ASR reccomended external crossovers?

[Jayce996]

The DCX2496 has a high output (+22dBu) or just under 10v so although it has a decent S/N ratio, that only applies if you have pretty insensitive power amps. With most power amps, there's some 18dB more signal and therefore noise than you need. I put 16dB attenuators on my DCX outputs, which attenuates both the signal and the noise, so preserving the S/N ratio, and noise just isn't a problem.

S

how did you do that?

 

[Eurasian]

is it just software crossover or hardware crossover as well?

Both are sota software solutions. You will need a suitable computer and multichannel dac with amplifiers to complete the system

 

[sergeauckland]

how did you do that?

I built a three resistor balanced attenuator into each XLR plug going into the power amps. There's comfortably enough room in an XLR plug for this. An attenuator using four resistors would give an improvement in common mode rejection, but frankly for the maximum 3ft cable length, it wasn't worth the extra effort in getting closely matched resistors as for a three resistor attenuator, 5% resistors worked fine, and it was easier to get them in the plug.

S

 

[MakeMineVinyl]

Both are sota software solutions. You will need a suitable computer and multichannel dac with amplifiers to complete the system

Aside from digital solutions like MiniDSP, the pure analog options are limited. Behringer and maybe others may have analog crossovers but these are usually geared for applications like sound reinforcement/PA. Elliot Sound Products makes kit crossovers but I think you will need to do a lot of the chassis work / soldering / assembly yourself.

 

[Jayce996]

Both are sota software solutions. You will need a suitable computer and multichannel dac with amplifiers to complete the system

hey @Eurasian digging deeper in the proposal you were referring, could you guide me to sites, posts detailing a little bit more how it works?
on my side, i need at least 2 Analog XLR input going to 2 XLR Outputs as this will only do the crossover thing, all the other things are driven directly via my Preamp XMC2 for Hifi & HC.
I don't understand right now how I can connect XLR cables IN/OUT to a computer based crossover.
If the desktop crossover is even able to manage my music I would be able to bypass my XMC2 and connect my Raspberry PI4 via USB to the crossover directly.

 

[Eurasian]

The computer will do the crossovers and any dsp you require. I use an Okto DAC 8 to my amps and subwoofers.

https://www.oktoresearch.com/dac8pro.htm

 

[Daverz]

The computer will do the crossovers and any dsp you require. I use an Okto DAC 8 to my amps and subwoofers.

https://www.oktoresearch.com/dac8pro.htm

They haven't been taking new orders for the 8-channel DAC for a long time.

 

[Jayce996]

The computer will do the crossovers and any dsp you require. I use an Okto DAC 8 to my amps and subwoofers.

https://www.oktoresearch.com/dac8pro.htm

what kind of computer card can i use to connect my 2 XLR ANALOG Inputs?

 

[Eurasian]

what kind of computer card can i use to connect my 2 XLR ANALOG Inputs?

Maybe an esi juli@ if you can find one.

 

[Daverz]

The Motu M4 has 4 analog inputs and 4 analog outputs, but I'm not sure how the routing would work to route the analog inputs to a loopback for processing in the host computer.

 

[multichannel_guy]

Hello all, how do you decide on the optimal crossover points for drivers on 2 way or 3 way PA speakers when implementing external crossovers? I would think PA speaker manufacturers themselves would suggest optimal crossover frequencies, but, i guess they don't.

 

[Keith_W]

Hello all, how do you decide on the optimal crossover points for drivers on 2 way or 3 way PA speakers when implementing external crossovers? I would think PA speaker manufacturers themselves would suggest optimal crossover frequencies, but, i guess they don't.

This is how I do it:

1. Take a nearfield measurement (mic almost touching the driver). This tells you the native frequency response of the driver.
2. Take a measurement at 1m at 86dB SPL, 96dB, and 106dB of each individual driver. Use this to look at distortion measurements.
3. Ideally, take off-axis measurements in an anechoic chamber, or do the best that you can. This tells you the speaker directivity.

Your aims when you design a crossover are:

1. The crossover points and slopes need to sum to flat.
2. Work around the natural roll-off of the drivers. If there is considerable overlap, you have more flexibility in choosing your XO point. If the overlap is narrow, that's where your XO point is going to be. You may also want to choose XO points which are away from bands of distortion - these are usually found at lower freqs of each driver.
3. Avoid boosting drivers by making it play louder than it "wants to" (i.e. where it is already rolling off). If you have to, that's where you need to look at your distortion measurements.
4. If it is any type of crossover except a FIR crossover, the XO will introduce phase rotations which might mess up timing, introduce comb filtering, or speaker lobing, or other artefacts at and around the XO point. You will need to look for those.

Don't forget to consider including baffle step compensation, Linkwitz transform, notch filters, etc.

I strongly suggest you use a digital crossover as a starting point, even if you plan to move to an analogue XO eventually. These are the most flexible and the easiest to adjust. It only takes me a couple of minutes and I have a new XO.

 

[multichannel_guy]

This is how I do it:

1. Take a nearfield measurement (mic almost touching the driver). This tells you the native frequency response of the driver.
2. Take a measurement at 1m at 86dB SPL, 96dB, and 106dB of each individual driver. Use this to look at distortion measurements.
3. Ideally, take off-axis measurements in an anechoic chamber, or do the best that you can. This tells you the speaker directivity.

Your aims when you design a crossover are:

1. The crossover points and slopes need to sum to flat.
2. Work around the natural roll-off of the drivers. If there is considerable overlap, you have more flexibility in choosing your XO point. If the overlap is narrow, that's where your XO point is going to be. You may also want to choose XO points which are away from bands of distortion - these are usually found at lower freqs of each driver.
3. Avoid boosting drivers by making it play louder than it "wants to" (i.e. where it is already rolling off). If you have to, that's where you need to look at your distortion measurements.
4. If it is any type of crossover except a FIR crossover, the XO will introduce phase rotations which might mess up timing, introduce comb filtering, or speaker lobing, or other artefacts at and around the XO point. You will need to look for those.

Don't forget to consider including baffle step compensation, Linkwitz transform, notch filters, etc.

I strongly suggest you use a digital crossover as a starting point, even if you plan to move to an analogue XO eventually. These are the most flexible and the easiest to adjust. It only takes me a couple of minutes and I have a new XO.

Thank you for the tips, will try to keep this in mind. I have a flex eight minidsp coming in the mail and will be staying digital. Lifting a 140lb speaker off the floor outside for measurements is looking a bit impractical at the moment. I contacted the manufacturer to get some measurements and recommendations to make things easier, no response.