Tri-amping KEF R3

[Music1969]

I know the R3 already measures superbly with it's passive crossover.

But I may be able to get a used pair for a really great price and was semi interested in bi-amping and doing DSP (crossover, driver time alignment and digital room EQ all on my computer). For fun.

They already have 4 terminals at the back for bi-wiring, which is great as I wouldn't need to drill any holes in the beautiful cabinet !

So I wonder if it's easy to by-pass the internal passive crossover?

Does anyone know what the inside looks like and if it should be easy to by-pass the internal crossover?

 

[Music1969]

Oops I now realise these are actually 3-way speakers.

So I'd still need an additional set of speaker posts.

Maybe they could replace the 'Link' knobs ?

 

[Music1969]

I saw @maty shared pics of R300 crossover which has very very similar crossover points and other specs.

https://www.audiosciencereview.com/...f-r3-speaker-review.12021/page-12#post-350014

 

[Doodski]

Remove the rear binding post plate, make a new plate with binding posts or simply have wire coming out of the speakers. Simple, effective and doesn't include drilling holes in the speaker cabinet.

 

[Music1969]

or simply have wire coming out of the speakers

Probably having a pair of wires coming out the 'Link' knobs will be easiest, for midrange amp and driver connection.

Should make it easy to go back to passive crossover again (if needed) without any physical damage done.

 

[Doodski]

Probably having a pair of wires coming out the 'Link' knobs will be easiest.

Should make it easy to go back to passive crossover again (if needed) without any physical damage done.

If you cut a new back plate from some wood or aluminum then you can leave all the stock KEF crossover and various wires intact and inside the cabinets so that the speakers can be returned to stock form easily.

 

[AudioJester]

Locally, guys were doing something similar using deqx units with older speakers for many years.
I think you are doing it wrong - as the Kef R3 passive xover seems to to be doing a good job, and the speaker seems the complete package all ready. There is better value identifying speakers where the passive xover is the weak link holding back the potential of the rest of the speaker. There are probably candidates from the speakers that have been reviewed by Amir.

 

[m_g_s_g]

I recently installed a couple of additional binding posts in the back plate of my two-way speakers for bi-amping. To evenly space them in the plate, I did cut four new holes and covered the old ones with rubber grommets. The crossovers are now outside of the speakers.

If you prefer to leave the back plate untouched and depending on where you live, parts-express.com sells several backplates for diy. Maybe one of them can fit in the back of the R3?

 

[Music1969]

the Kef R3 passive xover seems to to be doing a good job, and the speaker seems the complete package all ready

Yes noted and these are the very first words I wrote.

But it's not just for passive XO as previously mentioned - but driver time alignment and digital room EQ also.

A bit of fun and only for a great used price. I wouldn't try this buying new.

 

[AudioJester]

Yes noted and these are the very first words I wrote.

But it's not just for passive XO as previously mentioned - but driver time alignment and digital room EQ also.

A bit of fun and only for a great used price. I wouldn't try this buying new.

Makes sense. Look forward to seeing how you get along with it. Are you using Audiolense?

 

[Music1969]

Makes sense. Look forward to seeing how you get along with it. Are you using Audiolense?

Yep, that's the one that does all 3 things the easiest. Acourate can do it all (and more) but not as 'automated'.

 

[Absolute]

Audiolense will time-align the speaker regardless of it being active or passive, so the passive filter isn't restricting that possibility.
I'd be interested in seeing what effect such time-aligning/correction would have on the spinorama.

Would this affect a coax speaker more/less than a normal one? Will Audiolense/Accourate make things better/worse in every instance?
Will active crossover time-aligned reduce distortion compared to passive? So many questions!
I need a Klippel, dammit!

 

[Music1969]

Audiolense will time-align the speaker regardless of it being active or passive, so the passive filter isn't restricting that possibility.

Audiolense can attempt to time align the speaker as a whole (as best as possible with the passive crossover) but obviously cannot time align individual drivers unless... you tri-amp...

Would this affect a coax speaker more/less than a normal one? Will Audiolense/Accourate make things better/worse in every instance?
Will active crossover time-aligned reduce distortion compared to passive? So many questions!
I need a Klippel, dammit!

All great questions!

 

[tecnogadget]

If you ever get to open your R3 could you take some well detailed and illuminated photos of the insides, crossover, etc ?

 

[Music1969]

If you ever get to open your R3 could you take some well detailed and illuminated photos of the insides, crossover, etc ?

Sure but this is also what I was asking in the opening post.

If anyone has opened an R3 - even if just to look

 

[McFly]

I was planning on opening mine this weekend

 

[tecnogadget]

I was planning on opening mine this weekend

Finally a hero haha !!! I don’t know why I haven’t done it yet, since all it takes is to unscrew the binding post.
Maybe that’s because I want to keep them as virginal as possible

 

[Absolute]

Audiolense can attempt to time align the speaker as a whole (as best as possible with the passive crossover) but obviously cannot time align individual drivers unless... you tri-amp...

The filter is a constant and therefore a constant FIR filter from Audiolense will succesfully time-align the drivers.
I don't have many measurements on this computer, but here's a step response where Audiolense have time-corrected Kii Three with separate subs.
Same concept, although the crossover is done active in the minidsp it's still a constant delay being fixed by a constant fir filter;

 

[Music1969]

but here's a step response where Audiolense have time-corrected Kii Three with separate subs.

You're showing me an example of a DSP speaker (Kii3) to explain how Audiolense will behave with a passive crossover speaker (R3)...

There is only so much Audiolense or Dirac Live or Acourate or any PC based DSP can do with a passive crossover speaker... The Kii3 doesn't have a passive crossover, it uses DSP crossover.

Certainly what you show may be possible with a tri-amped R3 though. That's the point of my opening post.

 

[Absolute]

You're showing me an example of a DSP speaker (Kii3) to explain how Audiolense will behave with a passive crossover speaker (R3)...

There is only so much Audiolense or Dirac Live or Acourate or any PC based DSP can do with a passive crossover speaker... The Kii3 doesn't have a passive crossover, it uses DSP crossover.

Certainly what you show may be possible with a tri-amped R3 though. That's the point of my opening post.

Well, I'll show you the exact same with passive speakers if you give me a few minutes. Like I said, passive filters are a constant factor and can be corrected with a frequency dependant time-domain filter.


Edit; Here is before vs after Audiolense measured in the LP with Klipsch rp-160m + subs;

Here is with Kii Three included;