Is there any advantage in using an active crossover, compared to conventional passive crossovers. By using a couple GCs and OPs it should not be too difficult to come up with a basic design. Do active crossovers (and two amps per channel for a two way speaker) sound better? Is designing an active crossover easier?
Thanks, Tom
Thanks, Tom
Bill I would dissagree, I have had a semi active system where the bass and mid/tweet were driven separately linked by active. Then I went fully active, made a large difference.
I Know that with the power splitting it makes sense that acitve is better for bass drivers, as a split at 300hz is like giving 50% to one amp and 50% to another. Then higher up maybe 5% tweet and 95% to mid/bass. But still remember that if you drive the system hard and the amp clips with a passive then all the clipping is sent to the tweet too. Active this doesnt happen and the sound stays cleaner when pushed. Also your less likely to blow a tweet this way if you like loud music.
I can understand however where you are coming from, is going active worth the extra outlay in amplifiers etc in a two way, then no might be applicable, but on the basis of is it better. The answer is yes it is, but is it worth it. thats the real question. Is putting your hard earned cash into this better spent elsewhere.
I Know that with the power splitting it makes sense that acitve is better for bass drivers, as a split at 300hz is like giving 50% to one amp and 50% to another. Then higher up maybe 5% tweet and 95% to mid/bass. But still remember that if you drive the system hard and the amp clips with a passive then all the clipping is sent to the tweet too. Active this doesnt happen and the sound stays cleaner when pushed. Also your less likely to blow a tweet this way if you like loud music.
I can understand however where you are coming from, is going active worth the extra outlay in amplifiers etc in a two way, then no might be applicable, but on the basis of is it better. The answer is yes it is, but is it worth it. thats the real question. Is putting your hard earned cash into this better spent elsewhere.
Salinas said:
Bill Fitzpatrick said:
Ummm, well I'm probably prejudiced because I'm bi-amping a two - way, and think the results are much better -
But I am crossing over to subs at about 145hz. If I were to add something on top, I would use a passive crossover.
And while I agree with Bill F that he has a point, I wouldn't say that there is almost no advantage...etc. I believe that it might more accurately be said that if crossing over above 2-4k, that generally the advantages don't exceed the disadvantages by a great deal _big grin_
I don' think I'm in basic disagreement with Bill F on this one, more like I would choose a different wording. _grin_
Regards
Ken L
I'm with 5th Element on this one.
I've been actively crossed over to my subwoofer since 1983, but recently tried it midbass to tweeter.
I compared my speakers with passive and active xo - 2nd order at 2400 Hz using Leach amps as required, and liked the sound of the active XO better, even more so when I went to 4th order LR. Then plugged in Baffle step compensation and phase adjustment (ala S. Linkwitz) and WOW!
The result was much more realistic and transients have much more impact. When I put it back together passively, my 13 year old son was upset with me. He couldn't see anything wrong with having a bunch of circuits on pieces of MDF alligator clipped together in the living room and thought that active sounded much better.
The phase compensation made more difference to me than the BSC. Sinc you can pretty much dial in the phase change desired I think it is easier to get it right than building tilted/offset baffles. I couldn't begin to get my hands around the math to do it passively.
The BSC and phase compensation cost me a couple of bucks actively, haven't priced it passively, but I bet it is a bunch. Same for notch filters if your driver(s) need them. Of course, you have to figure in the cost of another couple channels of amplification to make it a fair comparison. But, I already had the extra amps
Now to find the time to assemble presentable boxes for the XO and my prototype speakers. BTW, the active XO uses trusty old NE5532s - It will be interesting to plug in some "better" chips to see what happens.
I've been actively crossed over to my subwoofer since 1983, but recently tried it midbass to tweeter.
I compared my speakers with passive and active xo - 2nd order at 2400 Hz using Leach amps as required, and liked the sound of the active XO better, even more so when I went to 4th order LR. Then plugged in Baffle step compensation and phase adjustment (ala S. Linkwitz) and WOW!
The result was much more realistic and transients have much more impact. When I put it back together passively, my 13 year old son was upset with me. He couldn't see anything wrong with having a bunch of circuits on pieces of MDF alligator clipped together in the living room and thought that active sounded much better.
The phase compensation made more difference to me than the BSC. Sinc you can pretty much dial in the phase change desired I think it is easier to get it right than building tilted/offset baffles. I couldn't begin to get my hands around the math to do it passively.
The BSC and phase compensation cost me a couple of bucks actively, haven't priced it passively, but I bet it is a bunch. Same for notch filters if your driver(s) need them. Of course, you have to figure in the cost of another couple channels of amplification to make it a fair comparison. But, I already had the extra amps
Now to find the time to assemble presentable boxes for the XO and my prototype speakers. BTW, the active XO uses trusty old NE5532s - It will be interesting to plug in some "better" chips to see what happens.
5th element said:
Yeah, but part of one's plan should be to use amps that won't clip at the level one wishes to play the system. I don't see the advantage to say, "great, the clipping isn't reaching my tweeters", while the woof/mid amp is clipping away and sounding very harsh. Kind of an expensive tweeter protection scheme if you ask me.
I still say there is almost no advantage to bi-amping a two way. If someone can give me a really great reason to do so, please let me know.
I can see active as a definate advantage if one were so inclined as to build new speakers on a regular basis. Especially if those speakers were built with high quality passive parts that have a high likelihood of being unuseable on the next project. A one time investment in a Rane 3 way seems like a very solid move from my beginner POV.
As for BSC and Notch Filtering, would the addition of a 1/3 octave EQ essentially fix you for life on that as well? Seems like the combination of an active XO and EQ could provide a very quick and effective solution to the fine tuning that does many of us less than proficient people in. Thoughts?
As for BSC and Notch Filtering, would the addition of a 1/3 octave EQ essentially fix you for life on that as well? Seems like the combination of an active XO and EQ could provide a very quick and effective solution to the fine tuning that does many of us less than proficient people in. Thoughts?
Seth Smith said:
The problem with the usual 1/3 octave EQ route is it's lack of adjustability. You're stuck with set center frequencies and no way to adjust Q. That makes it difficult to notch correctly.
If anyone is interested in my list of bi-amp advantages when crossing from the woof to the mid, see this page:
http://www.kbacoustics.com/ygbsm/2waycrossovers/biampadvantages/index.html
Boy, what a complex question! Is a turbo charged four better than a auto V8?
I have used active and passive systems for many years both professionally (FM station technician 15years) and at home. I have passive system in the dining room and active in the lounge room.
I would suggest that it is easier to get an accurate sound, (not what everyone wants) fron a passive system, (less to **** up).
If you want the ultimate in performance, would you buy and automatic transmission? Active systems are harder to drive, (read adjust properly) but when you get it right...
So if you are starting out I would usually recommend going passive. If you want the best performance, don't mind spending a lot of time tuning AND have a good back up system to listen to in the mean time go active. Just keep an eye on how much time you are spending in the garage in comparission to how much time you get on the road.
Enjoy, WALKER
I have used active and passive systems for many years both professionally (FM station technician 15years) and at home. I have passive system in the dining room and active in the lounge room.
I would suggest that it is easier to get an accurate sound, (not what everyone wants) fron a passive system, (less to **** up).
If you want the ultimate in performance, would you buy and automatic transmission? Active systems are harder to drive, (read adjust properly) but when you get it right...
So if you are starting out I would usually recommend going passive. If you want the best performance, don't mind spending a lot of time tuning AND have a good back up system to listen to in the mean time go active. Just keep an eye on how much time you are spending in the garage in comparission to how much time you get on the road.
Enjoy, WALKER
Although I agree a 50/50 % (20hz to 300hz/300hz to 20Khz) split will give the maximum benifit from two amps in terms of intermodulation and power ect. compaired to crossing over at a higher frequency (you could say that this is only one and a bit amping ) there are still some potential benifts, read this artical
http://sound.westhost.com/biamp-vs-passive.htm
Also it is easier to apply higher order slopes (eg. 24dB ect.) with an active crossover, depending on your speakers this could make a big diference,
So to sum up you may not get all the benifits of using two amps (like I said, its more like one and a bit amping) but you may get some benifits from the fact a linelevel crossover will work better than its passive counterpart,
I say go for it after all I cant see it making it worse!
) there are still some potential benifts, read this artical http://sound.westhost.com/biamp-vs-passive.htm
Also it is easier to apply higher order slopes (eg. 24dB ect.) with an active crossover, depending on your speakers this could make a big diference,
So to sum up you may not get all the benifits of using two amps (like I said, its more like one and a bit amping) but you may get some benifits from the fact a linelevel crossover will work better than its passive counterpart,
I say go for it after all I cant see it making it worse!
Besides making life more difficult for the power amp, passive XO parts have a strong tendency to "suck the life out of" a speaker... if you only have a single cap or a cap & an choke, then passive may be the way to go, but once you get more complex than that, active gets more & more of an advantage.
With the cost of chipAmps (& quality of well executed ones) these days, an extra amp is not an aweful lot of a compromise... often quite a bit less than the cost of quality chokes & caps for a complex XO.
dave
With the cost of chipAmps (& quality of well executed ones) these days, an extra amp is not an aweful lot of a compromise... often quite a bit less than the cost of quality chokes & caps for a complex XO.
dave
Bill Fitzpatrick said:
It is one of those very nebulous phases... i've heard few speakers with complex XOs that i could live with... many of them big bucks.
In playing with XOs on some speakers, starting out with complex XOs and then simplify, it seems the life came back into the speaker... so my friend came up with the phrase in the quotes.
dave
So you're saying that the 6.5" woof / 1" tweet systems with high order crossovers and possibly notch filters and baffle step comp. that people are putting together, often based on the info provided on this forum, are fairly lifeless?
The above described system is really popular around here. I, for one, would like to build one of your simple designs and make some comparisons. Can you recommend something?
The above described system is really popular around here. I, for one, would like to build one of your simple designs and make some comparisons. Can you recommend something?
Without question, you should have a second amp for everything below 150 hz if you have a large sub or woofer in a 3 way. A small amount of clipping will never be heard through a subwoofer, but will wreak havoc on the upper drivers. and If you've never looked at a well recorded source on a scope, you wouldn,t believe the transients. I would say that you need at least 500watts/channel to cover them with a single amp to prevent the peaks from ringing the tweeters instead of thumping your chest at even moterate volumes.
I haven't yet triamped my system, but I would expect a lot of room for gain by using different amps for there strengths in their ranges. Something of a lower power with great smoothness and finesse for the tweeters and something a bit more accurate with more power for the midbass is my goal. Not having the caps and coils in the line should help the amp have a simpler load and better damping of the speaker and allow you to tweak knobs until you find perfection.
I haven't yet triamped my system, but I would expect a lot of room for gain by using different amps for there strengths in their ranges. Something of a lower power with great smoothness and finesse for the tweeters and something a bit more accurate with more power for the midbass is my goal. Not having the caps and coils in the line should help the amp have a simpler load and better damping of the speaker and allow you to tweak knobs until you find perfection.
Bill Fitzpatrick said:
http://www.woodartistry.com/linkwitzlab/filters.htm - basically an all pass filter that SL calls delay correction. (looks like SL has found someone with excess transfer capacity to hold his data. His archive CD is wirth buying)
I was skeptical that 60 microseconds delay in the tweeter would be audible, but it reall changed the character of the attack. this made the biggest difference. between the active and passive.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.