Hello everyone, I have a serious idea of building my own speakers for some rehearsal room but I'd like your opinion on this. I need a pair of stage monitors/room PA but I'd like to keep it cheap, I don't need high fidelity at all, I'm more interested in (decent) volume and power. I had a look at these twin cone drivers:
Fane International Ltd Loud Speakers
(Fane Sovereign 12-250LT)
I've typed the T/S parameters in WinISD Pro, and I've come up with this idea of a box:
- sealed
- 50-60 litre MDF box with some bracing
- moderate stuffing so as not to harm bass response too much
I would achieve a 1.5dB hump in the upper bass (which is not too bad), f3 at around 65Hz and decent power handling (200W is not that much, but we will have to make do), it would cost around €100 per box and supposedly I would have decent reproduction up to 17kHz (but 12-13kHz would suffice really), can I trust the 5.25mm xmax spec though? Do you have any experience with this driver? Oh, with a twin cone you don't need crossovers, do you?
Thanks!
Fane International Ltd Loud Speakers
(Fane Sovereign 12-250LT)
I've typed the T/S parameters in WinISD Pro, and I've come up with this idea of a box:
- sealed
- 50-60 litre MDF box with some bracing
- moderate stuffing so as not to harm bass response too much
I would achieve a 1.5dB hump in the upper bass (which is not too bad), f3 at around 65Hz and decent power handling (200W is not that much, but we will have to make do), it would cost around €100 per box and supposedly I would have decent reproduction up to 17kHz (but 12-13kHz would suffice really), can I trust the 5.25mm xmax spec though? Do you have any experience with this driver? Oh, with a twin cone you don't need crossovers, do you?
Thanks!
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It's basically this driver.
http://www.diyaudio.com/forums/full-range/209490-phase-plugging.html
Which is pretty similar to the beta12. Neither drivers are what I'd class as acceptable for home use. As a general noise making device, they're good depending on the music. Good for vocals, die a quick death with complicated music.
http://www.diyaudio.com/forums/full-range/209490-phase-plugging.html
Which is pretty similar to the beta12. Neither drivers are what I'd class as acceptable for home use. As a general noise making device, they're good depending on the music. Good for vocals, die a quick death with complicated music.
for its rather high moving mass and inductance, the on-axis highs look very extended and off axis excellent (are those graphs correct?)
qts at 0.64 at is rather high for vented boxes - it might work in the recent "Karlsonator 12" project (?)
simple xmax based only on the winding depth and gap height would be only 1.5mm:
Magnetic Gap Depth 0.31” / 7.87 mm
Coil Winding Height 0.43” / 10.92 mm
3.05mm/2 ~ 1.5mm xmax
12LTA has a large xmax figure considering its overhang is only 0.08 inches - I think that's one reason it can sound weak dynamically on bass transients.
besides demand, are there practical reasons why this type can't be made with a stronger motor than the typical 38 to 56 ounce ferrite slug?
http://www.klippel.de/uploads/media/Assessment_of_Voice_coil_peak_displacement_XMAX_02.pdf
12LTA outdoors
the Karlsonator 12 is the best I've heard 12TA
qts at 0.64 at is rather high for vented boxes - it might work in the recent "Karlsonator 12" project (?)
simple xmax based only on the winding depth and gap height would be only 1.5mm:
Magnetic Gap Depth 0.31” / 7.87 mm
Coil Winding Height 0.43” / 10.92 mm
3.05mm/2 ~ 1.5mm xmax
12LTA has a large xmax figure considering its overhang is only 0.08 inches - I think that's one reason it can sound weak dynamically on bass transients.
besides demand, are there practical reasons why this type can't be made with a stronger motor than the typical 38 to 56 ounce ferrite slug?
http://www.klippel.de/uploads/media/Assessment_of_Voice_coil_peak_displacement_XMAX_02.pdf
12LTA outdoors
An externally hosted image should be here but it was not working when we last tested it.
the Karlsonator 12 is the best I've heard 12TA
An externally hosted image should be here but it was not working when we last tested it.
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What do you mean by "complicated music" and "die a quick death"? I was planning to amplify some keyboards, vocals, etc. (attenuating bass if necessary). I've read that xmax figures were stated around 1.5mm before, they state over 5 mm today, is this "optimistic"? I don't mind some harmonic distortion/compression (I stress that I'm not after fidelity, but volume), keep in mind that the alternative would be to buy cheap no-brand ABS stage monitors, and I still would spend more (I would keep the build as cheap as possible by skimping on aesthetics and ruggedness, after all the cabinets would never leave the rehearsal room). According to WinISD, I would be looking at around 116dB max SPL per speaker, which is not a lot but neither too bad (an incentive to keep volumes down 😀 ).
well............................
The bass tones modulate the vocals and highs.
So the more bass you have in the music, the more your driver will garble the voices.
The bass tones modulate the vocals and highs.
So the more bass you have in the music, the more your driver will garble the voices.
Isn't this a problem with all full range drivers that have to dig into the sub 150Hz range? A FAST with a XO to high pass the full range avoids this but most implementations that are fed straight from the amp are like this. Despite this, most folks on this forum will agree that the speakers do a pretty good job.
hmm, 150hz.............
That's a tough place to cross, right in the male range, causing phase problems (unless 6db crossover).
even an 80hz 18db crossover cleaned up the mids on my big double 15/horn setup.
I think 100hz would be fine (no matter what slope, but 6db best).
My volume levels (and type of music), I cannot run a 12" full range wide open (or combined area of), and since I'm adding eq, I don't want the horrible sounding active x-over also.
eek, what to do.
That's a tough place to cross, right in the male range, causing phase problems (unless 6db crossover).
even an 80hz 18db crossover cleaned up the mids on my big double 15/horn setup.
I think 100hz would be fine (no matter what slope, but 6db best).
My volume levels (and type of music), I cannot run a 12" full range wide open (or combined area of), and since I'm adding eq, I don't want the horrible sounding active x-over also.
eek, what to do.
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If I use 50L and I high-pass the signal from the mixer (say, cutoff freq. 80Hz, 12dB/oct.) I would avoid nasty overexcursion and the strong 3dB low-mid hump, right? I'm not against "small box" coloration, but 3dB seems a bit high to me.
By the way, high-passing the signal at 80Hz gives me f3 at around 80Hz (which means I would have decent reproduction of the low E of a bass, for example, 2nd harmonics of course). Then again, I could go with a small box and apply a 3dB cut around 125Hz, low Q, to smooth things up.
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