MiniDSP HA-DSP Discussion and Impressions

Discussion in 'Portable Headphone Amps' started by Velozity, Sep 14, 2017.
  1. Velozity
    I'm surprised that this piece hasn't been discussed on here yet. I'm a proud new owner and I wanted to share a little bit about it. I'm really impressed with it so far. As a car / home audio fanatic I am very familiar with DSPs in general. When I found out a portable headamp existed with DSP built-in I jumped on it. As I get to use it more I will post more impressions. For now here are a few pictures and features. I'll post some screenshots of the software a bit later.

    The highlights we care about:
    • Portable DAC / Amp utilizing ESS Sabre ES9018K2M 32-bit DAC
    • Amplification via TI TPA6120A2 chip- max 100 mW / ch at 32 ohms
    • 3300 mAh battery, fast charge capable
    • Asynchronous USB 2.0 controller
    • 400 MHz floating-point SHARC processor (the real magic of this piece)
    • 3.5 mm combo analog / mini-toslink digital input
    • DSD capable
    • 4 DSP presets
    • Aluminum housing


    headdict likes this.
  2. macro
    I get the impression a lot of people in the headphone community (and Head-Fi in particular) tend to shy away from signal processing either because they're purists or they just don't know how to implement it properly.

    I'm with you, though. I'm also passionate about home theater and car audio where signal processing is pretty much a necessity, so I'm definitely not afraid of EQing my headphones. I've been wishing for a system wide EQ solution for my iPhone for years.

    From what I've seen, miniDSP has a solid reputation. This one looks promising albeit a little bulky. I could see myself potentially using one on long flights, but it's definitely too big for my everyday carry. Looking forward to some more in-depth impressions! Also wondering if you can tweak your equalizer settings on the go with an iPhone app.
    Last edited: Sep 23, 2017
    Velozity likes this.
  3. Velozity
    You're right in your impression, but I also think a major reason more people don't gravitate to DSP solutions is because quite frankly there just aren't that many. I'm hoping with MiniDSP's release that other manufacturers follow suit. It would be absolutely amazing for a portable dacamp with the quality of a Chord Mojo to incorporate DSP. Maybe incorporate it into the new Poly streaming module and have it controlled by the smartphone app...(hint, hint Chord).

    Many people also have to get over the thought that using EQ is somehow a bad thing. We all know every speaker is different and all our hearing is different. In the car audio world EQ is a necessity to overcome the sound quality robbing effects of the listening environment. EQ can be equally beneficial to head-fi users to overcome deficiencies in frequency response for any number of reasons. I use the Kaiser Tone hi-res app as the media player for my iDevices. The EQ capabilities are second to none in my opinion.

    The thing I'm most interested to try on this HA-DSP (and sadly haven't had time yet) is the implementation of crossfeed algorithms. The ability to make listening to headphones sound more like listening to a pair of home speakers is extremely exciting.
    Last edited: Sep 25, 2017
    headdict likes this.
  4. tmuka
  5. macro
    Some more info I obtained via email for those who might be interested:
    The high output impedance obviously isn't ideal for a lot of low impedance portable headphones and especially multi-driver earphones with large impedance swings, although I imagine the equalization functionality of the MiniDSP could at least correct any frequency response imbalances the high Zout might cause.
    Last edited: Nov 1, 2017
    tmuka likes this.
  6. HiFiChris Contributor
    I'm somewhat surprised that it didn't really get any notable attention on Head-Fi as well. I guess it might come down to two things - 1) as mentioned, some people think that everything related to EQ and DSP is a "bad thing", and 2) people don't really know how to properly use EQs and DSPs.

    May I ask what the little switch on the back is for?
    And how do you load presets onto the HA-DSP (what software is required, what can be done, how many filters can be set, is the EQ fully parametric)? Could you probably even provide a screenshot of the interface?

    Anyway, I am glad and excited to see that their EverAMP idea that was announced a couple years ago is finally in production in form of the HA-DSP. And their just-announced EARS headphone and in-ear measurement station looks very exciting as well.
    kukkurovaca and tmuka like this.
  7. tmuka
    I think you're right about knowledge of how to configure DSP being a deterrent to some users for this type of device. The pc config software UI looks similar to my C-DSP. You can see a few pictures of it in the manual PDF on page 23, 30. User Manual.pdf

    From the manual, it looks like the rear switch changes the USB max charging speed, or possibly usb device mode for use with a usb hub, probably to reduce excessive power draw on mobile devices. It's not stated very explicitly, only mostly to leave it on position 1 trickle charging, or position 2 for faster charging.

    They probably also released the EARS measurement station along side this since that opens up the possibility of letting software do the math to configure the DSP corrections. At least in my car's miniDSP C-DSP, there are both input and output corrections available, so you can configure the output eq to set the speakers as flat as possible (better speakers enable more corrections) then you can setup the input eq with your preferred "house curve" for your listening preferences, eg, V shaped, sloped down toward treble or bass, etc... I use their calibrated mic and Room EQ wizard to generate the ideal pEQ settings. It looks like the HA-DSP has some even more advanced features for using FIR (impulse responses) which goes a step further than eq into being able to also alter the timing per frequency at a very low level, at various amplitudes, eg to make your bass tighter (if your phones can do it) or looser, etc.

    I don't have any connection with miniDSP except as a very satisfied customer of their C-DSP. I think there is a big technical divide between some of the amazing analog amp/dac designers (whom i greatly respect!), and those who additionally understand how to write code to take advantage of modern advances. I think the future will be rich with DSP.
    HiFiChris and kukkurovaca like this.
  8. HiFiChris Contributor
    Thanks for your detailed reply, mate!
  9. Velozity
    I'll try to find some time this weekend to post some screenshots of the UI to show exactly what it does. As far as the switch on the back, miniDSP has said to always leave it in position 2. I'm not sure exactly what it does. I think it's there for future updates. I don't see where it says position 1 is trickle charging... Regarding the EQ, yes is fully parametric with 10 bands per left and right channel. On top of that there's bass and treble input controls for each channel. The center frequencies are adjustable from 200Hz-750Hz (bass) and 750Hz-3000Hz (treble).
    tmuka and HiFiChris like this.
  10. tmuka
    yeah, sorry, it looks like I got the wrong idea about the switch from the manual where it was talking about USB hubs possibly being slower to charge. interesting and weird they don't actually define the purpose of the switch!

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