Biwiring out of the 2150?

Is it possible to biwire out of the 2150 using the A speaker side for the top end in the loudspeaker and the B speaker for the bottom end? I suspect it is. Running the 2150 in A&B speaker mode......if so, what is the power output and impeadence running out of both A&B? Would it drop to 4 ohm loads or stay at 8? Thanks!

Hi Penn,

Your best resource would be to ask Outlaw tech support for the definitive answer. Here on the forums, Search is your friend...

Here's a post with user experiences re: impedence and output running A&B, nothing on biwiring.

http://ubb.outlawaudio.com/ubb/ultimatebb.php?/ubb/get_topic/f/17/t/000059.html

One thing to keep in mind would be Bass management. If you are planning on running a sub, remember that bass management is only applied to the A speaker pair. So definitely attach A to the top end (tweeters) as you describe.

Here's a thread on biwiring:

http://ubb.outlawaudio.com/ubb/ultimatebb.php?/ubb/get_topic/f/17/t/000055.html

Good luck, and don't forget to let us know how it goes!

Tony.

Thanks, the speakers I'm running would be dantax vision 1's. Already running a 4 ohm load. I believe it would be much easier to run a single speaker this way. The post above the guy was running to different polk's. Of course outlaw set up the 2150 to run both a&b at the same time. If I were to run a sub, I would use the preout for that...which would then bypass the lowest frequencies off the speaker so the Dantax basically become a mid and high transducer...depending of course on the cut-off. Thanks!

I think you're right about the load, I've bi-wired Sonus Faber Concerto's (6 ohm load)with an old NAD 3240PE 40W integrated using A&B speaker outs with no trouble, even at high volume.

The Dantax Vision's look pretty sleek and sexy... Let us know how they sound with the 2150.

Enjoy!

I biwire (not biamp) my Magnaplanar 1.6QR's from an Adcom GFA535 running in A&B mode. Works fine. I don't know why the same wouldn't be true for any other amp that has A and B outputs that can be chosen at the same time. Biamping would be another matter entirely.

This may be a silly question, but does using the A&B outputs really serve as biamping? With only one channel of amplification driving each speaker, you shouldn't have any more power when using the A and B outputs as you would just bi-wiring from the A outputs - either way, you're asking the same single channel of amplification to drive the speaker.

D'oh! Of course you're right, gonk (you, too psyprof1). This scenario would indeed be bi-wiring, as was what I did with my old NAD. Thanks!

Gonk, you're right as usual; I tried biwiring the Maggies from the Adcom's A and B terminals because I'd read somewhere that there might be a sonic benefit from having separate wires for tweeter and woofer feeds. (What other reason for biwiring would there be?) And the sound does seem to me to be marginally more detailed, especially in the treble.
Of course, as in so much of subjective judgment in audio, it could be autosuggestion.

I'm running a 4 ohm speaker with biwiring capability...add to that a sunfire woofer and yes, biwiring does "add" to the sound quality. If biwiring didn't work, speaker manufacturers wouldn't do it, and save money..now, it has to be a true biwire in the speaker....the Dantax's are. The biwire bypasses the crossover...It does provide and easier route for the receiver to run a 4 ohm load. Theoretically...you should be able to run 2 4 ohm systems on A&B and have good output and definition....but you will pay the price on equipment fatigue. Some of which is attributed to heat buildup. My main system is run with Boulder amps and MBL loudspeakers. Biwiring these is a turkey shoot....They are designed for a single input even though they have biwire terminals. The MBL's however...are biamped, which provides a far more measurable benefit in sound....as always in audio, if it sounds good...do it!!!

Penn stythe, your statement that "the biwire bypasses the crossover" makes me think that you mean biamping, not biwiring. With biwiring the full-range signal coming in via the wire feeding the tweeter has to go through the high-pass filter section of the speaker's crossover network or the bass will reach and guickly burn out the tweeter; similarly the treble component full-range signal coming via the woofer wire has to be removed by the crossover's low-pass filter or it will be fed to the woofer and be wasted because of the mass of the woofer cone. In biamping the full-range signal is split by an external (and expensive) crossover network BEFORE being fed to the power amplifiers, of which there must be TWO for each channel if the speaker system is two-way, hence four power amps for stereo. (For five- or seven-channel HT, do the math and shudder.) The advantage is that the power amps' output goes directly to the speakers rather than to any internal crossover network the speaker may have - assuming it can be bypassed. But this theoretically superior method absolutely requires at least four power amplifiers. If there are only two, we are talking about biwiring, not biamping, and we're NOT bypassing the speaker crossover.
Of course a powered subwoofer system is essentially biamped if it's running in stereo, since either the sub's crossover or a unit like the 990 does split the full-range signal into two parts (the low bass and everything else) and sends the former to the subwoofer amp and the latter to the power amps (or power amp section if it's a receiver) to feed the main speakers, crossovers and all, plus whatever center and/or surround channels there are.
Clear, I hope?
BTW I would say, "as always in audio, if it sounds good...consider adding it to your list of financial desires and priorities. Where on the list is a matter outside the range of this discussion."

Psyprof1's got an excellent point: we need to keep biwiring and bi-amping separate, as they are two significantly separate concepts. For that matter, I'd suggest we maintain three specific separate concepts.

• Bi-Wiring: The speaker manufacturer has two sets of binding posts on the rear of the speaker, with jumpers that can tie the two together or separate them. The purpose is to allow two sets of speaker cables (or at least four separate conductors) provide separate positive and negative signal paths from the single amplifier channel for both high frequency and low frequency sections of the speaker. The reasons for bi-wiring are to decrease overall resistance (similar to increasing the wire size) and to separate possible intermodulation, generated by one driver, from influencing the other driver. How beneficial the second reason is can be a matter of some debate, but the first reason is pretty clear-cut.
• Passive Bi-Amping: In passive bi-amping, the source signal (from the pre-amplifier) is split and sent to two separate amplifier channels, each of which is then connected to either the high-frequency or the low-frequency section of the speaker. This provides more power for the speaker. It is possible to encounter problems when mixing amplifiers in this scenario because you can get output level differences that can skew the speaker's overal frequency response, so many people prefer to use identical amps for this. Some will argue that simply getting a single larger amplifier is an equally good solution.
• Active Bi-Amping: In active bi-amping, we get into a whole different level of complexity. The output signal from the pre-amplifier is split, just as with passive bi-amping, but after that we send each signal through a different external crossover network that must be custom designed for the speakers being used. After the two (or more) crossover networks, the separate signals are sent to separate amplifiers. The amplifiers' output go to the speaker, where they are connected directly to the speaker driver - there is now no crossover network inside the speaker. There are significant advantages to this approach: locating the crossovers before the amp can reduce the burden places on the amplifiers (especially the high frequency amp), and the crossover network is dealing much lower level signals. The problem is that very few speakers are manufactured and sold this way, so most active bi-amp setups are DIY - and you need to be very knowledgeable of both crossover circuit design and the speakers in question to tackle this sort of DIY project.

Going back to the case of a typical receiver, there are only two channels of amplification - one amp to drive the left and one to drive the right. This makes either form of bi-amping impossible unless you add external amplification, and leaves us with bi-wiring only.