Yeah, you read that right: FIFTEEN | (15) | {one-five} | [30/2] | \5*3/ watts...... per channel!!!
And they sound great, too - right up 'til clipping (probably that nice nested feedback!)
Pictured below is a 150mm woofer playing 44Hz in a sealed box. Its efficiency is 85dB/w, -6dB @ 55Hz, -12dB @ ~35
Small caveat: it only puts out 10 volts at frequencies down to 52Hz (at least with these speakers...) down at, say, 32Hz, the voltage can only reach like 8.3. Still decent! Still decent!
.. I did not expect this amount of power!!! I know - weird thing to do: solder some 14 gauge wire to a stereo 1/4" jack and then use the output to power some speakers! It's the first step I've taken to starting the project of my low powered active system. The speakers I'll be using are my ATC SCM20 Pro PSL Mk2s. The idea is, for lower powered monitoring, I'll use the active amp / filter combination to drive them, and when I want to listen louder, I'll use the passive crossover. I plan to use some high quality high current multi-pole switches so that I can just flip a switch and press a button on each speaker (or under - I'm not sure if I'm going to make some really nice enclosures yet - the stock boxes are pretty good with bracing and the material is 1.5" (front) and 0.75" (sides/back) constrained layer damped (CLD) material. Anyway... they've got a good passive 3rd order butterworth crossover which takes up the entire back of enclosure with massive high gauge air-core coils & capacitors. Which is great.. but no passive crossover, no matter the quality and design, can beat active! (obviously it has to be properly implemented and such, which I plan to do entirely)
So my plan was to use the L30 II to power the tweeters, then either my Arcam A18 (50WPC class ab), Kinergetics KBA-280 (140WPC, class a), or my Arcam A32 (100WPC ab) for the woofer. The Kinergetics has bass that feels authoritative (probably has something to do with its almost thirty 200 watt Sanken output transistors working in parallel...), but it's out of commission right now...
I've also got a Topping L70... If it can put out 25 watts per channel, maybe I'll use it for the woofers! (obviously I wouldn't use it near 25W... I could also use another L30 II... 15 watts is enough for the low powered mode! It's not like I can't swap in the future...
Hint to see how far the woofer is moving: look at where the wire for the voice coil pokes through (it's the light spot)
Edit: The thought just occurred to me.. the 15VAC adaptor which powers the L30 II, I'm not home now so I can't check... but I think it's only rated for 1A or 1.5A (the physical size is consistent with it). Drawing over 2.4A on the output would definitely pull the voltage down to probably around 11V. This might be the cause for clipping, at frequencies at abd above ~50 Hz. When I get home I will try testing just one channel at a time. This could be even better news for my using it to drive tweeters! I'm thinking one configuration at 1.6kHz 24dB, another 3rd order at 1.8 (instead of the 2.1 of the passive crossover)
Say 20 or 25 watts for 1.6kHz and above at 24dB/oct- the low pass portion would be 75-100W! If, driving one channel, the L30 II can do 30W, I could buy another and go full power with either my 100 or even 140W (140 class A batter) amp!
And they sound great, too - right up 'til clipping (probably that nice nested feedback!)
Pictured below is a 150mm woofer playing 44Hz in a sealed box. Its efficiency is 85dB/w, -6dB @ 55Hz, -12dB @ ~35
Small caveat: it only puts out 10 volts at frequencies down to 52Hz (at least with these speakers...) down at, say, 32Hz, the voltage can only reach like 8.3. Still decent! Still decent!
.. I did not expect this amount of power!!! I know - weird thing to do: solder some 14 gauge wire to a stereo 1/4" jack and then use the output to power some speakers! It's the first step I've taken to starting the project of my low powered active system. The speakers I'll be using are my ATC SCM20 Pro PSL Mk2s. The idea is, for lower powered monitoring, I'll use the active amp / filter combination to drive them, and when I want to listen louder, I'll use the passive crossover. I plan to use some high quality high current multi-pole switches so that I can just flip a switch and press a button on each speaker (or under - I'm not sure if I'm going to make some really nice enclosures yet - the stock boxes are pretty good with bracing and the material is 1.5" (front) and 0.75" (sides/back) constrained layer damped (CLD) material. Anyway... they've got a good passive 3rd order butterworth crossover which takes up the entire back of enclosure with massive high gauge air-core coils & capacitors. Which is great.. but no passive crossover, no matter the quality and design, can beat active! (obviously it has to be properly implemented and such, which I plan to do entirely)
So my plan was to use the L30 II to power the tweeters, then either my Arcam A18 (50WPC class ab), Kinergetics KBA-280 (140WPC, class a), or my Arcam A32 (100WPC ab) for the woofer. The Kinergetics has bass that feels authoritative (probably has something to do with its almost thirty 200 watt Sanken output transistors working in parallel...), but it's out of commission right now...
I've also got a Topping L70... If it can put out 25 watts per channel, maybe I'll use it for the woofers! (obviously I wouldn't use it near 25W... I could also use another L30 II... 15 watts is enough for the low powered mode! It's not like I can't swap in the future...
Hint to see how far the woofer is moving: look at where the wire for the voice coil pokes through (it's the light spot)
Edit: The thought just occurred to me.. the 15VAC adaptor which powers the L30 II, I'm not home now so I can't check... but I think it's only rated for 1A or 1.5A (the physical size is consistent with it). Drawing over 2.4A on the output would definitely pull the voltage down to probably around 11V. This might be the cause for clipping, at frequencies at abd above ~50 Hz. When I get home I will try testing just one channel at a time. This could be even better news for my using it to drive tweeters! I'm thinking one configuration at 1.6kHz 24dB, another 3rd order at 1.8 (instead of the 2.1 of the passive crossover)
Say 20 or 25 watts for 1.6kHz and above at 24dB/oct- the low pass portion would be 75-100W! If, driving one channel, the L30 II can do 30W, I could buy another and go full power with either my 100 or even 140W (140 class A batter) amp!
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