It seems we have a general consensus about the number of multimeters, but not he brand of an oscilloscope. It is arguable if a higher bandwidth or more channels are better. IMHO, for audio use as the OP has specified, more channels are king. A hacked DS1054Z will have much more than adequate bandwidth, 4 channels, and have all the other added extras for other work for less than the Siglent. 100MHz isnot really that much less than 200Mhz in real world use, but 2 channels more is a huge benefit.
But does the FFT and other evaluation functions are so much better in the Siglent that it gets over the lack of 2 channels?
rsjsouza states that "If you are interested in analog audio, I would be very biased towards the Siglent, given it is a more modern platform and has better FFT". Why? How much better? Is the FFT in the Rigol useless (toy feature) compared to the Siglent one? Why the "modern platform" matters?
Thanks guys!!!
I forgot about this comment of mine.
In general, an oscilloscope for analog audio does not require four channels nor very high bandwidth, although the more is usually the merrier. In this case, the Siglent has additional bandwidth (which is not necessarily an advantage in your case) and its two channels would not be limiting for audio. However, the much more accurate FFT (which helps evaluating the "purity" of a signal) and the newer processor being used (which is reported to bring a much more responsive oscilloscope) are two great features that help the Siglent to be highly considered for this particular case.
If in the future you intend to work with digital datastreams from ADC/DACs or signal processors, the Rigol may be a better option as its logic decoders (and the extra channels) are included in the price (the digital serial interfaces have multiple wires that need to be monitored). However, a cheap USB Logic Analyzer + an open source Logic Analyzer software (Sigrok) is also suitable for these digital datastreams for audio converters.
One thing that detracts from Siglent is their track record for fixing bugs - they tend be a bit slower on this regard. The bugs on the Rigol are well known and most of them are apparently fixed (although they were also slow to get them straightened up). If that is a topic that concerns you, another brand (GW Instek) may have a higher weight on your decision.
A thread that points to several others is:
https://www.eevblog.com/forum/testgear/rigol-ds1054z-vs-siglent-sds1202x-e/As others have said, the Analog Discovery is a nice tool as well, as it integrates a signal generator, a bit more resolution (14-bit) but slower (100MSPS) 2 channel oscilloscope, a 2 channel signal generator and a logic analyzer. It is priced quite reasonably for what it does ($279 + accessories), but keep in mind that it is a tool that does a lot but is usually more limited on each function when compared to standalone tools.
In the far future you should start considering something like a really nice audio signal generator (Krohn Hite 4400B) or the Keithley 2015, a bench multimeter that performs distortion analysis.