amp for bass and it will pay off.
Brad
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OP (explain to a 3rd grader) some of these responses are for physics majors)
I was ASSUMING your speakers had a removable jumper, AND their internal crossover was designed for OPTIONAL Bi-Amping (or bi-wiring).
EITHER
leave jumper installed: internal crossover performs as standard: full division of the signal input: resulting, after internal crossover: separate signals for each driver in the system (2 way/3 way)
OR, remove the Jumper, which then uses the internal wiring of the crossover differently: part of the crossover drives only the woofer; the other part drives only the mids and highs.
My AR-2ax crossover is designed for either bi-wire or biamp.
common ground: remove jumper, now crossover portion for the woofer becomes separate from the crossover parts for the mids and highs
NOTE: the circuit includes subsequent in-line connections for level controls to balance the volume of the mid and tweet relative to each driver. This allows you to adjust for a dead space or a live space, or your personal tastes. Many vintage speakers provided level controls, which is separate from removable jumpers.
Jumper removed, bi-wire is possible: choose a cable construction you believe is best for mid/high signals from the amp; and use a separate cable, it’s construction you believe is best for bass notes.
Jumper removed: bi-amp is also possible: one amp in/out of internal crossover feeds the woofer only. other amp in/out of the crossover feeds mid/high drivers only.
Using an external crossover is relative to the removable jumper/internal crossover design.
Bi-Amp ASSUMES, because the bass needs much more power than the mids/highs: use one amp (less power needed) for the mid/high side of the speakers to the external terminals that feed the mid/high side of the internal crossover
and
use a separate amp, more powerful for the bass hungry notes.
Thus, using 2 identical amps is providing the same max power to the crossover, which is why I said no real advantage.
..............................
thus my example: one amp (tube amp perhaps), less powerful for the mids/highs which need less power; and a separate more powerful amp for the power hungry bass, perhaps SS to get more power/less heat/smaller body than a big hot tube amp.
Affordability is also involved, large powerful tube amp for woofer is much more expensive than an equal powered SS amp.
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my words were dumb, I had 3 dr appts, wife was waiting, usually I have too much time, read all responses to learn stuff. This time, I wanted to send a quickie idea.
I don't understand the crossover stuff, however, MANY add self-powered sub-woofers to their existing systems. Existing system might be tubes, self-powered sub probably class D, that was what I was thinking about.
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Erratum : …”containment rolloff,…” would be most typically done with equalization rather than the suggested …”with passive parts.”…
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@elliottbnewcombjr , I had the courtsey of reading the other posts, including yours before jumping in with mine.
Experience has led many away from mixing amplifiers as the passive crossovers will still allow bleed from the amplifers into the other side of the crossover region. The effect of which will vary with the slope of the crossovers used. I think most have concluded that using identical amps advantageous. Most of the modern active loudspeakers are not using tubes in the mix.
Though biwiring typically shouldn't be confused with biamping, mixing cables might have similar effects.
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@lonemoutain, I think we are seeing the same thing from a different angle. The OP seeemed to suggest that he was considering biamping his speakers that have passive cross-overs already included, not active loudspeakers, as that would probably be moot.
Acitve loudspeakers have existed for some time now, though they seem to be more prevalent in the pro sound market than in the home audiophile market. Though there has been more recent growth in available active speakers geared towards the home market, What you have stated regarding active speakers and true DIY projects are certainly true. But I think that for the home market, speakers with passive crossovers have traditionally domiinated the market place.
Passive speakers can be designed with equaization and/or with compensation for driver irregularities, impedance smoothing, containment rolloff, time and phase corrections with traditional passive parts. I'm not suggesting that this built in compensation is typically user adjustable. Most traditional off the shelf active crossovers only give a number frequency bands for drivers and slope options. Newer digital crossovers offer much more customization.
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Probably been mentioned, I didn’t read, too many replies.
Bi-amping with matching amps is of no audible value.
You could Bi-Wire (if that is what the speakers are designed for), that is a different concept: use 1 cable construction for mids and highs; use different cable construction for lows.
Bi-amp is to use what you think is a better sounding amp for mids and highs, needing less power than bass. And use a different amp, perhaps less delicate, but more powerful for the power hungry bass.
You could even mix tubes for the mids and highs and a SS brute for the woofers. Think of self-powered sub-woofers, they typically use SS brutes, perhaps class D to avoid heat while delivering substantial power, while the primary speakers are driven by a ’better’ amp, often tubes.
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@unsound - You have a point there about active outboard crossovers, and there are very few available. Most active loudspeakers have a purpose built electronic crossover designed specifically for their speaker within their internal or external amps just like passive ones do. Outboard is not where you find most active loudspeaker’s crossover. It’s usually built into the same circuit board as the amps themselves. Its easy to implement the same level of quality throughout the entire signal path.
I think my point was you presented this as "passive crossover advantage is compensation built in" while that is certainly not what I have seen across a long period of time. Im not saying it doesn’t exist, but the typical passive crossover is a simple, passive device that cannot be adjusted and has no "processing". Maybe EQ? Is that what you mean by compensation?
Active is much more likely to include additional controls such as phase controls and individual [band specific] level controls to calibrate the drive units to work as seamlessly together as possible. This is the case with the brand I work with, ATC, and multiple other studio/home speaker companies. I have seen some companies offer full-on EQ within some of their control sets, in both analog and digital form, so a user can tailor a speaker to their liking. Now we are seeing a new wave of loudspeakers with room correction and/or adjustment software within their internal crossovers. Such companies are Genelec, Kii and Dutch and Dutch. This level of control or adjustment is not available in a passive crossover. This means that some common issues a designer chooses to address cannot be accounted for in passive crossover.
By the way, I am NOT advocating that passive speakers should be torn apart and modified- this is far too difficult for most of us to actually pull off without a lot of information that tells us exactly what to do. I am speaking about an active system designed as active by the manufacturer from the beginning with all the parts supplied vs a passive system of the same type designed as passive with all its needed parts. ATC does both active and passive so perhaps I am able to contrast these two ideas without getting lost in gear/brand/type differences.
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Bi-amping can be a bit complex, but let me explain it in a simple way for you:
Think of your speakers like a team of players in a sports game, and each player has a specific role to play. The internal crossover in your speakers acts like a coach, telling each player what they should do.
Now, in a regular setup (single-amp), one coach is in charge of both teams (high and low frequencies). But in bi-amping, you have two coaches, each specializing in their own team. Here's why people do it:
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Better Control: With two coaches, you can give more specific instructions to each player. This can make the players (your speakers) perform better because they're not confused by mixed signals.
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Less Interference: Sometimes, when both teams are listening to the same coach, they might argue or interfere with each other. Having separate coaches can reduce this interference.
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Power Distribution: If one team needs more power (let's say the low frequencies), you can give them a stronger coach (amp) to handle it, while the other team gets a different coach for their needs.
However, the naysayers have a point too:
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Speaker Design: Some speakers are designed with internal crossovers that work really well. In such cases, adding external crossovers and extra amps might not make a big difference, and it could even be a waste of resources.
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Complexity: Bi-amping can be tricky to set up correctly. If you're not careful, you might not get the expected benefits, and it can get expensive with extra amps and cables.
So, it's like having two coaches for your team – it can be beneficial if done right, but not always necessary. It depends on your speakers and your preferences. If you're unsure, you can start with a regular setup and see if you're happy with the sound. If you feel something is missing, then you can explore bi-amping later.
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@lonemountain, Perhaps you might want to reread my posts.Typical off the shelf active crossovers traditionally have not offered such compensation. The active crossover manufacturers would have had to know in advance what specific speaker parameters were to be considered. The possible variables would be nigh well infinite. As I previously posted; with DSP (and with appropriate measurements) post corrections become a much more practical proposition.
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@knotscott
Well thanks for taking a stab- I was thinking more of @unsound than you, as he made the comment about passive crossovers compensating for drier irregularities. But regarding youor comment, yes-its hard to not agree with you! I agree it is IS difficult to come up with a good clean electronic crossover that's not digital, and then most of those are low end pro units (Behringer, etc) that i wouldnt put in any hi fi rig. I think we'll see more of them in the future though. .
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@lonemountain
Why no comment about all the wire and passive components between the amplifier and driver ? ...
I’ll take a stab, but can only speak for myself and guess on behalf of others. If you own a pair of speakers that you love, or simply won’t part with, that have passive crossovers, removing the passive crossovers is likely not an option, so contemplating the amount of wire in the crossovers is likely just a moot point.
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@knotscott - yours is probably the only legit answer for not investigating active more thoroughly. I get that once invested downa path, its difficult to change.
@unsound - comment about passive crossovers having "implmentations to compensate" for driver anomalies sounds like you think active crossovers cannot offer the same or better "compensations". Actually this is one of the primary arguments FOR active, its much beeter to solve all these issues before the amplifier, not after.
Why no comment about all the wire and passive components between the amplifier and driver ? This seems to be the elephant in the room doesnt it? .
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@lonemountain
There are pros and cons with active, and with passive crossovers. In a perfect world, active crossovers have some distinct benefits....especially if starting up from scratch, but many of us get to the bi-amp situation once we’re already well invested in our current systems. Sometimes it just not feasible to backtrack to square one.
@unsound reiterated some of the benefits and situation need for passive crossovers. There are certainly active crossovers that can perform some, if not all, of the compensation requirements of some drivers, but what if you already own a really nice pair of speakers that you love and that have excellent, well designed passive crossovers with top shelf parts, and you want to dip your toe into bi-amping? I’d think even a serious audio buff would hesitate before proceeding to gut the crossovers from a pair of Magico, Wilson, or Sonus Faber speakers so they can experiment with active crossovers. Not everyone has the knowledge, expertise, or the will power to actually make such a bold move.....in many cases it’s simply not wise to risk the destruction of a wonderful pair of speakers to pursue an active crossover. If a great pair of speakers sounds good with passive crossovers in a single amp situation, they’re very likely to sound even better with a good bi-amp setup, even with the passive crossovers.
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^While active crossovers could certainly have advantages. Where as passive crossovers often have implementations to compensate for specific driver anomalies, impedance smoothing, phase and time considerations. Off the shelf active crossovers are typically rather clumsy in those regard, as well as potentially adding noise. Again, active crossovers can certainly have advantages. As was posted DSP could make active more finessed and practical.
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The very basics: a [speaker] passive crossover comes AFTER the amps, operating at speaker level. The drivers are connected to the crossover not the amplifiers; active crossover /electronic crossovers come BEFORE the amps, operating typically at [balanced] line level; the drivers are individually and directly connected to a specific amp channel that is for that driver and that driver alone.
It is hard to understand how anyone could think shoving a bunch of passive electronics with lots and lots of wire into an audio chain between the amplifiers and drivers could be a step up in quality and create a better, more pristine audio chain. I wonder if passive fans realize how much wire is in an air core inductor used in a high quality passive crossover (300-500 feet or more?). We don't do any other processing after amplifiers, why is the passive crossover somehow an exception?
There is so much science here that is quite established and well accepted, since the 60s-70s at least. ATC and Genelec were offering full [analog] active crossover loudspeakers to the market in the early 80s, some with internal amps, some with external amps. Both companies sold into home and pro simultaneously. Now there are many more companies offering active crossover speakers and some use DSP, some still analog.
There are plenty of options and choices as to how one can approach this active issue and adapt it to your liking, make it sound one way or another. It does require some work to understand what is happening, but its certainly not complicated. It is not more expensive or more difficult to operate.
I cannot help but observe the entire "passive crossover is better" argument appears to be a clear example of marketing not science.
Brad
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I had A pair of speakers that responded well to a krell kav300il on top but needed more juice for the bass. In that case horizontal biamp made sense. Starting from scratch I think I’m getting great sound with a pair of matching monoblocks 1 per channel and if you get powerful enough amps you should hear what the speaker designer intended. My current system Kef Blades has a fairly bumpy resistance so the Mac Mc611’s really get it done. The speaker amp combo can make or break your system.
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If one were to bi-amp with a tube amp for the tweeters and mids, and a SS amp for the woofers, how does one volume match the signals since these are different amps with different gain? Even if the same wattage the two amps might not be matched? Thanks.
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Bi-amping is not a "theory" neither are bi-(or tri)wiring. You just need to know what you are doing. Results will depend on the quality of the involved components and als the chief`s skill-level.
Some speakers has terrible passive filters, like the famous old Infinity Kappa 9. Bi-amping won`t solve this, but bypassing the passive filters and instead using an active filter would do.
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Multi-amping could have advantages even if done before the cross-overs, and even more so if each channel has its own power supply.
If a speaker has a challenging impedance / phase angle above or below the frequency range of the cross-over the amplifier will often run with more strain and corresponding deviation from ideal performance at these points. A single amplifier channels performance can be dragged down across the entire frequency range by these demands, where as multi - amplified frequency ranges will only be compromised at the particular point of the challenging load, freeing up the other ranges to be powered more optimally. This might be especially true in cases of so called Class A/AB amps where more of the more optimum purported Class A bias will be allowed to run longer before resorting to the less optimum purported Class AB or Class B (these classifications are somewhat nebulous, but the results are somewhat the same).
That these challenging impedance / phase angle loads are more typically found in the bass region where the power needs are greater but where our hearing is usually less sensitive, so meeting the power demands might be more important than ultimate fidelity. On the other hand the power demands of higher frequencies ranges are typically less, but our hearing is usually more critical, and the greater purity of amplification is appreciated more.
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@mceljo
No I don't bi-wire, there is nothing to bi-wire. All speakers cables are the same 10ga. All the interconnects are the same Audience OHNO single crystal developed by Dr. Ohno.
My rig is somewhat easy to understand...just think of it as regular old rig until you get to the x-over, then its like three stereos all playing the same music (in different frequency ranges). Simple.
Regards,
barts
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@barts - Please tell me that you also bi-wire in your tri-amp system. I’ve often pondered what the limit might be for a complex audio system. I would expect that the audiophiles with the most complex would also have the perspective that everything matters (why have a complex system otherwise?), so I can only imagine the challenge of optimizing cables and such, particularly every individual cable can be approached uniquely.
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I would generally agree with a good number of the responses that indicate a "great deal of added expense to do it right" but yet the benefits are there if there is cost no object.
But here in "beerville", after experimenting with multiple different jumper wires between my mids and highs of Aerial 10 Mk II, I did find one that I liked substantially (Signature series, AntiCable).
Then at the suggestion of long time friend/audiophile Duane, I tried some Mosaic advanced tech speaker cables (now defunct) in a bi.wire mode .. UnBeLieVabLe the difference!
If you want similar tech .. Bionic Cables are similar yet better. I am using their entry level RCA, it is also amazing (coming from much a-b'ing on my system)
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I had my system horizontal biamped with mac275s on top and mc601s for bass. Tekton set me up with 4ohm biamp xovers. The whole house rumbles
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If you removed the passive crossover from your JBL 4367’s and connected your amps directly to the compression drivers, I can assure you hiss would be audible to some degree
Nope. You are describing the scenario of what a normal system with an acceptable noise already present in the chain, but not when you are using absolute silent components. Lookup the AHB2 review from stereophile, the amp not only can adjust the sensitivity (9.8V RMS/22dBu, 4V RMS/14.2dBu, 2V RMS/8.2dBu), it has such a low distortion number, akin to the testing equipment that bench test the amp itself. If your upstream is absolutely silent, if theres noise/distortion in your horn, it's something else. Uber horn lovers pay big bucks for expensive tube amps, not just for it's tone/sound, more often it's for the silent. And they do directly connect to the compression driver with active setup.
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@asctim wrote:
With horn loading the problem is amp hiss gets highly amplified.
Indeed, but using a 16 ohm driver - if available - will help knock down hiss noticeably as well.
@btbluesky wrote:
Amp hiss, is not a normal thing. It’s a product of "too much gain in chain" + "not so good amp". I can crank up to over-concert level, and theres no distortion.
It doesn’t fall back on a "not normal thing" or a "not so good amp." High sensitivity, as has been stated just above, simply amplifies noise. If you removed the passive crossover from your JBL 4367’s and connected your amps directly to the compression drivers, I can assure you hiss would be audible to some degree - and yet your amps are the same; they didn’t suddenly get bad in the absence of passive crossovers (in fact they’d get better).
It’s great though you’ve found a good pairing amp-wise with the JBL’s.
@russbutton --
+1
Another major benefit is that you can use much, much lower powered amps when you use active crossovers. A lot of power is wasted having to push through a passive crossover. You really don’t need to push many watts into a tweeter or mid-range driver to get a lot of level out. You could even run a single ended tube amp on your tweeter, and a mid-level tube power amp on your mid-range driver, and a solid state amp for the bass driver. You have a lot of options.
Options are plentiful, yes. To me though the lesser power needed over the entire frequency range actively would be better served by spreading it out evenly, so to ideally use the same amps top to bottom, or certainly the same amp series/topology with a differentiated power approach for better coherency. To me coherency always comes first, and using similar amps is vital for this to come true in the best way.
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@asctim , I did just that. Starting with 1 AHB2 with a different speaker, notice the bass is tighter and it was not sterile/cold sounding. Smooth, highend, you are hearing really the upstream/preamp.
Then got another one, mono mode to each 4367, sounding great, everything falls into place. so I ordered another pair for my secondary system, but tested it biamp mono in JBL first, the realism, the "air" is just unbelievable. Diff between ya I can see the imaging, to "where did that sound come from!". Needless to say I left the pair there and got another pair for second system.
Amp hiss, is not a normal thing. It's a product of "too much gain in chain" + "not so good amp". I can crank up to over-concert level, and theres no distortion.
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@btbluesky
I have 4 AHB2 bi-amp on mono-mode to JBL 4367
I have no doubt that sounds great. What differences do you notice if you just use a single AHb2 in stereo mode compared to all four in mono?
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@russbutton
Now when you use an active crossover, an amp channel only has to manage a single driver. There's no passive, reactive component in between the amp and the loudspeaker driver. Then you don't need a megabuck amp to deal with it.
Indeed! It's amazing what you can get out of cheap amps when hooked up to speakers with an active crossover. With horn loading the problem is amp hiss gets highly amplified. For this reason I add a capacitor to my horn tweeters. It knocks the amp hiss down to below noticeable, helps with the EQ needed for constant directivity waveguides, and provides some protection for the tweeters. I'm not a purist.
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man you guys are still at it.
It works, so depends on your situation, if you can get a hold of it, try it. If you don’t hear the diff, sell it.
I have 4 AHB2 bi-amp on mono-mode to JBL 4367, which the crossover network is well built even its passive. Been building system for 20+ years, and first time ever, I do not foresee even the desire to make a change.
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@emergingsoul ....likely 'cause it's only a 'fringe' sort of thing that audioholics end up doing? ;)
It's the sort of thing that appeals to those that don't mind having the backsides of their rigs look like a incident in a pasta factory...😏
A amps and D amps together?! Dogs 'n cats cohabitating?! OHmG....*LOL*
Likely the sort of thing I'll end up doing anyway....*S*
(...I'd keep the day job...mho, fwiw....amazing what flies these dayz....)
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Phase: with ads 1230, only the ads 2000 biamp crossover will work.
. This is because the internal and ads 2000 crossovers do something to the phase of the woofer . I used an external analog crossover and had some big holes in the freq response as evidenced by using an audessey rc equpped reciever .
I think the culprit was a woofer that was out of phase by 90 degrees.
I thought about triamping my Valkeryie speakers which scream to be triamped but to do it actively would require some serious surgery so I’ll likely “ dumb” Triamp thrm ( passive) and use an old av receiver .
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@emergingsoul I believe McIntosh makes an amplifier like the one you described.
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- How come they don't design biamping amps that are both tubes for top drivers and solid state for bass drivers?
Maybe I begin to do this and make a lot of money
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Through my modified Signet floor standers, it is easily heard, the advantages of bi wiring and, passive bi amping. What a different set of characteristics, between running the system, horizontal vs. vertical. Using many different pairs of the same exact model amplifiers, I came down to really appreciating vertical. When going back to a single amp, things started to shrink, and collapse ( through the speakers, lol ). Over the many years of owning these, these Signets have bettered, ime, so many others. At this time, they are not in use...but they are one of my few audio products, I could never let go of. 🙂☹ My best ! MrD.
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I knew 2-3 people would show up here to drop their snark-bombs on the topic of biamping, and I wasn’t disappointed.
It has been many years since I biamped, but when I did, it was a noteworthy success. It probably would have sounded even better if I’d had access to one of the excellent, transparent external crossovers that are currently available, but were not back then.
Obviously biamping isn’t possible or recommended for certain setups; but in the right setup, and with the right amps, it can take the sound way higher...
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@kraftwerkturbo wrote:
I now assume that horizontal/vertical deals with the option of using 2 stereo amp for the 2x2 'feeds'. Either one stereo amp for each SPEAKER or one stereo amp for the woofers and one stereo amp for the mid/high. If that is the case, what is considered 'vertical'?
'Vertical' bi-amping is one stereo amp driving one speaker, its two channels divided over the two pairs of terminals on that speaker.
I read a few posts claiming BENEFITS of passive crossovers (vs active), but none mentions issues like phase shift from those passive components.
And can't those mentioned 'beneftis' of passive crossovers not 'simulated' or realized in active crossovers as well?
Active can do what passive does, and more - while not least getting out of the way between the amp and speakers.
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I read a few posts claiming BENEFITS of passive crossovers (vs active), but none mentions issues like phase shift from those passive components.
And can't those mentioned 'beneftis' of passive crossovers not 'simulated' or realized in active crossovers as well?
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Never heard of horizontal and vertical bi-amping.
My assumption for passive bi amping with speakers built for it always was that by removing the 'bridge', I get a low pass for the woofer and a seperate high pass for the mid/high. The use 2 amps to feed those.
I now assume that horizontal/vertical deals with the option of using 2 stereo amp for the 2x2 'feeds'. Either one stereo amp for each SPEAKER or one stereo amp for the woofers and one stereo amp for the mid/high. If that is the case, what is considered 'vertical'?
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I'm in the camp of using an active x-over and horizontal bi-amping w/different amps, using tubes to power the top and SS on the bottom. The woofers have been removed from the x-over and wired directly to the binding posts. (Speakers were built bi-wireable so two sets of binding posts are present.) I use an original Wavelet active x-over and just picked up a MiniDSP DDRC 88A/BM that I plan to substitute for the Wavelet as I want to see if DIRAC w/BM is an improvement over the Bohmer room correction.
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@russbutton *S* Someone who can R(ant) & R(ave)s' better than me.... ;)
...and does a fine cover of the sense of the process...
1st serious speakers were a pair of 901s2s' with it's active eq.... Yes, not a 'xover' in fact, but they'd sound all sort of strange without....
Next iteration was a pair of Infinitys' with an equalizer in the tape loop, which began to allow for a crude DSPish approach; xover still onboard the speakers, but edging closer....
Following that, the Kenwood L series with the outboard mono amps....an AudioControl C-101 eq with a calibrated mic that allowed to employ a more serious
launch into DSP. Sure, the AMT 1Bs' still had their onboard xover, but it was just a 2 way that handed most off to the large Heils'....and the xover just tweaked the point between.... I still have a pair of the xovers for references' sake, but on the shelf....
These days.....one could say 'in excess', but...*G* I prefer 'flexibility'....
Xovers': a Behringer, a dbx, a Parasound C2, and an ESS Eclipse 2241AM; the latter an unusual item I've devious designs upon....
Eq available: The 'puter can supply whatever wherever, pre or post....as can a pair of Behringers' and the C2. All of which can host a mic....
14 channels of amplification, 12 of which can be mono'd to 6.
And a self amp'd sub.
"Bi-amp....how...quaint...." ;)
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OK folks. Listen up. Here's WHY active crossovers are so very much better than passive. A single loudspeaker driver is an inductor, and provides a frequency dependent, reactive load to an amplifier. Looking at the image here, the blue line on the bottom is the frequency dependent impedance curve for an SB Acoustics SB29RDAC Ring Dome Tweeter, and it typical of any dynamic tweeter. As you can see, it is anything but flat, yet it is listed as having a 4 ohm impedance. It's 4 ohms at about 1200 hz, but at 600 hz, has an impedance of nearly 10 ohms.
Now if you put a passive crossover circuit in front of it, you add capacitors, resistors and inductors, which then give you a frequency dependent impedance curve which looks like a Coney Island roller coaster. And that's just for a tweeter high-pass circuit.
Now when you add in mid and bass drivers, with high and low pass filters there... It's a real mess. But we're not done there yet. Nope. Many of your extreme hi-end loudspeakers add in equalization to their crossover designs, which makes that impedance curve even worse. This is very hard for an amp to properly manage. That's why people drop many, many thousands of dollars on things like Krell, Threshhold, Bryston, or Rowland Research solid state power amps.
Now when you use an active crossover, an amp channel only has to manage a single driver. There's no passive, reactive component in between the amp and the loudspeaker driver. Then you don't need a megabuck amp to deal with it.
All of the Linkwitz loudspeaker designs use active crossovers. Earlier designs used analog crossovers, but his last designs were all digital crossovers. There are some digital crossovers that offer DSP EQ, which allows you to tailor the total system response for the room you are in. Then you're not just limited to whatever sound your speakers give you in the room you're stuck with.
The lowest cost active crossovers are typically pro grade, from manufacturers like Behringer, dbx, Rane or even Nady. There are many manufacturers. Some of the best known home audio digital crossovers are from miniDSP.
Another major benefit is that you can use much, much lower powered amps when you use active crossovers. A lot of power is wasted having to push through a passive crossover. You really don't need to push many watts into a tweeter or mid-range driver to get a lot of level out. You could even run a single ended tube amp on your tweeter, and a mid-level tube power amp on your mid-range driver, and a solid state amp for the bass driver. You have a lot of options.
So instead of dropping $7,000 on that Threshold Stasis 8.0 power amp. You could spend much less on an active crossover and the various much more modestly priced amps of your choice.
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Panzrwagn
"2) "Passive Bi-amping" is BS. You’re still delivering a full range signal to both the LF and MF/HF passive crossovers, the unused half of the signal is just turned to heat."
This is not true. There is no signal flowing through a circuit at frequencies that are filtered out by a crossover network, subject to the slope of the filter. The crossover network doesn't create an offramp for the filtered frequencies to be converted to heat.
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Seems biamping in an ideal way would be using a tube amplifier for upper drivers, and solid state for bass. I believe it's widely accepted that tube amps for bass drivers presents lots of less than ideal issues.
To me using solid state across all drivers when biamping will have benefits but if you go to this trouble you might as well go all the way with tubes.
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I biamp in one of my systems. I use a pair of mono amps to handle the bass and a different pair of mono amps to handle the mids and highs. The mid/high have the bass rolled off using high quality caps at the amp inputs and there is an adjustable unit to balance the bass (which goes through untouched) with the mids/highs.
This is the system that Richard Vandersteen uses and it works very well with my big Vandersteens, although many would prefer to avoid the complexity of four mono amps with an external adjustable crossover for the bass.
Does it sound better done this way? I was pleased to find that it does and the improvement warranted the extra system complexity.
Whether you would get the same gains depends entirely on your particular system.
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