Active and Passive Speakers

Paul,

Measurements by an independent third party would be ideal -- obviously -- but given that all I could find are some harmonic distortion plots by the manufacturer of his product in active and passive guise is there anything you can conclude from the data, now that the axes have been standardized and superimposed?

I realize it's hard to compare, as the passive ADM9.1 appears to have been played about 7 db louder than the active one for the 3 kHz signal, but if you mentally correct for that I'm not seeing a huge difference.

FWIW, HeadRoom lets you plot such data for various headphones -- for example, the Beyerdynamic DT880s vs the Sennheiser HD 800s.

Harmonic distortion of a 500 Hz sine wave input


If I'm interpreting the graphs correctly, there's a bigger difference between those two headphones than between the active and passive version of the ADM9.1s.

Joe

 

D'oh, the headphone graph didn't appear in line.

Just click the linky to see.

Joe

 

The first distortion product on the apparently hideously distorting Beyer appears to be 70dB down, which is 0.03% or thereabouts...

WRT the ADM9 I'd want to know why the passive crossover was causing distortion at the 100Hz test, there's no obvious reason for it to do so. Perhaps they used an unsuitable inductor...

There are many real advantages of active drive, I'm not sure this is a good demonstration of them.

Paul

 

Damn, I can't see the plots as images are blocked at work.
Looking forward to a giggle later.

 

A tiddly little iron cored one that is saturating perhaps.

 

Rob,

Would you like me to e-mail the pix to your audiosmile account?

Joe

P.S. The Linn and Quad brochures were mailed on Monday. You should have them soon.

 

Cheers Joe,

I think the images can wait until I get home but thanks for the offer.

Got quite a collection of nice old 70s copies of HFN recently with lots of vintage kit reviews, tests and designer interviews.
If there are any Tannoy related pieces I'll scan them for you and Tony.

 

Thanks, Rob.

Any ye olde material on Tannoys would be appreciated, but I'm particularly interested in tests on GRF rectangulars. I've googled my heart out but I can't find anything apart from an original brochure scan or two.

Joe

 

Yes.

300 times less distortion, my arse!

 

That should be the slogan for the HDD Forum!

 

And once the graphs have been normalised so we can see the true differences, what do you think, Rob? Would an average listener hear those differences - between active and passive?

Aside:

I am Cyprus now and taken delivery of my (according to some) horrid passive floor-standers that would cost £5000 to replace.

I'm glad they survived the journey! Sound very nice with my refurbed Quad 405-2 that also got here in one piece.

Squeezebox not yet working but I can play Flac from the laptop and stream few stations using Foobar - have the laptop perched on a stool on a table in the lounge window where it can see the neighbour's router through the orange trees!

My own broadband is three weeks away as the national telecom and a private cable company play silly games with each other!!

Even though the private company is a lot cheaper I still have to pay twice as much for a quarter of the speed I have in UK!!

 

Hi Brian,

IMO they should have done a standard swept distortion test like just about every other reputable manufacturer.
They don't even need to complicate things - just pop the ADM in anechoic or semi-anechoic condition and run a 40hz-20khz distortion sweep at different SPLs - say 80db and 90db at 1m.
There are plenty of existing passive systems with which to compare the results.
I do take the results as an admission that the original claims were entirely bogus, and that is at least some progress.

On the question of the differences being audible, that really depends on the behaviour of the drivers and passive crossover.
Peaky and badly behaved drivers will certainly perform better if driven by an active crossover that is able to tightly control the passband - this ensures that you hear the best of the driver while avoiding the problems. Similarly, an underspecified and perhaps saturating passive inductor will have quite distinct audible traits. I know I'm sounding like a broken record on this, but you really have to asses the speaker system as a whole. When you do so, the 'advantage' of active then becomes part of a complex mix of vices and virtues.

Glad to hear that the kit made it safely to the new home and that it performs well.

regards,

 

Polley or Lilly?

Do you mean Ben Lilly?

 

I used to have a pair of Philips RH544 speakers. Not only active 3 way but Motional Feedback too.
Made in the late 70's they punched above their weight. The bass quality was superb. Hard to find nowadays.

 

It was a long time ago (5 years or so) but sure it was Bob Polley.

 

Today I called in to Digital Village Southampton and listened to a few active nearfield monitors.

Adam A7

Genelec 8040 (They were set up and there were no 8030s in the shop.)

Dynaudio BM6 Mk II

Didn't like the Adams at all - particularly the treble (a ribbon tweeter), and I wasn't sure about the bass either.

The Genelecs were pleasant enough, but it was the Dynaudios that sang for me.

I listened to some classical piano solo music, some choral music on a particularly clear Gimmel recording and YoYo Ma on the cello.

And John Gielgud's speaking voice.

The man in the shop says he prefers the Dynaudios and that's what he sells the most of (he told me that after I had expressed a preference).

I was listening to the BM6, but he says the BM5 is just as good for rather less.

He suggests I listen to Focal CMS 50 or 65.

I would need to listen for much longer, but my initial impression was that although they were clear and clean they were not in a different league to the passive towers I have in Nicosia. I did not attempt this`afternoon to listen to a romantic orchestra in full fortissimo!

I have every couple of years for the last 20 years gone into HiFi shops for a listen, and come out thinking I would stick with what I have, for it measured up well.

 

Brian you really need to hear them at home, do they let you borrow speakers there?
Keith.

 

I can ask. I can't be too demanding as I couldn't buy them. My wife would not let them over the doorstep!

I was asking about grills. "Why", he said, "you won't be moving them"

It was beyond his comprehension that they might be cosmetically unacceptable.

Different worlds.

So that, at any sensible price brings me back to ADM 9.1 or passives.

And since I have a spare Quad amp . . .

 

But passives have three million times the distortion of actives!

 

Now let's be sensible, Keith - three million?

What I can't hear I don't care about.

I'm also told my re-built 405 has enough distortion to crack walnuts (or even Brazils.)

I think I should buy the Harbeths and keep then till I die - dirt cheap if you do the sums.

An active speaker I will write off in five years, 7-10 if I'm lucky.