As a preliminary for this project:
HyperboLine ™ new Player in the Old Game
I tested the JAMO 30466/30462 2-1/2" X 4" Shielded Speaker, from Parts Express, part #299-919 in a small line array.
I won't go in to a long description of the Dirty Dozen sonic attributes, as I'm not a fan of line arrays for home use in general. That said, for under $20 for two dozen speakers, this line is hard to beat for non critical listening.
It would also make a cute "Bose Killer" PA for musicians/house of worship on a budget.
Interior dimensions of the cabinet were 4.25 x 2 x 31.875 inches, using 3/4 inch plywood with 3/4" dividers between each series pair of speakers. The 12 drivers were wired in three 24 ohm series pairs (3 x 8 ohm) then the four paralleled, for a nominal cabinet impedance of 6 ohms (24/4=6). Sensitivity of the individual speakers is 83 dB 1 watt one meter, the Dirty Dozen is around 92 dB.
New test results with the speakers in a ported cabinet are in post #6.
The speakers individually can handle more than 20 watts sine wave for a short period of time, but distort with more than their rated input of 10 watts. With a few watts the the Dirty Dozen can get loud, much over 120 watts is not going to improve things.
The buyout speakers are incredibly cheap, but don't sound bad.
They do require a very precise hole cut, and since they are oval, a special router jig must be made unless you are extremely good (and incredibly patient) with a jig saw.Took a me a half dozen tries to make a decent template for the router. The 31.875 inch baffle height is just barely tall enough for 12 drivers with their edges touching.
The speakers have the "-" terminal wired to the frame, that wire must be cut or the frames touching will screw up the series parallel wiring. The speaker frames bend easily, final screwing should be carefully done by hand or the bent frame will result in a buzzing speaker. Fortunately, the speakers can be also be bent back in shape, the few "buzzers"(out of 96) I did not seat properly the first time were corrected by re-bending and re-seating.
Out of 120 speakers, four arrived dead, two had the color coding reversed, and the color coding of the wires soldered to the speakers is black for +, white for -, opposite from the usual convention.
Parts Express sent out replacements for the dead units. The speaker quality control was not bad, the frequency response of the line array is fairly representative of the average units. m The "Dirty D Rag" chart shows the response of three of the speakers, measured at about 1 foot, the back loosely sealed with a towel.
The unit labeled 2x4"in 1 (green trace) is the more usual, 2x4"in2 and 2x4"in4 are better than average.
8 out of the 120 tested showed this better than average response, they did not have as deep a dip at 8 kHz as the rest.
Most of the very high frequency output is emitted from the tiny dust cap, making for better HF response than many round speakers of the same height, and the additional cone area of the 4 inch width make the response strong to 200 Hz. The 4" speaker width is responsible for some erratic frequency response on and off-axis in the 8kHz region, but the rest of the response is fairly uniform from nearly omnidirectional at 200 Hz to about 75 degree (-6 dB points) at 16 K.
The polar charts below were done indoors at only one meter. The charts in in post #6 give a better idea of the polar response.
The drooping HF response and large peak centered at about 320 Hz response is influenced by the short measurement distance and the room, as can be seen in the chart 2x4lineIn, taken at 29 feet indoors, and 2x4Line dd, at 40 foot outdoors.
Cross over a woofer beneath, and they are good to go.
Use EQ to correct the major dips and peaks if you are picky.
A floor to ceiling line array costs less than $100 for a pair (assuming your ceiling height is less than 12.5 feet, not including cabinet costs) including a pound of solder.
Have fun!
Art
HyperboLine ™ new Player in the Old Game
I tested the JAMO 30466/30462 2-1/2" X 4" Shielded Speaker, from Parts Express, part #299-919 in a small line array.
I won't go in to a long description of the Dirty Dozen sonic attributes, as I'm not a fan of line arrays for home use in general. That said, for under $20 for two dozen speakers, this line is hard to beat for non critical listening.
It would also make a cute "Bose Killer" PA for musicians/house of worship on a budget.
Interior dimensions of the cabinet were 4.25 x 2 x 31.875 inches, using 3/4 inch plywood with 3/4" dividers between each series pair of speakers. The 12 drivers were wired in three 24 ohm series pairs (3 x 8 ohm) then the four paralleled, for a nominal cabinet impedance of 6 ohms (24/4=6). Sensitivity of the individual speakers is 83 dB 1 watt one meter, the Dirty Dozen is around 92 dB.
New test results with the speakers in a ported cabinet are in post #6.
The speakers individually can handle more than 20 watts sine wave for a short period of time, but distort with more than their rated input of 10 watts. With a few watts the the Dirty Dozen can get loud, much over 120 watts is not going to improve things.
The buyout speakers are incredibly cheap, but don't sound bad.
They do require a very precise hole cut, and since they are oval, a special router jig must be made unless you are extremely good (and incredibly patient) with a jig saw.Took a me a half dozen tries to make a decent template for the router. The 31.875 inch baffle height is just barely tall enough for 12 drivers with their edges touching.
The speakers have the "-" terminal wired to the frame, that wire must be cut or the frames touching will screw up the series parallel wiring. The speaker frames bend easily, final screwing should be carefully done by hand or the bent frame will result in a buzzing speaker. Fortunately, the speakers can be also be bent back in shape, the few "buzzers"(out of 96) I did not seat properly the first time were corrected by re-bending and re-seating.
Out of 120 speakers, four arrived dead, two had the color coding reversed, and the color coding of the wires soldered to the speakers is black for +, white for -, opposite from the usual convention.
Parts Express sent out replacements for the dead units. The speaker quality control was not bad, the frequency response of the line array is fairly representative of the average units. m The "Dirty D Rag" chart shows the response of three of the speakers, measured at about 1 foot, the back loosely sealed with a towel.
The unit labeled 2x4"in 1 (green trace) is the more usual, 2x4"in2 and 2x4"in4 are better than average.
8 out of the 120 tested showed this better than average response, they did not have as deep a dip at 8 kHz as the rest.
Most of the very high frequency output is emitted from the tiny dust cap, making for better HF response than many round speakers of the same height, and the additional cone area of the 4 inch width make the response strong to 200 Hz. The 4" speaker width is responsible for some erratic frequency response on and off-axis in the 8kHz region, but the rest of the response is fairly uniform from nearly omnidirectional at 200 Hz to about 75 degree (-6 dB points) at 16 K.
The polar charts below were done indoors at only one meter. The charts in in post #6 give a better idea of the polar response.
The drooping HF response and large peak centered at about 320 Hz response is influenced by the short measurement distance and the room, as can be seen in the chart 2x4lineIn, taken at 29 feet indoors, and 2x4Line dd, at 40 foot outdoors.
Cross over a woofer beneath, and they are good to go.
Use EQ to correct the major dips and peaks if you are picky.
A floor to ceiling line array costs less than $100 for a pair (assuming your ceiling height is less than 12.5 feet, not including cabinet costs) including a pound of solder.
Have fun!
Art
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