Complete Instruments Instrument Bodies
Generators Switching Power Supply
Synthesizers Synthesizer Controls
Amplifiers Loudspeakers Resonances Horns
http://www.parts-express.com/dayton-audio-ds115-8-4-designer-series-woofer-speaker--295-424
http://www.parts-express.com/tymphany-tc10fg00-04-4-full-range-line-array-driver-4-ohm--264-1360
http://www.parts-express.com/visaton-r10s-4-full-range-speaker-8-ohm--292-596
http://www.parts-express.com/visaton-m-10-4-sealed-back-cone-midrange-driver-8-ohm--292-594
http://www.parts-express.com/visaton-r10s-4-full-range-speaker-4-ohm--292-595
http://www.parts-express.com/quam-4c3z8ot-4-moisture-resistant-speaker-8-ohm--244-3226
http://www.parts-express.com/visaton-r10sc-4-4-fullrange-speaker-4-ohm--292-602
http://www.parts-express.com/visaton-r10sc-4-full-range-speaker-8-ohm--292-597
Speaker Model
At Exertion Instrument headquarters, we're researching ways to produce the loudest, most efficient portable electronic musical instruments. Here we present two useful spreadsheets so may also take part in this process. The first spreadsheet "Efficiency Bass Speakers" lists the predicted efficiencies for about 52 different speakers when used in the exponential Bass Horn configuration. The second spreadsheet, written and verified against another piece of Windows software by Michael Harradon, will help all of you instrument designers and builders to construct efficient bass horns. Seriously efficient bass horns. You may have read that horns can increase efficiency from the 1-3% of a typical loudspeaker, to "up to 50%." That seems to be the claim I keep running into. Our spreadsheet has predicted efficiencies of greater than 50%! Using parameters from real speakers, we have been able to design for 53 and 55%! Michael was able to show one easy way to predict the range of efficiency of the speaker when used in a bass horn configuration. Compute this coefficient: 1000 * Qes / Fs. That is, one thousand times the quality factor of the electrical system of the speaker divided by the speaker's Thiele/Small resonance. If that value is between 4.67 and 6.67, then the efficiency in a bass horn configuration will be about 50% or greater!
4-inch speakers at Parts Express on gdrive
Conclusions
Ever more Interestingly, we found that it's easier to find speakers in the 4 inch range with these characteristics than in the larger range, e.g. 8 inches and greater. This seems to be because the Fs of smaller speakers is naturally higher. In fact, Michael produced the "optimum" set of parameters for efficiency: Fs = Hz, Qes = . (hold on, retrieving numbers). Nevertheless, we were still able to find one speaker able to produce 40% efficiency at 8 inches. And guess what? It's not unfairly priced either! Speaking of cost, we found almost no correlation between the factor (1000*Qes/Fs) and the price of the speaker. This may due because most speaker designers are not concerned with efficiency of bass horns. Also, it was very difificult to find an appropriate 6" speaker with these specs. No 7" speakers were found which met the criteria of 4.6 < 1000*Qes/Fs < 6.6. Anyone who finds a reasonably-priced (<$50) 10" or greater speaker will get a small prize from the people who run this website. It remains to be examined why some speakers have a lower Qes per Fs and why some do not, but for now, let's buy some speakers. Here are our favorites so far:
In this section, we analyze some speakers we bought from Parts Express using the Dayton WT3 Woofer analyzer.
Exertion Instruments use common loudspeakers. For best results, choose speakers with:
Browsing speakers
http://www.parts-express.com/5-paper-cone-midbass-shielded-woofer-8-ohm--299-006
http://www.parts-express.com/dayton-audio-rs125t-8-5-reference-woofer-truncated-frame--295-340
www.parts-express.com/dayton-audio-rs125-8-5-reference-woofer--295-353
www.parts-express.com/hivi-f5-5-bass-midrange--297-435
www.parts-express.com/tang-band-w5-1611saf-5-full-range-speaker--264-918
www.parts-express.com/hivi-m5a-5-aluminum-magnesium-midbass--297-437
www.parts-express.com/dayton-audio-ds135-8-5-designer-series-woofer-speaker--295-426
http://www.parts-express.com/faitalpro-5fe120-5-professional-midbass-midrange-woofer-8-ohm--294-1141