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2.1 preamp

lofiguy

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Oh wise ASR recommendation engine! (TM)

I have a 2ch power amp.

For a 2.1 system, I believe I might want processing on the mains. At minimum a HPF but up from that, PEQ or Dirac. My listening environment is non-critical listening at my desktop, with small home theater satellites as the mains. I won't mention what they are because the system shouldn't be overly specific to the speakers, but I am not afraid to spend money there and they are the best such speakers I could find based on subjective reviews. They measure well anyway. But they are small. I'm giving up on my KEF meta and putting them back in the listening room. I can't get the KEF positioned well for my desk setup, which I can't change. I'm considering KEF in-ceiling or in-wall speakers instead of the HT satellites, but I'd still need the sub.

OK, I mention all this because in the past I've only ever used subs with HT and with AVR (pre/pro) which even back in the day, always had processing of some sort for the mains. But said processing comes for free with HT, so I'm not convinced it's necessary for 2.1 and more so, is it necessary for my deskbound near field listening during the day? And why do we typically with 2.0 systems not have HPF if it's so helpful? And for such physically small speakers, is it even more helpful or is it more irrelevant?

It's important because there are so few product choices that hit all my requirements. If there is not really much advantage to bass management for a setup like this, I can just do a line level splitter from my DAC and be done.

So the device I'm looking for can be a preamp or an inline DSP. Because I have an amp anything integrated won't work here, well I wouldn't want to waste the money spent on the amplifier section. If there's a streamer part that's ok I would use that. The requirements are:
  • Desktop form factor: half-rack width or smaller, 8" preferred. This is the hardest one!
  • Top quartile objective performance.
  • If digital inputs only, then must have physical volume knob.
  • Current production model.
That's it. Here's the products I've identified:
  • RME ADI-2 Pro FS R BE ($2000)
  • Motu mk5 ($600)
  • miniDSP 2x4 HD ($225)
  • DSPeaker Anti-Mode 2.0 Dual Core ($900)
  • Dayton DSP-408 ($250)
  • miniDSP SHD Studio ($950)
  • passive splitter with FMOD, Shure or DIY passive HPF ($40)
The DSpeaker seems to come with a mic, whereas the rest additionally require a mic as well.

I eliminated the miniDSP due to poor performance per ASR. The SHD Power does rank better but I don't want the extra amp. I'm very confident I can eliminate the Dayton and DSpeaker as well if the miniDSP didn't make the performance cut.

The motu may or may not be feasible. If it would work then any of the other models would also, like the AVB, which I like for the all rear I/O. Apparently the PEQ is not straightforward, so I don't know I want to spend time on it. I already know how to operate the RME.

If it is acceptable to treat the combined mains+sub as a single full range active speaker (pre->splitter->2.1), with passive HPF on the main split, then also:
  • RME ADI-2 DAC FS ($1300)
I think you can drive both the unbalanced and balanced analog out of the RME together, it's just they get the same signal (with the DAC model). So I don't need the external splitter then. For some other device that might not be the case.

I'll update this post as I get more feedback on the "need" for advanced vs simple bass management.
 
Last edited:

Staki

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SHD Studio should not have been excluded, it fits your requirement spec very nicely. It was never reviewed by Amir, but SHD (full version) was and got very good marks. And SHD Studio is basically SHD minus DAC and analog input.
 
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lofiguy

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Huh so this type of thread (2.1) seems quite common here. I've realized from those other threads and from https://nihtila.com/2018/01/08/minid-preamp-oled-tiny-minidsp-based-4-channel-preamplifier/ that an inline analog DSP ->(ADC>DSP>DAC)-> IOW between preamp and amp is likely going to be noisy even for my modest SPL level. So for an inline device I'm going to add a requirement of digital I/O, preferably USB. Maybe that requirement isn't necessary because any analog inline DSP isn't going to meet the top quartile requirement anyway.

The SHD Studio is looking better and better!

On the cheap and easy path, I'm going to try no filter on the mains (I'm worried about phase issue), and an inline DSP for the subs only. I found 3 products, the DSpeaker 8033, Dayton DSP-LF and OSD iDSP. The latter two both are configured with an app called iWoofer, so surely both of these are the same product. Lo and behold, iWoofer is written by @IVX who claims to be "just a normal engineer". This is the guy that designed and sells the E1DA dongles! Among other products. I only discovered that after I bought it, while writing this update. It does give me confidence that this will be a good-enough solution.

Yes, it's an analog inline DSP. But it's only on the subwoofer channel.
 

Willem

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I use a DSpeaker ANtimode 8033 and I am quite happy with it. It is easy to set up and the sonic benefit is quite audible.
 

phoenixdogfan

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Alternatively, if you are using a PC for all you music, you could use Dirac for PC, use JRiver or possibly Ekio for crossover and eq and send everything via usb to a Motu M4. Could get you everything for around $700. There are also threads using the M4 with a RP4 and Camilla DSP which may be even cheaper.
 
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lofiguy

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I need to support portable DAP over USB. (USB->S/PDIF dongle is ok). I am contemplating Mac Mini (I have old one laying around) running HQPlayer but how do I get the Mac to be recognized as a USB (or optical via adapter) DAC by the DAP? And then how to get HQP, Jriver etc, to use that input as the source?

I prefer an appliance rather than a PC for the processing. I would replace my amp and try the SHD Power but I don't find a vendor with easy returns. Deer Creek sells other miniDSP products on amazon but not the SHD Power. Via direct sale they require 15% restocking, so no.
 

ad_fletch

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I just discovered the MiniDSP Flex. Looks pretty interesting for your application.

Posted in my own 2.1 thread here.
 
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