speakers for 24/96 audio

I was trying to show that 16/44 recording wouldn't be a perfect process and that's why it is done in 24/192 but downsampling to 16/44 also takes away quality.

Digital reproduction (as well as analog) have limitations. Filtering screws up transient response and 16 bit resolution is less than perfect.

Why it is difficult to hear difference thru Benchmark? Possibly because available hi-res is often poorly made (many complains about that) while our systems and rooms have shortcomings.

Power amp might be limiting factor but it isn't as bad as Irvrobinson calculated. First of all S/N or THD+N of the amp is usually shown at 1W and many amps are better than 96dB. In addition we don't listen at 1W . For instance if we take Rowland 625 amp's S/N specification of 95dB at 1W at 8 ohm it will be higher at the output power of 300W. We might look as well at residual output noise specified by Rowland that is 55uV at 20Hz-20kHz unweighted. Since output voltage at nominal power of 300W is around 50V it makes S/N=119dB. SACD reproduction is roughly equivalent to 20/96 requiring dynamic range of 120dB. D/A converters are also limited to 20 bits performance.

So to answer original question - increasing resolution might be beneficial up to about 20 bits assuming good recording/file, system and room. Increasing rate will be always beneficial to avoid serious shortcomings I mentioned before.

I settled at standard redbook reproduction not only for practical reasons but also because I cannot stand hiss and pops of analog playback that don't allow me to forget I'm not sitting "there" at the concert.

And if they do sound so unpleasant, why when I listen to higher res stuff through a Benchmark DAC it doesn't sound noticeably better?

You can buy Tom Petty Mojo in CD or in HD and compare. There is a difference but most of the difference is due to audio compression applied to the CD master to make it "hot" - see CD loudness wars and what artists and producers try to do make the music to make it sell.

Basically they compress everything - especially drums - so that the dynamic range of peaks above RMS is usually no more than 6 to 10 db. Whereas a good recording in pop/rock may have 20 db peaks and a classical recording may have 30 db peaks above RMS.

The HD files - such as those on HD tracks are usually much less compressed than the 16/44.1 equivalents.

Shadorne, agree about compression but it is simply who is driving the market. Release uncompressed piano recording (about 96dB dynamics) and a lot of people will complain that on their boom boxes or shelf speakers woofers are constantly buzzing. Hi-res has different clientele so they reduced compression a bit but it is still bad. Also, as you mentioned, they try to make average loudness as high as possible because to inexperienced customer it appears as higher quality recording especially with poorly resolving systems.