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

Last updated: August 24, 2026

Short answer: the Ascend Sierra 1 v2 for better sound quality, the Pioneer SP-BS22-LR (Philharmonic AAM Mod) for the lower price. The Ascend Sierra 1 v2 ranks #3 of 74 bookshelf speakers at $1000. The Pioneer SP-BS22-LR (Philharmonic AAM Mod) ranks #51 at $168, $832 cheaper.

What the Pioneer SP-BS22-LR (Philharmonic AAM Mod) offers: 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. Watch for: 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.

What the Ascend Sierra 1 v2 offers: 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. 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. 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.

Buy the Pioneer SP-BS22-LR (Philharmonic AAM Mod) if the price matters more than sound quality. Buy the Ascend Sierra 1 v2 if sound quality matters more than the price.

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

Specifications Side By Side

Pioneer SP-BS22-LR (Philharmonic AAM Mod) Ascend Sierra 1 v2
Price$168$1000
Ranked#51 of 74 in Medium Size Bookshelf Speakers#3 of 74 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 kg18.5 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

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The Two Speakers In Full

Pioneer SP-BS22-LR (Philharmonic AAM Mod): $168 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.

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
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)
Weight9 lbs / 4.1 kg
Woofer Cabinetported, rear

Ascend Sierra 1 v2: $1000 Ascendacoustics eBay

Ascend Sierra 1 v2 ranking card

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.

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)
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)
Weight18.5 lbs / 8.4 kg each
Woofer Cabinetported