The Mac Mini is a great little device with huge amounts of sonic potential. Let’s take a walk through the Mac Mini and its infinite hardware possibilities to see what exactly can be done to make this device the ultimate audio/video machine.
Part One: Base Hardware
The Computer To Choose
There are lots of Mac Mini options available. To make things as simple as possible: The more powerful your Mac Mini, the better your sound.So start by looking for a computer with the most L3 cache you can find. The clock speed is secondary to the amount of L3 cache. So, for instance, a 2.0ghz Core i7 with 12MB L3 cache will be faster than a 2.6ghz Core i7 with 6MB L3 Cache.The cache memory directly relates to how quickly data can be prefetched for the CPU to process. Since all audio is processed in real time, it’s important to make that processing happen as quickly as possible. More latency = more noise. More noise = more amplitude distortion on the audio square wave. Note: memory playback is still a real time operation.
Operating System Installation and Drive Implementation
The operating system and the software used for processing plays a pivotal role in audio performance. The most common options for Mac Mini upgrades is to install the operating system on a solid state drive Change And Achievement related. This increases I/O speed and decreases access time, which decreases the time the data stays on the computer.
Going better than SSD
The ultimate solution for operating system installation is a PCIe SSD. We offer this option on our Kryptos Servers and it’s simply incredible.
Part Two: Upgrading Base Hardware
The Power Supply:
The power supply dictates 60% of the Mac Mini’s over all performance. The stock SMPS generates tremendous high frequency noise, removing it and using a Kaia power supply is the ultimate solution we recommend.
It’s well-known that computers generate and absorb tremendous amounts of EMI. Our Cryo-shielding technology is by far the most effective shielding solution for the Mac Mini computer. It both shields and absorbs EMI and RFI and can dramatically improve the computers performance.
- Efficient Intel Celeron N4020 Processor (4M Cache,...
- 11.6” HD (1366 x 768) Slim Display
Passive cooling can provide a small sonic benefit to your sound, but should only be done if it’s an audio-only Mac Mini. The additional heat generates shot noise, which can be quite a bit more harmful than the electrical noise of the fan.
DC and AC Cabling
With the faster transient response of our Kaia power supply the DC Cable is a direct extension of our regulator’s output stage. The better DC Cables offer lower capacitance and inductance, which improves transient response and reduces both self noise and external noise. The AC Cabling is designed to provide instantaneous current, and lots of it. Proper AC Cabling like our Kenai AC Cable and power distribution actually improve slew rate, which in turn improves the transient response of our power supplies and your resulting sound quality by reducing noise. Make sure to use a great AC cable even on a great linear power supply. While AC noise is somewhat irrelevant, transient response and instantaneous power delivery are quite critical to your sound quality and the ability of the power supply to filter higher frequencies of noise.
Mac Mini Atomic Platform
The Atomic Platform was designed based on the resonant frequency of the Mac Mini. The company measured the Mac Mini’s resonant frequency and designed the platform to cancel that resonance. It’s highly highly effective and no mac mini should be without it.
Part Three: Audio Outputs
Conventionally folks have been using USB Audio with their Mac Mini. It’s possible to use USB into a USB DAC or grab a USB to SPDIF converter. Both of these methods can sound very good, but are also a huge bottleneck to your sound. I am fond of the XMOS based USB-SPDIF converters, but note that not all XMOS USB receivers are created equal. Running a better clock and power supply to the USB converter is a tremendous upgrade and hugely important if you decide to go the USB route. In most cases a good USB converter (to SPDIF or I2S) is going to sound much better than the USB input on most DACs just because of power supply applications.
The better solution: Merging Technologies HAPI.
The HAPI is an ethernet audio interface, which uses the Ravenna Protocol. It’s basically an audio co-processor and dedicates on CPU core specifically to the transport and monitoring of audio from your playback software to the HAPI. Because of the way Ravenna technology works, rather than taking I2S over USB and using an algorithm to regenerate a clock signal at the receiving end, Ravenna monitors both data and clock packets in real time and is virtually immune to distortion, jitter, and errors. Meaning you can have your mac mini in one room and the HAPI a mile away and the sound quality is the same as if they were right next to each other.
The HAPI offers multichannel AES outputs stock, so it’s excellent for active crossovers. With the DA8P card it is one of the best DSD256 native DACs on the market, cost no object. So you can run one ethernet cable distortion-free, then multichannel DSD off to your amps, or AES out to some fully digital amplifiers. The HAPI accepts an external linear power supply and word clock for even greater performance, which also means you can power both the Mac Mini and HAPI from one of our dual rail Kaia power supplies. Welcome to the future!
UPDATE: OSX now supports Blu-ray Playback. So you can also use the HAPI for home theater along side JRIVER Media Center. Active Crossovers, Auro-3D 16 channel surround sound, and a multichannel system where all channels are as good as your mains anyone? Gotta love the elimination of D/A conversion!
Part Four: Optimizing the Operating System
There are several guides to this all over the web, so I won’t spend too much time here. If you need more detail, do a google search for the particular item. We won’t provide support for this section, so proceed at your own risk.
- Close stuff! If you have applications running that you aren’t using, close them to save CPU resources for ones you are using.
- System Preferences
- Disable unused languages under “Language and Text”
- Disable IR Receiver under “Privacy and Security”
- Disable WiFi and Hardwire via Cat7 Wire, then shield Wifi Noise
- Disable Blutooth (using a USB Keyboard/Mouse will remove HF Noise)
- Disable Spotlight (uncheck all boxes)
- Disable unused Login Items under “Users and Groups”
- Disable Automatic Updates
- Disable Time Machine Auto Backup (do this manually, your HD will inevitably fail!)
- Disk Utility Optimization
This is more important than any other OS tweak you will ever do!
- Applications > Utilities > Disk Utility
- Select your OS Hard drive
- Repair Disk Permissions
- I recommend doing this at least once a month. If permissions are damaged the computer has to find another path to find a file. That takes more time and can create tremendous amounts of distortion.
- It can take A LONG TIME!
- Disable Journaling
- Option click the “file” drop-down menu and select disable journaling. It may already be disabled.
- Using Terminal
- Do this at your own risk. Enter the code in bold and press ENTER. They may need to be re-done if you reboot.
- Disable Finder – defaults write com.apple.finder QuitMenuItem 1
- Killall Finder
- Disable Dashboard
- defaults write com.apple.dashboard mcx-disabled -boolean YES
- Killall Dock
- Disable Spotlight
- sudo launchctl unload -w /System/Library/LaunchDaemons/com.apple.metadata.mds.plist
- Automatic Termination
- defaults write -g NSDisableAutomaticTermination -bool TRUE
To re-enable any of these…
- Automatic Termination Change TRUE to FALSE
- For Finder, Change 1 to 0
- For dashboard change YES to NO
- For Spotlight change unload to load
Dirac Live Room Correction
This is a new addition to this guide, but room correction is of supreme importance to getting the best sound. With good room treatment it’s possible to eliminate many of the dramatic peaks and nulls, but room treatments cannot adjust phase response or flatten the frequency response.I offer and recommend Dirac Live mainly because I find it to be the best sounding system by a substantial margin. It’s not necessarily cheap, but compared to spending thousands on room treatments it’s quite a bargain for a whole lot more gain. Don’t get me wrong, my room is well treated, but dirac is another special layer.Dirac Live works as the output device in your Mac. So the correction curves work for all pieces of software, netflix, movies, spotify, and so on. The configuration we offer includes RTA Mic and USB mic pre to help with easy setup and adjustment.
Many people use USB interfaces for audio and storage. The Mac Mini has only one USB Bus and so it must dynamically switch between outputs as data is being transferred. So if you are utilizing both a storage device and USB output you will face increased latency. Our recommendation is, if you are using USB audio, do not use USB storage.
- Boost: 1518 MHz/ Base: 1265 MHz in Gaming Mode
- Boost: 1544 MHz/ Base: 1290 MHz in OC Mode
Our favorite storage is NAS because it’s totally disconnected from the system.
With the new Mac Mini the thunderbolt outputs are on their own bus and isolated from USB.
The final Build
- Mac Mini with Largest amount of L3 Cache
- Kaia Power Supply
- Internal Wiring Level 5 + DC S5 Hardwired Pure Silver variable gauge Wiring ($300 per inch yikes!)
- Cryo Shield Upgrade
- Dirac Live Room Correction
- Stillpoints Ultra 5 Feet
- Vibration creates magnetic fields and noise, conducting this vibration away from the system is critical for the best performance
- Atomic Audio Labs Mac Mini platform
- Merging Technologies HAPI Ethernet Interface for audio output — Forget that USB stuff this is the future, folks!
- NAS For storage and expansion