Yes, in low power situations where multiamping isn't a necessity there's no reason not to use simple passive crossovers combined with DEQ. The end result is still perfect room adjusted response. There is an advantage to going DEQ with all discrete amps, that being that passive crossover components do cause phase issues and have insertion losses that you don't get with multiamping, but the advantage to the other scenario is that you don't have to go out and buy a bunch of new amps.
Hi Markp,
Re your "A good electronic crossover can cost more than 10 times that of a passive." - I would agree, but only if you include the cost of the extra amplifiers.
I've been pricing here in Aus, and for $300 (+ about $100 for lead, wiring, boxes, etc) I can get a pretty good active x-over. Using Hovland caps and Hepta-litz inductors, I can make a 1st order with a couple of extras to tame inductance peaks for around $400, but this doesn't include any where to put them (except inside the cabinet).
I'm still going to use a passive for the ribbon to the mids, as they're about 4.5% efficient anyway (and the woofer is about 1%).
Considering the money you can save by matching the amp to the specific driver, I would say that active is the way to go (if you have the space). But... it could be The Glenlivet talking...
Re your "A good electronic crossover can cost more than 10 times that of a passive." - I would agree, but only if you include the cost of the extra amplifiers.
I've been pricing here in Aus, and for $300 (+ about $100 for lead, wiring, boxes, etc) I can get a pretty good active x-over. Using Hovland caps and Hepta-litz inductors, I can make a 1st order with a couple of extras to tame inductance peaks for around $400, but this doesn't include any where to put them (except inside the cabinet).
I'm still going to use a passive for the ribbon to the mids, as they're about 4.5% efficient anyway (and the woofer is about 1%).
Considering the money you can save by matching the amp to the specific driver, I would say that active is the way to go (if you have the space). But... it could be The Glenlivet talking...
The only example of a passive xover that sounded better than bi-amping for me is the D'Ap, Audax AP170/TMO25 MTM front, but that may be because the expense and effort putting it together had a pleasant psyco-acoustic "whew" effect.
I often think about this when comparing the cost of a couple BrianGT kits to some passive xover designs.
In my listening room, I like the ability to tweak the sound at the Behringer, but my real interest is in putting together systems that others can enjoy as a gift or at modest cost.
So sure, you have to decide what you're designing for. Family room, computer room, a dorm room? A new set of fronts? You get the picture, the possibilities, (and compromises) are endless.
But with the cost and effort it takes to build a nice amp case, and especially four or five channel, for bi.1, this isn't what I can afford to give away. OTOH, the idea of active speakers, maybe a simple two-way, trading the cost of passive parts for better amps might be putting money in the right place for nice sound. (I knew I bought these 4-channel pots for something)
Good amps, good drivers, nice woodwork, less machining and connectors, I like it....Given that a couple BrianGT basic kits would be the foundation for power, what might be suggestions for drivers? I have lots of TB 871s, but I'd be very interested in other opinions. Please bear in mind that I'm a carpenter, not an electronics expert, and I'd be happy to trade for design advice.
I often think about this when comparing the cost of a couple BrianGT kits to some passive xover designs.
In my listening room, I like the ability to tweak the sound at the Behringer, but my real interest is in putting together systems that others can enjoy as a gift or at modest cost.
So sure, you have to decide what you're designing for. Family room, computer room, a dorm room? A new set of fronts? You get the picture, the possibilities, (and compromises) are endless.
But with the cost and effort it takes to build a nice amp case, and especially four or five channel, for bi.1, this isn't what I can afford to give away. OTOH, the idea of active speakers, maybe a simple two-way, trading the cost of passive parts for better amps might be putting money in the right place for nice sound. (I knew I bought these 4-channel pots for something)
Good amps, good drivers, nice woodwork, less machining and connectors, I like it....Given that a couple BrianGT basic kits would be the foundation for power, what might be suggestions for drivers? I have lots of TB 871s, but I'd be very interested in other opinions. Please bear in mind that I'm a carpenter, not an electronics expert, and I'd be happy to trade for design advice.
From a newcommers point of view here..
1st off - ive never heard the difference between active & passive.
However my electronics skills are NOT up to creating or assembling an active xo. Its not all that hard to cut boards or have someone else cut boards or buy a kit.
But I also find it interesting that a lot of kits offer the option of getting a pre-assembled xo.
The added expense of extra amplifiers is also a huge minus, say nothing about the WAF on top of that.
It probably Does sound better.. but having to go from 6 amp channels to 14 amp channels isnt worth it.
1st off - ive never heard the difference between active & passive.
However my electronics skills are NOT up to creating or assembling an active xo. Its not all that hard to cut boards or have someone else cut boards or buy a kit.
But I also find it interesting that a lot of kits offer the option of getting a pre-assembled xo.
The added expense of extra amplifiers is also a huge minus, say nothing about the WAF on top of that.
It probably Does sound better.. but having to go from 6 amp channels to 14 amp channels isnt worth it.
Any time you put more silicon in a signal path you are not doing it a favor. You cant believe that a $300 digital box is going to have the sound quality of a $10k amp and will not hurt the signal. I like active crossovers from a sub to satellite to take advantage of the amp's power distribution but above that passive to limit the amount of signal degradation due to active elements.
markp said:
You are right it's not sensible to compare difference price point products, but just because a passive has less in the signal path doesn't mean it's better. Those passive parts are quite likely not able to control the cone as well. Comparing technologically 'equivalent' items the active will win every time. It will also probably win over the next level up passive model as well.
passive xo
I used to work for a company called wilmslow audio, we had bins full of caps, an inductor winding machine, racks and racks of drivers and all manufacturers data. we used to supplt 20 odd differenet kits and in the corner was a filling cabinet with all past designs of note.
I fiddled and fiddled with all these bits. it was before the days of fast computers ( ie zx 81 almost) had to do all evaluation with music and ears.I could say so much, but suffice I went active in approx 1990 and have never looked back. however sometimes i found a combination of inductor on bass, cap resistor inductor on treble whose sound i still search for now. passive can yeild excellent results audibly but active is more precise and fullfilling I find.
I used to work for a company called wilmslow audio, we had bins full of caps, an inductor winding machine, racks and racks of drivers and all manufacturers data. we used to supplt 20 odd differenet kits and in the corner was a filling cabinet with all past designs of note.
I fiddled and fiddled with all these bits. it was before the days of fast computers ( ie zx 81 almost) had to do all evaluation with music and ears.I could say so much, but suffice I went active in approx 1990 and have never looked back. however sometimes i found a combination of inductor on bass, cap resistor inductor on treble whose sound i still search for now. passive can yeild excellent results audibly but active is more precise and fullfilling I find.
markp said:
Really? Bumps in response within a driver's bandwidth are very easy to take care of with active crossovers. Would you care to elaborate on what else consititutes "lots" of things passives do that actives don't? I, for one, can't think of any except impedance correction... which is completely uncessary when using active designs. In fact, there are many things that active designs can do a lot better than passives, such as dipole equalization or acoustic center alignment.
And what about non-linear inductors, and time deteriorated and heat affected resistors and capacitors used in passive designs? The logical conclusion is that a well executed active crossover (which need not be digital) will do much less damage to the signal than a typical passive one.
Let's assume for a moment that it is correct that active is better than passive if well implemented. Now I want to shift focus back to my original question:
Can a diy speaker builder equal a high end passive crossover with an active crossover with a reasonable effort?
The pro might have years to devote to this task (although not full time), and a lot of expensive equipment. The diyer will have a basic budget measurement setup, and some weekends to spend on it, although he doesn't want to wait years to get a result he's happy with.
Can a diy speaker builder equal a high end passive crossover with an active crossover with a reasonable effort?
The pro might have years to devote to this task (although not full time), and a lot of expensive equipment. The diyer will have a basic budget measurement setup, and some weekends to spend on it, although he doesn't want to wait years to get a result he's happy with.
Still, even given that limitation, a diyer can get pretty accurate data for on and off axis frequency response, driver acoustic centers, power compression, distortion, cabinet vibration, etc, etc, etc. And he STILL doesn't have to worry about what happens with batch-to-batch variations in drivers.
The limiting factor will be the skill in using his tools, interpreting his results, the quality of his ideas, and his ability to implement them.
The limiting factor will be the skill in using his tools, interpreting his results, the quality of his ideas, and his ability to implement them.
That's setting one's sights far too low. The best passive crossover is simply not capable of doing what even an inexpensive digital crossover can, and the digital crossover will cost less to boot, sans the expense of the additional amps, and class D and T amps are closing that gap rapidly as well. Already a Class D sub amp is cheaper than a passive 80 Hz crossover with even mid priced components. There are those who will insist on the superiority of passive components; very few of those naysayers actually own digital crossovers. I'm sure that somewhere there are still proponents of the abacus over the PC.
Bill, I marvel at how opinions can vary so much on these things. I suppose as some point you have to trust your ears and try things out! I'm also wary of the fact that I might be tempted to try something because it seems more tricky or clever or sophisticated, or gives me an excuse to build more diy audio stuff!!!!
paulspencer said:gyrators? please explain!
take a look at page 45 of this document (was originally printed by Burr-Brown)
http://focus.ti.com/lit/an/sboa093a/sboa093a.pdf
paulspencer said:
I would say yes. Two hard parts of getting passive crossovers right are the troubles that the impedance variation and driver sensitivity differences gives you. With these out of the equation by going active it all becomes so much easier to solve. Not only that, but the benefits of consistent and improved damping take the active another level higher.
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