Bass Management (High Pass Filter) in an ASR Approved System?

[RocketLeague]

I struggled to decide which category to post this but thought I might find the most patient helpers here

I am looking to build a high quality 2.1 front end for bookshelf speakers + a sub, and want to avoid sending full range to the bookshelves.

By high quality I mean something like:

SMSL SU-8 DAC which doubles as a pre-amp for Volume Control, currently available on Drop for $189
https://drop.com/buy/smsl-su-8-dac

A power amp using the Hypex NC252MP or NC502MP, such as this one from Audiophonics:
https://www.audiophonics.fr/en/powe...reo-amplifier-ncore-2x250w-4-ohm-p-14185.html

But I still need a way to add a high pass filter for the signal going to the speakers (and ideally a matching low pass filter for the sub, but that is easier to apply manually on the sub itself if needed).

It seems like one of the best options available are the offerings from MiniDSP (the "MiniDSP 2x4 HD" or the Dirac Live Version "DDRC-24"), but I'm struggling to understand how to implement one without sacrificing the benefits of a high performing DAC like the SU-8. Is that possible? Is there a similarly priced alternative that either maintains the signal quality of the SU-8 or matches it with an all-in-one device? I see they have an all in one streamer device with a nicer DAC but that's $900 and I don't really need the streamer, although it would be nice. It appears I'll be sacrificing the option to use balanced outputs as well if I go with one of the lower MiniDSP devices, but that's not a deal breaker. My target budget for this is ~$500 before the cost of the amp (so for volume control, bass management, and DAC). Thanks in advance for any feedback or suggestions my friends.

 

[georgeT]

If your source is a PC/laptop ditch the 2 channel DAC, they are useless. Get a 4 channel USB interface with decent specs and you're golden.

Edit: Honestly this should be a sticky for beginners, with a list of multi channel interfaces, even if ASR has an adversity towards them.

 

[QMuse]

Get a 4 channel USB interface with decent specs and you're golden.

I don't remember seeing much of those, can you post a link?

 

[andreasmaaan]

I don't remember seeing much of those, can you post a link?

You're mostly in the pro world with this kind of device: Focusrite Scarlett 2i4 or Clarett 4Pre, various Motu units and RME units, etc.

It seems like one of the best options available are the offerings from MiniDSP (the "MiniDSP 2x4 HD" or the Dirac Live Version "DDRC-24"), but I'm struggling to understand how to implement one without sacrificing the benefits of a high performing DAC like the SU-8. Is that possible? Is there a similarly priced alternative that either maintains the signal quality of the SU-8 or matches it with an all-in-one device?

You could consider something like MiniDSP Nanodigi, which is 1 x SPDIF in / 4 x SPDIF out. You could then route the SPDIF outputs to a pair of SU-8s (one for the speakers and one for the subs).

 

[QMuse]

You're mostly in the pro world with this kind of device: Focusrite Scarlett 2i4 or Clarett 4Pre, various Motu units and RME units, etc.

Yep, I'm aware of these. I wonder when will the companies like Toping, SMSL etc start to produce decent 4 channel USB DACs instead of upgrading current units which brings no real additional value to their products.

 

[suttondesign]

better subs have post-low-pass outputs for the main speakers. line in then line out. rythmik, for example. cheap and easy.

 

[DWPress]

For the ultimate cheap way out you could install some bass blocker caps inline with your main speakers. This is most often done in car audio but I've done it in my house system with great results. You'd need to know in advance what your XO would be for the mains and the sub though and get capacitors that match the mains 4 or 8 ohm rating.

In my studio where the real sound system abides I use a Minidsp 4x10 for a 2.3 active system and also use Roon's DSP to run filters and that's a lot more flexible and accurate way of dialing things in as you've noted.

 

[Koeitje]

better subs have post-low-pass outputs for the main speakers. line in then line out. rythmik, for example. cheap and easy.

With a high pass filter on them? I don't think they have that.

Edit: I was wrong, I was thinking about high level because I was looking at that before.

@RocketLeague what I am planning is a MiniDSP SHD with hypex/purifi amplifier and double subwoofer. That means I can high pass my normal speakers, low pass the subwoofers, apply room correction and also do everything in the digital domain.

Yep, I'm aware of these. I wonder when will the companies like Toping, SMSL etc start to produce decent 4 channel USB DACs instead of upgrading current units which brings no real additional value to their products.

A multichannel dac with a build in cross-over/dsp would be awesome.

 

[georgeT]

Yep, I'm aware of these. I wonder when will the companies like Toping, SMSL etc start to produce decent 4 channel USB DACs instead of upgrading current units which brings no real additional value to their products.

As long as the audio community has no problems running 120db SNR DACs through 80db SNR crossover circuits these companies will continue to churn out 2 channel DACs.
Review sites/youtube channels (ASR included) should just start ignoring these glorified headphone dacs and advise users to keep away from them.

 

[waynel]

This particular issue is something I’ve been thinking about a lot. Currently I have a Benchmark DAC3 and an AHB2 and am using a JL CR-1 in between as a crossover. I also have an AVR for home theater and I feed the left and right line level signals into the DAC3 in home theater bypass mode. I also have a miniDSP Dirac live all digital box upstream for room correction. It works fine but a digital solution would be better and way cheaper. Alternatives that I’ve considered are:

1) Anthem STR preamp. This has all the functionality that I need and would replace 3 boxes (dac3, CR-1, and miniDSP). However I’m concerned that the DAC quality and output level would not be as good as the benchmark dac3.
2) MiniDSP SHD. Would replace the same 3 boxes and dac measures well. However lack of a low latency, Home theater bypass mode is a deal breaker for me.

what I really want is something with the quality and usability of the Benchmark DAC3 with 3 or 4 outputs all controlled by one volume control (don’t want to involve a PC in my system)

other thoughts:

1) Bass blocking caps is not an optimal solution as it forms a 1st order filter which combines with the speaker roll off to form an undefined suboptimal roll off response. I think a 4th order linkwitz Riley above the natural roll off is better
2) it would be interesting to measure the Ashley XR-1001 as a cheaper analog crossover.

 

[georgeT]

The theme in audiophile circles: Everybody wants DSP before analog conversion but ain't no one wanna involve a PC.

 

[Kal Rubinson]

The theme in audiophile circles: Everybody wants DSP before analog conversion but ain't no one wanna involve a PC.

We'll just dress up the box so it won't look like a PC.

 

[Koeitje]

The theme in audiophile circles: Everybody wants DSP before analog conversion but ain't no one wanna involve a PC.

Its fine if its a PC, but you will also have to sort out inputs for non-pc playback.

 

[georgeT]

Its fine if its a PC, but you will also have to sort out inputs for non-pc playback.

Yes, a slight drawback. But hey, there's no such thing as a free lunch.
And spending 3k in benchmark audio gear only to use a 90db THD+N crossover sounds bonkers to me, no offense @waynel

 

[waynel]

Yes, a slight drawback. But hey, there's no such thing as a free lunch.
And spending 3k in benchmark audio gear only to use a 90db THD+N crossover sounds bonkers to me, no offense @waynel

It sounds bonkers to me too and its 5k in benchmark gear! As far as no PC, I want a stereo that my family can use with a universal remote, Spotify connect, etc. is that to much to ask?

 

[Ron Texas]

https://www.parts-express.com/harrison-labs-fmod-inline-crossover-pair-100-hz-high-pass-rca--266-274

Passive, 12db/0ctave RCA plugs, inexpensive.

 

[waynel]

https://www.parts-express.com/harrison-labs-fmod-inline-crossover-pair-100-hz-high-pass-rca--266-274

Passive, 12db/0ctave RCA plugs, inexpensive.

Not a great solution , I don’t want 2 cascaded real poles with a slow roll off.

 

[georgeT]

https://www.parts-express.com/harrison-labs-fmod-inline-crossover-pair-100-hz-high-pass-rca--266-274

Passive, 12db/0ctave RCA plugs, inexpensive.

I'm not an expert but aside from the phase issues and the fact that no one uses 100hz crossover, does THD take a hit by using these?

 

[waynel]

Here is my system . The CR-1 predates the benchmark gear. How do I get benchmark like performance , a digital crossover , and no impact to usability? Money is not the issue , I just want the best measured performance.

 

[Tks]

It sounds bonkers to me too and its 5k in benchmark gear! As far as no PC, I want a stereo that my family can use with a universal remote, Spotify connect, etc. is that to much to ask?

From audio companies? Of course it is.