Bill Fitzpatrick said:
It is really popular the world over... of the most recent systems worked thru, there is the VIFA P13WH-00-08 and modified D27TG-45-06... ended up with a single cap (5 uF), the other, 2 Fostex 9" extended range Fostex in a bi-pole with a Heil Air Motion ribbon... single cap, single coil (+ tweeter padding)
Most of the systems i do run close to full range, T coming in at 7-13k. My favorites usually around the Foster FE103A (typically 35-40 years old). Lately i've been listening to a set of Visaton B200s in an open baffle...
I get exposed to quite a few typical commercial multiways...
dave
Ken L said:
I should have qualified my earlier statement to say passive, first order
planet10 said:
Dave _heh heh_ said it better than I
Bill Fitzpatrick said:
I didn't see where he said that _grin_.
In a general discussion of merits of active vs passive, there are quite a few variations on a theme and I didn't see his comments as saying anything that specific. I always enjoy reading Dave's posts and pay particular attention when they pertain to speakers because he is quite knowledgeable on them.
I have also been quite interested in reading Bob Ellis's posts along with 5th elements comments.
Well, maybe my comments and thinking are mired in the fact that I believe it would be prohibitive in terms of size and space to duplicate the GM70 amp I am assembling parts for.
If one is not concerned with cost, space or complexity tradeoffs, (disadvantages I was previously concerned with ) hey - why not have an amp per driver?
As we move further into the digital era, it wouldn't surprise me at all if we eventually moved to a fully digital chain that went to a DAC at each speaker.
On the other hand, I'm tired, sleepy and not sure I'm as coherent as I would like. Or for that matter if I'm ever as coherent as I would like _big grin_
Regards
Ken L
Speaking from the point of view of someone who has "designed" and built his own amps a couple of times, building a speaker with a passive XO llooks really intimidating! There are a number of very, very excellent commercial speakers using passive XO's, but the more I read about what goes into good passive XO's the more impressive they are. By comparrison, an active XO such as Rod Elliot's, Siegfried Linkwitz's or Randy Slone's (just the first three that come to mind) seems quite strightforward and not respecially mysterious.
I suspect that from a DIYer's point of view, the chances of getting an active XO "right" the first time or at leat the second are much better than a passive one unless you are just putting together a kit.
The above are just my impressions and may be total bunk but at leat they are my own.
I suspect that from a DIYer's point of view, the chances of getting an active XO "right" the first time or at leat the second are much better than a passive one unless you are just putting together a kit.
The above are just my impressions and may be total bunk but at leat they are my own.
Active cross over - any advantages?
There is advantage, some of them already mentioned.
For me, I prefer to create a fully active system - no passive crossovers.
My reason is the real time tweaking ability of the active crossover
provided that I use one that has variable controls (ie potentiometers).
Sometimes I feel the need to tweak certain parameters depending
on my listening mood not necessarily the technically correct
setttings. Sometimes the variables are only a few hundred hz
and sometimes it's level controls (gain).
If your speaker design is not integrated well from a driver point of
view, then add your favorite eq to the mix, graphic or parametric.
This is expensive - not for everyone, therefore the passive crossover
route makes more sense for most people.
There is advantage, some of them already mentioned.
For me, I prefer to create a fully active system - no passive crossovers.
My reason is the real time tweaking ability of the active crossover
provided that I use one that has variable controls (ie potentiometers).
Sometimes I feel the need to tweak certain parameters depending
on my listening mood not necessarily the technically correct
setttings. Sometimes the variables are only a few hundred hz
and sometimes it's level controls (gain).
If your speaker design is not integrated well from a driver point of
view, then add your favorite eq to the mix, graphic or parametric.
This is expensive - not for everyone, therefore the passive crossover
route makes more sense for most people.
The "trinity" of crossover, speaker and poweramp should be looked at as one single system, designed to achieve a predefined design goal (i.e. frequency response, transient response, SPL, size ....).
In order to achieve this, using an active topology is nothing but a logical step.
Regards
Charles
In order to achieve this, using an active topology is nothing but a logical step.
Regards
Charles
Hi.
Genelec has some good explanations why active is better than passive. One of them is that the amplifier can be optimized for the driver and the driver's efficiencies don't need to match with each other.
Also the designer don't need to care about the impedance curve of the
driver, designing crossover is therefore much simplier.
Anyway, all speakers manufactured by Genelec, are fully active.
I have listened most of their models and they are pretty good.
http://www.genelec.com
Best Wishes,
Karoliina
Genelec has some good explanations why active is better than passive. One of them is that the amplifier can be optimized for the driver and the driver's efficiencies don't need to match with each other.
Also the designer don't need to care about the impedance curve of the
driver, designing crossover is therefore much simplier.
Anyway, all speakers manufactured by Genelec, are fully active.
I have listened most of their models and they are pretty good.
http://www.genelec.com
Best Wishes,
Karoliina
Another point to make is a continuation of what Dave said regarding the additonal cost. Yes an extra chip amp isnt an awful lot. But also good quality passive caps DONT come cheap. You could say the same for active caps yes you can go silly if you want to buying paper in oils etc.
A cheap and nasty polyester cap costs me about 0.15p, these do sound actually very good in comparison to what a rubbish alcap can sound like with regards more prestigeous number, read solen or wilmslow supersound polyprop caps.
A good polystyrene costs me £0.80 where as you have seen the prices on Hovlands etc.
In the long run I would say active is cheaper. If you intend to redo the speakers, new everything etc, there is a good chance that all you might have to do is alter a few resistors in the active xover which would cost maybe £0.50. And hey presto new speaker.
If this was passive there is an almost certain chance that you would be buying all again.
I have just upgraded all the important caps from polyester to polystyrene in my three way active xover. This cost me £20. For the highpass and low pass on the mid and high pass on the tweet. 18db electrical lowpass 12db highpass and another 12db highpass. If this was an upgrade from solen to hovland your looking at £20 for ONE cap.
Not to mention you dont have any ugly inductors adding miles and miles of wire between the amp and your woofer.
A cheap and nasty polyester cap costs me about 0.15p, these do sound actually very good in comparison to what a rubbish alcap can sound like with regards more prestigeous number, read solen or wilmslow supersound polyprop caps.
A good polystyrene costs me £0.80 where as you have seen the prices on Hovlands etc.
In the long run I would say active is cheaper. If you intend to redo the speakers, new everything etc, there is a good chance that all you might have to do is alter a few resistors in the active xover which would cost maybe £0.50. And hey presto new speaker.
If this was passive there is an almost certain chance that you would be buying all again.
I have just upgraded all the important caps from polyester to polystyrene in my three way active xover. This cost me £20. For the highpass and low pass on the mid and high pass on the tweet. 18db electrical lowpass 12db highpass and another 12db highpass. If this was an upgrade from solen to hovland your looking at £20 for ONE cap.
Not to mention you dont have any ugly inductors adding miles and miles of wire between the amp and your woofer.
sam9 is absolutely right in posting #23 above, it's much easier to get an active XO working correctly, if you can afford the extra amps.
My first set of DIY speakers were finished last summer, and I built them 3-way active XO direct, after reading Rod Elliotts highly convincing article on bi-amplification. I can just say I'm very satisfied with the results, and am currently looking into a second tri-amped project (this DIY "just one more..." thing never stops).
To explain my reasoning before starting my first speaker project, I searched the web extensively, and got a lot of info on both the passive and active way of building XOs. The passive XOs just scared me off, with different people saying different things, and generally reminding me of grammar classes in school (numerous exceptions to every rule). The active way, OTOH, looked like a clean, straight-forward, engineering kind of solution, and it was just so much easier to understand what I was doing.
People able to design good passive XOs have my respect, but I just dont understand why they don't go active; really good components for passive XOs are not cheap.
I just bought a Behringer DEQ2496 to check how well my speakers are doing, and I noticed that there are some anomalies around the XO frequencies, possibly due to the fact that I don't have any BSC circuitry done yet. There's always one more thing to tweak...
Just my $0.02
My first set of DIY speakers were finished last summer, and I built them 3-way active XO direct, after reading Rod Elliotts highly convincing article on bi-amplification. I can just say I'm very satisfied with the results, and am currently looking into a second tri-amped project (this DIY "just one more..." thing never stops).
To explain my reasoning before starting my first speaker project, I searched the web extensively, and got a lot of info on both the passive and active way of building XOs. The passive XOs just scared me off, with different people saying different things, and generally reminding me of grammar classes in school (numerous exceptions to every rule). The active way, OTOH, looked like a clean, straight-forward, engineering kind of solution, and it was just so much easier to understand what I was doing.
People able to design good passive XOs have my respect, but I just dont understand why they don't go active; really good components for passive XOs are not cheap.
I just bought a Behringer DEQ2496 to check how well my speakers are doing, and I noticed that there are some anomalies around the XO frequencies, possibly due to the fact that I don't have any BSC circuitry done yet. There's always one more thing to tweak...
Just my $0.02
It's easier to control the phase with active XOs - at least if you can use DSP tools and design an FIR filter which takes account the measurements of the frequency and the phase (of the speaker elements) to calculate the filter kernel. You can delay signal / phase also with passive XO but again it's not practical neither economical. That said with almost ideal elements and with serial structure (which makes some things easier) you don't need that many components to implement a very good passive XO. I haven't heard (or read) of any blind tests, that would be interesting, guess if this speaker you're listening has a passive or an active XO.
What exactly are you talking of ? Do you mean comparison of speaker X using active crossover and speaker Y with passive crossover. Or do you mean to compare an active and a passive version of the same speaker ?
If you mean the second I am convinced that I would hear the difference !
And I don't count myself to be one of those capable of hearing much difference between different types of mains plugs.
I have an opinion that might sound a little heretic and maybe snobbish as well, but IMHO there is no apparent technical reason for using passive crossovers anymore nowadays.
An exception may be simple two-way systems with tweeters that are crossed over fairly high.
Regards
Charles
mhelin said:
With ideal drive units as well! Real drive units require things like impedance compensating networks to compensate for voice coil inductance, and for the rise in impedance at resonance. Even a simple first-order 3-way crossover starts to look a lot more complicated when you add those networks across the drive units.
Active crossovers don't require that the speakers have any impedance compensation,as the amps will have an output impedance much lower than the speakers they are driving.
There's a fairly simple explanation of why the man who invented the Linkwitz/Riley crossover prefers active here:
http://web.archive.org/web/20030605092109/linkwitzlab.com/crossovers.htm
Given my choice of speakers I have no choice but to go active, but given the low cost of amps and active xover technology for DIYers I can't see why you wouldn't.
Steve
http://web.archive.org/web/20030605092109/linkwitzlab.com/crossovers.htm
Given my choice of speakers I have no choice but to go active, but given the low cost of amps and active xover technology for DIYers I can't see why you wouldn't.
Steve
Relative Power Reqirements
Has anybody done any experiments as to typical dynamic range per-frequency? Tweeters need less power than MWs (if I understand correctly) so one could reduce the expense considerably by XOing at a higher frequency, correct? If I crossed over at 4KHz I might even get away with a little 12W multimedia amp on the tweeter, huh?
Has anybody done any experiments as to typical dynamic range per-frequency? Tweeters need less power than MWs (if I understand correctly) so one could reduce the expense considerably by XOing at a higher frequency, correct? If I crossed over at 4KHz I might even get away with a little 12W multimedia amp on the tweeter, huh?
High SQ and large radius
Hi. This seems like the ideal place to post this question. I have the MB Quart QSD 164 and QSD 210 combo. In addition to this, I have three JL Audio 18W6 subwoofers. Between these, I plan on adding four 10" fast-attacking sub/midwoofers for the upper portions of the sub-bass spectrum, since the 18s are mainly for infrasonic-to-60 Hz range.
In addition to that, I am planning on four to eight 8" midbass drivers for the gap between the tens and the QSD 164 6.5" speakers.
Yes, this is for a car. But, I plan on using the car for in-car listening, yes, but also for a mobile KoncertWagen (new, in dealer showrooms now from Germany)
or something similar.
My question is I would prefer, as a natrual bent, to control every channel going to every speaker individually. But the MB Quart sets have very nice passive crossovers included from the factory. I would assume that these crossovers are well-matched to the speakers, but, of course, I don't know for sure if using a 6-way (12 total amp output channels) active crossover would sound better than using a 4-way crossover and letting the included passive Xovers do their own thing as set up by MB quart at the factory. I was also thinking of doubling to quadrupling the number of QSD speakers for extra volume at no expense of quality.
Of course, I plan on using twin 31-band graphic equalizers too to make up for whatever environment I happen to be in at the time (by the ocean, by myself, on the road, whatever)
Cost is not really a great object, but, I don't want to spend $1000 US more for a 1/100th of a percent of sound quality improvement.
So. Active or passive? Which is better?
Hi. This seems like the ideal place to post this question. I have the MB Quart QSD 164 and QSD 210 combo. In addition to this, I have three JL Audio 18W6 subwoofers. Between these, I plan on adding four 10" fast-attacking sub/midwoofers for the upper portions of the sub-bass spectrum, since the 18s are mainly for infrasonic-to-60 Hz range.
In addition to that, I am planning on four to eight 8" midbass drivers for the gap between the tens and the QSD 164 6.5" speakers.
Yes, this is for a car. But, I plan on using the car for in-car listening, yes, but also for a mobile KoncertWagen (new, in dealer showrooms now from Germany)
or something similar. My question is I would prefer, as a natrual bent, to control every channel going to every speaker individually. But the MB Quart sets have very nice passive crossovers included from the factory. I would assume that these crossovers are well-matched to the speakers, but, of course, I don't know for sure if using a 6-way (12 total amp output channels) active crossover would sound better than using a 4-way crossover and letting the included passive Xovers do their own thing as set up by MB quart at the factory. I was also thinking of doubling to quadrupling the number of QSD speakers for extra volume at no expense of quality.
Of course, I plan on using twin 31-band graphic equalizers too to make up for whatever environment I happen to be in at the time (by the ocean, by myself, on the road, whatever)
Cost is not really a great object, but, I don't want to spend $1000 US more for a 1/100th of a percent of sound quality improvement.
So. Active or passive? Which is better?
Bill Fitzpatrick said:
Julian Vereker always said that you wanted to use your highest quality amp on the top... and i tend to agree with him.
If you are designed from scratch, a purpose built tweeter amp can give very good results. ie Because of generally smaller power requirements a nice Class A amp (with good overload behavior) is much more practical, than FR Class A.
dave
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.