2 x 1080 vs 1 x 1090

[Stevebez]

Mmm intersting one wouldn't you say especially if you bi-amp... any thoughts??

Seems much of a muchness between the two alternatives... thing is I already have one 1080 and like it so much I want another. The 1090 is fabulous but it is a bit of a mountain.

Will be used to power 803D B&W's ... one 1080 is fine for normal SPL's but the 803's deserve more headroom I think.

Rgds Steve.

[booktrunk]

Hummmmmmmmmmmmmm, I really think that you are going to have to try a demo and decide for yourself.

I suppose if you bridge your 1080 and use it on one speaker you'll get a vague idea of what the 1090 is like No, seriously it's all down to personal preference. Also how close are the amps... will a second run of cables cost a fortune?

You have to admit a 1090 does look a bit kick arse!!

So my conclusion.. go and try for yourself.. DOH!! Bit pointless me offering suggestions wasn't it Oh well Good luck.

Steff

[Stevebez]

Even though the 1090 is more impressive unit - its just a bit of a bulk to harbour in my cabinet ... I can put 2 1080's side by saide ... but would not bridge them but bi-amp the 803's...

Not sure what the transformer specs are of the two units - but basically the 1090 is more or less 2 1080's in one chassis ... I think...

Thing is if I biamp does using one channel for low end and the other for high end cuase any issues in terms of balance of current. I would think one side would always be overstrssed and the other less so... so I guess this is less than perfect. Anyway an intersting comparison for me ... that an audition would resolve I am sure.

Rgds Steve.

[JDH]

Thing is if I biamp does using one channel for low end and the other for high end cuase any issues in terms of balance of current. I would think one side would always be overstrssed and the other less so... so I guess this is less than perfect. Anyway an intersting comparison for me ... that an audition would resolve I am sure.

Rgds Steve.

Probably not a good idea connecting the channel for low end to the left channel after all the issues with left channel fuse failure on the RB-1080. No point risking blowing the fuse if you can set it up to try and avoid this occuring.

[Aussie Geoff]

SteveBez,

I asked B&W UK this very question (they also distribute Rotel in the UK. Here was their answer.

I have to admit that I am always in two minds over the question of bi-amping. Is it the right route or, given a certain budget, are you better off getting a single, more powerful amp? If you listen fairly loudly such that you often approach the voltage limits of the amplifier, then I would go for a more powerful amp to lessen the likelihood of clipping. Bi-amping gives you no more total power transfer. A RB-1080 in bi-amp mode still delivers just 200W worth of sound level. What matters is the voltage swing. What bi-amping can do is give each amp an easier load. For example, the difficult part of the load of these speakers (most of ours come to that) is the low point in the impedance just above the box/reflex resonance peaks in the bass - around 100 - 200Hz. If you split the amp load, the one feeding the MF/HF of the 3-ways does not have to cope with this current-sucking region and may perform to a better quality level by being less stressed. Once you get to the better amps, though, this is actually less of a problem as they tend to have better current reserves.

Geoff

Geoff

[PewterTA]

But doesn't that only occur if you are using an active crossover before the amps? Otherwise the amps are STILL pushing out the full range frequency to both the LF input and MF/HF input on the speaker. So in effect it's still having to amplify the lower frequencies, it just gets blocked by the crossover in the speaker?

The way I look at it is to go with whatever fits your budget better. The 1090 will be pushing 380 watts total to the speaker, the 1080 (dual, bi-amped) will only still be pushing 200watts (granted it's 200 to the LF and 200 to the MF/HF). But it's still only 200 watts. So I'd think the 1090 is a better way to go, but the 2 1080s gives you a little more flexibility (if you went to a multichannel setup).

[csuzor]

I agree with PewterTA, bi-amp only if you have an active cross-over (before the amp) at exactly the same frequency as the speaker requires.

The 803D crossovers are 350Hz and 4kHz... You will need to split at 350Hz... but that does require additional hardware.

With 200W into each side (300+W near that critical 3.0ohm frequency in the B&W) form the RB1080, I doubt you will run anywhere near clipping (just how loud do you like it?!), so the B&W advice suggests bi-amping would be better sonically in this case (as long as the active cross-over is sonically clean...)

[GSamF]

Active Crossovers

I've been following threads like this now for quite some time, and I'm interested in maybe biamping with an active cross-over.

Does anyone have one, have any links to one, know the approx costs of one (or is it asking like how much does an amp cost?), or have any info on any specific brand?

thanks