2. speakers
  3. 185948-12620

DSP Active Crossover

I'm considering trying a DSP-based active crossover in my system. I did a search to see how much this has been discussed, and most of the posts are pretty old or about active speakers. DSP technology has changed a fair amount in the last 15-20 years.

My system is digital only, and my speakers are 3-way, so it's not particularly complicated. I've been looking at the Danville Signal dspNexux 2/8 which has two channel in (with digital inputs) and eight balanced analog outputs. This appears to be available with AKM AK4499 DACs which are fairly well regarded sigma-delta DACs (although I don't know how good their implementation is).

This product has a fairly rich DSP software environment for programming filters, time delays, etc., so it should be fairly straightforward to set it up to replace my passive crossovers. 

My biggest reservations are 1) giving up my Denafrips Terminator+ DAC and nice-quality DIY preamp, and 2) using the DAC's digital volume adjustments. 

This unit is about $3K (maybe a bit more with the AK4499 DACs), so isn't terribly expensive. From the limited research I've done, this unit appears to be higher sound quality than the miniDSP or DEQX boxes, but I could be wrong. All my amps have balanced inputs, so I'd prefer to use a unit with balanced outputs. 

So, what I'm wondering is if the benefits of active crossovers and dsp equalization will outweigh the lesser DAC quality (assuming this is the case) and lack of analog volume control (currently using a relay switched attenuator). I'm also wondering if there are other dsp audio processors that I should consider (digital inputs, at least six channels out, ideally with balanced outputs).

128x128jaytor

Showing 1 response by lewinskih01

lewinskih01
907 posts
 

@jaytor 

Great system, and sorry I'm arriving 2 weeks late!

I also do DIY, dipole, AMT tweeter driven by SET, although have 4 sealed DIY Rythmik subs. And use DSP for digital xo and room correction. I use Acourate software for this, and believe Audiolense is also great. A great write-up by Mitch Barnett can be found at Computeraudiophile from years ago - there is a basic walk-through and an active xo walk-through, where he explains the setup and process, and results. He late wrote an ebook, and did an article on Audiolense I think.

My setup is an "audiophile" computer running Roon, convolving filters made with Acourate that account for linear phase xo and digital room correction (and time-alignment, etc), that outputs to a 8 channel DAC (Lynx Hilo) thru USB, that drives 8 amps directly connected to the drivers. Hilo has DAC and ADC capability, which is important to take the measurements to create the filters to be convolved. This is sort of the DIY approach to what boxes like DEQX do. One ADC/DAC I've had my eye on is Merging Hapi, but haven't gone there yet.

As I started venturing into active xo, I first used the Rythmik xo to relief my tube amp from reproducing sub frequencies. This was good, but going active with Hilo/Acourate far surpassed this solution. To me there is no going back. Given your DIY skills and willingness to dedicate time to get it done, I suspect you'll be on a similar path.

Please keep us posted on your journey!

More to discover