Tom: What you bring up is a good point and something that most people never really think about. I have often wondered about the effects of "everything on one side of the line" type crossovers in the past. I have discussed this with my Brother at times, but we've never actually taken any type of measurements on stuff like this.
While most will argue that "it's an AC signal, so the amp sees the same load regardless of what polarity the crossover is on", that is only true of a Class A amp. That's because the Class A output stage is conducting both sides of the AC waveform. In comparison, a Class AB amp would typically have different types of output devices conducting each individual half ( positive and negative ) of the waveform being reproduced. As such, the Class B amp would see a non-linear load due to having all of the crossover components on the positive leg of the waveform whereas the negative leg has a shorter signal path with a reduced parts count / reduced reactance level to deal with. The ideal thing would be to divide the parts count evenly between both legs, providing both halves of the waveform with a reasonably common load.
Given the differences in electrical characteristics of the various devices used for each "rail" of the amps output polarity, it's no wonder that most amps, which are low level AB circuits, demonstrate different measurements ( levels of electronic stability ) and sonics into various loads. This could be part of the reason why Class A amps tend to sound "more cohesive" and less "disjointed" than Class B amps and do so more consistently with different loads. That is, a Class A output stage is always conducting and sees all of the load whereas an AB output stage sees half of the load without equal levels of the crossover network's reactance equally distrubuted between them. I would think that such an approach would help an amp to offer better stability into a wider range of loudspeakers AND reduce non-linearities in the amp when recovering from overload / momentary saturation.
There's a LOT to think about in the question that Tom brought up and the response that i just posted. I've never really seen anyone go into depth on the subject and it may help to explain a lot of things that are somewhat "unexplainable". That in itself is food for thought on a whole 'nother topic / thread.
None the less, maintaining a consistent nominal impedance for the entire circuit should theoretically ( and in my experience ) produce better results. The fact that most all of my amps operate in Class A for a longer than average period of time may also help things out. Others that have high bias AB or "pure" Class A amps are also in the same boat. Amps running in low level AB or straight Class B would probably be more susceptable to the aforementioned problems with "one polarity" crossovers coming into play. If you're wondering how this specific scenario applies to your system, if your amp idles anything below VERY "warm" to the touch with no signal applied, your amp is not a high bias unit. That would make it either a very low level AB amp or a straight B. This assumes that you're not running some type of "high efficiency" aka "switching amp", which typically idle cool as a cucumber.
With all of that in mind and as most that have read more than a few of my posts should know, i typically prefer "direct drive". That is, amplifier / speaker cable / driver with the crossover duties being taken care of upstream of the amplifier electronically. This removes the aforementioned "problem" out of the equation along with resolving all kinds of other situations. The difference between "direct drive" aka using a good quality electronic crossover and using the same amps / speakers with passive crossovers between them is pretty staggering to say the least.
Rooze: I see nothing wrong with what you want to do. Before buying anything else though, drop me an email with the specifics of what you need. I have some smaller sections of MI-1 that i may be able to help you out with. No promises though as i have to dig it up and see how much i have. I purchased some cables that were damaged and ended up trimming some short sections off during the repair. This "might" be enough for what you need to accomplish your desired goals.
Taking that a step further though, couldn't you just have Goertz build some inductors with the values that you needed with longer leads coming in and out of the inductors themselves? This would leave you with even fewer connection points and a more direct signal path. I don't know if you had considered this, but it would be the simplest and purest way to achieve your desired goals.
As far as "break-in" goes with this cable, i think it is more a matter of your ears adjusting to what you are hearing than the cables themselves "changing parameters". After all, you've only got one conductor per polarity with minimal amounts of a high grade dielectric. There's not much potential for the cabling to shift around internally, altering the impedances and / or the dielectric to change spacing or density, etc...
Out of curiosity, did you receive / install the Zobel networks? Sean
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