Article: MartinLogan Motion 40i Review

[audiobomber]

> "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. 

[audiobomber]

On 12/25/2019 at 10:37 PM, Sonis said:

Bi-wiring doesn’t really do anything positive. As far as cable is concerned, it’s like upping the gauge to the wire, but if you are splitting the woofer and tweeter by removing the shorting straps at the speakers and connecting them back together at the amplifier, all you are really doing is moving the place where the woofer and tweeter are joined from the back of the speaker with just a very short, low-resistance strap to a long, higher resistance cable. Sure it can change the sound, but I assure you it is subtracting something rather than adding anything. If you like that better, well, that’s up to you. But you really should know what’s actually going on. 

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. 

[audiobomber]

On 12/25/2019 at 10:37 PM, Sonis said:

Also, while we’re on the subject, bi-amping a speaker that won’t let you bypass the built-in cross-overs, is also, mostly futile. For proper bi-amp performance you want a small signal crossover BEFORE the amplifiers. Now you’ve got the true advantages afforded by bi-amping! There is an exception to that. Even if you are stuck with the speaker’s built-in crossover, you will still get benefit if, for instance the two amplifiers you are using have vastly different sonic signatures. For instance, if you prefer the bass of a solid-state amp, you might want to put that on the woofer, but if you prefer the sweet open high-end often attributed to tubes, then you might want to use a good-sounding tube amp on the tweeter (perhaps even a low wattage SET).

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

[audiobomber]

1 hour ago, audiobomber said:

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

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

 

[audiobomber]

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.

[audiobomber]

2 hours ago, gmgraves said:

Long term listening is great for getting used to changes between any new configuration or hardware over the previous configuration or hardware. It also helps the memory of the previous configuration or hardware fade. 

I listen for flaws. If a cable does something poorly, it will become evident with extended listening.

[audiobomber]

8 hours ago, gmgraves said:

all cables are lossy, so in reality, all cables do something poorly if they change the sound. Cables that change the sound are designed to suppress some portion of of the audio spectrum and they charge a good amount of money for the privilege. My opinion backed by a Masters in EE.

My opinion is backed by decades of listening in my room, with my system and my music.

 

There are a gazillion examples of "Masters in EE" who disagree with audiophiles, and I would point out, with designers, some of whom also hold Masters in EE. I like to hear all opinions, from all sides. In the end I decide for myself what I like best.

[audiobomber]

8 hours ago, gmgraves said:

Cables that change the sound are designed to suppress some portion of of the audio spectrum and they charge a good amount of money for the privilege. 

I use Cardas Neutral Reference bi-wire speaker cables. Tonally, they are a little warmer than neutral, which suits my system and preferences. The other characteristic they have is a deeper soundstage compared to the Linn K400 bi-wires and generic 12ga cables I own.

 

The Cardas speaker cables, which I purchased second-hand, provide a complementary tonal balance, along with resolution that allows subtle depth details to come through. There may be some cheaper cable that I would like just as well, possibly even better, but I don't know where I would find these among the multitude of choices, because measurements unfortunately do not tell the whole story. 

[audiobomber]

19 hours ago, gmgraves said:

Like I said. It’s just an incontrovertible fact of physics that if two interconnects sound different, it’s because the two cables are attenuating different portions of the audio spectrum and both are wrong. Speaker cables are different in that the impedances involved are low; less than  1 Ohm usually for the amplifier (assuming solid state here), and nominally four or eight Ohms for the speaker.   That means that the longish cable runs add significant resistance to the overall impedance characteristics of the amp/speaker interface. Again, different brands of cables affect the speaker sound differently. I use Sewell Direct “Silverback” speaker wire in six foot (only) lengths. This cable is 12 Ga, 259 strand, OFC cable and in such short runs, changes the overall impedance of the system by less than a quarter of an Ohm. It has minimum effect on the system’s sound. My opinion is that using cables, either interconnects or speaker cables as a fixed “tone control” is wrong-headed. 

I measured the resistance of my right speaker cable out of curiosity: 0.2 ohms, including connectors. Here are the rest of the specs:

Outside Diameter: .600"
Dielectric Type: Teflon®, Air
Inductance uh/ft/loop: .034
Capacitance pf/ft: 117
Cable awg: 8.5
Conductor Type: Golden Ratio, Constant Q, Crossfield, Pure Copper, Litz

 

I am 100% confident that the Cardas cables let info through that your inexpensive cables lose. IME, it's pointless to argue with someone who believes there's "one true way" to build a audio system, and this is all off-topic, so I'll leave it at that.