Flex has Bluetooth streaming still while UL5 does not. If you're buying DSP there's not much difference and Flex is just another dac. If not then there's another difference.

Some people have an analog only path (e.g. for turntables) and would still want to implement active speakers and/or equalization for room modes. Let's see how we do here: The UMIK-1 is an omni-directional USB measurement microphone providing Plug & Play acoustic measurement. From speaker & room acoustic measurement to recording, this microphone provides low noise and accurate results you can rely on. Forget about driver installation, OS compatibility and un-calibrated mics. The Umik-1 is a USB Audio class 1 device automatically recognized by all Operating Systems (Windows/Mac) and Ipad with Camera Connection Kit. It is provided with a unique calibration file based on the serial number to insure an accurate measurement. Combined with our recommended acoustic measurement software, it is the perfect match for a plug&play measurement system. Features

What a nice combination of functionality, usability and performance! As with many DAC companies, it is clearly Minidsp has put strong focus on chasing away sources of noise and distortion. Yes, there is some work left to do with intermodulation distortion but other than that, measurement after measurement put a smile on my face. All AV processor and receiver companies lose any excuses they have for not providing this level of performance seeing how the Flex also implements various signal processing modules. For stereo system (e.g. 2ch dirac live, single speaker measurement), use the 0deg file and point the UMIK-2 at the speakers SWITZERLAND: As a company specializing in improving room acoustics, we are happy about the miniDSP products, which make our work more efficient. With the miniDSP UMIK-1, you have an easy way to get started with acoustic measurement: to optimize and equalize your subwoofer, to correct for room effects, or even to design your own loudspeakers! In this application note, we'll show you how to get up and running with the UMIK-1. The miniDSP SHD can be used with a Logitech® Harmony® remote. For this app note, we tried two of the most affordable Harmony remotes, the Harmony 650 and the Harmony 350. The Harmony 650 has a small screen and is easier to set up, while the Harmony 350 is a bit cheaper. This short app note shows you how easy it is to set up!

Special features such as calibrated SPL measurement enabled under free Room EQ Wizard (REW) software As a standard USB audio microphone, UMIK-2 is compatible with any software. The following proven platforms with plug&play integration. NETHERLANDS:SoundImports carries a wide line of DIY boards. We're excited to have them part of the miniDSP family. The Flex Eight is the latest member of the miniDSP Flex family of advanced audio processors. We’ve taken advantage of our flexible hardware architecture to cram a full eight channels of DSP and a world-class analog output stage into the compact enclosure.Equalization – the DSP is used to alter the frequency response of the audio signal, to improve the listening experience So unlike many AV products that resample everything to 48 kHz, here we have end to end sample rate of 96 kHz (my guess). Bandwidth is in excess of 35 kHz. The miniDSP Flex Eight is the perfect solution for a modern compact integrated active speaker/subwoofer system. You just need to let your creativity do the rest! Hardware Features In this app note, we will demonstrate subwoofer integration for miniDSP'sstereoDirac Live processors using only the Dirac Live app for measurement MiniDSP is pleased to introduce the UMIK-2, its second-generation omni-directional acoustic measurement microphone. The UMIK-2 has everything that made the first-generation UMIK-1 one of our best selling products, including a convenient plug-and-play USB connection and a unique calibration file for each microphone to ensure accuracy.