A very quick sim of 2 of my favorites for this job:
The 10FE330
The 12FE330
Both go more than loud enough for your room, and can be crossed relative high (above 2kHz for the Faital 10FE330 with the right horn, above 1.2kHz for the 12FE330) if you use steep crossover (at least 2nd order, preferable 4th order or higher). And they are relative cheap.
The 12PR430 is great, but it's more a subwoofer type of speaker, not so good in the higher frequencies. The FE330 series are more like the older big woofers genre JBL and Altec and are better suited for a wide frequncy range. But they need a bigger cabinet and don't go that loud. I don't think you need 120dB in your room altough...
I would go fro the 10FE330, because it's a smaller box but still goes more than loud enough. It's what i'm actually doing for a similar build. I'm still designing, but this could be how the result looks (Onken style cabinet for bass, and horn on top). It's an id, not a full plan yet... A regular ported cabinet can also off course, but that is boring in my personal opinion (i did that already long ago)
View attachment 1365138
The 10FE330
The 12FE330
Both go more than loud enough for your room, and can be crossed relative high (above 2kHz for the Faital 10FE330 with the right horn, above 1.2kHz for the 12FE330) if you use steep crossover (at least 2nd order, preferable 4th order or higher). And they are relative cheap.
The 12PR430 is great, but it's more a subwoofer type of speaker, not so good in the higher frequencies. The FE330 series are more like the older big woofers genre JBL and Altec and are better suited for a wide frequncy range. But they need a bigger cabinet and don't go that loud. I don't think you need 120dB in your room altough...
I would go fro the 10FE330, because it's a smaller box but still goes more than loud enough. It's what i'm actually doing for a similar build. I'm still designing, but this could be how the result looks (Onken style cabinet for bass, and horn on top). It's an id, not a full plan yet... A regular ported cabinet can also off course, but that is boring in my personal opinion (i did that already long ago)
View attachment 1365138
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Is it possible to show the low-frequency response graphs with a 10Hz to 200Hz frequency range and raise the speaker's curve? The responses would be easier to interpret.
As noted, the 12PR430 has a bit of breakup at its high-frequency limit. See below.
It would need to cross over to a smaller driver at around 400–500Hz. With DSP filtering, it could easily be used successfully in such an application. Adding in an 8-inch midrange would improve the directivity of the system.
The 12FE330 is certainly much better behaved. See below.
As noted, the 12PR430 has a bit of breakup at its high-frequency limit. See below.
The 12FE330 is certainly much better behaved. See below.
I try not to, but with such a high Xmax required to do it all at high SQ is a bit too much to ask for IME.
Its fs = 42Hz is on the high side to try and get much low-frequency extension from this particular driver. If you have a 90-litre enclosure to work with, the following is about the best that can be achieved. Here fb=40Hz. The resulting f6=37Hz, while f3=44Hz. These are good, but by no means fantastic results.
If you have access to DSP in the amplification (e.g., a suitable 3-way or 2-way plate amplifier module), then we have a lot more scope to get the best out of this driver, while still protecting it from over-excursion at very low frequencies below FB.
If we de-tune the enclosure from fb=40Hz to fb=33Hz, and then go ahead and add a 2nd-order peaking high-pass filter to the system, then with filter f0=35Hz and Q=1.5 we can achieve the following response. This has a quite respectable f3=34.6Hz (a not insignificant 10Hz better than before), and f6=31.3Hz. This vented system should do reasonable justice to the "heartbeat" sound at the start of Dark Side Of The Moon, which is centered on 30Hz or so.
At a nominal power input of 44 watts re 8 ohms, we obtain the following simulated responses. Here we see that Xmax is just being reached, and that the infrasonic displacements well below fb are being well controlled. We have only pumped in an extra 4dB of power at around 40Hz (the thick red line). Since the system is producing about 112dB SPL, then it's going to be quite loud while still being within its power handling and cone displacement limits.
2x6.5" drivers won't give you a very high maximum SPL. Their displacement volume is likely to be quite small.
Correct roughly same size and lower Fs to use a single 12"
Stopped building bandpass in high school.
Was trendy then, and achieved better sound with normal vented.
Subjective? sure. Heard a few bandpass that do fine.
You notice port sound issues over time. But could push them with power
or at least seemed like more power
Stopped building bandpass in high school.
Was trendy then, and achieved better sound with normal vented.
Subjective? sure. Heard a few bandpass that do fine.
You notice port sound issues over time. But could push them with power
or at least seemed like more power
Hmm, the Mezzo Calpamos uses a fully baffle step compensated XO so I don't think that's the problem, although still can be tuned more towards low frequencies. Room/placement can be or the speaker have that "short" bass of a typical PA woofer and/or tuning. It's like the woofer bites off the decay of the bass notes earlier than needed. The source of this also can be the too high Fb (the M. Calpamos tuned about 40Hz) imo because it limits the low frequency extension and cuts off the natural long decay of the lowest notes.
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The 12FE330, paired with an f0=36Hz and Q=2.0 peaking high-pass filter, can produce reasonable-looking results if a little bit of ripple in the low-frequency response can be tolerated. See below, which are the results for a nominal 26 watts re 8 ohms of input power.
The dub/reggae bass requirement is a stringent one. You need both bass extension as well as good driver displacement capability to handle lots of low-frequency bass reliably and faithfully. If using an enclosure that will be no larger than 90 litres in size, it seems that quite long vent lengths will be required to tune the enclosure with a vent of sufficient cross-sectional area, in order not to exceed VituixCAD's vent turbulence warning.
Using something like the Hypex FusionAmp Plate Amplifier, either in 2-way or 3-way form, you should be able to achieve good results. If opting for a 2-way system, a 4th-order Linkwitz-Riley low-pass filter with –6dB point at 1.2kHz will provide about 20dB of attenuation by 2kHz, which is about where the cone breakup starts with some 12-inch drivers. A broad EQ dip added to the cone breakup region should control it even further.
This is a correction to my previous Post #28. I inadvertently plotted some simulation results for the FaitalPRO 12PR330 and not the 12FE330. Apologies for my mistake!
The 12FE330, placed in a 90-litre vented enclosure tuned to fb=26Hz, and paired with an f0=31Hz and Q=2.0 peaking 2nd-order high-pass filter, can produce reasonable-looking results. The f3=30Hz, and f6=27.5Hz. See the results below, where a PEQ of −1.6dB at f0=59.5Hz with Q=0.80 has also been applied to remove a slight low-frequency boost. The results correspond to a nominal 45 watts re 8 ohms of input power, with the driver reaching its Xmax at 37.8Hz at that power level. For this design, the vent parameters were Lv=36.9cm, with two vents each 7.5cm in diameter.
Yeah, though they were designed for this and are special double spider thing.
I don't listen to pro level volume (condo here). But it seems not all related to spl and displacment but also to the way the volume of air is exited/compressed : seems there is no remplacement for big Sd ! 🙂 ! But better to have mancave for bigger cabinets 😉
Thank you for the sims and suggestions.
Other than the lighter mms, are there other reasons to like the 12FE330 over the 12RS430?
Other than the lighter mms, are there other reasons to like the 12FE330 over the 12RS430?
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higher QTS, flatter cone, less resonances, less xmax (so less disturbed high), lower BL, ....
This driver is less made to make subbass very loud, and so better suited to play up higher in the frequency range and is so de facto a midwoofer with a low fs and enough xmax to back it up.
The 12RS430 is a way better subwoofer than the 12FE330, but not a midwoofer. It would be a very good bass driver for a 3 way, and i then i would rate it above the 12FE330, but not if you cross it above 400Hz.
This driver is less made to make subbass very loud, and so better suited to play up higher in the frequency range and is so de facto a midwoofer with a low fs and enough xmax to back it up.
The 12RS430 is a way better subwoofer than the 12FE330, but not a midwoofer. It would be a very good bass driver for a 3 way, and i then i would rate it above the 12FE330, but not if you cross it above 400Hz.
I think my original question has been answered. The 3-way/sub idea in small closed boxes is not a good idea, so 2-way it is.
Going through possible drive candidates, there are not too many that fit the bill. The 12FE330 looks good but I can't find any more information or measurements on it. I found the SB Acoustics SB34NRXL75-8 that sims very nice and the Beyma 12BR70 that looks about the same as the Faital.
These measurements show some big peaks in THD around 600hz and I won't be crossing below that.
Thoughts?
Going through possible drive candidates, there are not too many that fit the bill. The 12FE330 looks good but I can't find any more information or measurements on it. I found the SB Acoustics SB34NRXL75-8 that sims very nice and the Beyma 12BR70 that looks about the same as the Faital.
These measurements show some big peaks in THD around 600hz and I won't be crossing below that.
Thoughts?
The Beyma is a good candidate but needs a huge box to go low. I made speaker like that for a friend last summer and it's huge. Tweeter is a Faital HF-201 in a P-sound clone of a JBL 2380A horn, woofer is the Beyma 12BR70 tuned to 30Hz in an MLTL with the crossover (with dsp) at 900Hz 48dB/Oct and some eq. Here we were testing it in the garden of the owner last summer. You could cross that woofer a lot higher if you want, arround 1500Hz is still good behaving. But it needs a big cabinet, bigger than you want. This is over 200L here and is on casters for a good reason.
The SB34NRX78-8 is that not, it's not usable above 500Hz, even with steep filters the resonances are way to fierce. It's more like the Faital 12RS430, a (very good) woofer/subwoofer but not a midwoofer. And it's a big high sensitive midwoofer that you need.
The SB34NRX78-8 is that not, it's not usable above 500Hz, even with steep filters the resonances are way to fierce. It's more like the Faital 12RS430, a (very good) woofer/subwoofer but not a midwoofer. And it's a big high sensitive midwoofer that you need.
I love the box with a thousand buttons 🙂
I've been working on a box for the 12" and decided to go active with a hypex plate amp.
Box is 100 liters so minus the driver, amp, port etc. is will be ~90L. With a bit of dsp'ing it should be able to do 105dB@30hz which is more then enough.
Any comments on bracing or other aspects of the design?
I've been working on a box for the 12" and decided to go active with a hypex plate amp.
Box is 100 liters so minus the driver, amp, port etc. is will be ~90L. With a bit of dsp'ing it should be able to do 105dB@30hz which is more then enough.
Any comments on bracing or other aspects of the design?
Baffle is 34cm, back is 15cm. Full height is 90cm.
I wish I had a good promo talk about how the facetted walls push the internal resonances out of the audible spectrum, but it's just for aesthetic reasons (although I do think it should help reduce resonances 🙂 )
I wish I had a good promo talk about how the facetted walls push the internal resonances out of the audible spectrum, but it's just for aesthetic reasons (although I do think it should help reduce resonances 🙂 )
Hi,
if at all possible, make a simple prototype first and test whether noise from the port is bad or acceptable. If it is bad, you can now move the port to a different location, or change proportions of the box, or do what ever to get rid of it.
The box is tall and modes happen, which tend to leak from the port and might cause coloration to sound. There is plenty of these in the passband since it's two way speaker woofer, on a subwoofer not that big of a deal but on a two way this stuff might be critical. Leak from the port in worst case could be louder than the helmholz resonance itself, making the port redundant, because if you try and dampen the leak with damping material inside the box the lows also disappear and only thing that fixes it is to block the port altogether. Or, move it to a better place. Even small port inlet position movement can affect dramatically the "leak". Worst place is near boundaries, and this is not near so by luck it works fine. If you wanna be sure it works, make it adjustable somehow, prepare to change it's location for example.
The port hsa to be usable, because otherwise you got more bass by sacrificing midrange, which is a bad deal because you could get more bass just by adding another bass box without sacrificing midrange. This is tought process from sound quality perspective, and does not consider cost and complexity which are often important in projects, but this is decided by you.
Have fun with the project!🙂
ps. in general bracing is more effective if you get higher aspect ratio panels. So, a tall box like this is more effecively braced if the braces run the long dimension, vertical. Often practical issues dictate something else, like how you are going to assemble the thing, so just something to keep in mind. Bit unintuitive as brain wants to put the braces by looks, symmetrical and nice and neat 🙂 You can search about this on the forum, or with Google.
if at all possible, make a simple prototype first and test whether noise from the port is bad or acceptable. If it is bad, you can now move the port to a different location, or change proportions of the box, or do what ever to get rid of it.
The box is tall and modes happen, which tend to leak from the port and might cause coloration to sound. There is plenty of these in the passband since it's two way speaker woofer, on a subwoofer not that big of a deal but on a two way this stuff might be critical. Leak from the port in worst case could be louder than the helmholz resonance itself, making the port redundant, because if you try and dampen the leak with damping material inside the box the lows also disappear and only thing that fixes it is to block the port altogether. Or, move it to a better place. Even small port inlet position movement can affect dramatically the "leak". Worst place is near boundaries, and this is not near so by luck it works fine. If you wanna be sure it works, make it adjustable somehow, prepare to change it's location for example.
The port hsa to be usable, because otherwise you got more bass by sacrificing midrange, which is a bad deal because you could get more bass just by adding another bass box without sacrificing midrange. This is tought process from sound quality perspective, and does not consider cost and complexity which are often important in projects, but this is decided by you.
Have fun with the project!🙂
ps. in general bracing is more effective if you get higher aspect ratio panels. So, a tall box like this is more effecively braced if the braces run the long dimension, vertical. Often practical issues dictate something else, like how you are going to assemble the thing, so just something to keep in mind. Bit unintuitive as brain wants to put the braces by looks, symmetrical and nice and neat 🙂 You can search about this on the forum, or with Google.
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Thanks for the valuable information.
I always understood the placement of the port to be arbitrary. I'll do some more research on that topic.
I was/am not sure about the bracing but because the sides are thin, long pieces (90cm long, ~12cm wide) glued together at an angle, I figured it wasn't helpful to add vertical braces, only maybe for the baffle.
I always understood the placement of the port to be arbitrary. I'll do some more research on that topic.
I was/am not sure about the bracing but because the sides are thin, long pieces (90cm long, ~12cm wide) glued together at an angle, I figured it wasn't helpful to add vertical braces, only maybe for the baffle.