Summit dislikes Bi-Wiring?

[bluenote56]

Hello,

it seems to me, as if I get no optimal results when bi-wiring my Summits. I´ve tried different kinds of Speaker Cables and the effect was always the same. To play it safe, i´ve made two sets of identical cables today, one of them bi-wired. Same story.

When bi-wired, the soundstage is definitely bigger and deeper, but there are almost no lower frequencies. To be precise: no impression of the potent bass a Summit is able to deliver. The woofers move, but i can turn the woofer controls to max with very little results. Its just getting more "booming", inaccurate and without any control. In addition, the higher frequencies become harsh at high levels. With single-wired speaker cables, everythig works fine. Very strange.

Any ideas? Anyone here with a similar experience?

Br
Johann

 

[robertawillisjr]

The Summits do not require bi-wiring. They are configured for bi-wiring only because many previous ML owners have/had biwire cables.

 

[bluenote56]

The Summits do not require bi-wiring. They are configured for bi-wiring only because many previous ML owners have/had biwire cables.

Yes, i´m aware of that. But i still am curious why my Summits show such a dramatic sonic degradation when bi-wired. There is no such hint in the users manual. Is this the reason why the "X" has no second set of binding posts, because someone at ML figured that out too?

 

[Feltran]

I'm not sure what to tell you, I currently have three sets of speaker cables (2 shotgun sets that I am currently using to biwire with the 2 different outputs on my Sunfire amp) and a set of internally biwired cables. In any configuration, I think my Spires sound is at least as good when biwired. I don't see any reason the Spire and Summit should differ in this regard.

 

[Rich]

I'm not sure what to tell you, I currently have three sets of speaker cables (2 shotgun sets that I am currently using to biwire with the 2 different outputs on my Sunfire amp)

If you are using two different outputs on your amp, isn't that actually passive bi-amping, rather than bi-wiring? And isn't that specifically discouraged in the Spire User Manual?

 

[robertawillisjr]

Yes, i´m aware of that. But i still am curious why my Summits show such a dramatic sonic degradation when bi-wired. There is no such hint in the users manual. Is this the reason why the "X" has no second set of binding posts, because someone at ML figured that out too?

Quite right. I was moving too fast and didn't complete my thought. Which is not relevant now due to the other responses.

 

[Feltran]

If you are using two different outputs on your amp, isn't that actually passive bi-amping, rather than bi-wiring? And isn't that specifically discouraged in the Spire User Manual?

The Spire manual does discourage passive bi-amping, but I don't think this qualifies. According to the Sunfire manual, you can bi-amp by using outputs from either the Front Current Source Output or Front Voltage Source Output coupled with the Rear Output. Alternatively, you can bi-wire by using both the Front Current Source Output and the Front Voltage Source Output. My understanding is that by doing this, you're essentially getting the power from only one output, but you're sending a 0 ohm impedance signal to the woofer and a 1 ohm impedance signal to the panel (the benefit of this is you still get the boom from the woofer that is missing with 1 ohm, but you dampen the brightness of the panel to make it a little more soothing).

If you'd like, you can refer to the amplifier's manual which can be found at http://www.sunfire.com/pdf/TGA5_manual.pdf

 

[vertigo]

Interesting

The Spire manual does discourage passive bi-amping, but I don't think this qualifies. According to the Sunfire manual, you can bi-amp by using outputs from either the Front Current Source Output or Front Voltage Source Output coupled with the Rear Output. Alternatively, you can bi-wire by using both the Front Current Source Output and the Front Voltage Source Output. My understanding is that by doing this, you're essentially getting the power from only one output, but you're sending a 0 ohm impedance signal to the woofer and a 1 ohm impedance signal to the panel (the benefit of this is you still get the boom from the woofer that is missing with 1 ohm, but you dampen the brightness of the panel to make it a little more soothing).

If you'd like, you can refer to the amplifier's manual which can be found at http://www.sunfire.com/pdf/TGA5_manual.pdf

As an audio-n00b let me see if I can share something that came to me while reading your post.

If you're bi-wiring and sending a 0ohm signal and 1ohm signal what is the actual cable impedance? It may just be that the signal is squashed trying to get through...

Also, I noticed reading around that a lot of people try to bi-wire and bi-amp claiming better results etc. at the end of the day it's about what sounds best to you. If bi-wiring with your speakers sounds worse, then just don't do it. So what, you'll just get to be the guy in the forums who doesn't bi-wire. Big deal right?

 

[Bruce Weiland]

Johann,

Just a bit of info to help you be content with your results.

Bi-wiring "should" sound better. That does not guarantee that it "will" sound better.

If you go to the Audioquest website and read through their 26 page theory paper, you will find an easy to understand explanation of why bi-wiring "should" sound good.

However, it does not always. As a case in point. I have prodigy speakers which are bi-wirable. I also have the pair of old Moscode 600, tube hybrid amplifiers. The manufacturer of the amplifiers has always held that vertically bi-amping will sound better than bridging the amps.

In two earlier attempts at bridging the results were as he had predicted. However, using just one channel of each amplifier to drive the speaker full range always produce a better result than vertically biamping.

Now that should not be the case even though it's passively vertically bi-amped. One half of the amplifier was handling the upper frequencies and the speaker wire connected to that channel, and the other half of the amplifier was handling the woofer section with the wire only having to care low-frequency.

I was eventually able to bridge the amplifiers in a way to produce a better result than using just one channel of each amplifier driving speakers. :rocker:

You, I, and others have found, in many instances, that biwiring does not sound as good as using a single wire handling the entire frequency range, even when all wires are of equal quality.

Within the past six months Audioquest has discontinued both their Volcano and Everest wires. The impression I get is this was brought about because of many requests for bi-wiring. Their latest series that replaced those two models have similar metal content but are structurally different to make bi-wiring more easily accomplished and effective.

Martin Logan obviously found that bi-wiring this Summit, in most cases, did not produce a better result. Therefore, the summit X no longer has the option.

Remember, your mileage may vary. What really matters is NOT what should sound good, but what DOES some good, to you. :devil:

Bruce :music:

 

[Speedskater]

Getting back to the Carver amplifier. The 0 Ohm output is the MORE dampened output. The 1 Ohm output is the LESS dampened output. Some woofer circuit alignments can have interesting frequency response changes with the 1 Ohm output. Speaker systems with complex impedance curves will have frequency response changes with the 1 Ohm output.
Speaker cable characteristic impedance has nothing to do with the amplifier output impedance discussion.

 

[Bruce Weiland]

Some additional information about Sunfire amplifiers.

The current and voltage source binding posts in the Sunfire stereo, and signature stereo amplifiers are wired exactly the same, with two exceptions. I would assume it is no different in the multichannel amplifiers.

The exceptions are these; there is an exceptionally large, wire wound, 100 W resistor in series with the positive binding post of the current source, along with a fuse. The voltage source is a direct connection and has no fuse in line the speaker. So, with the current source you are listening through a resistor, a fuse, a fuse holder, and the mechanical connections involved.

Among other things, the additional one ohm of resistance in line will lower the damping factor. Therefore using the current source on the woofer section should produce a " looser" bass.

If the upstream equipment has any harshness or brightness to the sound, then the current source feeding the ESL may be much more pleasant.

When I used a Sunfire Stereo Signature, 600 W per channel, I always got much better results using the voltage outputs.

Bruce

 

[Speedskater]

I think that the terminology confusion is because "damping" and "damping factor" are opposite sides of the same coin. In one case "damping" a low number is good, in the other "damping factor" a high number is good.
In my earlier post "dampening" should have been "damping".

 

[bluenote56]

Today, I did some further research. First, i made some new bridges for the Bi-Wiring terminals using a short rest of my favorite Speaker Cable (Neutrik´s Speakonflex 2) with high grade spades. Whow. I did not expect, that this short piece of a simple wire would make such a difference.

Next, I tried biwiring again and mounted a bi-wired version of the same cable, and: yes, there are distortions and lack of bass. It seems to me, that the poweramp has much more work to do when connected bi wired. My Krell gets definitely hotter and obviously operates at a higher level of the sustained biasing. This may explain the distortions on higher volume levels. It simply seem to run into clipping, or at least close to. An ultra stable amp like a Krell should never show this!!!

Is it possible, that the built-in ICE-Modules do not properly start-up and therefore the poweramp can "see" the load caused by the woofers?

Back to single wiring, i can run tremendous levels. Sound stays always "clean" and the Krell gets only lukewarm. So i´ll stay with that configuration. Perfect perfomance!

But i still would be interested in the technical details that come into play when biwiring. Maybe there is some technical expert for this issue who can give me a hint. You know, I´m an engineer and always am curious about things I have no explanation for. This second piece of wire, could it make a difference in terms of electricity (most likely no) and have an effect on electronics (again no) ? Not a simple question, eh?

Your input will be appreciated.

Johann

 

[Feltran]

Today, I did some further research. First, i made some new bridges for the Bi-Wiring terminals using a short rest of my favorite Speaker Cable (Neutrik´s Speakonflex 2) with high grade spades. Whow. I did not expect, that this short piece of a simple wire would make such a difference.

I don't understand what you mean by this. More information, please?

 

[bluenote56]

I don't understand what you mean by this. More information, please?

Due to somewhat strange legal circumstances, the Summits are delivered in Europe without any bi-wiring jumpers (to connect both pairs of binding posts). Therefore, i´ve made my own.

 

[Feltran]

Due to somewhat strange legal circumstances, the Summits are delivered in Europe without any bi-wiring jumpers (to connect both pairs of binding posts). Therefore, i´ve made my own.

Ah. But when you biwire, you're not using jumpers, right?

 

[Bruce Weiland]

Due to somewhat strange legal circumstances, the Summits are delivered in Europe without any bi-wiring jumpers (to connect both pairs of binding posts). Therefore, i´ve made my own.

Johann,

It is just as well. Here in the US we get a flat piece of metal that most agree, does not sound that great.

Two other experiments you might try. I assume the single pair of wires you are now using are connected to the "stats" and the jumpers go down to the woofers.

1) Try a double run (since you have two identical pair) of your wires to the stats, and of course continue to use your DIY jumpers.

2) Put the plus and minus of one set of wires together and run it from the plus on the amp to the plus on the speaker. Do the same with the second run of wire, but of course connect it to the minus on the speaker and the amp.

Let us know what your hear.

By the way, this may be a really silly question, since you are an engineer, but have you use a VOM to make sure you don't have any strands shorted in each set of wires? I can't think any other reason your amp would run hotter with biwiring.

Bruce

 

[Bernard]

1) Try a double run (since you have two identical pair) of your wires to the stats, and of course continue to use your DIY jumpers.

Why would you try a double run AND jumpers?

 

[Bruce Weiland]

Who the heck knows???

Because he can. It won't take long to try, since he already has the wires. It could sound much worse, or maybe, just maybe, better. :music::music:

It certainly is not going to hurt anything.

Who knows what twice the wire/half the resistance will sound like. Of course both capacitance, and inductance will be different too.

Since most of us agree that wire makes a difference, he ought to give it a try.

It is really difficult to predict what something will sound like in any particular system, made up of several different components, and in differing electrical environments.

I certainly have been disappointed by the sound of certain components in my system, that were supposed to sound good.

I have also been pleasantly surprised, at times, by wire, and pieces of equipment that I did not expect to shine in my system.

I find it fun to tweak and experiment, especially when it does n