Pioneer SP-BS22-LR (Philharmonic AAM Mod) vs Ascend Sierra 1 v2

Last updated: October 9, 2026

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 Pioneer SP-BS22-LR (Philharmonic AAM Mod) ranks #111 (rated 2.8/5) and is discontinued, so it is only an option used.

Pioneer SP-BS22-LR (Philharmonic AAM Mod) vs Ascend Sierra 1 v2

The case for the Pioneer SP-BS22-LR (Philharmonic AAM Mod): This is Dennis Murphy’s “Affordable Accuracy Monitor” (AAM) mod of the discontinued, budget Pioneer SP-BS22-LR: the stock tweeter is swapped for a Peerless BC25TG15 dome and a redesigned 3rd-order crossover is built to match it to the stock 4” woofer. Watch for: Some directivity error appears near the crossover frequency.

The Ascend Sierra 1 v2 is the more accurate, deeper-bass choice. 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 5.07 for the Pioneer SP-BS22-LR (Philharmonic AAM Mod). Its bass reaches about 55Hz before falling 3dB, against 78Hz for the Pioneer SP-BS22-LR (Philharmonic AAM Mod). The catch: 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.

Buy the Ascend Sierra 1 v2. It is rated higher for sound quality; the Pioneer SP-BS22-LR (Philharmonic AAM Mod) is no longer sold new.

Still deciding? The full Passive Home rankings cover every ranked option.

Specifications Side By Side

Pioneer SP-BS22-LR (Philharmonic AAM Mod) Ascend Sierra 1 v2
Price$168 per pair Discontinued$1000 per pair
Ranked#111 of 160 in Medium Size Bookshelf Speakers#3 of 160 in Medium Size Bookshelf Speakers
Bass Extension (-3dB)78Hz (measured, Audio Science Review)55Hz (measured, Erin’s Audio Corner)
Bass Extension (-10dB)60Hz (measured, Audio Science Review)39Hz (measured, Erin’s Audio Corner)
Drivers1x 4” curvilinear-cone woofer (stock Pioneer), 1x Peerless BC25TG15 1” silk dome tweeter (replacement)5.25” proprietary mineral-filled polypropylene cone with cast aluminum frame woofer, 26mm aluminum/magnesium alloy dome tweeter with titanium former (SEAS Titan)
Weight9 lbs (4.1 kg)18.5 lbs (8.4 kg) each
Sensitivity83dB (2.83V/1m, measured by Audio Science Review)81.5dB (measured, Erin’s Audio Corner)
Impedance8 ohms nominal (approx. 5 ohms minimum, measured by Audio Science Review)8 ohms nominal, 7 ohms minimum (measured, Erin’s Audio Corner)
Crossover Frequency3000Hz-
Dimensions12.6”H x 7.1”W x 8.5”D (320.0 x 180.0 x 215.0 mm)14.2”H x 7.5”W x 10.5”D (361.9 x 190.5 x 266.7 mm)
Woofer Cabinetported, rearported
Spinorama Preference Score5.076.65
Spinorama Preference Score with Perfect Sub7.828.61
DIY KitYesNo

How Ascend Sierra 1 v2 compares with other leading options:

Prices on this page were last checked October 9, 2026 at 8:01 AM UTC. Product prices and availability are accurate as of that date/time and are subject to change; the price and availability shown on Amazon at the time of purchase will apply to the purchase of this product.

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The Two Speakers In Full

Pioneer SP-BS22-LR (Philharmonic AAM Mod): $168 per pair Discontinued eBay

Pioneer SP-BS22-LR (Philharmonic AAM Mod) ranking card

Pros: This is Dennis Murphy’s “Affordable Accuracy Monitor” (AAM) mod of the discontinued, budget Pioneer SP-BS22-LR: the stock tweeter is swapped for a Peerless BC25TG15 dome and a redesigned 3rd-order crossover is built to match it to the stock 4” woofer. CEA2034 spinorama shows only small variations from a flat on-axis response with some directivity error near the crossover, a marked improvement over the unmodified Pioneer, which the reviewer notes shows much more variation from flat. Distortion at 86dB SPL/1m is reasonably controlled above 200Hz, and tweeter distortion barely rises even at 96dB SPL/1m. Measured bass extension of 78Hz (-3dB), with a measured sensitivity of 83dB.

Cons: Some directivity error appears near the crossover frequency. Distortion climbs in the woofer’s range (below 200Hz) at both 86dB and 96dB SPL/1m. Minimum impedance dips to about 5 ohms with a couple of resonance peaks. This is a DIY project, not a finished retail product: Murphy sold ~$168 pre-built pairs for a while but no longer does, so it now requires sourcing a used/discontinued Pioneer SP-BS22-LR pair plus building the crossover and swapping the tweeter yourself. The mod itself is public domain, but there is no current turnkey way to buy this speaker.

Bass Extension (-10dB)60Hz (measured, Audio Science Review)
Bass Extension (-3dB)78Hz (measured, Audio Science Review)
Crossover Frequency3000Hz
DIY KitYes
Dimensions12.6”H x 7.1”W x 8.5”D (320.0 x 180.0 x 215.0 mm)
Drivers1x 4” curvilinear-cone woofer (stock Pioneer), 1x Peerless BC25TG15 1” silk dome tweeter (replacement)
Impedance8 ohms nominal (approx. 5 ohms minimum, measured by Audio Science Review)
Sensitivity83dB (2.83V/1m, measured by Audio Science Review)
Spinorama Preference Score5.07
Spinorama Preference Score with Perfect Sub7.82
Weight9 lbs (4.1 kg)
Woofer Cabinetported, rear

Ascend Sierra 1 v2: $1000 per pair Ascend Acoustics eBay

Ascend Sierra 1 v2 ranking card

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.

Bass Extension (-10dB)39Hz (measured, Erin’s Audio Corner)
Bass Extension (-3dB)55Hz (measured, Erin’s Audio Corner)
DIY KitNo
Dimensions14.2”H x 7.5”W x 10.5”D (361.9 x 190.5 x 266.7 mm)
Drivers5.25” proprietary mineral-filled polypropylene cone with cast aluminum frame woofer, 26mm aluminum/magnesium alloy dome tweeter with titanium former (SEAS Titan)
Impedance8 ohms nominal, 7 ohms minimum (measured, Erin’s Audio Corner)
Sensitivity81.5dB (measured, Erin’s Audio Corner)
Spinorama Preference Score6.65
Spinorama Preference Score with Perfect Sub8.61
Weight18.5 lbs (8.4 kg) each
Woofer Cabinetported