This is my first attempt at bi-amping and I'm awfully green. In fact I don't even deserve a colour.
This is my first thought:
I will use my H/K (55wpc) as a pre-amp. I am thinking of running the pre-out to an active crossover and then to a Carver cube (400-500wpc) on each woofer (97dB @ 1 w). I want to then take the high end and put it back through the pre-in on the H/K for the tweeters (108 dB @ 1 w). I am thinking that with the difference in sensitivity, this might be a good match.
Please comment on this part, then tell me about the active crossover. I have no idea of good from bad. It would be great to be able to order from Parts Express.
I don't even know the difference between what they call an electronic crossover and a signal processer
Is this something I could use?
Active crossover
Thank you for your input, I'm not looking to wing it this time.
Cal
This is my first thought:
I will use my H/K (55wpc) as a pre-amp. I am thinking of running the pre-out to an active crossover and then to a Carver cube (400-500wpc) on each woofer (97dB @ 1 w). I want to then take the high end and put it back through the pre-in on the H/K for the tweeters (108 dB @ 1 w). I am thinking that with the difference in sensitivity, this might be a good match.
Please comment on this part, then tell me about the active crossover. I have no idea of good from bad. It would be great to be able to order from Parts Express.
I don't even know the difference between what they call an electronic crossover and a signal processer
Is this something I could use?
Active crossover
Thank you for your input, I'm not looking to wing it this time.
Cal
JMO but I wouldn't hold out for too much tonal purity using a
carver cube for midrange.
Your sensitivity vs power arrangements sound perfectly sensible.
But the whole arrangement seems over SPL'ed for domestic use.
I've looked at the specs for the Beringher, will work, but you'll
still need to add pre-eq between pre-out and the c/o for baffle
step compensation and any tonal tweaking of the bass/mid.
sreten.
carver cube for midrange.
Your sensitivity vs power arrangements sound perfectly sensible.
But the whole arrangement seems over SPL'ed for domestic use.
I've looked at the specs for the Beringher, will work, but you'll
still need to add pre-eq between pre-out and the c/o for baffle
step compensation and any tonal tweaking of the bass/mid.
sreten.
Hi sreten,
These are for outdoor PA use. Purity and tonal quality take a back seat here.
Baffle step compensation? Is that like time alignment? The coils are already in line, this is in an A7 box.
If need be, I can ad an EQ at a later date. No?
Hi JohnSz,
You're right it's the Main-ins I will be using. Pre-ins meant only as a generic term.
Thanks to you both,
Cal
These are for outdoor PA use. Purity and tonal quality take a back seat here.
Baffle step compensation? Is that like time alignment? The coils are already in line, this is in an A7 box.
If need be, I can ad an EQ at a later date. No?
Hi JohnSz,
You're right it's the Main-ins I will be using. Pre-ins meant only as a generic term.
Thanks to you both,
Cal
Cal Weldon said:
Umm, well I think you're putting the cart before the horse here _grin_
Let's talk active crossover and that should get you further down the road.
I suggest you either go with a Marchand active crossover or a Behringer digital DCX 2496. or possibly a Driverack PA unit
You really need to go as high a quality here as you can because you're introducing an extra liink in the chain and your sound will only be as good as the weakest link in the chain.
The active crossover will have adjustments that will take care of gain matching.
Cal Weldon said:
I either don't understand what you are saying here or it doesn't work this way.
you come out of the preamp with one set of interconnects into the active crossover - the active crossover does the gain matching and crossover functions and splits the signal - leaving the crossover you have two pair of line level interconnects, each pair will go into the inputs of one power amp.
There was a post in another forum recently about the particular Behringer unit that you linked to. The poster was unhappy with the quality, and said it was unsuitable. Another poster was happy with his unit.
We all have different budgets and timing for purchases of things in our hobby of audio.
If you go as high a quality as possible with the crossover, it should remain with you for some time as you change out amps, preamps, etc. as you go along on the path of continual upgrade that we seem to follow _big grin_
There are several threads here on the Behringer -
Active pro crossovers that are not in the digital domain - such as Behringer, Rane and similar units have a questionable reputation for use in high resolution home audio systems.
I was one of the early adopters of the DCX 2496 and have been happy with it - some users have had problems with low-level noise - I have a need for delay in this configuration so in my case I needed to go digital. Most people do not need delay, and could do quite well with a marchand or similar unit.
The great thing about going digital is tremendous flexibility to match your current setup and then can make changes for future configurations.
DCX2496 can be had for $325.00 to your door in the US, I have seen Driverack PA on E-bay for under $400.
Marchand has a number of kits and configurations- and frequently turn up used on Audiogon.
The DCX2496 also has EQ functions that can easily do the EQ Sreten mentioned.
I am a beleiver that digital crossovers are the way of the future and that they are in their infancy for high resolution home audio. This means also that they will have growing pains that go along with it.
Regards
Ken L
I'm too slow typing - looks like there were posts while I was composing _grin_
OK well Ill fill in the blanks and say what baffle step is.
Basically a loudspeaker radiates every sound it produces in the high frequencies forwards from the drive units out to the listener. But at lower frequencies the sound starts to radiate round the back of the enclosure. If you have listened to a loudspeaker from behind you may notice that you dont get as much high frequencies the lows, this is because of this.
What happens is above certain frequencies the speaker radiates 2pi and at others 4pi, when this happens is determined by the width of the front baffle. As the wavelength of high frequencies is small in comparison to the baffle width they all fly foward. But as the wavelength goes beyond the baffle width the sound starts to "Creep" and bend round the sides of the cabinet. This means you get some sound going direct to the listener and some dissapearing round the back of the speaker.
http://www.seas.no/excel_line/excel/e0015.pdf
look at this data sheet from seas, it highlites BS brilliantly.
As you can see here the frequency response starts to decrease in SPL at about 800hz, which is odd because this is a bass driver and can easily operated below this keeping up the SLP. The driver can operated lower then this before the roll off in the bass, look further along at about 150hz, you'll notice that the response evens out again, then rolls off as you would expect at about 100hz. This roll off between 150 and 800hz is due to baffle step.
Bare in mind that theoretically BS gives a slow roll off to the tune of 6dB from start to finish. In the real world however you get some gain from the room so the full 6 isnt normally required, usually 3dB will suffice.
I hope thats clear, I have a really hard time making things coherent.
Matt
Basically a loudspeaker radiates every sound it produces in the high frequencies forwards from the drive units out to the listener. But at lower frequencies the sound starts to radiate round the back of the enclosure. If you have listened to a loudspeaker from behind you may notice that you dont get as much high frequencies the lows, this is because of this.
What happens is above certain frequencies the speaker radiates 2pi and at others 4pi, when this happens is determined by the width of the front baffle. As the wavelength of high frequencies is small in comparison to the baffle width they all fly foward. But as the wavelength goes beyond the baffle width the sound starts to "Creep" and bend round the sides of the cabinet. This means you get some sound going direct to the listener and some dissapearing round the back of the speaker.
http://www.seas.no/excel_line/excel/e0015.pdf
look at this data sheet from seas, it highlites BS brilliantly.
As you can see here the frequency response starts to decrease in SPL at about 800hz, which is odd because this is a bass driver and can easily operated below this keeping up the SLP. The driver can operated lower then this before the roll off in the bass, look further along at about 150hz, you'll notice that the response evens out again, then rolls off as you would expect at about 100hz. This roll off between 150 and 800hz is due to baffle step.
Bare in mind that theoretically BS gives a slow roll off to the tune of 6dB from start to finish. In the real world however you get some gain from the room so the full 6 isnt normally required, usually 3dB will suffice.
I hope thats clear, I have a really hard time making things coherent.
Matt
Thanks to Ken L,
I won't need to worry about upgrading amps etc. I should have explained these are my personal speakers, not used for pro PA. I believe the digital is a bit more than is required for the set-up at this time.
Thanks to sreten,
I believe you are the one who understands what I am attempting with the back feed into the H/K the best
Thanks to 5th element,
That makes baffle step compensation easier to understand.
Thanks to navin,
I will be using the level adjusters on the xover for my final matching.
Let me explain once more what I intend to do for those a little confused at this point:
My H/K AVR40 receiver will be used as a pre-amp AND an amp.
The low voltage output (pre-amp) will go to the new active Xover.
The bass frequencies low voltage output from the Xover will be split into two Carver cubes, one for each woofer.
The low voltage high frequencies from the new Xover will be taken back into the H/K low voltage input. The tweeters will then be run from the main speaker terminals in the H/K. I will not be running any high voltage back into the H/K.
I though that the sensitivity of the drivers would match well with the differences in the wattage.
I will do my final adjusting of the woofer/tweeter levels on the new Xover.
So I will have 55wpc into the tweeters, 500wpc into the woofers.
Hope this clarifies some issues.
Thank again for your inputs, bring on more!
Cal
I won't need to worry about upgrading amps etc. I should have explained these are my personal speakers, not used for pro PA. I believe the digital is a bit more than is required for the set-up at this time.
Thanks to sreten,
I believe you are the one who understands what I am attempting with the back feed into the H/K the best
Thanks to 5th element,
That makes baffle step compensation easier to understand.
Thanks to navin,
I will be using the level adjusters on the xover for my final matching.
Let me explain once more what I intend to do for those a little confused at this point:
My H/K AVR40 receiver will be used as a pre-amp AND an amp.
The low voltage output (pre-amp) will go to the new active Xover.
The bass frequencies low voltage output from the Xover will be split into two Carver cubes, one for each woofer.
The low voltage high frequencies from the new Xover will be taken back into the H/K low voltage input. The tweeters will then be run from the main speaker terminals in the H/K. I will not be running any high voltage back into the H/K.
I though that the sensitivity of the drivers would match well with the differences in the wattage.
I will do my final adjusting of the woofer/tweeter levels on the new Xover.
So I will have 55wpc into the tweeters, 500wpc into the woofers.
Hope this clarifies some issues.
Thank again for your inputs, bring on more!
Cal
Cal Weldon said:
Duhhhh.
Hey Cal - please don't let my wife know that there are people out there who find happiness with one system _big grin_
I apparantly mistook you for another individual that is suffering from a similar condition to the one I apparently have which goes kinda like this -
I upgraded my system to the best I had ever had, a couple of years ago - then changed out the amp, then changed out the speakers, then the wires, am working on another pre-amp and amp now.
Sooooo, I figure that by the time I get the pre-amp and amp finished and dialed in, I'll be working on bass horns, or other front horns.
kinda like, if you take your time and do it thoughtfully, one component at the time, it'll be say, every four or five years you've over that period changed everything in the system out. _really big grin_
I never said it was _rational_
regards
Ken L
Hi Dave,
Not to worry. These cubes are in hand and that's what I will start with. You see, like many other projects, this is kind of snowballing on me and I think I better pull in the reins for now. If you've read Ken's responses you'll see what I mean. I think the cubes are fine for a woofer that only goes to 45 Hz. Besides this isn't some system I'm entering in a show, it's just for friends to rock to.
Ken,
What do you mean not rational? Spending money you don't have, on things you don't need, making loved ones shake their heads, isn't rational? Dammit I seem to have this all wrong! _GREAT BIG grin_
And yes, I understand the itch to up the system every year or so, but this is my first experience with the PA drivers and Bi-amping so maybe I should start on the bottom rung of the ladder.
If anyone has a good reason I SHOULD or SHOULDN'T start with the Behringer CX3400 Xover, please let me know ASAP.
I feel an itch coming on.
I want to use my Keno winnings before they're gone!
Thanks for all the help to this point.
Cal
Not to worry. These cubes are in hand and that's what I will start with. You see, like many other projects, this is kind of snowballing on me and I think I better pull in the reins for now. If you've read Ken's responses you'll see what I mean. I think the cubes are fine for a woofer that only goes to 45 Hz. Besides this isn't some system I'm entering in a show, it's just for friends to rock to.
Ken,
What do you mean not rational? Spending money you don't have, on things you don't need, making loved ones shake their heads, isn't rational? Dammit I seem to have this all wrong! _GREAT BIG grin_
And yes, I understand the itch to up the system every year or so, but this is my first experience with the PA drivers and Bi-amping so maybe I should start on the bottom rung of the ladder.
If anyone has a good reason I SHOULD or SHOULDN'T start with the Behringer CX3400 Xover, please let me know ASAP.
I feel an itch coming on.
I want to use my Keno winnings before they're gone!
Thanks for all the help to this point.
Cal
tough call
I'm using a pair of the CX3400 as sub XOs on my surround channels. I think they'd be OK for PA use but you might find that setting the XO levels would not be adequate equalization (depending on your needs). In that case you could use 2 of these
http://www.zzounds.com/item--BEHPEQ2200
(They're mono) I'm using a pair in part of my ambience system.
But by that time you've got 130 + 80 + 80 = $290 The digital unit (Ultra-Drive) would do every thing you need and better but it costs $350.00
BTW zzounds has great service.
I'm using a pair of the CX3400 as sub XOs on my surround channels. I think they'd be OK for PA use but you might find that setting the XO levels would not be adequate equalization (depending on your needs). In that case you could use 2 of these
http://www.zzounds.com/item--BEHPEQ2200
(They're mono) I'm using a pair in part of my ambience system.
But by that time you've got 130 + 80 + 80 = $290 The digital unit (Ultra-Drive) would do every thing you need and better but it costs $350.00
BTW zzounds has great service.
5th element said:
Close but no cigar !
You just needed to add why the Seas plots show this effect whilst
other plots don't. Seas tested drivers in real boxes in free space
(as you know) (I used the past tense because they seem to have
stopped doing it) whilst other manafacturers use a large flat baffle.
(and that with 3db of BSC = forced close to wall mounting,
and 6dB of BSC = free space mounting away from walls)
sreten.
Unless I missed it in one of the posts, above, I suggest anyone interested in bi-amping look at Rod Elliot's article at http://sound.au.com. Second look at the artical(s) on Linkwitz-Reilly at www.rane.com.
For my money, the aspect of having double the number of amplifiers is more of a spin-off neccessity than a benefit. The real beneifts come from potential of achieving constanf phase and even response across the XO region. and mostly are a much more important consideration than the pros and cons of particular amplifiers.
If the poster is willing to to do some diy-work either marchand or ESP are good sources fot DIT active XOs. The Behringer that was mentioned has one special feature that may or may not be of value depending on the physical layoout of the loudspeakers - the ability to introduce a slight time delay in one of the drivers. The Rane article, above, the "why" in one of the illustrations. I don't think there is a readily available diy equivalent that is simple to build.
For my money, the aspect of having double the number of amplifiers is more of a spin-off neccessity than a benefit. The real beneifts come from potential of achieving constanf phase and even response across the XO region. and mostly are a much more important consideration than the pros and cons of particular amplifiers.
If the poster is willing to to do some diy-work either marchand or ESP are good sources fot DIT active XOs. The Behringer that was mentioned has one special feature that may or may not be of value depending on the physical layoout of the loudspeakers - the ability to introduce a slight time delay in one of the drivers. The Rane article, above, the "why" in one of the illustrations. I don't think there is a readily available diy equivalent that is simple to build.
Get The Dcx !
Cal,
I strongly urge you to consider the digital Behringer (Ultra-drive DCX) as opposed to the analog version. You will not regret it. I was very disillusioned with my RANE active analog crossovers until I started messing with the new Behringer. The possibilities for tweaking are close to endless: equalization on every speaker, compression, limiting, delay, various filter curves and slopes, instant store and recall of parameters, wash, dry, rinse - you name it. I am willing to bet that you will sell that other Behringer after a couple of weeks to get this one. Oh, yes, and they do throw in a digital input, two analog inputs and six 2496 D/As.
The merits of the unit has been discussed substantially in this forum.
Cheers
Cal,
I strongly urge you to consider the digital Behringer (Ultra-drive DCX) as opposed to the analog version. You will not regret it. I was very disillusioned with my RANE active analog crossovers until I started messing with the new Behringer. The possibilities for tweaking are close to endless: equalization on every speaker, compression, limiting, delay, various filter curves and slopes, instant store and recall of parameters, wash, dry, rinse - you name it. I am willing to bet that you will sell that other Behringer after a couple of weeks to get this one. Oh, yes, and they do throw in a digital input, two analog inputs and six 2496 D/As.
The merits of the unit has been discussed substantially in this forum.
Cheers
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