audiobomber

I have one, but there's no way I'm going to run my main speakers through a miniDSP, the quality is just not sufficient. Their SHD Studio looks interesting though.

Yes, digital crossovers have an advantage there. But the point I originally made is that people who think they can simply use active LR4 crossovers and done are highly unlikely to achieve a good result.

I don't understand what you mean. The Bryston 3B-ST for example is a dual mono amp, it has separate power supplies for each channel, but both channels are amplifying bass and treble frequencies. Using a single 3B-ST for stereo does not fit the definition of biamping, where bass and treble are handled by separate channels. I have friend who uses a pair of 3B-ST's in vertical biamp mode with B&W N802 speakers. Biamping is notably better than a single 3B in his system due to double the current capacity and lower IM.

I was thinking primarily of phase. For example, where the woofer drops by 6dB/octave due to its internal inductance, so a 2nd-order Butterworth is used with 3rd order on the tweeter for a final BW3 transition.

The amp you describe is a stereo amp. You need two stereo amps for biamping.

Sorry, I did indeed.

I agree that cables are subtractive, but they can also be used to flavour the stew, with subtle but important changes in tonality, detail, soundstage and PRaT. It is commonly stated that long interconnects with short speaker cables is preferred over the opposite. At a very minimum, biwiring is equivalent to halving the length your speaker wires. The IM and phase improvements vs. single wire are a bonus. Judging the value of a cable swap is best determined with extended listening time. Initial impressions can be misleading, it takes time to determine a cable's strengths and weaknesses. Quick changes and A-B testing are useful but not definitive.

Do you mean why not just stick with a passive loudspeaker and one amp? Yeah, definitely the best option for most people. Experimenting is fun though, a way to get more personalized sound quality, and can provide superior performance if done well. The downside; it can be tortuous.

Maybe an acoustic engineer. Just being an electrical or mechanical engineer doesn't give you enough knowledge to design a great loudspeaker without specific training. There are plenty of DIY'ers who know more about designing speakers than most engineers will ever know. Well designed passive crossovers use techniques that most people are unaware of. They think you can just replace a passive crossover with active fourth order slopes at some chosen frequency and that's going to be an improvement. In fact it will likely sound like crap, because of improper driver timing and no baffle step correction.

https://audiophilestyle.com/forums/topic/58081-bi-amping-discussion/

In the comments section of the MartinLogan Motion 40i review, biamping was raised. I am starting this new thread for an in-depth discussion of the topic. I find it endlessly fascinating and far more complex than some would have you believe. The notion that ripping out the passive crossover in your loudspeakers and connecting an active crossover will bring instant nirvana is simply bogus. My moniker on Audio Asylum is Audio Fan. I co-wrote this AA FAQ with another member in 2000: https://www.audioasylum.com/messages/general/57210/biamplification-basics-an-article I am happy to say that I still agree with virtually everything in the FAQ. Vertical Biamping "The purpose of vertical biamping is to reduce the current demand on an amp. Because the main current draw is in the low frequencies, each power amp in a vertical setup only drives one woofer. The channel driving the woofer gets to hog most of the current provided by the amp's power supply, since the channel driving the high frequencies doesn't need as much current. This is particularly advantageous if the amp uses a common power supply for both channels. Vertical biamping in this manner requires identical amps for each channel to maintain balance integrity." I have a pair of 50W stereo amps. Driving my 4-ohm 89dB/W/m speakers with a single stereo amp sounds OK. Driving the speakers biwired to a single channel of both amps sounds much better, more detailed, more dynamic, tighter bass. There is a small further improvement when I drive the speakers in vertical biamp mode. I no longer use the 50W stereo amps in my main system because the Meitner 100W monoblocks sound best, so clearly biamping is no panacea. Horizontal Biamping "In horizontal biamping, one stereo amp is connected to the low-frequency speaker posts on both the left and right channel, and a second stereo amp is connected to the high-frequency posts of the left and right speakers. This arrangement is used for biamping with dissimilar amps. The purpose of this arrangement can be to maximize the virtues of different amplifiers. If amp X has superb bass and amp Y is a bit soft on bass but has a glorious mid and top then amp X is used for low end reproduction and amp Y for the upper end of the spectrum." I tried horizontal biamping with a 50W Meitner in combination with various other SS amps (50W NAD, 70W Classe, 100W Bryston). While I could easily achieve better bass and treble with these combos, none were as satisfactory as a single stereo amp powering both channels. In all cases, the horizontal configuration resulted in a loss of coherence. The sound was more hi-fi, less musical and quite disappointing. I did not experiment with tube amps, but I find it very hard to believe that a SS/tube amp combo would make me happy, due to the different sound signatures. I don't doubt that some combination of gear and sonic preferences may arrive at a different conclusion on the merits of horizontal biamping. I have been experimenting with active and passive systems for twenty years. I currently own a Marchand XM44 three-way active analog crossover, a two-way Marchand XM46 passive line level crossover, a miniDSP 2x4 digital crossover and several pairs of FMOD inline crossovers. Even though I have these crossovers, I am running my (sealed) monitors full range with the subs connected in parallel to the main speakers, via the miniDSP ([email protected] Low Pass, with Linkwitz Transform and correction for the main room node ([email protected], Q=5)). The main reasons I have settled on the above configuration are listed in the AA FAQ: 1. Quality speakers are designed with a crossover network matched to the particular characteristics of the drivers. Substituting an active crossover defeats the speaker designer's efforts to truly match the drivers, cabinet, and crossover together. 2. Anything that is added to the signal path alters it in some way. Passive components do too (a cable is a passive component, for example), but they may be less likely to add coloration than active components. 3. An active crossover performs a sophisticated function, roughly similar in complexity to a phono stage. An active crossover has the potential to degrade the sound of a system if its quality does not match the rest of the components. Ultimately arguments for or against either configuration are academic - the proof is in the listening. As with all links in the chain, the quality of the active crossover influences the sonic result. A poorly designed active crossover might not yield better results than the internal high quality passive crossovers in a well designed loudspeaker with components carefully matching the drivers. The reason not listed above is that I value simplicity these days, I don't want to go back to tri-amping, though I admit the miniDSP SHD Series processor/streamers are a temptation, LOL! All comments are welcome.

I intend to start a new thread on this topic, as I find it fascinating and complex. I will link the new thread here.

I asked if you had ever tried biwiring, you responded with reasons why you believe it isn't worthwhile. I assume that you have not tried, and are therefore working with limited information. I investigated biwiring my system with dual and single 10' runs of Linn K400 13ga cable. Every configuration sounded different; single run to tweeters with short K400 jumper cable to woofer, same except connected to woofers first, and finally biwired. I have 12ga zip wire, Linn K400 single and biwire runs and Cardas Neutral Reference bi-wires. There are significant and easily heard differences between them, all in favour of the more expensive options. The opinion often stated by "objectivists" is just to use 12ga from a hardware store does not hold. You agree that capacitance, inductance and resistance change with biwire vs single run. These base parameters are enough to change the sound, IMO, but there are other potential factors as well, e.g. phase effects: http://www.empiricalaudio.com/computer-audio/audio-faqs/bi-wiring-speaker-cables and IM effects: https://www.qacoustics.co.uk/blog/2016/06/08/bi-wiring-speakers-exploration-benefits/ Biwiring is in no way essential, but if I have speakers with dual terminals and biwire cables, I will definitely use them.

Any plans for a commercial DAC?

> "bi-wiring if one believes in such a thing" Have you ever tried bi-wiring? It made a significant and easily noticeable difference in the two pairs of speakers I tried it on. The sound also changed when I single-wired with jumpers on the tweeters vs. jumpers on the woofers. Martin Logan speakers would definitely rate a look if I were shopping. The price is reasonable and the AMT tweeter is an amazing device. Quite a few designs used an AMT at the Toronto audio fest. I'm not a fan of ported speakers either. I would want to block the ports and cross over to my subs. I am not a fan of previous ML speakers. Crystalline highs but no body.