Originally Posted by iliasmd
I tried looking for an answer for all the forum including from the manufacturer but no luck. I have 5 channel Amplifier Anthem A5. Can i use this to bi amp and run my LR and leave one channel blank? The Amp says 180 driving all channels and one channel 225. If i use main and surround for left and right to do the biamp, will the speakers get double the power of 360 instead of 180 watts?
With music or typical signals--no.
If you installed a microphone in your system, passively bi-amped it and ran some high level feedback through it---yes, you just blew your tweeter up--congrats!
Passive bi-amping really does not do anything--because it can't--that passive crossover does not allow you to change anything but the gain.
The REAL answer is "active bi-amping" This is going to take some work--a lot of work and knowledge if you don't want to blow up anything--you have been warned!
To actively bi-amp, first you remove the passive crossover and throw it on the bench. Then directly wire the drivers to the input terminals--be a good idea to put a capacitor inline to protect the tweeter from turn on thumps from amplifiers to prevent blowing them out.
Next step, get an active crossover box--two channels for the two speakers. Set the crossover at the stock points with the stock filters as a start. Connect the amplifier channels directly to the drivers--make sure the crossover is turned on first (of course) then turn on the amp channels. Once you verify again that the crossover settings have not been changed, feed it a signal. You now have actively bi-amped your speakers and probably voided all the warranties but such is life.
If you want to "improve" your speakers and make them "better" than the stock crossover points, you can start with using steeper crossover filters--that can help protect the drivers or why active processing is used with pro sound speakers. If you can, look up your specific drivers and get the "white papers" or the tech specs on the drivers--very common in pro sound. They might state the mid is good for say 100 watts when crossed over at 500 watts at 12dB per octave filter but can handle 200 watts when crossed over at 800 Hz at 24dB per octave filter. Adjust the crossover to those settings and now you gained 3dB more output!
This does not mean it will sound good but if the degredation of sound quality does not bother you, enjoy your increased SPL.
You can also put limiters on the amplifier channels, say the woofer handles 500 watts and the tweeter (compression driver) handles 50 watts. Now you can put limiters of 500 for the woofer and 50 watts for the tweeter to protect your speakers. You can play with the gain controls on the amplifiers to get the balance right, good to run a quick sweep when setting gains for best results--check it with a meter. Dumping the passive crossover also is more efficient, you don't waste power heating up the "L-pad" or power resistors which saves on electrical draw and heat generation (another of the reasons it is used in pro sound)
So if you get all the required knowledge to safely do active crossovers/amps correctly so you don't blow up the speakers--well worth the hassle.
Now if you think a passively "bi-amped" speaker gains anything--it can--if you want to boost the treble or the woofer range past the stock settings--that is up to you. However, if you think you gain real, actual power or anything in real world use--you won't. Well, unless you want to make the tweeter louder, softer or whatever. In reality, you are just wasting electricity, stringing extra wire around and an attempt to gain something that is reserved for ACTIVE bi-amping--you won't get it.
I had a pair of 3-way pro sound PA speakers back in the day. On the back there was a switch for bi-amping. It would disconnect the passive crossover from the woofer completely and the high pass filter from the midranges. This allowed me to set whatever I wanted for the woofer to mid crossover point, allowed to change the levels of them and I ran a 750 watt amp to the woofers and limited the mid/high amp to 250 watts from the other amp. I went with a steeper filter at the crossover point and if I needed max power, I would move the point from 500 hz to 800 Hz and push the limiter higher. That was off the manufacturers information on those mids. The tweeter was protected by the passive crossover between the mid and tweeter with overload protection. My big gain was from the woofers--I could run much higher power to them. Not a good idea to have a 750 watt amp hooked up full range when they can be exposed to feedback at 750 watts per channel!
Those frequencies will blow up the mids (don't ask me how I know!)
What the speakers did not do was allow "passive bi-amping" or using the stock passive crossover with two amps. It had connections on the back specifically for active biamping and the switch had to me moved to that position for them to work. I would of blown the mids quickly if I didn't have an electronic crossover doing the filtering--read the manual! There was no option for passive bi-amping for good reason, it would not do anything in reality. I've never heard of a pro sound speaker that could be passively bi-amped--although it is easy to do that--just never heard of one. Your choices are full range or active bi-amping with switches, different connectors and the warning to read the book! Probably why they call it "professional sound" so aim away from face and do at your own risk.
In summation, passive bi-amping really does not do anything of value past adusting the levels of the drivers with amp gain. If you are happy with the balance, then passive bi-amping is a waste of electricity and wire--don't waste money on it. Now if you want to actively bi-amp your speakers, now you need the manufacturer specs on the drivers, need to fully understand crossover filters, know what range you can change the frequencies or filters and ways to protect the unprotected drivers from amp thump and other things. Is the juice worth the squeeze? That is up to you, generally speaking for consumer sound if there are no provisions for active crossovers stock--probably be a good idea to avoid that. You can always contact the manufacturer for information to properly actively bi-amp your speakers--they might tell you---or not. Generally speaking, doing that will voic your warranty and they don't want to be on the hook for sending you new drivers--so don't get annoyed if they pass on your request.
For more information, there are books and web sites that will give you more information how speakers work, how to configure them certain ways and what works--and what does not. Very interesting if you ever want to step over to the dark side of active speakers, just be aware that things can go badly if you do it wrong. Good luck and enjoy your system.