[MattCassidy]

OK then. I have my Aksa 100W-N and I now have some pretty swanky speakers B&W 805s's. I have a reasonable CD player (Arcam 73T), and I am almost finished my GK-1R. Which leads me to the inevitable question as to what is next. The speakers were a major upgrade.

Bi-Amping is something I am interested in exploring. What would I do? Same amp again, or perhaps a 55W for the tweeters? Or perhaps make the 100Wn into a 100W N+?

After all a man has to have a project.

Any suggestions or recommendations welcome.

[andyr]

OK then. I have my Aksa 100W-N and I now have some pretty swanky speakers B&W 805s's. I have a reasonable CD player (Arcam 73T), and I am almost finished my GK-1R. Which leads me to the inevitable question as to what is next. The speakers were a major upgrade.

Bi-Amping is something I am interested in exploring. What would I do? Same amp again, or perhaps a 55W for the tweeters? Or perhaps make the 100Wn into a 100W N+?

After all a man has to have a project.

Any suggestions or recommendations welcome.

Hi Matt,

Weeell, I seem to remember Hugh published a "points chart" of AKSAs and their upgrades ... which suggests to me that upgrading from 'N' to 'N+' should be your #1 upgrade.  Not THAT much money and a whooole lotta improvement!!  

However, then, definitely bi-amp!  Even though, I guess, with your new B&W 805s it will be passive bi-amping ... that's still better than "mono-amping"!!!

Of course, if you want to get REALLY serious and rip out the passive crossover so you can actively bi-amp ... then you'd really be talkin!!  

What you need for this is preferably the crossover schematic ... or at least the slopes and crososver frequencies.

Regards,

Andy

[MattCassidy]

I will now demonstrate my ignorance.

You are saying that passive bi-amping is where the crossover is still active so that even though I have two sets of binding posts each being fed by their own amp, the crossover is still active and allowing some current to go to the other drivers?? Is this a bad thing?

N+ Hey? What is the time requirement for this upgrade now that I am an accompliished solderer?

Kind regards
Matt

[andyr]

I will now demonstrate my ignorance.

You are saying that passive bi-amping is where the crossover is still active so that even though I have two sets of binding posts each being fed by their own amp, the crossover is still active and allowing some current to go to the other drivers?? Is this a bad thing?

N+ Hey? What is the time requirement for this upgrade now that I am an accompliished solderer?

Kind regards
Matt

Hi Matt,

CROSSOVER THEORY 101

You speakers - and most, save for those beloved by our sadly departed Sydney friend or Quads - have a crossover which splits the total frequency range into that which the drivers can cope with.

If a speaker has 2 or 3 sets of binding posts, all this means is that if the jumpers are removed, each set of binding posts leads to a different section of the overall crossover which can work independently of the rest.

In a 2-way system, with 2 sets of binding posts, you would have one amp feeding the woofer and another feeding the tweeter.  The lowpass crossover prevents the high frequencies from reaching the woofer and the highpass crossover stops low frequencies from reaching the tweeter.

So it's not correct to think of this situation as "allowing some current to go to the other drivers".  Each amp is only dealing with one driver but there is still some power being lost in the crossover ... but less than if one amp was feeding the entire crossover.

The above is a simple arrangement and all it needs is a second (stereo) amp ... as long as your speakers have 2 sets of binding posts.  In my opinion, the next stage "up" is to go active.  This means the passive crossover components are ripped out so all you have left in the speaker cabinet is the raw drivers ... with appropriate impedance compensation.

You would then insert an active crossover after your GK-1 and feed the two amps with the output of this crossover.  However, the amps are then directly connected to the drivers so (if you don't have an AKSA!) you might be in trouble if your tweeter amp has a loud "power-on thump".

Luckily, AKSAs do not suffer from this problem!  

Regards,

Andy

[Seano]

The N+ upgrade from N will only take a couple of hours per board absolute max.  It isn't that tricky although some physical changes are necessary.

Main thing is that it'll take another 5 to 50 hours depending on your ears for the best of the N+ upgrade to take effect. There's something about BG Caps that means that they initially behave like a drunk in a bar and not only sing all the wrong notes but they never hit the same note twice in quite the same fashion........good thing is that they quickly sober up.

As for the bi-amp proposition there's no reason why you can't go for a standard 55 for the tweets.  But I'd do the N+ first simply on a bang for buck basis.

[stvnharr]

Matt,

"Bi-Amping is something I am interested in exploring"

Why is this something you are interesting in exploring?  Is money falling out of your pockets?  Passive biamping those 805's will give neglible effect, and there are a lot of things to consider in making an active system.
The N+ is good bang for the buck.  Spend the rest on music and just listen.

Anyway, those are my thoughts.

[DSK]

Matt,
I agree with AndyR and Seano, the N+ upgrade is a no-brainer. The improvement from Nirvana level to Nirvana Plus level is greater than that of standard level to Nirvana level ... no question. I would not have replaced my Plinius with the 100N, but did so enthusiastically with the 100N+.

Seano's comments on burn-in of the Blackgate caps in the N+ are spot on. From memory, they settled down at around the 80 hour mark. Lengthy? Yes. Worth it? Absolutely!!

[DSK]

Matt,

"Bi-Amping is something I am interested in exploring"

Why is this something you are interesting in exploring?  Is money falling out of your pockets?  Passive biamping those 805's will give neglible effect, and there are a lot of things to consider in making an active system.
The N+ is good bang for the buck.  Spend the rest on music and just listen.

Anyway, those are my thoughts.

I agree completely! The 805's are not a difficult load for the 100w AKSA. Using two of them via the 805's internal xo's is unlikely to yield any real sonic benefit at all. Actively bi-amping them with an external xo *may* provide audible improvement (depending on the quality of the 805's internal xo that you bypass and the quality of the active xo you choose) but this becomes expensive to do well and provides no guarantee of any audible improvement either. I would rather see you save the money, put it into more music, or seek an upgrade elsewhere in the system that has a higher likelihood of improvement and degree of improvement.

If the AKSA 100w was marginal for the 805's then adding another one may provide some improvement ...but it's not. Or, if you were using two different amps (one that excelled at highs and one that excelled at lows) then it might be worth considering (though there are pitfalls in doing this too). Or, if the 805's passive xo's were total crap (in parts quality and/or design) then you would definitely get improvement from bi-amping ...but the improvement is from the external active xo, not the result of adding another amp.

Sometimes theory sounds great but it doesn't always provide audible improvement in practice. Sometimes it does, but not in all systems. If you are determined to bi-amp, I'd suggest that you keep researching the topic while you install and burn-in the N+ kit. Please, don't jump too soon as you may end up wasting a lot of time and money.

Cheers & Good Luck!  

[Seano]

Actually as a bit of a follow-up, I've tried bi-amping my Krix Lyrix floorstanders (see www.krix.com.au) using the 100W driving low and a Yamaha 100W driving high.

Compared to the AKSA driving the lot the result was...different.

Better? Surely it must've been. More grunt, more stuff, more ummm....

...nope. Just different. Given the hassle of switching one or the other I gave up playing and just went with whatever was hooked up.

For the last six months the AKSA's been sitting around not connected cause temporary accomodation and a temporary setup doesn't suit it.

Add to that a GK-1 with a dire case of tinnitus and we have a hassle.

So it's back to the one box suits all Yamamha integrated at the mo'.  

Fortunately that's not too foul either.......just different!!

[bluesky]

Hi Matt

I would be happy for you to borrow my 55 watt Nirvana to try your biamping experiement on your new speakers.  The only hitch is that Hired Goon has first dibs on it and I will be going over to his place tonight to drop it off and you can have it after that for a few days if you want.

PM me if you're interested, but be warned my email has had a life of it's own recently.

Cheers

Bluesky

[bluesky]

Hi Matt

I would be happy for you to borrow my 55 watt Nirvana to try your biamping experiement on your new speakers.  The only hitch is that Mr Hired Goon has first dibs on it and I will be going over to his place tonight to drop it off and you can have it after that for a few days if you want.  Be prepared to have to fight your way through kids and pets!  I have recently taken on a young Korean homestay student and things can be a bit hectic in chez Bluesky at times!    

PM me if you're interested, but be warned my email has had a life of it's own recently.  

Cheers

Bluesky

[MattCassidy]

Hey Bluesky,

Thanks for the offer, I think i will leave it for now as it sounds like a bit involved than first meets the eye. The GK-1 is in the home straight so perhaps we can get together then and do a bit of bi-amping and have a listen to the GK-1 too.

Cheers
Matt

[Rhythm Willie]

I agree that bi-amping can be a bit of a mixed bag, it really depends on the quality of your amplification and loudspeaker i.e. can be a complete waste of funds.

I tried bi & tri amping my Vaf Research I-93's. At the end of the day,tyhe clear winner was one Aksa monoblock per channel(tri wired).

As the Aksa 100n+ drive them to huge SPL,s with ease there was only disadvantageds to amping them with anything not up to Aksa drive,bass control,speed  & tonal quality. If you have a difficult,inefficient speaker then certainly bi amping may help.

IMO if you have a high quality speaker design with good drivers and passive crossover design (i.e. large air cored inducters,high quality metal poly caps,resistors etc I am not convinced that biamping or active amps/ crossover systems are any better in domestic situations(have compared to expensive active Meridium speakers),than the best of the passive Xover systems that seem to dominate the "best speaker reviews".

Summing up I believe one's money could be spent better elsewhere with much greater gains - especially in the speaker area. I have a number of friends who have paid a fortune for expensive imported amps ans speakers(i.e. Naims, Linn etc), that have been magically transformed to a completely higherl by much cheaper Australian speakers a fifth of the price of their pretty average  imported designs. In fact some of these expensive speakers are using pretty cheap  drivers.