Will do this stream of consciousness style... Given the all this talk of RS1x and RS2X (I do have RS1x incoming), I figured it would be nice to do a review of the SR225x. The SR225x is a nice complement to the metal cup SR325x reviewed here: https://www.superbestaudiofriends.org/index.php?threads/grado-sr325x-review-and-measurements.11120/ LIke the others in the SR line, the latest x iteration comes with the F cushions, similar to the the TTVJ Deluxe Pads discussed here: https://www.superbestaudiofriends.o...rs2-ttvj-deluxe-pad-appreciation-thread.8952/ I feel the F cushions could be slightly better than the TTVJ pads because they seem to provide lower bass extension while sounding less dark and more open. The foam appears to be less dense. Lots of factors here which really belong in another discussion when it comes to pads. Later in this thread, perhaps we'll examine the differences with other Grados such as the RS2e. We are going to discuss the SR225x for now. Grado SR225X Frequency Response FPC Compensated The SR225 in the Grado lineup has always be thought to be the high-value model. That is the price point knee where very good performance is obtained before serious things start to get very expensive. The SR225X is no different, although the SR325X is very compelling as well for not that much more. I think it's best that I cover the differences: The SR225X is the more neutral sounding of the two. It's less outright bassy and not as dark as the SR325X. The SR325X is just very slightly more muted in the highs and stronger in the bass with lower extension. The SR325 with its metal outer shell does exhibit more focused, sharper, harder-hitting transients; and this tends to make up for its darker signature. (Again, the SR325X is nothing like the older SR325s that came with the bowl pads where many folks screamed bloody murder of them being too bright and aggressive). Below are the differences between SR225X and SR325X. The differences are quite small. A few db drop in the lows and highs on the SR225X. It's not much, but it's enough to give it a noticeably less dark sound. SR225X (BLU/RED) vs SR325X (GRY) Frequency Response (Y-axis zoomed in) FPC Compensated Finally, what's not indicated above are the "technicalities". The SR325 driver does sound like it's another class with respect to "plankton", capturing the nuances and expressiveness of recordings. Grado has always been good at this with higher models having higher resolution. Contrary of what some people suspect, an SR125 in a RS2 cup does not give you RS2 sound! It will be interesting to look at distortion or other measurements.