Short answer: the Ascend Sierra 1 v2. It ranks #3 of 160 bookshelf speakers by sound quality (rated 4.7/5) at $1,000 and is still sold new; the Boston Acoustics A25 ranks #59 (rated 3.6/5) and is discontinued, so it is only an option used.
The Ascend Sierra 1 v2 is the more accurate, deeper-bass pick. Formaldehyde-free layered bamboo ply cabinet with a 1” dome tweeter over a 5.25” midwoofer, mated by a 4th-order acoustic crossover rather than a stock textbook design. Its measured preference score, a predictor of how neutral it sounds, is 6.65 against 3.53 for the Boston Acoustics A25. Its bass reaches about 55Hz before falling 3dB, against 90Hz for the Boston Acoustics A25. Watch for: F3 of 55Hz and F10 of 39Hz mean in-room extension tops out in the mid-40s Hz; the reviewer still recommends a subwoofer for full-range material.
What the Boston Acoustics A25 does well: CEA2034 spinorama is decent once you ignore a peak around 900Hz and a dip around 3kHz: directivity is good enough that the response can be EQed and won’t be too room-dependent. The tradeoff: A crazy port resonance and a tweeter with a steeper rolloff than the woofer both show up in the near-field driver measurements, creating the 900Hz peak and the crossover-region dip.
Buy the Ascend Sierra 1 v2. It is rated higher for sound quality; the Boston Acoustics A25 is no longer sold new.
Looking for alternatives? See the complete Passive Home rankings.
Specifications Side By Side
| Ascend Sierra 1 v2 | Boston Acoustics A25 | |
|---|---|---|
| Price | $1000 per pair | $299.98 per pair Discontinued |
| Ranked | #3 of 160 in Medium Size Bookshelf Speakers | #59 of 160 in Medium Size Bookshelf Speakers |
| Bass Extension (-10dB) | 39Hz (measured, Erin’s Audio Corner) | 55Hz (measured, Audio Science Review) |
| Bass Extension (-3dB) | 55Hz (measured, Erin’s Audio Corner) | 90Hz (measured, Audio Science Review) |
| Dimensions | 14.2”H x 7.5”W x 10.5”D (361.9 x 190.5 x 266.7 mm) | 10.7H x 7.25W x 8.9D in |
| Impedance | 8 ohms nominal, 7 ohms minimum (measured, Erin’s Audio Corner) | 8 ohms nominal |
| Sensitivity | 81.5dB (measured, Erin’s Audio Corner) | 85dB (2.83V/1m, measured, Audio Science Review) |
| Drivers | 5.25” proprietary mineral-filled polypropylene cone with cast aluminum frame woofer, 26mm aluminum/magnesium alloy dome tweeter with titanium former (SEAS Titan) | 1” Kortec soft dome tweeter, 5.25” ceramic/glass-fiber polymer mid/woofer |
| Weight | 18.5 lbs (8.4 kg) each | 10.1 lbs (4.58 kg) each |
| Woofer Cabinet | ported | ported, rear |
| Spinorama Preference Score | 6.65 | 3.53 |
| Spinorama Preference Score with Perfect Sub | 8.61 | 6.19 |
| DIY Kit | No | No |
| Frequency Response | - | 55Hz - 25kHz (Manufacturer specified) |
| Power Handling | - | 10-150W recommended |
Related Speaker Comparisons
More worthwhile head-to-heads for Ascend Sierra 1 v2:
- Ascend Sierra 1 v2 vs Audio First Fidelia
- Ascend Sierra 1 v2 vs Philharmonic Ceramic Mini
- Ascend Sierra 1 v2 vs KEF LS50 Meta
- Ascend Sierra 1 v2 vs XMechanik Mechano23 DIY
- Ascend Sierra 1 v2 vs Ascend Acoustics HTM-200SE2
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The Two Speakers In Full
Ascend Sierra 1 v2: $1000 per pair Ascend Acoustics eBay
Same family: the Ascend Acoustics Sierra-2EX V2 (larger bookshelf, rated 4.3/5), the Ascend Acoustics Sierra-LX (larger bookshelf, rated 4.3/5), the Ascend Acoustics Sierra Titan Tower (floorstanding, rated 4.4/5) and the Ascend Acoustics Sierra Horizon V2 (center, estimated 4.3/5).
Pros: Formaldehyde-free layered bamboo ply cabinet with a 1” dome tweeter over a 5.25” midwoofer, mated by a 4th-order acoustic crossover rather than a stock textbook design. In-room response is extremely linear (the reviewer called it “textbook”) a clear step up from the earlier V1, which had boxiness around 700Hz-1kHz and sibilance around 4-6kHz. Preference score of 8.4 with a subwoofer (6.8 without), which the reviewer calls topnotch. Wide, even horizontal radiation of about ±70° up to 6kHz. Better vertical directivity than its tweeter-to-woofer spacing would suggest, thanks to the steep 4th-order crossover slopes. No mechanical noise, port chuffing, or woofer bottoming even driven to 96dB/1m. In a three-way comparison against the Dynaudio Emit 20 and a Revel bookshelf model (all around $1,000/pair), measured as the most linear of the three and was the reviewer’s personal pick over both, despite the Dynaudio’s deeper bass and higher output capability. Independent ASR Klippel measurements corroborate Erin’s findings: superb off-axis response with only slight on-axis variations, and an in-room response the reviewer called “incredibly smooth and accurate. Amazing for a non-DSP speaker.” Distortion above 200Hz at 86dB/1m is very low for the class. Measured bass extension of 55Hz (-3dB), with a measured sensitivity of 81.5dB.
Cons: F3 of 55Hz and F10 of 39Hz mean in-room extension tops out in the mid-40s Hz; the reviewer still recommends a subwoofer for full-range material. Diffraction dips appear around 3kHz and 5-6kHz, and the 1” dome tweeter starts beaming above roughly 6.7kHz, narrowing the soundstage radiation in the top octave: a straightforward consequence of dome size rather than a design flaw. At 96dB/1m the 5.25” midwoofer shows increased distortion in the midrange, likely tied to motor topology; high-passing to a subwoofer around 80Hz largely clears it up. Moderate sensitivity (~81-82dB average) with a 7-ohm minimum impedance. ASR’s power-sweep testing found response holds steady up to 96dB SPL/1m, but pushing to 102dB causes midbass below 400Hz to sag with distortion “through the roof”: a harder output ceiling than the 96dB tests alone suggest. Vertical directivity also narrows above about 1kHz, so the reviewer recommends staying at tweeter-axis height for best results.
Full Ascend Sierra 1 v2 review and specifications →
| Bass Extension (-10dB) | 39Hz (measured, Erin’s Audio Corner) |
|---|---|
| Bass Extension (-3dB) | 55Hz (measured, Erin’s Audio Corner) |
| DIY Kit | No |
| Dimensions | 14.2”H x 7.5”W x 10.5”D (361.9 x 190.5 x 266.7 mm) |
| Drivers | 5.25” proprietary mineral-filled polypropylene cone with cast aluminum frame woofer, 26mm aluminum/magnesium alloy dome tweeter with titanium former (SEAS Titan) |
| Impedance | 8 ohms nominal, 7 ohms minimum (measured, Erin’s Audio Corner) |
| Sensitivity | 81.5dB (measured, Erin’s Audio Corner) |
| Spinorama Preference Score | 6.65 |
| Spinorama Preference Score with Perfect Sub | 8.61 |
| Weight | 18.5 lbs (8.4 kg) each |
| Woofer Cabinet | ported |
- Links
- Reviews, Comparisons and Sound Samples
- Erin’s Audio Corner: NEW! Ascend Acoustics Sierra-1 V2 Review More from Erin’s Audio Corner →
- Erin’s Audio Corner Website Ascend Sierra 1 v2
- Audio Science Review Ascend Sierra 1 v2 More from Audio Science Review →
- Erin’s Audio Corner: 5 AWESOME SPEAKERS Under $1000 You Won’t Regret
- Erin’s Audio Corner: I Tested 250 Speakers So You Don’t Have To!
- Erin’s Audio Corner: My Top Picks of 2023: Must-Haves Under $3000
- Manufacturer Measurements (spinorama.org)
- Head-to-Head Comparisons
- Ascend Sierra 1 v2 vs KEF LS50 Meta
- Ascend Sierra 1 v2 vs Philharmonic Ceramic Mini
- Ascend Sierra 1 v2 vs Audio First Fidelia
- Ascend Sierra 1 v2 vs XMechanik Mechano23 DIY
- Ascend Sierra 1 v2 vs Ascend Acoustics HTM-200SE2
- Ascend Sierra 1 v2 vs Arendal 1961 Monitor
- Ascend Sierra 1 v2 vs Ascend Acoustics Luna V2 Mini-Monitor Titan
- Ascend Sierra 1 v2 vs Aalto Speakers Aalto 1 EVO
- See all 48 comparisons
Boston Acoustics A25: $299.98 per pair Discontinued eBay
Pros: CEA2034 spinorama is decent once you ignore a peak around 900Hz and a dip around 3kHz: directivity is good enough that the response can be EQed and won’t be too room-dependent. Cabinet fit and finish is well above its price class, and dynamics were strong with no distortion audible even at high volume on well-recorded material. Discontinued, but the reviewer suggests hunting for clearance pricing on remaining stock. Measured bass extension of 90Hz (-3dB), with a measured sensitivity of 85dB.
Cons: A crazy port resonance and a tweeter with a steeper rolloff than the woofer both show up in the near-field driver measurements, creating the 900Hz peak and the crossover-region dip. The rear port itself measured audibly distorted up close, though it wasn’t noticeable from normal listening distance in the reviewer’s room. Discontinued.
Full Boston Acoustics A25 review and specifications →
| Bass Extension (-10dB) | 55Hz (measured, Audio Science Review) |
|---|---|
| Bass Extension (-3dB) | 90Hz (measured, Audio Science Review) |
| DIY Kit | No |
| Dimensions | 10.7H x 7.25W x 8.9D in |
| Drivers | 1” Kortec soft dome tweeter, 5.25” ceramic/glass-fiber polymer mid/woofer |
| Frequency Response | 55Hz - 25kHz (Manufacturer specified) |
| Impedance | 8 ohms nominal |
| Power Handling | 10-150W recommended |
| Sensitivity | 85dB (2.83V/1m, measured, Audio Science Review) |
| Spinorama Preference Score | 3.53 |
| Spinorama Preference Score with Perfect Sub | 6.19 |
| Weight | 10.1 lbs (4.58 kg) each |
| Woofer Cabinet | ported, rear |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
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