This is a review and detailed measurements of the Ascend Acoustics Sierra 2 "Reference" Stand-mount Speaker with "RAAL tweeter. It is on kind loan from a member. I *think* they cost $738 each or $1448 for a pair.The model I have is made out of bamboo but finished in black:The back panel shows a large, flared port and nice quality binding posts:I was impressed with how stiff the cabinet was as even under heavy load of pounding bass, it would hardly transmit much to the outside. It is still a small speaker but even using one unit, it could fill my large space with sound. You won't confuse it with a 6 foot tower speaker but didn't sound like a little clock radio either.Measurements that you are about to see were performed using the Klippel Near-field Scanner (NFS) . This is a robotic measurement system that analyzes the speaker all around and is able (using advanced mathematics and dual scan) to subtract room reflections. It also measures the speaker at close distance ("near-field") which sharply reduces the impact of room noise. Both of these factors enable testing in ordinary rooms yet results that can be more accurate than anechoic chamber. In a nutshell, the measurements show the actual sound coming out of the speaker independent of the room. All measurements are reference to tweeter axis with the grill removed.Around 800 points around the speaker were measured (from 20 to 20 kHz) which resulted in well under 1% error in identification of the sound field across full frequency response of 20 to 20 kHz. Final database of measurements and data is 1.2 Gigabytes in size.Acoustic measurements can be grouped in a way that can be perceptually analyzed to determine how good a speaker can be used. This so called spinorama shows us just about everything we need to know about the speaker with respect to tonality and some flaws:We don't have a dead flat response but with variation being mostly peaks, a bit of EQ in those areas should tame them.One oddity is that the company measurements show a rising response climbing to 20 kHz. Don't know what explains the discrepancy. Regardless, I rather have it my way than theirs when it comes to sound.Directivity index is not perfect either but is close enough that should allow for some judicious EQ per my note above:Finally, this is a prediction of what sound you may get in a typical room:It is as to be expected based on measurements we saw before it.The company specifies minimum impedance of 6 ohms but my sample dipped well below that:Given the bass efficiency of 85 dB and lower, you better have lots of power for amplification.Distortion measurements showed a concerning peak:The ribbon tweeter likely hitting some kind of mode and running away on its own. We have a peak in frequency response after it that may be caused by this.In the following two graphs, look for least amount of "beard" below the main axis response:Contour graph shows that good response remains for a wide window of +- 80 degrees:That means you can have a wide sweet spot, or ability to point the speaker forward and listen to them off-axis.Vertically is the opposite though:Best to put them at ear height (relative to center of the tweeter as I measured).I don't have a controlled setting for hi-fi speaker testing yet. I just place a single speaker close to my Revel Salon 2 and use its amplifier to listen to single channel. There, the Sierra 2 produced better than expected sound. Its nice and solid enclosure allowed me to turn it up quite high and most of my reference tracks sounded "good." I could move around the speaker left and right with almost no tonality difference (i did this prior to confirming with contour plots above). Vertically though, the angle is quite limited so per earlier note, use stands that allow you to have them at your ear height.The Ascend Sierra 2 is not perfect but overall, it seems to be a good package. You are getting much better build quality and SPL capability in a small package. And frequency response variations should be correctable to some extent with EQ.I personally want more perfection in the speaker so would not be buying it myself but you have the data to decide for yourself.------------As always, questions, comments, recommendations, etc. are welcome.I have been so busy with equipment testing that I have not started my vegetable seedlings. Fortunately, I read on the Internet that they sell a special liquid you put on the seeds that makes them sprout 10 times faster! I love to get some but they want $100 for a little bottle. So pleasesome money so I can afford to get them and catch up on my gardening using