bi-amping or bi-wireing

[admin_exported]

ive have a Onkyo TX-NR807 and Monitor Audio Bronze BR2 5.1 AV Pack can can somebody please explain whats the diffference between the two and which is the best option to go for if any...? also what speaker cable would you suggest i purchase ?

thanks rob

 

[Big Chris]

Well. The Onkyo is an A/V amp and the M.A Bronze AV Pack is a speaker system.

To Bi-Amp, you use the unused* surround rear channels to power your tweeters (for example), while the regular left and right front surround channels power the mids on the same speakers. Bi-wiring uses just the single set of speaker terminals on the amp, but uses 2 lengths of wire to each front speaker.

You have to remove the links (usually small brass bars) between the sets of speaker terminals on the front speakers to do this.

Also. You will have to make sure your amp can operate in this way and go into the set-up menu to configure it properly.

*If you're going 7.1 or thinking of going 7.1 in the future, you're not gonna be able to bi-amp, but bi-wiring is still open to you.

Bi-amping is favoured and if you're going to stick to 5.1, you might as well put those unused surround rear channels to use.

Most people tend to use either QED or Chord cabling. If money is tight, you can use a better quality speaker cable for the front 3 speakers than for the surround pair, but if you can, use the same cable all round. (i.e. QED Silver Anniversay XT for the fronts, and QED Micro for the rears, or use the Silver Anniversary XT all round)

 

[Anonymous]

hi chris thanks so would you suggest i dont bother with either...? im new to this so your help much apprieciated

rob

 

[Big Chris]

trebor34:

hi chris thanks so would you suggest i dont bother with either...? im new to this so your help much apprieciated

rob

I'd bi amp the fronts if you can. As I said above, your amp has got 7 channels of power, if you're sticking with 5.1, you might as well use those unused 2 channels*. You just have to remember to buy 7 lengths of wire (1 length to each surround speaker, 1 length to the centre and 2 lengths to each front speaker.)

The only reasons I haven't bi-amped my A/V system is that I'm running 7.1 so have no spare channles of amplification, and probably more importantly, my speakers are small style speakers and only have a single pair of terminals, and thus, are not biwirable/biampable.

*The Onkyo manual should state whether it can function in this way.

 

[Anonymous]

cheers im off to get some cable today so your input much appriecated

rob

 

[Tonya]

Bi-amping is the way to go of course.
The difference in sound is obvious, providing you take care in setting the crossover frequencies first!

 

[Anonymous]

Certainly agree on bi-amping over bi-wiring but am I missing something? What exactly do you mean by setting the cross-over frequencies Tonya?

I've got an Onkyo NR905 which is I'm currently using in BTL mode although I might go back to bi-amping. If I did I can't see any option in the Onkyo set-up to set the cross over frequencies, care to explain?

 

[Tonya]

Sorry for the delay, just saw your post, 2oldnslow!
Excuse me if I over-simplify but I'm not sure how technical you are.
Normally, a loudspeaker cabinet is fed a full range signal to it's + and - connections on the back, which delivers the electrical signal to a passive (non-powered) crossover of indeterminate quality (usually a few cheap capacitors which change characteristics over time) which splits the signal into high and low frequency ouputs which are then fed to the respective high and low speaker assemblies.
Different loudspeakers have different crossover frequencies, hence the passive crossover inside each loudspeaker cabinet design is different, there is no real one size fits all design.

It's more sonically efficient to split the full range signal at line level inside the reciever before the main amplification stage.
On professional rigs, this duty is performed in a device called an active crosover, indeed it's not unusual to split the full range line signal into several bands such as sub bass, bass, lo-mid, hi-mid, top, hi-top, etc.
In that way the amplifiers and speakers are matched to produce the best sound possible in each specific frequency range and the energy of each band can be adjusted indefinately.

Back to the domestic reciever, I'm not familiar with your particular Onkyo model, but I'm sure there will be an adjustment entry in the menu somewhere if you select the bi-amp option.
In this way you can select the frequency cutoff point where the reciever splits the line signal between the high and low amplifiers.
As I mentioned earlier, this cutoff point will vary from each model of loudspeaker but such information is easily available from most manufacturer's websites.
Selecting the wrong crossover point will result in a "hole" in the frequency spectrum which is not a good idea.

One last tip : if your Onkyo is fitted with the Audyssey auto setup system, don't be afraid to spend some hours tweaking the settings as the result it arrives at is not always perfect!

I hope this answers your questions!
Just as the point of woofers and tweeters is that one single cone doesn't have the capability to reproduce both low and high frequencies at the same time with any accuracy, the advantage of bi-amping is that there are dedicated amplifier channels for bass frequencies and seperate amplifier channels for high frequencies.
This results in a much cleaner sound as the amps don't work so hard.

Please note that the above explanation is much over simplified, but I think you'll get the idea!

 

[Anonymous]

Sorry to hijack but my question is sort of related.

I've often wondered why on some sats/subs systems does it requires you to set your sats to small. I know this is to limit the sound frequencies which can damage the speakers. However if you bi-amp/bi-wire some full size speakers you do away with the crossover, surely this means the tweeter is getting a full frequency range. Why doesn't it get damaged in the same way a sat would?

 

[Anonymous]

Hi Tonya,

thanks for the explanation just out of interest I searched through the set-up menu's of my Onkyo NR905 last night but could find nothing specific relating to which frequencies get "sent" to which amplifier channel/drive unit when I run my amp in bi-amp mode.

So I'm guessing that the only control I have over this (if any) is limited to telling the amp to "use bi-amping" and defining the cross-over frequency between front and sub. In my case setting the fronts to be "full range". The amp then (presumably) routes the appropriate frequencies to the front Left/Right channel amps and speaker outputs (tweeters) and the surround back Left/Right channel amps and speaker outputs (woofers).

Does this make sense ?

If there is some hidden menu option I'd love to know as any settings the amp applies can only be arbitary and it would be great to "tune things to my particular speakers.

 

[Anonymous]

Reply to NSYGunner

I would say that it is because most sat speakers don't have a crossover being Full Range, and you set them as small because being they small and usually plastic boxes they have a response of 120HZ or even more 150HZ in smaller speakers, and the sub then will make the job for them. the Crossover on bi-wireable speakers will tahe frequencies which are allowed by the crossover.........

 

[Tonya]

NSY Grinner - Bi-amping and bi-wiring are totally different.
In the former, you are actually using four amplification channels and the electronics in the reciever is doing the frequency split.
When using bi-wiring, you are using only two channels of amplification that provide the full frequency range, sending the identical full range signal to the woofer and tweeter terminals at the rear of the loudspeaker cabinet, but the passive crossover circuity behind each woofer and tweeter driver is taking care of the frequency separation.
With bi-wiring the audiable difference is marginal at best, whereas bi-amping is superior because you are dedicating a two channel amplifier stage just for lower spectrum and a further two channel amplifier stage just for the higher spectrum.
In this case, the crossover is determined actively by the receiver and not passively by the circuit attatched to the loudspeaker.
In both cases, you never eliminate the crossover, but merely select to use an active or passive one.

As for setting your sats to small, you are probably referring perhaps to a Dolby ProLogic 5.1 setup where the signals directed to the rear are of limited bandwidth as they are multiplexed within the main channels?
With the advent of the newer lossless Dolby True and DTS Master Audio, this limit is no longer the case and you can (and very often do) get substancial information sent to the rear back and side channels, should you have a 7.1 system.

2oldnslow - By letting the subwoofer take care of the low bass and providing the frequency split is correct, will free your front woofers of the job of trying to reproduce both the low bass and midrange at the same time, resulting in a clearer sound image.

The crossover menu shouldn't be a hidden item, but if available, should appear when you select the bi-amp option, but again I am not familiar with your exact model of receiver.
According to the spec of your amp on Onkyo's website, it has an adjustable crossover of 40/50/60/70/80/90/100/120/150/200 Hz so the facility to tune your crossover is in there somewhere!
On most domestic receivers, selection the option of "I have a sub woofer" should automatically relieve the front set of loudspeakers of the sub bass frequencies, although you usually have the option to override it and instruct the amp to deliver full range to the fronts should you want.

I'm sure there are smarter people than I who can explain this more clearly.

 

[Anonymous]

Tonya the point I'm making is the cross over frequency from the front speaker woofer to the front speaker tweeter isn't adjustable simply the cross over from front speaker to sub a totally different kettle of fish and as far as I can tell for a Jamo C809 it's around the 2000Hz mark So I can only assume that there either a preset function of made when selecting bi-amping in the set up menu, >2000hz to the front l/r to drive the tweeters and <2000 hz to whatever you set the sub crossover to sent to the back surround l/r to drive the woofer.

Well either that or both drivers get a full range signal which seems a bit sub optimal.

Does anyone know? Presumably if you bi-amp with a "regular" pair of stereo amps as opposed to an AV amp you give each driver a full range signal. But that would be the point presumably for an active crossover ala Behringer or similar.

 

[Tonya]

Ahh, now I see what you mean, apologies for misunderstanding your plight, it's me that is too old and slow!
The setting I was referring to when I said 40/50/60/70/80/90/100/120/150/200 Hz of course referrs to the bass crossover point, i.e. the frequency cutoff point to the front speakers with anything under the selected value being diverted to the separate powered sub woofer.

I have a frantically complex setup at home, as I also use a dbx sub-harmonic synthesizer with it's own electronic crossover that generates a bass signal an octave below whatever is playing, to an ultrabass amp and woofer and a very smart fellow that I work with has installed a KX3 electronic crossover into the heart of my system together with something called a Genesis processor which to this day I have no idea what it's supposed to be doing.
It was some stuff that was left over from work and he thought it would be a nice surprise when I came back from my holidays.

As far as the Onkyo is concerned, when using the supplied mic and the Audyssey calibration on a standard setup, I was led to believe that the receiver itself adjusts the crossover points and signal levels when using the bi-amp mode by measuring the sonic performance of the woofer and tweeter units during the sweep callibration, setting both the crossover points and the equalization.

But I may be wrong, I'm not that familiar with the inner workings of the Onkyo, I'm more into the end results and mine sounds fantastic.

 

[Anonymous]

Thanks Tonya,

your system sounds like a tweakers delight

I think you're right about the Audessy thing but I suspect both amps output a full range signal even in bi-amp mode. No problem for an AV set up it sounds pretty good I just like tweaking.