Mono or 2ch amplification for Bi-amp capable speakers???

[rommel]

In my pursuit of looking for more power for my Motion 40s I keep thinking of different configurations as to power them.  But my question is.  What would be better, as an example, using a 300w mono channel running each side with the jumpers or say 2ch of 150w without the jumpers/bi-amp?  Is there any benefits of having 2ch of amplification powering/controlling as opposed to 1ch/mono?  Does the question make sense?

[repeetavx]

Here you go.

And here too.

[leonski]

Biamp with in-speaker crossovers really has minimal advantage.
One factor NOT discussed in repeetavx links is the crossover frequency. And don't forget that no matter the load, the amp is still swinging the voltage the FULL waveform calls for.

Crossover frequency is important for a apportionment of potential power needs.

I'd agree that in MOST cases, going to a true active system is daunting. But these days, lots of helps exist from companies like MiniDSP which will also sell you a calibration mic which also works with REW. (Room EQ Wizard, free software)

For a Slightly Different slant on biamping, here's another link.

sound.whsites.net/bi-amp.htm

[bootman]

In other words, for your speakers and the way they are built you will get very similar results either way.

Bi-amp connections on speakers with built in crossovers (99.9% of those sold) are really just there just so folks buy more amps.
If you open your speakers and disconnect the crossover thus really directly driving the individual speaker components, you must have an external crossover like a mini-dsp.
In this case bi-amping is mandatory not optional.
I'd argue that with really good speakers the crossover is just as important if not more so than the drivers selected.
I know I don't know more about crossover design than the well known speaker builders out there.

But this is just my opinion based on reasoning.

[clearear]

Feb 24, 2018 7:32:32 GMT -5 bootman said:

Bi-amp connections on speakers with built in crossovers (99.9% of those sold) are really just there just so folks buy more amps.

Why would speaker manufacturers care if you bought another amp?

[bootman]

Feb 24, 2018 14:54:28 GMT -5 clearear said:

Feb 24, 2018 7:32:32 GMT -5 bootman said:

Bi-amp connections on speakers with built in crossovers (99.9% of those sold) are really just there just so folks buy more amps.

Why would speaker manufacturers care if you bought another amp?

For the same reason amp manufactures care that you keep upgrading to more power hungry (or in the case of HT just more) speakers?

It's the circle of audio.

[leonski]

Keep in mind that 99% of the time that Speaker designers and those that voice them AND amp designers do NOT SPEAK.

That's how you end up with some of the very wacky speakers dropping to 2ohms with 60degree phase angle.
Or the same speaker being rated as a 'nominal' 8 ohms.
And the SAME speaker having a sensitivity of 88db 1watt/1meter.

The only exception I can think of is the majority of speakers intended for primary HT duties are not all that difficult to drive.
Seldom will you find 4ohm speakers in this category where some HT receivers have a 6ohm minimum and some kind of
switch on the backside which is actually intended to SAVE the PS from abuse of too demanding a speaker. They don't
SAY that, but thats' what it is.

[jmilton]

I could not ... resist:

www.cnet.com/google-amp/news/how-to-stop-worrying-about-speaker-impedance/

[405x5]

The best place to start for powering loudspeakers is with the company that actually built the things.

Active, passive crossovers, db. goals, biamping options etc. should be readily addressed there.

Biamping is surely nothing at all new... my first encounter with biamping was over 40 years ago.

My own systems have a biamping option that I don’t use (passive crossover) and run 400 wpc. @8ohm. to a nominal 6 ohm load.

Bill

[leonski]

Any discussion of speaker impedance which does NOT include mention of PHASE is nonsense. Including the CNET article, above.

A speaker which is 4 ohms and nearly resistive is a Far Cry from a speaker which at the same frequency is Also 4ohms impedance but with a phase angle of 60 degrees.

Using the concept of power factor, which ranges from 0 ->1, with 0 being a purely reactive load in which No power is delivered to 1 which is pure resistive, all speakers fall in between to
various degrees at various frequencies.
Some of the truly difficult loads which speakers can attain are VERY reactive with a very low power factor.

www.rapidtables.com/electric/Power_Factor.html

Above link included for the 1 or 2 people who 'get it' and are willing to at least understand the gist of the arguement.

[mgbpuff]

Feb 24, 2018 22:16:53 GMT -5 leonski said:

Any discussion of speaker impedance which does NOT include mention of PHASE is nonsense. Including the CNET article, above.

A speaker which is 4 ohms and nearly resistive is a Far Cry from a speaker which at the same frequency is Also 4ohms impedance but with a phase angle of 60 degrees.

Using the concept of power factor, which ranges from 0 ->1, with 0 being a purely reactive load in which No power is delivered to 1 which is pure resistive, all speakers fall in between to
various degrees at various frequencies.
Some of the truly difficult loads which speakers can attain are VERY reactive with a very low power factor.

www.rapidtables.com/electric/Power_Factor.html

Above link included for the 1 or 2 people who 'get it' and are willing to at least understand the gist of the arguement.

This discussion of power factor is intended for unifrequency power line correction only.

[leonski]

Yes, If I owned a factory I'd be concerned with Power Factor. Some electric utilities will charge a premium if the PF drops below a certain level. And note that I never mentioned CORRECTION which can be applied to factories and even an individual power supply.
I can't offhand name the manufacturer, but at least one used PFC in its advertising.

But the Application to a stereo amp is just an extension. How WELL does an amp work into some of the wacker speaker loads? Are all the same? That's why I've been an advocate of a REAL dummy speaker load for years now. Instead of a simple resistor which is unlike ALL
speakers except at specific frequencies which even vary from speaker-to-speaker, a REAL dummy load is used with known reactance. Than at least you could compare amps based on ability to work with something approaching a Real Speaker.

The Math applies, too, but most won't care about that and I can hardly blame them. Real data is nearly impossible to get and even Stereophile simply publishes the graph with comment concerning only a few nasty points. The rest? Good Luck.

For a one-size-fits-all approach? Power Cube is as good as any and better than most. This will stress an amp to its limits with both high angle Capacitive and Inductiive loads. As well as straight resistive.

audiograph.se/

Down at the bottom of the 1st page is a graphic showing a measured amp at one set of points. I think the article is under the 'documentation' section and is a good, easy and non-technical read.