[Rick Craig]

If the goal is having a speaker output response closest to the input signal from your source then  DSP is the way to go. Someone mentioned trying to replicate a passive transfer function with an active filter. The real challenge is to have a passive crossover that can duplicate what a DSP crossover can do. In many instances it cannot.

[cheap-Jack]

Hi.

(1) It goes between the preamp and the power amp. If you're concerned about the cables from the passive crossover to the power amp, then build the circuit into the power amps.

(2) Whether this is an "active" system is I suppose a matter of definition.

(1) That what I would do to make thing simplest possible.

(2) It is "active" to me as the power amp acts as signal booster for the R/C line filter. Harmonic & phase distortions will be boosted together with the music signals. Such thing would not happen to passive X-overs inside a loudspeaker which is at the end of the audio chain.

c-J

c-J

[cheap-Jack]

HI.

If the goal is having a speaker output response closest to the input signal from your sourc, then DSP is the way to go.

This is quite impossible to do even with DSP or whatever active digitals factoring in the room acoustics.

Any brandname loudspeakers (with built-in passive X-overs) are designed & measured in enechoic chamber to get its 'net' response free of room acoustics.

So where one can get access to an enechoic chamber to measure an active X-over?




c-J

[Pez]

Why would you need one? Your speakers aren't being played in an anechoic chamber they're being played you your friggin' living room. Only DSP can correct for your rooms specific shortcomings. Something that no amount of tuning in a chamber can compensate for.

[Davey]

Hi.
(1) That what I would do to make thing simplest possible.

(2) It is "active" to me as the power amp acts as signal booster for the R/C line filter. Harmonic & phase distortions will be boosted together with the music signals. Such thing would not happen to passive X-overs inside a loudspeaker which is at the end of the audio chain.

c-J

c-J

How much harmonic distortion do you think a passive line-level filter like this would produce?

Also, a power amplifier doesn't "amplify" phase distortions.  The resultant phase shift ("distortion" as you call it) seen at the speaker transducer will be identical whether the filter is located before the amplifier or after at it.  This is a minimum-phase response in either case.

cheers,

Dave.

[Tyson]

Can you tell us why you chose the miniDSP over the others specifically the DEQX.

Started with a modded DCX and sold it to get the DEQX.  Then decided to "downsize" my system for non-audio related reasons.  Got a stock DCX, used it for a while, realized how bad it sucked stock, stuck it in the closet and get the miniDSP.  I think the DEQX sounded better, but the miniDSP still sounds good enough for me, and the price is right.

[Tyson]

Hi.
(1) My very picky ears tell me so. They are my personal "gospel".

(2) Yes, I agree single pole 6dB/octave first order filter gives the lowest harmonic & PHASE distortions & it sound the BEST to my ears. BUT  passive ONLY, not active. Sorry.

FYI, my KEF 2-way bookshelves also got similar very simple 6dB first order filter passive X-over network - only 2 chokes & 1 cap !!!! But the X-over was built so cheap (like most brandname loudspeakers, regardless of price!) that I decided to rebuild it.

As I posted here before, I upgraded it by modifying the X-over to passive bi-wiring, rebuilt on a large fibreglass PC board. Also replacing the lousy tiny stock non-polar 'lytic caps with large over-rated metallized PP film aps & rewired the entire loudspeaker with heavy AWG#12 oxygen-free pure copper cables thru-out.

Knowing the 'downside' of passive bi-wiring, I moved the upgraded X-over board, out of the loudspeaker box & housed it in a plastic box (no metal please!) & seated it floating on the floor just behind the power amps.

The idea of OUTboard X-over networking is to get shortest run of loudspeaker cables from the power amp to the X-over, reducing the 'X-talking' of HF & LF along the samle cable. - the alleged 'pitfall' of passive bi-wiring or multi-wiring.
In fact, quite a few brandname loudspeakers got similar outboard X-over networking systems.

I can tell this vintage KEF loudspeakers sound so much better like nite & day after such passive bi-wiring modification. Yet it did not need to go thru the nite-mare of active bi-wiring & still sounds better.

(3) YES, you have said it - "matching the levels" different drivers is a PAIN for active X-over networking when the room acoustics kick in.

We have to understand any frequency filters get phase shifts as this is the way how a filter works - to dealy the signals to compute how the signals will behave in the immediate future. This time delay is manifested as 'phase shift'.
It is therefore our job to make sure the phase shift is minimized.

Any active networking invovles gain which can only get phase shift worse instead of limited to the amount of phase shift generated inside a passive filter as used inside a loudspeaker X-over.


c-J

To quote my favorite movie, The Princess Bride, regarding your use of "Phase distortions":

Inigo Montoya: "You keepa using that word. I do not thinka it means what you thinka it means."

So, you upgraded an existing speakers passive network, outstanding!  I've done that too.  And you really, really, really, really like your vinyl and passive preamp.  Outstanding. 

When you have more experience in the digital world, then maybe you will have more relevant information to share other than "My system is the best and I loooooves my system".  Saying the equivalent of "Digital sux, vinyl rulz!" is not particularly enlightening or helpful to anyone.

[cheap-Jack]

Hi.

When you have more experience in the digital world, then maybe you will have more relevant information to share other than "My system is the best and I loooooves my system".   Saying the equivalent of "Digital sux, vinyl rulz!" is not particularly enlightening or helpful to anyone.

May I suggest you don't start a fight here, bud.

Please don't put your BIG words in my mouth! Which my post ever stated "My system is the best......:" Show me if you can!


Not to start a fire here, if I love digital sound at all, I would not have nearly given up my CD player & my DVD-audio player for a year now because my ears can't stand any digital clinical sound vs vinyl analogue musicality.

Before I ask your musical credentials , may I sugest you to step back & cool it.


c-J

[Tyson]

Have you ever actually designed a crossover or gotten a speaker up and running from scratch?

And you concern with speaker wire length is rather funny.  You save what, maybe 4 feet by using an external passive crossover?  The COIL in the crossover is DOZENS of feet long.  If you really want a "short path", then removing the coils from the signal path is far more important.  So, you up for removing some coils?  Course, then you'd have to use an active crossover.

And, you've stated again, you hate the clinical sound of digital and love your vinyl.  That's exactly what I said you said.  I don't think that's putting words in your mouth at all.  And you still have not addressed the question of what the heck you are talking about when you say phase distortions get magnified by an amp.  That suggest to me that you really, truly don't understand how crossovers actually work....

[JohnR]

I can tell this vintage KEF loudspeakers sound so much better like nite & day after such passive bi-wiring modification. Yet it did not need to go thru the nite-mare of active bi-wiring & still sounds better.

Hi c-J - you are saying it sounds better than "active bi-wiring"? Or just that it sounds better than before you rebuilt it? If the former, how do you know - did you build both and compare it?

[macrojack]

Disclamer: The way this conversation is progressing makes me want to clarify something. I am not related to cheap-Jack. He must be from a different Jack lineage. In my family, we don't use any upper case.

What I'm getting from this discussion is confused. Aside from the usual insistent but unqualified assertions, I see a lot of differing opinion. But Jason wasn't asking for opinion. He was very clear about wanting experienced testimonials for either option. But we can't do that because we don't even agree on goals. For my part, I've tried just about every configuration at one time or another and have just abandoned my fifth or sixth active crossover arrangement. And this is about crossovers so no need to point out that single driver is active since it does not have anything between amp and driver.

So let's keep to the original topic and try to enlarge upon that. Many of you should just respectfully lurk and absorb if you haven't actually done any of this yet - and if questions arise vis a vis how to pursue this yourself, start your own thread. It's free and easy and will probably attract many of the same contributors you are reading now. And that's a better, more apropos way of bringing attention to yourself than sidetracking Jason's query.

[Pez]

Great point macro-jack. As I have said previously. I have experienced active vs passive on a number of setups through the years and it has been pretty much universal that active had always had a deeper more life like soundstage and image. It is also the case that I have been able to tune out some of the worst problems with my system as a direct result of going full active.

In my current setup with my current speakers I have gone from bi-amping to full on triamping and the difference was not subtle or minuscule. It was tremendous absolutely transformational. Both macro and micro dynamics improved, sure, but mostly it's about nuance coming through that I had no idea was there. Passive just loses so much information and your amps will have a much easier one driving an active speaker per section than with passive. A happy amp = happy ears.

[Russell Dawkins]

Just the other day I came across a passive crossover that, I'm thinking, might challenge active alternatives, since it employs no series capacitors.  I gather that capacitors are the worst sounding crossover component and that really good caps of the value (and voltage rating) sufficient to handle speaker level signals are very expensive. I know this must be old hat to many of you, and I had heard of serial crossovers before but never really looked into them. I guess this also might be similar to what Sonus Faber used in one of their early models which claimed not to use capacitors. The design does not allow bi-amping, though.

The simplicity is intriguing to me:
http://arhifi.dk/store/product.php?id_product=22

Has anyone experience with this alternative?

Fritz Speakers uses this type of crossover, by the way, and they are well regarded.

[sts9fan]

Cheap-jack stop being so aggressive. This is not that sort of place. Your shit stinks like the rest of us. 
Everyone else, let's keep this civil. This has been a very nice thread.

[medium jim]

Hi.
So what can be more reliable than beng PASSIVE?

FYI, I am using passive linestages for many years as they virtually generate zero harmonic & phase distortions.

I have the phonostages driving the passive linestage, driving the power amps.
My picky ears approved it along with hi-fives from my elder son, a veteran
classical pianist (by hobby) with gifted accurate pitching ears.

Hearing is believing.

I think I was clear that passives were more reliable....

Jim

[Tyson]

Agreed, passives are both more reliable and more 'set and forget' with regards to ease of use/ownership.  Caps in-line with the tweeter do a good job of protecting it from nastiness from your amps, like on/off thumps.

[Tyson]

Just the other day I came across a passive crossover that, I'm thinking, might challenge active alternatives, since it employs no series capacitors.  I gather that capacitors are the worst sounding crossover component and that really good caps of the value (and voltage rating) sufficient to handle speaker level signals are very expensive. I know this must be old hat to many of you, and I had heard of serial crossovers before but never really looked into them. I guess this also might be similar to what Sonus Faber used in one of their early models which claimed not to use capacitors. The design does not allow bi-amping, though.

The simplicity is intriguing to me:
http://arhifi.dk/store/product.php?id_product=22

Has anyone experience with this alternative?

Fritz Speakers uses this type of crossover, by the way, and they are well regarded.

I've heard the Fritz speakers several times and thought they sounded outstanding.  I've also heard those Acoustic Reality speakers several times as well and they were pretty meh.  Both companies used similar drivers and similar crossover topologies (I assume), yet Fritz produces magic and AR produces boredom.  It's all in the implementation!  As will most things, I suppose...

[Trismos]

Hi.
May I suggest you don't start a fight here, bud.

Please don't put your BIG words in my mouth! Which my post ever stated "My system is the best......:" Show me if you can!


Not to start a fire here, if I love digital sound at all, I would not have nearly given up my CD player & my DVD-audio player for a year now because my ears can't stand any digital clinical sound vs vinyl analogue musicality.

Before I ask your musical credentials , may I sugest you to step back & cool it.


c-J

LOL  self important

[medium jim]

Agreed, passives are both more reliable and more 'set and forget' with regards to ease of use/ownership.  Caps in-line with the tweeter do a good job of protecting it from nastiness from your amps, like on/off thumps.

Turn on the preamp first, then the amp(s), reverse said order when turning off, e.g., turn off the amp(s) first!!!

Jim

[Pez]

What is this reliability thing everyone speaks of? Seriously why is there an assumption that an active amp is less reliable than a passive? Even a novice can install a dc coupling cap in line with a tweeter to insure its safety. I suppose it's slightly more likely that amp trouble will blow a driver, but it's what should be in the forefront of your mind with active. A worse issue would be hooking up your woofer section to your tweeter.