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High Sensitvity 92 db 2-way Speakers Using JBL 127H-1 and Dayton RST 28-4F The modern high quality HT speakers tend to have typically 86db/2.83v sensitivity, limited primarily by the relatively smallish woofers used in them. The newly introduced Dayton RST-28F4 has a sensitivity of 93.5db even without a waveguide or horn. In addition, it can be crossed low(1400 hz). I jumped at the opportunity to use it in a pair experimental 2-way high quality DIY speakers with sensitivity around 92 db/2.83v. For the woofer, I just happen to have a pair JBL 127H1 woofers available. JBL127H1 has advanced magnetic structure, 2-inch voice coil and was used in many commercial and professional speakers (4410A, XPL 160A, L80T and T3). The measured sensitivity was 92db with very low distortions (less than 0.5% even at 95db SPL for most frequencies), according to a review by High Fidelity magazine. In a fully stuffed sealed cabinet of 0.7Ft3, I estimate the Q of the box will be around 1.1 and -3 db around 60 hz, plenty low for a HT speaker. One can choose other options if deeper bass is desired. TS parameters and suggested enclosure sizes are published here. http://ampslab.com/blog/2018/05/06/jbl-127h1/ The current crossover (GS-1) is voiced mostly by listening and probably can be simplified further. My reference speakers are Infinity Reference 162 as reviewed here. https://www.soundandvision.com/content/infinity-reference-r162-speaker-system-test-bench. My big surprise is the spectral balance of my JBL127H1 /RST28 F4 is very similar to Infinity R162 and certainly no lacking of details and spaciousness. I would rate the transient response of both speakers to be equally outstanding. I can listen to either speaker for a long time without listening fatigue. In conclusion, you can build a higher sensitivity speaker by using a high quality large diameter woofer without losing sound quality.