Andrew Jones discusses pros and cons of active speakers

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JoshK

Re: Andrew Jones discusses pros and cons of active speakers
« Reply #40 on: 20 Jun 2016, 10:44 pm »
@Josh

Now that sounds pretty interesting. What available stuff I've read about the new JBL models is uniformly positive. Pro Sound awarded two models the Best of Show recently. I have always had faith in JBL, and once shoehorned a 2226 into my Leslie, transforming it and the Hammond into a monster.

I will be returning later this summer for awhile, and will be in Toronto for upward of a month. I would trade a nice dinner out on St Clair W., for a listen to those babies..

Yeah, definitely look me up when you are in town!  St. Clair West isn't too far from me depending on how far west.   I am in the Annex near Bloor/Spadina area.

Dmason

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Re: Andrew Jones discusses pros and cons of active speakers
« Reply #41 on: 20 Jun 2016, 10:57 pm »
Bathurst/St Clair. Perfect. A 15 minute bicycle ride to the Annex. I'm doing a rotation at Sunnybrook then returning to my pulapa in the Caribbean.

I will mention that rather hidden in all the new JBL fuss WRT these big buggers, are two new models within this group, the obscure 5 and the 8. The smaller one has very similar specs, and won #1 Best of Show recently, and that says mucho...when one considers that within this field are some very seriously evolved designs such as the new Genelec stuff, Neumann, TAD, et al, very serious contenders. A pro audio friend in LA says these new small compressors are: "to die for," sonically, having listened extensively at the Anaheim show, and that all four of these new models share a VERY similar overall gestalt. He basically described them as a game changer.

it sounds as though you are in for a ride!!

JoshK

Re: Andrew Jones discusses pros and cons of active speakers
« Reply #42 on: 20 Jun 2016, 11:01 pm »
I'd love to hear the JBL M2s as well. They would appear to be Greg Timbers' swan song project, unfortunately.
I'd be particularly intrigued to hear them side by side with the Ocean Way HR4 system (at half the price), even though the latter is not one piece and meant for the console bridge with the subs out of sight below and behind:
http://oceanwayaudio.com/hr4/ system
http://oceanwayaudio.com/ocean-way-audio-now-shipping-new-high-res-near-mid-field-monitors-pro2a-hr4-hr4s/

Those are interesting and strange looking speakers.  I don't discount them based on looks, just thought they were peculiar.   Also note that I didn't pay the full MSRP on the M2 system.  Speakers I got with a mild discount as they are clearing their fiscal year end and the amp is a lot less than the officially recommended one and street price is a bit lower than that. 

JDUBS

Re: Andrew Jones discusses pros and cons of active speakers
« Reply #43 on: 20 Jun 2016, 11:05 pm »
An "active" speaker system is one that utilizes a line-level crossover, rather than speaker-level crossover.  Where you split the frequencies upstream is up to the architect of each system.  Note that a fully active speaker system has a separate amplification channel connected to each individual driver, though a partially active system may have one amp channel for the woofer with a second amp channel driving the mid-range and tweeter through a passive crossover.  Taking the woofer out of a passive speaker level crossover provides the biggest bang for the buck.  (The woofer generates, by far, the largest back-EMF, etc.)

In my case, I split the frequencies after my pre-amp, rather than after my source, as you describe.  I have a 2-channel DAC feeding a 2-channel pre-amp, that then feeds my analog line-level crossover, which splits the frequencies between my tweeters and woofers.  (If I can ever get my multiple subs built, I'll use the second output of my pre-amp to feed the modded DCX that I bought from you years ago to control them all.)

That said, my line-level crossover is only handling frequency splitting duties, not driver correction.  I handle driver correction in the digital domain using a convolution filter in HQPlayer.  (Eventually I may implement a house curve digitally as well, but I have some room treatments to finalize yet, and so haven't played with it.)

Also, even an active system may have a handful of passive parts between the amps and the drivers, usually for protective purposes or to improve the impedance response of a driver.  (I'd definitely recommend DC block caps on tweeters, for example.)  Those parts in no way connect the drivers to each other, however, so you still have a fully active speaker system.

Just in case things weren't confusing enough, the use of a line-level crossover that distinguishes a speaker system as "active" may, itself, be either active or passive, meaning powered or unpowered.  An unfortunate overuse of the term "active" in this case.  My line-level crossover is active, and is capable of generating up to almost 18 dB of gain depending on the number of poles I set in my filters and how I adjust the woofer vs. tweeter levels.  Because of this gain, my pre-amp is passive, as I already have more than enough total voltage gain in my system.

The upside of an active speaker system is significant, but there is definitely a learning curve if you're planning on doing it yourself.  Having the speaker designer implement it is definitely a huge savings of time and energy on the part of the customer.  Of course, if one is already prone to tweaking cables and tubes, this is the ultimate tweaker's paradise... everything is endlessly adjustable.

Thank you very much, brj.  This is helpful.

Although it sounds like you're still dealing with passive components even if before the amplification.   

Also, do amps really have the dsp processing power to do a good job?  Like why even have a  DAC if you're just going to convert that signal with some crappy ADC and then back again with (another crappy) DAC?

-Jim


JoshK

Re: Andrew Jones discusses pros and cons of active speakers
« Reply #44 on: 20 Jun 2016, 11:11 pm »
Well in the case of the Crown DCi/Itech amps, I don't think they are crappy.  Synthesis line is used for mastering 90% of all blu-rays.  Yeah it is an extra ADC/DAC conversion, which can theoretically be bypassed although I haven't looked into it yet.   JBL engineers claim that the built-in DSPs in the amps have a SNR improvement over the equivalent external DSP + amp.   Somehow they managed to optimize a bit.    I am keeping an open mind for the time being. 

And apologies, didn't mean to hijack the thread with my latest gizmo. 

Russell Dawkins

Re: Andrew Jones discusses pros and cons of active speakers
« Reply #45 on: 21 Jun 2016, 12:07 am »
A pro audio friend in LA says these new small compressors are: "to die for," sonically, having listened extensively at the Anaheim show, and that all four of these new models share a VERY similar overall gestalt. He basically described them as a game changer.

Did you mean 'monitors' instead of 'compressors'?

I have hear particularly good things about the JBL 708. An engineer friend in Mexico City, in a comparison between the  JBL 708s and 508s and the new Amphions (One15 and One18, both extremely hot for the last year among mixing engineers) described the 508s as little 'congested' sounding, strangely. I would have guessed the opposite.

Rusty Jefferson

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Re: Andrew Jones discusses pros and cons of active speakers
« Reply #46 on: 21 Jun 2016, 12:18 am »
@JoshK  Congratulations on the M2 purchase.  I'm green with envy.   However,  I don't believe they would be considered "active".  The amps/crossovers are mounted externally.  The speakers are passive.

Has anyone heard the passive UB5 in their home yet?

Dmason

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Re: Andrew Jones discusses pros and cons of active speakers
« Reply #47 on: 21 Jun 2016, 12:47 am »
Russell -- I meant compression drivers, whose design apparently are very modern. Also, apparently my Jordan Eikonae have landed at the house in Canada. Part of the attraction, separate from all their obvious virtues, is that they are weather-proof and will not corrode or immediately grow mold like paper would, here in the Caribbean.

I would not have expected the word congested being used to describe the 8 model. Interestingly, it was the 5 model that won the best of award in Anaheim. Not being at all current with the pro stuff, but did hear some high dog production of London Symphony/John Willliams stuff through the current Genelecs and it was really a trip. Wonderful. So...

Im very much looking forward to hearing the JBL's at Josh's place in T.O.

Saturn94

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Re: Andrew Jones discusses pros and cons of active speakers
« Reply #48 on: 21 Jun 2016, 01:20 am »
...Has anyone heard the passive UB5 in their home yet?

Yes.  A friend of mine bought a pair and brought them over.  I was quite impressed with how good they sound given the price (my friend bought a "blemished" pair for $100 less).  I would not hesitate to recommend them for someone seeking great SQ on a limited budget.  :thumb:

brj

Re: Andrew Jones discusses pros and cons of active speakers
« Reply #49 on: 21 Jun 2016, 01:25 am »
Thank you very much, brj.  This is helpful.

Although it sounds like you're still dealing with passive components even if before the amplification.   

Also, do amps really have the dsp processing power to do a good job?  Like why even have a  DAC if you're just going to convert that signal with some crappy ADC and then back again with (another crappy) DAC?

Sorry, my reference to the DCX may have confused things.  My DCX will be used solely to control the subs.  The only DAC in the signal path to my mains is my Auralic Vega.  I had been trying not sidetrack the thread's discussion of active speakers in general by detailing my personal system, but...

To start with, my music is stored on a NAS which connects to a Mac Mini via Ethernet.  On the Mac Mini, I run Roon for music browsing and HQPlayer to apply the driver EQ correction and upsample to the native sampling rate of my DAC.  The HQPlayer-processed digital output is fed by the Mac Mini to my DAC over USB.  The analog output of my DAC is then sent to my Bent TAP-X passive pre-amp, which has two simultaneously driven outputs.  One pre-amp output is sent to the active gain-stage equipped, analog, line-level crossover (a Pass XVR-1), then the Pass XA30.5 amps, and finally to my 2-way speakers.  When I get my subwoofers finished, the second output of the pre-amp will route to the DCX, which will then control the full array of subwoofers.

So yes, the DCX imposes an extra ADC/DAC, but only to the subwoofer signal path, not the mains.

A few misc notes...
  • The mains path is fully differential from end to end.  The subwoofer path is fully differential except for the DCX, which is impedance balanced, but not truly differential.
  • HQPlayer's unique polysinc reconstruction filters are viewed by many to be superior to those found in almost any DAC, thus the choice to upsample to the DAC's native DSD128 sampling rate on the Mac rather than rely on the DAC's reconstruction filter to do it.  (HQPlayer is also the only software or hardware that I know of that can apply EQ correction to a DSD audio stream.)

To clarify for the sake of multiple other posts, an active speaker system is one that has the cross-over implemented before the amplification stages, when the signal voltage is at line-level.  A passive speaker system has the crossover implemented after the amplification stages, when the signal voltage is at speaker-level.  The active/passive distinction does not depend on whether the line-level crossover is digital or analog, or whether the amplification is internal or external to the speaker.

Again, it's unfortunate that "active" is used in audio both to distinguish between powered vs. unpowered components (or more precisely the presence of a powered gain stage), and systems using line-level vs speaker-level crossovers.  For example, there are many "powered monitors" out there that are not "active" in the sense of having a line-level crossover.... they simply have a built-in amp that still feeds an internal speaker level crossover.

Hope that helps.

We now return to lusting after Josh's JBL M2s...  oh wait, I mean Andrew Jones's discussion of active speaker benefits!  :)

RoadTripper

Re: Andrew Jones discusses pros and cons of active speakers
« Reply #50 on: 21 Jun 2016, 01:35 am »
I have a question that I hope is germane to the topic generally. Using the JBL setup recently purchased by JoshK, what is there that completes the system? Specifically, does this JBL setup need a pre-amp?

richidoo

Re: Andrew Jones discusses pros and cons of active speakers
« Reply #51 on: 21 Jun 2016, 03:48 am »
Actually I have the DCi 4|600n.  n version has the necessary DSP and costs a bit more.  However, it is basically the studio install version of their Itech series and thus are cheaper as they don't have to have things that make them bullet proof for touring duties.  They still apparently have noisey fans so the amp will go in the closet in all likelihood.   The dealer sent me the file to load into their DSP for the M2s.   I haven't received the M2s yet but I have received the amp.

I see, I was reading the non dsp version manual. Cool!
Is the setup file tweakable at all, or do you even care?  :green:

Russell Dawkins

Re: Andrew Jones discusses pros and cons of active speakers
« Reply #52 on: 21 Jun 2016, 04:16 am »
Russell -- I meant compression drivers, whose design apparently are very modern. Also, apparently my Jordan Eikonae have landed at the house in Canada. Part of the attraction, separate from all their obvious virtues, is that they are weather-proof and will not corrode or immediately grow mold like paper would, here in the Caribbean.

I would not have expected the word congested being used to describe the 8 model. Interestingly, it was the 5 model that won the best of award in Anaheim. Not being at all current with the pro stuff, but did hear some high dog production of London Symphony/John Willliams stuff through the current Genelecs and it was really a trip. Wonderful. So...

Im very much looking forward to hearing the JBL's at Josh's place in T.O.
Sorry, I got the numbers wrong. It was the 705 that he found sounded congested compared to the 708. Looking at the size comparison between the two, you can see that it is bound to be a different story as to how they sound.

708i and 705i
I think the 705 astounded people who could see how small they were, but the 708, I gather, is a whole other story, and probably mostly to do with the bass/mid drivers and box size, not the compression drivers which I am sure are pretty special in both.

I am intrigued with the Eikona drivers, too, and would have bought a pair to play with if I had not just committed to a pair of Yamaha NS-1000SMs.




richidoo

Re: Andrew Jones discusses pros and cons of active speakers
« Reply #53 on: 21 Jun 2016, 04:38 am »
I have a question that I hope is germane to the topic generally. Using the JBL setup recently purchased by JoshK, what is there that completes the system? Specifically, does this JBL setup need a pre-amp?

The crossover is just moved from inside the speaker to inside (and before) the amps. So consider it the same as any normal system, you connect your analog preamp or volume controlled analog source directly to the amp, with some caveats. In a professional environment, usually it will be driven by mixing board, but it can be driven with any source with volume control. Source should have enough current to drive the amp's 10kohm balanced input impedance or 5kOhm SE input. That's pretty low for consumer audio standards, so some consumer tube preamps would have trouble. Also, it's a professional "install amp," so no jacks or posts, i/o is hardwired.

JoshK

Re: Andrew Jones discusses pros and cons of active speakers
« Reply #54 on: 21 Jun 2016, 01:21 pm »
I have a question that I hope is germane to the topic generally. Using the JBL setup recently purchased by JoshK, what is there that completes the system? Specifically, does this JBL setup need a pre-amp?

I read somewhere that one can use a digital input into the amps bypassing the first ADC.  I don't know how this would work in terms of controlling the volume.  I imagine digitally, the normal throw bits away way.    Most who I know who own them run their preamp outputs into the amp, so the amps then convert to digital and do their thing before the amp stage. 

I'll be using my relatively recently acquired Allnic L1500 into them.  To JDUBS' point, it does feel sacrilege from an audiophile's view*, to use a hi-end dac in the source and then convert it back to digital again.   However, I am pretty confident that the end results is still hi-fi.  I may look into trying it out directly digitally driven for comparison.

richidoo is right on the details.  You get hardwired pheonix clips I believe to use with your ICs.  I come from a pretty DIY background and often re-terminated my own cables, so no harm there for me (also not a huge believer in the benefits of super fancy wire). 

The Allnic uses a step down output transformer that I think will provide low enough Zout and Iout to drive the amps.  Its manual says it provides a constant 150ohm output.  That should do it.   The output transformer trades the high gain of the E810F (D3A) for lower output z.   

That is enough tangent on my setup.   Those LCR70xi  look pretty good and from what I've read they are pretty darn good and match well with the M2s for surrounds.   If I decide to merge my systems at some point and the M2s trump the DSLs, then I might be looking to grab a pair or two of them.  They are not active, but I think there are provisions to use them with either JBL's SDEC or similar Crown DSP enabled amps, but I am not 100% sure on this.  They are targeted at studio installs, so often a bit more custom tailored if needed.  I'd really love to hear the 708i against a more traditional consumer audiophile speaker given the 708i is passive and would fit into the system without gerrymandering.

richidoo, I haven't played with it yet but you download Audio Architect software which you use to load the files into the amp.   The software is pretty flexible apparently and assuming you have measurement gear (I have and I've used it before too) you can also do a lot of other things like room correction and such.   Normally the Synthesis group within JBL will come and down and do a whole setup for a studio when they buy the complete package including room correction, etc.  With the M2s, consumers were never the intended audience, they just happen to get enough of guys like us who are using them that way.   Its also why they spec the M2s with 1250wpc recommended (versus my 600wpc).  The apparent demand in studios can be very high.   600wpc will be fine for me.  I want to keep my hearing that I have.

* I'm becoming increasingly less and less traditional 'audiophile'.  I still like tubes in the system (a touch of color maybe, but a fine sounding one) and I like fine engineering and execution, but I lean more and more to the objective side when it comes to speakers, amps and acoustics and I don't believe in spending a lot of the budget on fancy cords and wire. 

maty

Re: Andrew Jones discusses pros and cons of active speakers
« Reply #55 on: 21 Jun 2016, 01:48 pm »
Very instructive commercial post.

Why don’t you just make a 2-way bookshelf speaker?

-> http://www.code-acoustics.com/#!Why-dont-you-just-make-a-2way-bookshelf-speaker/jaafl

Quote
Active speaker:


Passive Speaker:


Quote
A 3-way speaker has a tweeter covering high frequencies, a midrange driver covering the midrange only, and a bass driver covering the bass range only. Our crossover frequencies are 4.5kHz and 250Hz.

Code SYSTEM-1 crossover (4th order 24dB per Octave L-R filters):


The most sensitive part of our hearing is 1-5kHz, so you need to be VERY careful about what your crossover is doing in this range. So putting your crossover slap bang in the middle of this band as in a 2-way is far from ideal.

However, the 2-way designer is forced to do this. The 6.5" mid / bass driver is not acting as a piston in this region, and has real problems with 'break up modes'. This means it's impossible for the designer to move the crossover up to the 4-5kHz range. The other solution is to push the crossover down to 1kHz, but this isn't an option either as this will put too much excursion through the tweeter. So 2.5kHz it is, even though this is far from ideal!

Mid / Woofer breakup:


In contrast, our mid-range driver is 4" diameter. This means it's 'break up nodes' are far higher up the frequency range than the 6.5" mid /bass, which is why we can comfortable shift our crossover point to 4.5kHz. Another advantage is our tweeter is working FAR less hard that the 2-way tweeter, partially because of the higher crossover point, and partially because of our crossover slopes:

To keep costs down, passive 2-way's often use 2nd order crossover slopes, which drop at 12bB per octave. Our speakers use 4th order slopes, which drop at 24dB per octave (far steeper)...

mcgsxr

Re: Andrew Jones discusses pros and cons of active speakers
« Reply #56 on: 21 Jun 2016, 01:55 pm »
If JoshK isn't careful he is going to find me lurking around his building when those JBL's are up and running!   :lol:

I am still very happy with my Maggies and Crown XLS amp, but have no doubt that my next evolution will involve active speakers.  I may go with a much smaller setup (Dynaudio etc) but can see the benefits of active for sure.

mojave

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Re: Andrew Jones discusses pros and cons of active speakers
« Reply #57 on: 21 Jun 2016, 02:09 pm »
JRiver DSP Studio was the best for adjustment and SQ, but finding a truly audiophile quality multichannel DAC on a budget was impossible. For all the flaws presented by passive XOs, it is still the best practical solution for me, using high quality passive xo parts was better than anything I could do at line level. . . . There is a new multichannel USB>I2S adapter from diyinhk.com with mating ES9016 8ch DAC kit which I think will finally enable active dsp crossovers to achieve audiophile sound quality at a very low cost.
I use JRiver with Audiolense convolution filters for XO and a MOTU 1248 AVB with dual ESS9016s DAC chips. The MOTU is connected via Thunderbolt. I like it better than my Lynx Aurora 16 Thunderbolt.

undertow

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Re: Andrew Jones discusses pros and cons of active speakers
« Reply #58 on: 21 Jun 2016, 03:33 pm »
Seminarian,

I think the confusion here is we are talking about 100% PASSIVE speakers on every level, but outboard Active / Bi-amp / Tri-amp setups. They are simply missing passive crossovers in the conventional known designs.

Truth is there is no Active speaker. But the closest to the layman in terms of active is that you have internal amplified speakers such as a subwoofer with its own filter contained in the electrical realm, vs. a passive crossover such as Butterworth, or Linkwitz using resistors, capacitors, and inductors creating a choke point of passive components on each speaker driver, and yes ATC is a world known brand with built in Class A amplification that has been doing active bi-amping, and tri-amping with active filters internally of the "speaker cabinet" for years. This system would simply run off a single pair of XLR or RCA coming out of your standard preamp just like any mono block amps would, but you obviously also have to drag power cords to the back of each speaker as well to power them.

Most of the time to create an active system of course you would use "Professional Audio Speakers". They don't have any passive components inside, and just hook up each driver to a tap on the cabinet which you can wire each driver to a separate source of amplification.

This does have some advantages as you can put a good 40 watt amp on a tweeter, a 100 watt amp on the midrange, and a 1000 watt amp on your woofer vs. being fed off one amp with impedance going all over the place driving all 3, and losing not only 60% or more of the power thru your passive crossover, but then the remaining current will be sapped up by your woofer as well which is the biggest advantage of running an Active Bi-amp / Tri-amp system.

But there are so many challenges in getting an active system running for most "Audiophile" types at home it's just not a realistic need. You need more power cords unless your running some type of a 6 or 8 channel amp that feeds off one power cord. You will need a fairly sophisticated DSP which can then divide your single stereo outputs from a preamp into the active outputs for each octave feeding each of your amp channels.

And all this can take a lot of tuning, and playing around. Also, problem is you can't really just decide to put a tube amp on your tweeters with 5 watts, and a couple other solid state amps to run your mids, and woofers. It turns into a whole other ball game level matching so you need to adjust the gain for each, also each amp will have different input impedance, and damping factors etc...

So in the end most are better off with really good 2-way passively crossed over speaker trying to not handle anything below 50 hz with high efficiency, and adding actively powered subwoofers if anything cutting down cables, screwing around with excess components, costs, and tuning it all to work correctly.

Live music P.A. systems are of course ran with Active amplification, and filters which is what we are really talking about here, but they are not active speakers.

In home active speakers for the long and short work well, but just try to buy some used ATC's if you want it done right all the matching, and component power adjustments are made for a well balanced system cutting down cables, and endless headaches.

richidoo

Re: Andrew Jones discusses pros and cons of active speakers
« Reply #59 on: 21 Jun 2016, 03:59 pm »
The MOTU looks cool mojave. Decent price for what you get, compared to similar high end pro interfaces. They always made great gear, one of the first big players in computer audio since late 80s. They used to be Mac only, but now it says works on any DAW with USB. My budget allowed lesser, 'garage band' level interfaces like Aardvark 2496, Firepod 10, etc. But the SQ on those was not so great. 

I did try AudioLense once, back when the demo filter made no changes. I didn't know that so I measured and tweaked the targets and listened for a month, imagining that I heard changes, but eventually decided the changes I imagined weren't big enough to warrant the purchase.  :lol:  But audiolense was pretty darn easy to use. I'm nervous about the infamous Acourate steep learning curve. Mitchco's new Kindle book makes it seem doable. I haven't looked at rePhase yet either.

I appreciate the benefits of flexible xo tuning, active amplification and low distortion line level filters, but I've tried active IIR filters and I still hear the phase error. To me, steep filters sound more closed in and stuffy compared to shallower filters with less phase error. My passive speakers have pretty flat phase 200-10k, and I've come to love the easy relaxed feeling of flat phase. Same with Danley and all single driver speakers, Quad, etc. So I'm most interested in active crossover because using a computer to host FIR filters allows a flat phase response. I want to hear what perfect zero phase response top to bottom sounds like.