Amp upgrades in the future perhaps with higher damping factor and power. For now It does the job. Been modeling this TH with a Lab12C and if I am doing things correct it does 107,8dB @ 18Hz with 20V-100W input to get to xmax of 13 mm. That's not much more compared to that cheap gziw 300 (106,3dB @ 18Hz 15,75V-62W xmax of 9,2mm).
Off course the build quality of the driver is not in the same class but the price difference is huge.
Off course the build quality of the driver is not in the same class but the price difference is huge.
I can second the idea for a high damping factor amp.
I got a big Cerwin Vega (run the fans in series so half speed and quiet).
Really grabs the cone.
Much better control than other amps I've got and even a mega bucks exotic hifi one that was brought round😂
Any love for Eminence drivers and this type of sub?
I got a big Cerwin Vega (run the fans in series so half speed and quiet).
Really grabs the cone.
Much better control than other amps I've got and even a mega bucks exotic hifi one that was brought round😂
Any love for Eminence drivers and this type of sub?
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Here is a better gziw driver, the 12xspl-d2. Costs around 180 euro, which is half the price of a lab12c and outperforms it by roughly 3dB. Build quality of the driver looks pretty good. Took an average value for Sd to get to the manufacturer given Bl factor and used roughly 1/3 of the manufacturers given xmax (34mm). 110,7dB@18Hz with 24V (145W) input, compared to the lab12c's 108dB@18Hz with 20V (100W) input.
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Alpine swg-1244 vs lab12c. Costs about 120 euro, but can be purchased from Germany at the moment for around 80 euro. Shipping costs not included.
Same performance and a decent woofer according to manufacturer info. Little bit eq @ 50Hz -3dB and LP @ 60Hz and we are are basically there. Room eq comes later. This probably the best bang for the buck option right?
Same performance and a decent woofer according to manufacturer info. Little bit eq @ 50Hz -3dB and LP @ 60Hz and we are are basically there. Room eq comes later. This probably the best bang for the buck option right?
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If the Alpine SWG-1244 Xmag of 23mm (the displacement at which the BL product has fallen to 70% of its value at the cone's rest position) is correct, it should outperform the LAB 12C by a good margin in peak output while costing considerably less. That said, the power handling looks a little light for the excursion capability, but a lot of bang for the buck.
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The LAB12 has the same 13mm Xmax rating as the LAB12C.
My distortion/excursion testing of the LAB12 showed pretty clean response to Xmax (<10%), than very rapid distortion increase past Xmax, which would indicate Xmax and Xmag being near the same value.
The Alpine Type-R SWR-1223D has 22mm Xmax at 10% distortion, but uses a 44mm deep coil and a lot more magnet.
I still think the Alpine SWG-1244 may have a bit more clean excursion then the Lab12, but not as much as I thought in post #336
My distortion/excursion testing of the LAB12 showed pretty clean response to Xmax (<10%), than very rapid distortion increase past Xmax, which would indicate Xmax and Xmag being near the same value.
The Alpine Type-R SWR-1223D has 22mm Xmax at 10% distortion, but uses a 44mm deep coil and a lot more magnet.
I still think the Alpine SWG-1244 may have a bit more clean excursion then the Lab12, but not as much as I thought in post #336
The Alpine SWG-1244 and Eminence use the same formula for Xmax ( Voice coil height minus top plate thickness, divided by 2)(Hvc-Hag/2) to figure Xmax.
The Alpine SWG-1244 Xmax is rated for less than the LAB12, but it's Xmag of 23mm is probably more, my guestimate (based on 10% distortion) is the LAB12 has an Xmag of around 13-15mm.
The mechanical determination of Xmax is not always predictive of Bl at different excursion levels- B&C woofers Xvar is slightly more or less than Xmax depending on the construction.
The Klippel test of Xmag (or Xvar as B&C call it) is really where it's at for excursion, voltage can't control the cone when the magnetic force drops off too far.
The Alpine SWG-1244 Xmax is rated for less than the LAB12, but it's Xmag of 23mm is probably more, my guestimate (based on 10% distortion) is the LAB12 has an Xmag of around 13-15mm.
The mechanical determination of Xmax is not always predictive of Bl at different excursion levels- B&C woofers Xvar is slightly more or less than Xmax depending on the construction.
The Klippel test of Xmag (or Xvar as B&C call it) is really where it's at for excursion, voltage can't control the cone when the magnetic force drops off too far.
Alpine related measurements for three different 12" models in this TH design....
https://www.stereonet.com/forums/topic/282701-alpine-12-tapped-horn-home-theatre-subwoofer-build/
A different TH but I still went with the Alpine because its greater clean Xmax meant it could get more SPL than the other options...
https://www.stereonet.com/forums/topic/572095-bp-mth-266-versatile-15-tapped-horn-subwoofer/
https://www.stereonet.com/forums/topic/282701-alpine-12-tapped-horn-home-theatre-subwoofer-build/
A different TH but I still went with the Alpine because its greater clean Xmax meant it could get more SPL than the other options...
https://www.stereonet.com/forums/topic/572095-bp-mth-266-versatile-15-tapped-horn-subwoofer/
Greets!
A flat plywood/whatever disc, i.e. it's not the material, but how rigid they made it.
Hover over the S2 field and it's displayed at the very bottom of the input screen.
Group delay is more about decay time by 'x' frequency rather than peak amplitude and IME if mostly decayed away by ~35 Hz, don't care how high it is based on its 'tightness'/'heart attack fast' LF, etc., transients of the many low tuned EBS alignments I did way back when I hadn't known there was another name for it. Regardless, the first of many threads around the WWW that made me aware.
Anyway, considering your 60 Hz low pass it seems 'much ado about nothing' to me, especially since a very cheap JBL mobile Audio 12" woofer I did a TH design for a neighbor's Honda Accord some years ago now had much higher GD, but a more rapid decay that allowed a 120 Hz XO with no complaints from me or the others, though of course YMMV, FWIW, etc..
Anyway, considering your 60 Hz low pass it seems 'much ado about nothing' to me, especially since a very cheap JBL mobile Audio 12" woofer I did a TH design for a neighbor's Honda Accord some years ago now had much higher GD, but a more rapid decay that allowed a 120 Hz XO with no complaints from me or the others, though of course YMMV, FWIW, etc..
Group delay is a measure of the rate of change of phase with respect to frequency, and is positive when the phase slope is negative.
The phase slope is generally the inverse of the frequency response:
Like GM says, considering your 60 Hz low pass, nothing much to worry about.
That said, if you were to push the drivers into distortion, the resonant delay of the distortion harmonics ringing can be a problem. If I'm right about the Alpine SWG-1244 Xmag of 23mm being considerably more than the LAB12s, that ringing would be far less when driven past Xmax.
Danley used damping and absorption tubes in the DTS20 "Tower of Power" to reduce the ringing problem and increase it's usable range.
The phase slope is generally the inverse of the frequency response:
Like GM says, considering your 60 Hz low pass, nothing much to worry about.
That said, if you were to push the drivers into distortion, the resonant delay of the distortion harmonics ringing can be a problem. If I'm right about the Alpine SWG-1244 Xmag of 23mm being considerably more than the LAB12s, that ringing would be far less when driven past Xmax.
Danley used damping and absorption tubes in the DTS20 "Tower of Power" to reduce the ringing problem and increase it's usable range.
Because of my room layout and available space I'm going for a different port placement. If I am correct te surface area is 379,6 cm squared. Looking at the picture that I've obtained from another forum there seems to be added a small diagonal piece internally. Is this necessary for proper function or can I just make a square exit that has one side slightly diagonal (right side)? Minor trapezoid-ish.
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