I'd like to bi-wire my speakers (which are able to do this) using my Outlaw 1050. is this possible? also, can anyone reommend good pre-wired bi-wire cables?

Yes, it is possible. I've had good luck bi-wiring with spades at the 1050 (two speaker runs from the same binding post, so two spade lugs on the same post at the 1050).

I haven't used any pre-made bi-wire cables, so don't know what to recommend there, but I've used several different kinds of wire. I've done this with Home Depot wire (bare wire in that case -- do not try to get Monster Cable spades, as the ones I got were too thick to be manageable for bi-wiring), BetterCables premium wire (spades to bananas, which is what's on my center channel right now), and TMC Gold Label.

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gonk -- Saloon Links | Pre/Pro Comparison Chart | 950 Review

how about if i just twist the wires together and shove them in the hole on the post at the 1050? Does this work as well?

It worked for me (I stuck the wires in opposite sides of the hole, but that's basically the same thing).

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gonk -- Saloon Links | Pre/Pro Comparison Chart | 950 Review

I was curious about the power rating when biwiring. How do you figure that? Would it still just be 65W to each speaker or 65W to each line to the speaker (or 130W). What would happen if you went to a bi-amp solution? If that's the case here, I could definetely see getting one of those wonderful 7.1 channel amps and sending double power to the mains.

Before you bi-wire, consider this: The last length of wire in your speakers is probably a much smaller gauge than zip cord.

I had a problem with an Audax tweeter in my center channel, a DIY speaker, where the post pulled out when I disconnected it to finish the veneering. When I investigated the problem, by pulling apart the voice coil, I found the coil wire that connected to the post was thinner than a hair. I have RS 14ga running to the speaker, and some other 14ga inside, but the final wire size is so small that I didn't believe it could actually run current through it. (I was actually able to fix the thing though, to solder that wire to the lead I needed a magnifying glass. If you ever have a spare speaker, you should take it apart, pry open the drivers, just to see how it is really put together.)

And that hair fine wire will be (usually) many feet long. Gives pause for thought.

Well, even if it's say, three feet of small guage wire in there, it's not nearly so bad as running 20-30' of it from your amp.

It's resistance is also probably accounted for by the speaker's designers.

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Matthew J. Hill
matt@idsi.net

[This message has been edited by Matthew Hill (edited September 06, 2002).]

Yeah - if it only were so short.

A typical woofer voice coil can have 30+ feet of small gauge magnet wire!

Tweeters are tiny gauge, but can still be over 10 feet.

And you are correct - it certainly is compensated for, but so also is the internal wiring of the speaker, yet there are some who feel a burning distrust of the designers of their 'wunder-speker' and will actually use premium wire to redo the insides. IMO if the designers are that incompetent one should take a pass on the entire design - know what I mean?

Charlie

[This message has been edited by charlie (edited September 06, 2002).]

My philosophy is, deliver as unmodified a signal as possible to the rear of the speaker, and from there let the designer take over. By modifying the resistance characteristics of the internals of the speaker, I'm deviating from the original designer's intent, and could very well be making things worse instead of better.

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Matthew J. Hill
matt@idsi.net

Absolutely.

Either you trust them or not. If so, buy, if not, keep shopping.

Just my $0.02

Charlie

www.sonicdesign.se//biwire.html

BI-WIRE, NOT ONLY AN ADVANTAGE

A popular method to connect an amplifier to a loudspeaker is to use something called bi-wiring. The technical idea behind this special way to connect has not reached the public in other words than "better definition in the mid range", "the bass will be faster" and "the treble more in focus" or similar nonsense. The problems and faults that arise have not been mentioned, of course.

THE ADVANTAGES FIRST

The idea with biwiring is to connect the amplifier to the filter halves separately to prevent intermodulation, generated by one driver, to influence the other driver.

If you look at the damping factor that reduces the unwanted signals however you will find that they differ very little with or without cables (with 5 or 0 metre long cables for example). When using a tube amplifier, the cables in practice have no influence at all to damp the signals from one side of the filter to the other, because the damping factor is too low already in the power amp. The signal will slip through anyway to the other driver, despite the cables.

Apart from that, a well-designed crossover filter will provide a certain protection against "leaking" intermodulation since each half of the filter (in a two-way system) will damp each half of the frequency range.

Another point using double cables is the ability to choose separate cables that are especially suitable for each half of the frequency range. On the other hand, there are cables made along these lines without being double. (Monster, Isoda, MIT, and others) even if they do not work as the manufacturers claim, they have this in common, that for each frequency range, or level, they have different strand (different materials, areas, winding techniques and such) that are parallel connected. If you assume that the signal always takes the easiest path, the right strand will be chosen automatically.

AN ALTERNATIVE METHOD

You do not have to use separate cables to each driver, but may connect two or more cables in parallel if you think they have good qualities in different parts of the frequency spectrum and therefore may supplement each other. By that, it is not certain that you always can make such summing. If you think that it is possible to add a capacitor (that conducts at high frequencies) and a coil (that conducts at low frequencies) and get a circuit that conducts at all frequencies, you will be surprised when nothing gets through (!) at a frequency where each conducted decently before the connection. Cables, however, are less reactive and may therefore be summed without greater trouble.

THE DISADVANTAGE WITH BI-WIRE

One thing that happens when you biwire your loudspeakers is that the input of the high- and the low-pass filters are fed with different input signals. The difference is a result of the high frequencies and the low frequencies being forced to travel different paths, perhaps through different types of cables, but under all circumstances through cables who have seen different loads (a tweeter with a high pass filter has a completely different impedance response compared to a woofer with a low pass filter!).

What happens is that the drivers will work less good together than when their filter halves were fed with equal signals. The result is a generation of more static and stochastic phase error sounds at different directions from the loudspeaker. The stochastic phase error sounds appear because there may be different types of unlinearities in the low- and high-frequency paths.

What does this sound like? Well, usually, just as you may expect from physics, it appears as a change in the reproduction of space and sound stage. Often, the first impression is that the "biwired" sound presents extended "dimensions", more "air", and is more "living". The impression after a week or month, however, is that all recordings sound very much alike, and the "airiness" appears on all records. It does not even sound like air anymore, instead more like a slime that pollutes every record you play. No wonder, since it is not a real, recorded quality but a "speaker characteristic" added to all reproduced material. "Sameness" is another word for it.

This information is nice to know and all (I don't mean to sound like a snot here), but what about the power distribution? My original question.

Your questions have already been answered above. I posted the info just an FYI - so you would have more info before you jump in.
After all, at the end of the day, it's you who would decide if it works for you. Power distribution was not in your original question. It should matter I guess if you are going to bi-amp (using separate amps). Perhaps other members could provide info on this but I prefer (long ago) to leave my speakers alone.

Maybe something is wrong with me, but I did not see where my question was answered. My question was if I went to a biamp solution, if the power going to the speaker was doubled. I have a set of mains that can take a much larger amount of power than the center of surrounds will. 300W for the mains, 175W for the center, and 125 for the surrounds.

Now, I was thinking of getting a 7 channel amp and use two channels to go to each main. My question is if the mains would be getting twice the power as the other speakers. I would think so as there are two separately amplified lines coming in, but I want to make sure of this.

If this is true, I could look into something like the 7100, which would most likely output around 150W into 4 ohms and give me 300W to the mains and 150 to the center and surrounds. That way I would have only one amp, plenty of power for the mains and not have to worry about overloading the other speakers. Does this seem like it will work?

Sorry to stray before actually helping. My bad.

Bi-Wiring is generally defined as feeding a full range signal to an amp, going to the speaker with two pair of wires and discretely connecting the wires to distinct sections of the crossovers. This makes me laugh. Most of the theories around this one stem from folks envisioning the current surging down the wires. In fact at the frequencies and distances involved all points on any of the connected conductors see essentially the same voltage.

Bi-Amping (what you seem to want) generally refers to feeding a full range signal to a pair of amps and wiring each amp such that it drives a section of the crossover. This would isolate the two driver sections, but the amps are still driven full range. So although the current draw per amp would be reduced the onset of voltage clipping would be altered only a little in most cases. One advantage is that clipping in the bass amp would not blast harmonics into the tweeter.

The one that gives best results but is hardest to get right is Bi-Amping with active crossovers, where the amps are not driven full range. There can be benefits here, but the sonic characteristics of the speaker can also be easily compromised if done badly. This one works best inside powered speakers or if the manufacturer has specific provisions for it.

I'd just get a bigger amp.

Yes- no real change in "power rating".

I think you may be confusing bi-amping with "bridging" an amp here, Benjamin. I would not believe the new 7100 would come with this capability (bridging) and allow you to "double the power" to your speakers. So, the answer would be- no. Hope this helps!

The 7100 will not support bridging (assuming that it follows the same design approach as the 750, 770, and 755 did; the full feature list isn't out yet), but you can still use two of its channels to bi-wire a speaker (thus taking a 7x100W amp and creating a 2x200W and a 3x100W, which I think is what Benjamin is considering). From what I've been able to find (and as charlie said in his last post), you would get more power to the bi-amped speakers than you would if you bi-wired or "mono-wired," but bi-amping may be in some ways more hassle than simply going with a bigger amp (like the 755). In addition to charlie's last post, there's some more info at SMR and at soundstage.com that might be of use.

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gonk -- Saloon Links | Pre/Pro Comparison Chart | 950 Review

[This message has been edited by gonk (edited September 10, 2002).]

Bridging would be nice. Also this obsession with odd numbers of channels should go away.

Charlie

I have to disagree. If you biamp your speakers with either 2-100 watt per channel stereo amplifiers or with 4 channels of the 7 channel amp, you are still only providing a maximum of 100 watts to each side of the crossover. Each side will only see 100 watts max(assuming no dynamic headroom, etc.) and would not be doubled. To get 200 watts, IMO, you would have to bridge channels.

A good way to look at it is considering what the effective impedence will be. Driving a full range signal into, say, a properly crossed over tweeter will result in 'normal' current flow only in the treble range, so taken as a whole (voltage v. current) the apparent impedence of that load would be very high. So your treble amp might see an equivelent (depending on signal) of 20+ ohm load while the mid-bass amp might see a 11 ohm load (just pulling numbers out of air for illustration.)

The amp may run cooler, suffer from less rail sag, etc, but you won't actually get rated output except in limited conditions, such as an input signal that falls completely within it's frequency range. In this case the effective impedence would be back to the expected value.

Steves & Gonk, I think there may be a semantic difference in the way you are describing the same thing. I agree that each side of the X-over would see a maximum of 100W (using the 7100 with 2 channels bi-amping). But there are both a high and a low pass X-over (assuming typical 2 way bi-wireable speaker with passive X-overs) therefore the speaker cabinet has a total potential of delivering 200W.

If the same speaker had jumpers between the bi-wire terminals, then the voltage would be the same, but the current would be divided between the two crossovers. Assuming (the impossible!) that the characteristics (impedance, phase shift etc) of the low and high X-over and their related drivers were identical in every way, then half the current would go each way and therefore the wattage would be 50W per X-over for a total of 100W per speaker cabinet.

The above is assuming that every item acts as the ideal and losses/shifts etc are not accounted for. I am not considering Charlie's suggestion of an active X-over, as I have absolutely 0 experience. What he said makes sense, though. If there is an obvious omission, please correct, as we are all learning every day.

Last thought: Since you have to double power for a + 3db gain, is it worth bi-amping for an SPL approach only? Gut feeling is no. . .

S.

Gonk seems to have the right idea with what I was asking. I was kind of nervous about going with a larger amp as the center and surrounds are rated to 175 and 125 Watts of input power(both are 8 ohms nominal, 4 ohms minimum). I could go with the more powerful surrounds that can handle 300 watts at 6 ohms, but this would cost more. I'm all for cost effectiveness as I'm sure many of you are too.

The 4 ohms min is what gets me going about using the 770 or 755. 300 Watts into 125 or 175 recommended seems to be kind of far over. I would not be playing at extremely loud levels, but I would like to eliminate the chance of overdriving them as much as possible.

This leads me to another question, with the resistance ratings of these speakers, will the amp always try to output at 4 ohms? Or will it be a little lower? I realize that technically the resistance is not entirely constant, but on average, what will it do?

Mr. Sandman, I know doubling the power will only give 3db more, but at the same volume level the sound will come through better.

Here is a message straight from Scott. Less than two hours for a reply too!

Hello Ben,

Thanks for contacting the Outlaws!

Amplifiers increase or decrease amperage based upon the impedance or resistance that a speaker pushes back on the signal. This means that the lower the impedance, the higher the amperage and in turn the higher the output wattage. So in answer to your inquiry of "if the speakers are capable of handling a 4 ohm load, will the amp always try to output at 4 ohms", the amp will increase or decrease the amperage based on whatever impedance it sees. As your speakers increase and decrease their impedance over the frequency spectrum, the amp will adjust automatically. Since they have a nominal impedance of four ohms, the amplifier will operate those channels at 4 ohms for the majority of the time.

As for your bi-amping inquiry, the mids and highs would receive 150 watts and the low frequency drivers would also see 150 watts, bringing the total to 300 watts. As a side note, you may want to check with Mirage to ensure that you do not need an external cross-over when bi-amping their speakers.

Please do not hesitate to let me know if you have any other questions.

Best Regards,

Scott

I'm not sure where you stand as far as electrical theory in your background. If this seems overly simple please forgive me - I'm just trying to offer a complete explaination.

Scott is correct in that you would have N x 2 watts AVAILABLE, however that would not really be delivered.

Watts are computed by multiplying amps by volts. So an 8v RMS sine wave into an 8 ohm impedence would drive one ampere, resulting in an 8 watt power disipation across the load.

Amplifiers are a voltage source - the output voltage is designed to be a magnified version of the input voltage instant by instant. They are also capable of supplying a relatively large amount of current, but the actual current draw is not controlled tightly by the amp. The load is allowed to draw whatever it needs at the currently applied voltage, instant by instant.

A speakers impedence will not be altered by your amplifier.

If a uniformly distributed (noise) signal is used as an example, and it is driven into a speaker with a crossover that splits the current (and power) in half, and the overall speaker impedence with this signal is 8 ohms, then under these conditions each half of the speaker is exhibiting a 16 ohm impedence. If the speaker inputs are split between two amps each amp (all else not changed) would see a 16 ohm effective load. Total power available to this system would be whatever the amps can deliver into 16 ohms (NOT 8) x 2.

So you may get a bit more power, but I doubt it would be much, as most amps are optimized to drive loads 8 ohms and below.

[This message has been edited by charlie (edited September 11, 2002).]

I think you are right. While trying to simplify things, I was ignoring the SUM of the watts available to both sides as I figured it might be confusing and not really give Benjamin the answer to what I thought he was looking for. That will teach me for thinking! All the follow up replies have been excellent-even I understand now.