Yamaha YST-SW45
An old 8-inch Yamaha sub now only found used. Official specs list 30–200 Hz (–10 dB), 70 W/5 Ω, and a 50–150 Hz low-pass (–24 dB/oct). No credible modern third-party measurements exist for this exact model; real extension is modest. Advanced YST/ANIC was clever for its time but shows no proven advantage in recent comparative data. At ~USD 75 used, we could not verify any cheaper product clearly equal-or-better in user-facing functions and likely extension; cost-performance therefore caps at 1.0. Age-related reliability is the main risk.
Overview
A compact 8-inch powered subwoofer from decades ago, the YST-SW45 survives on the used market. Yamaha’s Advanced YST with ANIC is the headline technology. Official specs are modest, and there are no credible current bench tests. At very low used prices it can make sense as a “first bass” add-on for small rooms; otherwise, newer budget subs are safer choices.
Scientific Validity
\[\Large \text{0.4}\]No credible recent third-party measurements (FR/THD/max-SPL) were found for this model. The manufacturer lists 30–200 Hz (–10 dB), high-cut 50–150 Hz (–24 dB/oct), and amplifier output 70 W/5 Ω [1]. Because the response window is –10 dB (not –3 dB), actual in-room extension will be higher in frequency than the catalog 30 Hz. With independent data absent, we start from 0.5 and adjust down to 0.4, documenting manufacturer specs as provisional [1].
Technology Level
\[\Large \text{0.4}\]Advanced YST with ANIC (negative-impedance drive + Helmholtz resonator “air woofer”) is clearly described by Yamaha for this generation and its successors [1][2]. It’s inventive but, lacking modern A/B measurements against today’s budget subs, we cannot claim a measurable edge. Score 0.4.
Cost-Performance
\[\Large \text{1.0}\]Price basis (review target): representative used price USD 75 (eBay example listing) [4].
Cheapest equal-or-better comparator we could verify (US new): Dayton Audio SUB-800, 8”, 80 W, rated 40–140 Hz, high/low-level I/O, USD 154.98 [3]. Functions and likely extension are at least comparable; warranty and new electronics favor the comparator, but it is not cheaper than the review target. Therefore, no cheaper equivalent exists → CP = 1.0 (cap), per rules.
Reliability & Support
\[\Large \text{0.2}\]Discontinued, no official support; typical age-related risks (capacitors, auto-standby, surround wear). No warranty and uncertain parts availability warrant a low score.
Rationality of Design Philosophy
\[\Large \text{0.4}\]The YST/ANIC approach is technically coherent and not pseudo-science, but it doesn’t demonstrably surpass modern low-cost ported subs in measured outcomes. As a cheap, compact solution it’s rational; as a platform for deep bass or high SPL, it is not.
Advice
If you can find a clean unit around USD 75 and accept the risk of failure, it’s a reasonable way to add some bass to small speakers in a small room. If you need deeper extension, higher output, or warranty coverage, step up to current 8–12” budget subs.
References
[1] Yamaha — YST-SW45 Owner’s Manual (specs incl. 30–200 Hz (–10 dB), 50–150 Hz LPF, 70 W/5 Ω). https://usa.yamaha.com/files/download/other_assets/2/319752/YST-SW45.pdf (accessed 2025-08-29).
[2] Yamaha — NS-SW100 Product Page (Advanced YST II overview). https://usa.yamaha.com/products/audio_visual/speaker_systems/ns-sw100/index.html (accessed 2025-08-29).
[3] Parts-Express — Dayton Audio SUB-800 8” Powered Subwoofer (price/specs incl. 40–140 Hz, I/O). https://www.parts-express.com/Dayton-Audio-SUB-800-Powered-Subwoofer-300-627 (accessed 2025-08-29).
[4] eBay — Yamaha YST-SW45 Powered Subwoofer (Used) — example listing (representative USD 78 ask). https://www.ebay.com/itm/256421901170 (accessed 2025-08-29).
(2025.8.30)