In the overwhelming majority of loudspeakers, active or passive, the major source of non-linear distortion (e.g. harmonic distortion and intermodulation distortion) is due to the drivers themselves. The measurements of harmonic distortion which are published with KEF products are full system measurements including the drivers and the crossover.
Active or passive is just one choice among a plethora of design decisions. There are plenty of other areas where the designer can get it right or get it wrong.
that's basically what I was trying to convey over here for some time. it's nice to have backing from a guy from the industry.
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When using a 6dB/octave (1st order) crossover it will only be 12dB quieter 2 octaves below the crossover point. This means that the tweeter will still be audible and thus will be distorting because it's at too low a frequency. A 2nd order crossover is better but will still suffer from the same problems.
With an active crossover a 4th or 8th order filter is possible allowing the drivers to reproduce only the frequencies at which they work best. This means that they will distort less and give better clarity.
that's why you've got drivers and drivers. you need quality, linear drivers for 1st order xover. EDIT: and you need to know what your drivers are capable of. when you set the xover point with caution you can't be wrong. you don't need to go all the way down to freq response threshold of the driver to set the xover point up.
for instance Dynaudio is using exclusively 1st order in their passive speakers. and they cut pretty low too, below 2kHz mark. do you think they get it wrong?
also there are B&W, Vandersteen, Thiel, Analysis Audio and many more who use 1st order xover. I guess they too know what they are doing.
2. The passive crossover adds a considerable abount of audiable distortion but an active crossover does not.
sigh... go to page 3 in this tread and read my post #7 if you still haven't done so. it's about quoted harmonic distortion from new KEFs and Event Opals...
Please read this carefully to understand why passive crossovers have more distortion than an active crossovers: http://hddaudio.net/viewtopic.php?id=886
I actually did. a few weeks ago. the guy is using the worst inductors possible. that's why he's getting poor results. why don't you ask him to put an air core ribbon coil instead of those he used and then compare the results. you'd be surprised. but of course he's not going to do that because it's going to ruin he's marketing argumentation.
It's futile trying to compare the measurements of the Kefs to the Opals as both have been measured in isolation. For the measurements to mean anything they would've had to be measured at the same place using the same equipment.
well, this is just lovely!
when you don't have any more arguments left why don't you just suggest that measurements are inconsistent. well Steve, I'm pretty sure that both tests were performed on calibrated, specialised equipment. you could argue the way you do if one of those test was made in your bed room, through some cheepo mic and of-the-shelf soft. but that didn't happen, did it?
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David @Frank Harvey Hi-Fi, Coventry
Mitsubishi HC7000 / Oppo BDP103 / Audiolab 8200AP / Rotel RMB1575 / kick ass speaker system
The speakers were measured in two different rooms with different acoustics, under different condititions using two different pieces of equiptment.
Even if you measured two identical speakers under these conditions the results would differ.
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They're limited to using either 1st or 2nd order crossovers with passive speakers but their active speakers use a 4th order crossover which is better because they have a steeper filter slope.
Wow, this got a long conversation started!
Right, well I went and had my demo yesterday and got to listen to a lot of options! Without meaning to inflame any more argument the passive options were quickly dismissed compared to the actives, as much for practicality as for the fact I felt they sounded far "cleaner" and more natural in general. This is just my relatively uninformed or trained opinion.
With actives chosen as the desired route I can confidently say that all I listened to sounded different from each other. The ones that made my final shortlist were:
Adam A7x, Acoustic Energy AE22, Genelec 8030a, Yamaha HS80M.
Adam: Very good but large ports on the desktop seemed to make bass a little overblown at times, on stands they may well be better. Treble a little too sharp at times though great detail.
Acoustic Energy: Very good again but this time with far more natural bass, at first seemed too subtle compared to Adam's but on longer listen it's all there but in good proportion to everything else in the mix, only downside is that they're a little large but my desk is wide so not a massive problem.
Genelec: Again a nice speaker but for me seemed to struggle a little compared to the larger models, the strain made them sound less natural.
Yamaha: Good price but for me far too midrange forward. I found them uncomfortable on a longer listen because of this.
The outcome: For me the Acoustic Energy AE22's offered the best balance of everything and despite having quite a large "footprint" they will be fine for me in my room. The shop told me they were designed to be used on a mixing desk so this may have helped them in position on the desk! In short, next payday I'll be picking up my pair. I probably had a slight soft-spot for them already as since I've been back I've been really enjoying my AV system from the same company!
With regards to pre-amp, this shouldn't be a problem as my soundcard has all this built-in I think - I will double check though!
Many thanks for all the great advice and debate, it's been an interesting read!
System: Sony EX 503 TV, Onkyo NR509 AV Amp, Monitor Audio Radius 5.1
It would be interesting to know what amp/passive combinations you tried for comparison...
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I tried some JBL Control 5's and the passive version of the Acoustic Energy AE22's. The other passive speakers were either very cheap or very expensive, those I tested were by no means bad but on both I felt the easy detail and bass definition especially was not as good as the active models. There was far less choice overall with the passives though. The amplifier was an ART one but I didn't see close enough as to what model, I think they said it was 140 watts so should have been plenty to power the speakers well.
Ok, thanks for the reply. But it would be interesting to know which passive speakers at a similar price point you tried. The JBLs are pretty cheap monitors compared to those AE.
The ones you say were very expensive, what were they, and did the AE22 sound better? Or was it a case of the expensive passive ones being better, but not worth the difference?
After starting this thread regarding the KEF's Rob, I find it odd that you're not going to try them!
I apologise for participating in the somewhat derailing of your thread.
I'm glad to hear that you've found some speakers that you like. I considered the AE22's myself, they're great sounding and fantastic value speakers.
Yes, quite agree. Did i miss something ?
@fr0g: There really wasn't that much passive choice, nothing else really around the £1000 and under point I was looking at, the other models were well into the thousands so I dismissed them. My point wasn't really to have a passive vs active competition but to find the best speaker for my needs and budget really.
@FrankHavrey: Unfortunately no pro stores near me seem to stock them, at least yet. From my discussions with the shop and looking at some pro forums it seems passives really aren't very popular in the home studio field. I must admit I much preferred the pro shopping experience, last time I went Hi-Fi shopping the dealers were far more pushy about certain brands and models, often citing reviews and awards rather than just letting me listen to product I wanted to try. They seemed to have more of an agenda which was strange as I'd be buying the product from them anyway?? The pro shop was very easy going and accommodating.
@steve_1979: Thanks! Don't worry about the thread, it's an interesting read. Funny that the Hi-Fi community seem largely on the passive side and the "Pro" on the active side. I guess this has to do with character versus accuracy or something? I don't really know enough to get that involved in the debate!
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