advertisement


Beolab 50 - addressing the speaker/room interface.

He was talking about the advantages of DSP crossovers, multiple dedicated ampification channels and DRC algorithms.

There can be no doubt whatsoever that driving a pistonic driver with a dedicated amplifier (or channel) is going to give you a better result than one stereo amp driving multiple drivers via a passive crossover. If you haven't tried bi-amping your JBLs then you should give it a go. Greg Timbers quad-amps his Everest DD67000s. DSP can be a mixed blessing if not done well and if you don't fancy it there are alternatives; check out the First Watt B4 electronic crossover. Alternatively, a Pass designed DIY version will soon be available via the DIYA Store.
 
I tried it Ian and I just use one Devialet per channel and the Timbers designed analogue crossover these days.

I often use analogue sources as well. I often listen A/D, D/A, A/D, D/A. Sounds great. Sounds far more authentic than a lot of my work did before, digital or analogue.

I'm not knocking digital crossovers per se, just saying that for me personally there are more important things to address.
 
I tried it Ian and I just use one Devialet per channel and the Timbers designed analogue crossover these days.

I often use analogue sources as well. I often listen A/D, D/A, A/D, D/A. Sounds great. Sounds far more authentic than a lot of my work did before, digital or analogue.

I'm not knocking digital crossovers per se, just saying that for me personally there are more important things to address.

So you are already doing it :)

I wasn't aware of the Timbers designed crossover. Where can I get more info on it? (That said, it would have to be exceptional to beat something designed by NP).
 
I previously used a Pass Labs XVR-1 with Tad and JBL drive units in a custom design. I used it because it was audibly better than the DEQX I also tried.

I'll take the 9800 with it's old fashioned passive crossover thanks.

The thing with the 9800/9900/6500/6600/6700 and the others is they were carefully voiced by some of the finest minds in audio. They are coherent in a way that is revelatory for many.

I'd love to pretend that I was as knowledgeable as these guys but, over time, I've had to confess to falling short in that area.
 
I previously used a Pass Labs XVR-1 with Tad and JBL drive units in a custom design. I used it because it was audibly better than the DEQX I also tried.

I'll take the 9800 with it's old fashioned passive crossover thanks.

The thing with the 9800/9900/6500/6600/6700 and the others is they were carefully voiced by some of the finest minds in audio. They are coherent in a way that is revelatory for many.

I'd love to pretend that I was as knowledgeable as these guys but, over time, I've had to confess to falling short in that area.

And that's it in a nutshell. A speaker that has voicing built into the crossover cannot be "improved" by going active with textbook Sallen-Key active filters.
 
The principal advantage gained by going active doesn't derive from improving the speaker . . .
 
Well that's your view, but it flies in the face of a technical analysis of what happens when 1 amp drives 1 driver vs 1 stereo amp driving multiple drivers via a passive crossover.

My point wasn't clear I guess. Multi-amping a speaker system in and of itself isn't an improvement unless the same effort is put into voicing the active filter as was put into the design of the passive filter it replaces. i.e. a well-designed passive system will outperform the same drivers in an active system if the latter uses off-the-shelf filters. However, with a bespoke filter the active system can shine, as we have seen with the new B&O and Kii designs.
 
A lot of audio engineers and musicians too Keith. You too it would seem :)

Kii3

imgext.php


JBL K2 - taken at 96db ( so the red trace on the Kii)

21319164_10155644311789076_2915943888546830840_o.jpg


Physics is a bitch isn't it Keith...

Joking aside, distortion is often quoted as a reason to go active, particularly when it comes to the modern digital active monitors. The truth is there is far more to it than that and physics dictates what you can get out of a drive unit. The JBL benefits from a 15" cone, working optimally, within it's design parameters, and compression drivers with vanishingly low distortion. Big IS better.

IME, the Japanese are the masters as they gravitate towards big, low distortion monitors whose FR is designed to work in small listening rooms. For most UK use, their reference designs are often perfect.
 
Yes Keith, and compare the levels of distortion at 60hz or even 50hz.

I'm sure you are familiar with room gain - that's why most of the larger TAD's and JBL's of old start rolling off there.
 
Keith, it is inevitable that the Kiis have much more distortion in the bass, that is what Merlin meant with physics.


I'd like to see distortion measurements of the Devialet eggs.
 
Pop up a microphone and measure yours, it would be interesting to see an 'in-room' measurement.
Keith

This is a fair comment.

I'm trying to work out why boundary reflections should affect distortion, but in-room measurements would demonstrate/prove it one way or another. It removes the effects of test methodology.
 
My point wasn't clear I guess. Multi-amping a speaker system in and of itself isn't an improvement unless the same effort is put into voicing the active filter as was put into the design of the passive filter it replaces. i.e. a well-designed passive system will outperform the same drivers in an active system if the latter uses off-the-shelf filters. However, with a bespoke filter the active system can shine, as we have seen with the new B&O and Kii designs.

Fair enough, I think we are in broad agreement.
 
As, Ian, does an awful lot of the audio world. :)

Take valve amps and vinyl for starters.

I get that and I'm actually in the analog sounds better camp. Also, whilst my Neurochrome amps measure extraordinarily well and sound absolutely fantastic I also think there is something special about a good SET amp. However what is happening in electronic terms when one amp drives one driver vs the alternative is not subject to those vagueries - it's just the laws of electronics in action.
 


advertisement


Back
Top