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Computer Audiophile


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About untangle

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  1. For those wishing to do a digital crossover on a Mac... Firstly, this requires DSP so DSD must be converted to PCM. From there, two approaches are common: 1. USE A PLAYER WITH THIS FUNCTIONALITY BUILT-IN. PM is the pioneer here, and their implementation is very clean sonically. Of course, as usual with the product, the user interface gymnastics required are arcane and difficult. Thankfully, the docs are pretty good. Other players may now have digital crossover capability, but I haven't kept up. 2. ROLL YOUR OWN. You will need three components for this: an audio router, a host for audio plugins, and the DSP plugins themselves. I usually use Jack, Plogue Bidule, and Fabfilters respectively. This is more flexible and a ton of plugin choices are available (yes, they all sound different). Jack and Bidule must be launched prior to launching your player. I believe that I have explained the process in greater detail elsewhere on these forums and won't repeat it here. As you have probably gleaned, these solutions require dedication and specific knowledge. Measurement equipment is highly recommended. They also require multi-channel amplification and many cables. But IME the control afforded is exquisite (e.g., time alignment of drivers) and the sonic reward is rich. Bob Walters President, Bay Area Audiophile Society
  2. Ncore amp

    DRO: I disagree that you will necessarily fail. The task is challenging but possible. It'd be great to somehow A/B your result with the OEM SMPS. I'd also suggest that you search DIYaudio and/or start a thread there. Good luck! Bob
  3. Multiple A/D D/A Conversions

    A typical loopback test for your use case would quantitatively examine the accuracy of the miniDSP in performing the A/D->D/A task (with no signal processing in play). The figure-of-merit is often the ratio (in dB) of the error term magnitude to the signal. Better converters produce better numbers. The audibility of the differences is disputed, as usual. Bob
  4. Ncore amp

    I agree with barrows fully on his assessment of the NC400. I would add that I detect no trace of "Class D" artifacts. If it sounds like anything, it sounds like a clean-and-hyper-detailed (high feedback) solid state amp. A bit acetic, but clean and powerful. Lots of bang for the buck. I have not heard an NC1200. Bob
  5. Multiple A/D D/A Conversions

    Loopback testing is common in the pro world, represented by the Gearslutz forums. Here is an example. Bob
  6. Article: Auralic Vega Digital Audio Processor Review

    Great review with the most cogent argument that I know of for "why I should want DSD capability in my DAC." Add measurements (gasp) and your reviews would be the best in the business. Truly outstanding. Bob
  7. Audirvana Plus optimizations

    I have no problem with 1.5.4. My guess is that I'm in the majority (but most keep silent). But I archive all past versions - just in case. Bob
  8. Article: 2012 Product of the Year Readers Choice

    Even support for a single AU (at a time) would be a huge plus for a great player. Consolation prize: 5-band (or more) PEQ. Bob
  9. iFi-audio Jumping... Terrific product, especially when paired with iUSB. Consider spending some of the remaining $500 on USB cables. (Note: Not balanced out.) Bob
  10. How do I use the Pure Music crossover?

    The Mac TOSLINK out can send either: (1) 2-ch LPCM -or- (2) multichannel encoded (e.g., Dolby or DTS). It cannot send multi-PCM. But that's OK for your gameplan. However, AFAIK, there is no easy way to encode the (LPCM) output of PM into Dolby or DTS. If what I said is true, it's a show-stopper. Bob
  11. Getting started in digital crossovers (using a Mac)

    Thanks, Gordon. While you make some good points, let's please keep this thread on track as a DIY for those who want to implement an active xover in PM. Perhaps another thread could be started to capture that pro's and con's of of active xovers, DSP, subs, etc. With respect, Bob
  12. Getting started in digital crossovers (using a Mac)

    1. The subject of RCA-to-XLR conversion is a deep and well-documented one. The three classes of solutions are: adaptors (a la Guitar Center), custom cables, and active solutions. Adaptors are the best way to start IMO, and - for me at least - custom cables (DIY) are the place to end. You will probably be surprised at how good these sound. Be cautious with active pro units, most of which are meant for sound-reinforcement applications. 2. You can implement polarity inversion and "time alignment" (delays) directly in PM. Beyond that, recognize that PM implements minimum-phase filters, not linear-phase filters, in its crossovers. This decision eliminates pre-ringing but introduces phase errors. Since the ear is quite sensitive to pre-ringing (ever hear a drum strike before it's stuck?) and insensitive to most phase issues (the room introduces a ton anyway), the PM filters sound natural to most listeners. Through plugins, you can implement phase-linear systems of any ilk quite easily. Bob
  13. Getting started in digital crossovers (using a Mac)

    A thorough discussion of this topic would fill pages. I recommend trying two approaches: 1. Replicate the analog crossover (if known) digitally. It's usually easy to find this out from vendor specs or a phone call. If not, it can be reverse-engineered. Doing this, you can assess how your active/digital system compares to "stock." Shallow-order slopes also sound more open and dynamic - esp at low-to-moderate volume levels. 2. Implement an all-4th-order (24dB) solution. This leverages your newfound ability to do steep slopes for free. The 4th-order slope has inherent advantages. This approach will generally lower distortion and allow you to play at loud(er) volumes. Most times, I end up here. Bob
  14. Getting started in digital crossovers (using a Mac)

    Many multichannel pro audio interfaces* work well on the Mac. Chances are, if it has a firewire connection, it'll work well. (If it has USB, it prob will too - but less surety of that.) The tougher question is, how does the unit sound? Some units that I am familiar with that have sound quality commensurate with their price range: RME Fireface 800 ($1700) Apogee Ensemble ($2000) Metric Halo Leo 8 ($3000, on sale) Sonic Studio Amarra 4 ($4000) Prism Orpheus ($4400) IMO, the Apogee and the Metric Halo (at its sale price) represent the best value. I use Orpheus. (All prices from Vintage King.) There are several decent options below $1000, but I lack enough experience with them to comment. Bob * These combine a data-level connection - USB or firewire - with the DAC. This is what I recommend. Many reasons.
  15. Getting started in digital crossovers (using a Mac)

    This is exactly the way that I would suggest folks go - get an affordable (used) multichannel DAC and go from there. I would, for example, pit a Behringer DAC + $100 in parts against much of the audiophile stuff out there (96k and blw for the Behr). Thanks, Bob