1 Topic by anjora (edited by anjora 2017-08-07 10:40:06)

  • Registered: 2017-08-07
  • Posts: 2

Topic: suitable for digital XO?

How suitable is the adi-2 for digital 2-way crossover, 12dB/octave?

I have been thinking about building a new system for a while but i need a crossover between subwoofers and speakers, i may also want to use digital XO between tweeter+squawkers & woofer.

I like to have dsp support at 768KS/s, i do not need a dac+adc now but i was temped to grab the anniversity edition or whatever.

It was mentioned in another thread that you could not set the a LP filter below 200hz which means i will need another eq for the subwoofers(Linkwitz transform & 70hz LP filter).

  • Registered: 2017-09-06
  • Posts: 9

Re: suitable for digital XO?

As far as I know, the API-2 Pro cannot be used as a crossover itself. The reason for that is, that you cannot setup different EQs (or crossovers in this case) and send each modified signal to a different output.

What you could do however, is to use the digital output of the API-2 Pro and send its signal to a DSP-enabled amplifier. Setup your crossover in that amplifier, and send that signal to your subwoofers.

Your mains would be connected to another amp, which would receive the analog output from the API-2 Pro. The only issue then is, that you would still get the full range at the main speakers (e.g. the low-end not filtered out). The only way to avoid that would be with an active 2-way crossover, or some other type of filter in front of the main speakers or main amp.

The latter could be avoided if your DSP-enabled subwoofer amplifier has a digital through link; feed that to another DSP-enabled amplifier, which would then set the appropriate crossover for your mains and amplify these.

I find that solution quite interesting myself... the ADI-2 Pro makes a great Pre-Amp, and the Lab Gruppen IPD-1200 or IPD-2400 would make some great amplifiers, which offer DSP and also a digital input and through link.

Let me know what you think, or if you have a better idea. I have plans along the same lines.

3 Reply by MC

  • MC
  • MC
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  • Registered: 2007-04-06
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Re: suitable for digital XO?

Apart from that this topic has been discussed here several times already, this one

> As far as I know, the API-2 Pro cannot be used as a crossover itself. The reason for that is, that you cannot setup different
> EQs (or crossovers in this case) and send each modified signal to a different output.

is incorrect. All 4 outputs can be equalized individually.

Regards
Matthias Carstens
RME

MC's Website

  • Registered: 2017-09-06
  • Posts: 9

Re: suitable for digital XO?

Of course you can, sorry about that.

When talking about outputs, I tend to think of the outputs on the back only. And those in the back, the analog and digital outputs, will have the same EQ setting, correct?

The secondary headphone output in the front however, can have different EQ settings than the rest. That's what I understand from the manual.

  • Registered: 2017-08-07
  • Posts: 2

Re: suitable for digital XO?

I was of course talking about the headphone outputs in the front. I plan to build a 3 way system(sealed) i will not need a lowpass filter for the woofers, i will ad subwoofers later if i view it as necessary.

I would use the raal 140-15d so i cannot go for digital XO only.

It seams the adi-2 pro isn't suitable for tge subwoofers and thus i will have to use something else for that in the future. I will wait until i have started building speakers until i get a dac, maybe something better will come.

  • Registered: 2017-09-06
  • Posts: 9

Re: suitable for digital XO?

anjora wrote:

I was of course talking about the headphone outputs in the front. I plan to build a 3 way system(sealed) i will not need a lowpass filter for the woofers, i will ad subwoofers later if i view it as necessary.

I would use the raal 140-15d so i cannot go for digital XO only.

It seams the adi-2 pro isn't suitable for tge subwoofers and thus i will have to use something else for that in the future. I will wait until i have started building speakers until i get a dac, maybe something better will come.

I don't see why the Raal tweeter would not work with a digital crossover?

Your chain would be source -> preamp -> crossover -> 3 x amplifier -> woofer, mid, tweeter (fed from each amp)

There are many possibilities. One decision to make is wether you want a digital, or an analog crossover. Both will work.
As I described earlier, a DSP-enabled amplifier would also work. You could do it with three... or just one for the woofers, and a digital or analog or even passive cross-over with amp(s) for the mid/hi.
Or get a digital crossover, and do everything there.

As you can see, the possibilities are endless, which makes it difficult to decide!

There are a few things to consider though:
- If you use a digital crossover, I would suggest to "feed" it digitally. Otherwise you will have a double conversion for your digital sources.
- Not all DSP software is created equal. I highly recommend testing the crossover software before purchasing a digital crossover. Most of the programs can be used without a connection to the actual device (e.g. you don't need to buy the crossover just for testing the software). I have tried quite a few, from unusable to very nice...
- Digital crossovers are much more flexible than analog ones
- Some say analog crossovers sound better, having no (A/)D/A conversion; you need to test and decide for yourself whether you can hear differences...

If you want to go analog, you will have a hard time finding a quality analog crossover. Well, at least if your budget is limited. If you don't want to "DIY", then I would suggest checking out the offerings from Marchand Electronics. These are highly regarded by many.

I would also suggest to pursue another forum for more help, as this is not really RME specific. Personally, I prefer DIYAudio.com, where people are rather rational, and not blinded by marketing or "ultra-high-end" claims...

Nevertheless, you should not rule out the ADI-2 Pro. It would make a really great pre-amp for your active system. The many great features (variable loudness, EQ, 2 separate headphone outputs, bass/treble adjustments, great variety of inputs, nice display, proper volume control knob...) are at your fingertips. In my opinion, a very sweet pre-amp solution for an active system.

To make a long story short: I did buy the ADI-2 Pro to be used as a pre-amp in my active system smile