the impedance on the SE846 is approximately 9 Ohm but can drop even lower at some frequencies. There is a general rule that the output impedance of anything used to drive a headphone needs to be at least 8 times LOWER than the impedance of the headphone itself (as a minimum).Thanks @IEMusic!
Do the iFi IEMatch need to be plugged into my SR25, or another source (like my phone) - can you recommend any other portable daps that I can look into?
I do really like bass, that's the thing but like I said in my previous comment, the BLON bass sounds more textured (and to me a tiny bit deeper) - if that makes sense?
Make sure that anything you use to drive your SE846's has an output impedance of 1 Ohm or even less. Considering the fact the impedance of the Headphones drops to (I think) about 4 Ohm I would even recommend you avoid anything that has an output impedance of 0.5 Ohms or above.