Hey guys,
I have been thinking of trying out active bi-amp, currently have a passive bi amp system.
However, don't seem to be a lot of options on how to go about doing so? I will need an active electronic crossover, but there are not many available in the hi-fi market. I am aware of some pro-audio active crossovers, and also read about some DIY projects.
What would be the best way to get started? Not too keen on DIY, think will be too much for me at this point.
Thanks and appreciate the advise.
I have been thinking of trying out active bi-amp, currently have a passive bi amp system.
However, don't seem to be a lot of options on how to go about doing so? I will need an active electronic crossover, but there are not many available in the hi-fi market. I am aware of some pro-audio active crossovers, and also read about some DIY projects.
What would be the best way to get started? Not too keen on DIY, think will be too much for me at this point.
Thanks and appreciate the advise.
This:
http://sound.westhost.com/project09.htm
may make a nice starting point, though there is often more to a practical crossover system. Read here for more details:
http://www.linkwitzlab.com/filters.htm
What speakers are you using? Presumably commercial ones with built in crossovers? Bear in mind you'll have to by-pass these to take advantage of an active setup and that without driver responses, designing a suitable crossover will be very difficult to do well. There is the possibility to make the existing crossover as an active unit though
http://sound.westhost.com/project09.htm
may make a nice starting point, though there is often more to a practical crossover system. Read here for more details:
http://www.linkwitzlab.com/filters.htm
What speakers are you using? Presumably commercial ones with built in crossovers? Bear in mind you'll have to by-pass these to take advantage of an active setup and that without driver responses, designing a suitable crossover will be very difficult to do well. There is the possibility to make the existing crossover as an active unit though
Use a cheap pro-audio unit to start with, put a query in the trading post section for a Behringer CX 2310.
Do an online search for the item and you will find a lot of opinions on this unit, I use them and I'm happy ; so long as I keep the XO frequency below 250/300 Hz i can't hear the noise and distortion claimed by some users
Here in Melbourne they go on sale for AUD$99- every now and then, paid that for my last unit.
Good way to get your feet wet for relatively cheap price, then you can go on the buy or build good quality units if you need to.
Regards
Do an online search for the item and you will find a lot of opinions on this unit, I use them and I'm happy ; so long as I keep the XO frequency below 250/300 Hz i can't hear the noise and distortion claimed by some users
Here in Melbourne they go on sale for AUD$99- every now and then, paid that for my last unit.
Good way to get your feet wet for relatively cheap price, then you can go on the buy or build good quality units if you need to.
Regards
Dr EM: Thanks for the links. I have read the westhost site before, that was the main reason that got me interested in active crossovers. Actually i was planning to use the Recession Kit for the mid+high, and another set of dual 6 or 8 inch woofers for the low. Planning to use the active crossover at 250-300Hz for this.
Am rather intimidated by the option of DIY for my first project though.
Moondog: Thanks for the link on the Behringer. Unfortunately, i don't think they are easily available in Singapore. I have also come across an Ashly pro-audio crossover. However, they all seem to use balanced or XLR connectors. how would i connect that to home audio RCA plugs?
What about the Reckhorn S-1 as an electronic crossover for the 250-300Hz split between the woofers and the recession buster kit?
Another side question, would i have to remove the baffle step correction in the recession buster crossover, since i am only using it to about 250-300Hz?
Oh, the woofers will go down to about 60 Hz, will also be having an active sub, using the O Audio plate amp.
Thanks!
Am rather intimidated by the option of DIY for my first project though.
Moondog: Thanks for the link on the Behringer. Unfortunately, i don't think they are easily available in Singapore. I have also come across an Ashly pro-audio crossover. However, they all seem to use balanced or XLR connectors. how would i connect that to home audio RCA plugs?
What about the Reckhorn S-1 as an electronic crossover for the 250-300Hz split between the woofers and the recession buster kit?
Another side question, would i have to remove the baffle step correction in the recession buster crossover, since i am only using it to about 250-300Hz?
Oh, the woofers will go down to about 60 Hz, will also be having an active sub, using the O Audio plate amp.
Thanks!
When you've tried bi- or even tri-amping with a decent filter, you'll never go back to passive again.
It simply sounds better. Much, much better.
I was inspired by Rod Elliott and I think his no-nosense writing is what got me on track. After a lot of work with DIY speakers and low-level electronics (preamp / XO) I was in for my first listen. After a couple of seconds of listening I was completely sold on the concept of active crossovers / multiple amps. It literally rocks!
It simply sounds better. Much, much better.
I was inspired by Rod Elliott and I think his no-nosense writing is what got me on track. After a lot of work with DIY speakers and low-level electronics (preamp / XO) I was in for my first listen. After a couple of seconds of listening I was completely sold on the concept of active crossovers / multiple amps. It literally rocks!
Dr.EM said:
If you're going to DIY something permanant:
Siegfried Linkwitz sells boards with better topologies (notch filters, shelving filters for baffle step/dipole/driver equalization, all-pass for phase alignment), tweaks to avoid RF problems (low-pass filters for RF on the input and op-amp feedback loops), proper power supply decoupling at the op-amps, etc.
They're dead quiet (at least the Phoenix boards which evolved to the ASP and Pluto boards).
The ASP boards allow for a 3-way with out-board amplification:
http://www.linkwitzlab.com/pcb.htm
The Pluto boards are 2-way with an LM3886 for one channel and bridged LM3886s for the second:
http://www.linkwitzlab.com/Pluto/supplies.htm
A solderless breadboard will do for prototypes.
If you are experimenting, then breadboards are the way to go.
Cost only about $10 and you can pretty much do anyting quickly.
That picture is 3-way, 24db/oct xo.
If this is your 1st time, build a 12db LR. Only need 3 TL072 op-amps for a two-ways. 1 buffer and 2 for the actual xo.
Then move on to 24db/oct.
Download the calculator tool from this link. It's a real time-saver.
http://sound.westhost.com/project09.htm
Cost only about $10 and you can pretty much do anyting quickly.
That picture is 3-way, 24db/oct xo.
If this is your 1st time, build a 12db LR. Only need 3 TL072 op-amps for a two-ways. 1 buffer and 2 for the actual xo.
Then move on to 24db/oct.
Download the calculator tool from this link. It's a real time-saver.
http://sound.westhost.com/project09.htm
I am using a dBx DriveRack PA active crossover which you can find at Parts Express or on E-Bay. It will handle two or three way set-ups, has independently adjustable slopes and crossover frequencies, it has EQ, and you can boost or cut the levels to the different drivers. It is a very powerful crossover that can be adjusted on the fly to dial in the sound of your system. It does use XLR connectors and cables which is no big deal for me since my preamp and amps have that option. Once you get the hang of it, it is really easy to use.
I think the Behringer DCX 2496 does a lot of the same things but has an additional advantage of a computer interface that can be used to program the adjustments. Being able to sit in your listening spot and adjust the crossover to dial in the sound of your system would be a real advantage.
I think the Behringer DCX 2496 does a lot of the same things but has an additional advantage of a computer interface that can be used to program the adjustments. Being able to sit in your listening spot and adjust the crossover to dial in the sound of your system would be a real advantage.
Drew Eckhardt said:
I didn't realise this, I already have ESP boards. They look fairly decent though, and I can add capacitors under the IC's I suppose. I will need seperate boards for my notches and possibly phase correction.
Here is my breadboarded 3-way 24dB LR with notch filters and BSC (highpass is 18db Butterworth, tweeter cap forms 4th pole):
An externally hosted image should be here but it was not working when we last tested it.
Using TL074 op-amps, keeps things compact and if you find capacitors with various lead pitches you can minimise the use of wire jumpers
Yours looks much nicer though gainphile, those long leaded box caps are cool!
Wow, thanks for all the info. Not sure what you mean by Sallen-Key topology, but will try to look it up.
Some questions about DIY : How do you connect the breadboard to your pre amd out, and power amp input? RCA connectors to bare wire into the breadboard?
Being the clumsy careless me, i will probably blow my amps before i'm done testing.
Nevertheless, a picture speaks a thousand words. Thanks for sharing the breadboard photos.
Any pics of finished / operational units? Powered using wall warts?
Thanks!
Some questions about DIY : How do you connect the breadboard to your pre amd out, and power amp input? RCA connectors to bare wire into the breadboard?
Being the clumsy careless me, i will probably blow my amps before i'm done testing.
Nevertheless, a picture speaks a thousand words. Thanks for sharing the breadboard photos.
Any pics of finished / operational units? Powered using wall warts?
Thanks!
FWIW I've used the Behringer CX2310 and the dbx driverack PA both mentioned it this thread.
First of all using XLR connections on the input is no big deal you can just buy adapters. The dbx unit has a switch on the back to accept consumer level inputs (this is important as the unit is digital). However you'll either need to use pro-amps or pad down the dbx outputs. Padding down the output is as simple as building L-pad or H-pad into you cables (pretty easy to do for first DIY project).
The dbx unit is fantastic when used with a RTA mic. You can basically eq the unit to give you a flat frequency response at the listing position, all with the push of a button. It's a crossover AND room correction device all in one. It also sounds very good IMHO and I'm using mine with some pretty high end compression drivers & horns.
Before I bought the dbx I had two CX3210's. They are great for the $$, but the crossover points are very vague due to the markings on the knobs. You really need to measure your speakers to figure out when cx3210 is actually crossing over. It really is appallingly vague. On the positive side it's not a noisy unit and because it's analogue you don't have to mess with padding down the output signal, you can just use the gain controls.
The room correction is really amazing on the dbx, so if you can spring for it, it's the way to go.
The Behringer dcx2496 does have the ability to eq using peq filters, but IIRC it doesn't have a 32 band rta like the drive rack pa. To do that with the Behringer equipment you'd need both the dcx and deq units.
First of all using XLR connections on the input is no big deal you can just buy adapters. The dbx unit has a switch on the back to accept consumer level inputs (this is important as the unit is digital). However you'll either need to use pro-amps or pad down the dbx outputs. Padding down the output is as simple as building L-pad or H-pad into you cables (pretty easy to do for first DIY project).
The dbx unit is fantastic when used with a RTA mic. You can basically eq the unit to give you a flat frequency response at the listing position, all with the push of a button. It's a crossover AND room correction device all in one. It also sounds very good IMHO and I'm using mine with some pretty high end compression drivers & horns.
Before I bought the dbx I had two CX3210's. They are great for the $$, but the crossover points are very vague due to the markings on the knobs. You really need to measure your speakers to figure out when cx3210 is actually crossing over. It really is appallingly vague. On the positive side it's not a noisy unit and because it's analogue you don't have to mess with padding down the output signal, you can just use the gain controls.
The room correction is really amazing on the dbx, so if you can spring for it, it's the way to go.
The Behringer dcx2496 does have the ability to eq using peq filters, but IIRC it doesn't have a 32 band rta like the drive rack pa. To do that with the Behringer equipment you'd need both the dcx and deq units.
This pic may be helpful too:
It shows a bit further back! I utilised a 19" rack case (which was going to be the final X-over case, but didn't have good enough build quality or internal space I decided) to hold the phono inputs and power inlet. A small power supply is included for +/-12V DC from 12VAC input feed from a wallwart. Simple and safe. Outputs on 3.5mm stereo for convenience really, I have lot's of those cables to twin phono around
Can see I have yet to make it stereo! It's 3-way stereo when done.
PS: Specifically my phono's are connected to an oversized stranded cable with a pin (resistor lead) soldered to the end and both joints heatshrinked. Is more durable than bell wire this way
An externally hosted image should be here but it was not working when we last tested it.
It shows a bit further back! I utilised a 19" rack case (which was going to be the final X-over case, but didn't have good enough build quality or internal space I decided) to hold the phono inputs and power inlet. A small power supply is included for +/-12V DC from 12VAC input feed from a wallwart. Simple and safe. Outputs on 3.5mm stereo for convenience really, I have lot's of those cables to twin phono around
Can see I have yet to make it stereo! It's 3-way stereo when done.
PS: Specifically my phono's are connected to an oversized stranded cable with a pin (resistor lead) soldered to the end and both joints heatshrinked. Is more durable than bell wire this way
I agree. Therefore I prefer the MFB (multible feedback) topology - go to second circuit about
Design and Dimensioning of Active Filters
But even Mr. Nelson Pass prefer the Sallen-key topology - go to post #55 about
http://www.diyaudio.com/forums/pass-labs/2646-pass-labs-xvr1-crossover-6.html
Unfortunately there are no commercial units at whole; therefore I have start this thread:
http://www.diyaudio.com/forums/soli...ss-commercial-unit-between-pre-power-amp.html
Thus it is much more difficult to find a commercial unit like the XVR1, but with MFB topology.
BTW - a must used englich term for an active crossover is "Electronic Crossover". An also often used partly term is "processor". Maybe some other, that I don't know.
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lmfao, best use for an Apple FDD I've seen in a while.
I've wanted to build a sub crossover like that for a while, copper is too expensive to do passive sub crossovers anymore.
I use a Behringer CX3400 that you can get for around 120 Euros + a flatrate shipment of 50 Euros to Singapore (per shipment, not per item if you also need some cables and other stuff!) from Thomann.de Behringer CX3400 Super X Pro - Thomann UK Cyberstore
They are totally reliable, cheap and trustworhty and are true professionals when it comes to advise on equipment. They have a large physical shop in Germany and most of the staff speak English, if you phone them. (And no, I don't work for them or anything. I'm just a satisfied costumer).
The crossover has balanced XLR input/outputs so you will need XLR/RCA adapters or a DI-box, which basically is a 'bal/unbal'-converter. I use this one: for getting the signal into the crossover (from a small mixer I use as a preamp/switch between audio sources and tone control). Note that it has 1/4" jack sockets for input so in this case you need RCA/XLR cables or adapters if your signal comes directly from e.g. a CD player: Behringer DI20 - Thomann UK Cyberstore.
My amplifiers have balanced XLR inputs so I don't need any further adaptors from the output of the crossover. But getting an unbalanced signal out of a balanced XLR output is just a matter of not using one of the pins. Just search around on the Thomann site for the cables and adapters that suits your need.
I originally planned just to use the CX3400 to establish the frequencies for crossover, then build a smaller one with fixed parameters for my system. But why bother? I still use the Behringer and it sounds brilliant to me. Besides, I like the option of constantly tweaking levels and frequencies.
They are totally reliable, cheap and trustworhty and are true professionals when it comes to advise on equipment. They have a large physical shop in Germany and most of the staff speak English, if you phone them. (And no, I don't work for them or anything. I'm just a satisfied costumer).
The crossover has balanced XLR input/outputs so you will need XLR/RCA adapters or a DI-box, which basically is a 'bal/unbal'-converter. I use this one: for getting the signal into the crossover (from a small mixer I use as a preamp/switch between audio sources and tone control). Note that it has 1/4" jack sockets for input so in this case you need RCA/XLR cables or adapters if your signal comes directly from e.g. a CD player: Behringer DI20 - Thomann UK Cyberstore.
My amplifiers have balanced XLR inputs so I don't need any further adaptors from the output of the crossover. But getting an unbalanced signal out of a balanced XLR output is just a matter of not using one of the pins. Just search around on the Thomann site for the cables and adapters that suits your need.
I originally planned just to use the CX3400 to establish the frequencies for crossover, then build a smaller one with fixed parameters for my system. But why bother? I still use the Behringer and it sounds brilliant to me. Besides, I like the option of constantly tweaking levels and frequencies.
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