Hi everyone,
At this early point I'm just trying to get feedback on a simple & easy [for me] to build Fullrange And Subwoofer Technology enclosure.
I have read through Dave's [Plant10] Tysen thread with interest and have seen a few other FAST designs posted here. Sitting here listening to the FH3 with A7.3, I find them to be beautiful sounding speaker and quite suitable for ~75% of the music I listen to. However, not suitable for all.
The FAST idea looks like a good way to go for me, and should provide the extra depth I'm after while keeping the things I now love about full range drivers.
I used WinISD and AJSealed, with each drivers T/S and a system Q of 0.707, both programs gave the same volumes for their sealed enclosure.
Fullrange: Mark Audio Alpair 7.3 = 6.4L f3 = 93Hz
Woofer: Scan Speak 26W8534 G00 = 70.61L f3 = 41Hz f10 = 23.5Hz
Hope to be using active XO [possibly miniSharc] , feeding 4 mono amps.
I like the size of the FH3 and a similar footprint would fit the room nicely.
First box: I stuck close to the Golden Ratio box dimensions WinISD suggested, but added the volume of the A7's enclosure to the 26W's volume. Allowing for a sealed box within the main box and giving slightly smaller outer profile.
HxWxD: outer dimensions are (986 x 236 x 449)mm based on 18mm board thickness.
I downloaded Sketchup this morning and put together a quick image based on the box dimensions...
All thoughts and comments welcome.
At this early point I'm just trying to get feedback on a simple & easy [for me] to build Fullrange And Subwoofer Technology enclosure.
I have read through Dave's [Plant10] Tysen thread with interest and have seen a few other FAST designs posted here. Sitting here listening to the FH3 with A7.3, I find them to be beautiful sounding speaker and quite suitable for ~75% of the music I listen to. However, not suitable for all.
The FAST idea looks like a good way to go for me, and should provide the extra depth I'm after while keeping the things I now love about full range drivers.
I used WinISD and AJSealed, with each drivers T/S and a system Q of 0.707, both programs gave the same volumes for their sealed enclosure.
Fullrange: Mark Audio Alpair 7.3 = 6.4L f3 = 93Hz
Woofer: Scan Speak 26W8534 G00 = 70.61L f3 = 41Hz f10 = 23.5Hz
Hope to be using active XO [possibly miniSharc] , feeding 4 mono amps.
I like the size of the FH3 and a similar footprint would fit the room nicely.
First box: I stuck close to the Golden Ratio box dimensions WinISD suggested, but added the volume of the A7's enclosure to the 26W's volume. Allowing for a sealed box within the main box and giving slightly smaller outer profile.
HxWxD: outer dimensions are (986 x 236 x 449)mm based on 18mm board thickness.
I downloaded Sketchup this morning and put together a quick image based on the box dimensions...
All thoughts and comments welcome.
Attachments
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Second Enclosure
Second box: Again close to the optimal box size recommended, but the smaller enclosure isn't contained within the volume of the woofer enclosure. Over all, a slightly deeper enclosure but it'd still fit in the space available.
HxWxD: (994 x 236 x 505)mm
Not sure which to use, or if both would be as usable as each other as far as the basic design goes. Also intend to add bracing and fill...
Paul
Second box: Again close to the optimal box size recommended, but the smaller enclosure isn't contained within the volume of the woofer enclosure. Over all, a slightly deeper enclosure but it'd still fit in the space available.
HxWxD: (994 x 236 x 505)mm
Not sure which to use, or if both would be as usable as each other as far as the basic design goes. Also intend to add bracing and fill...
Paul
Attachments
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Hi Paul.
I have a little bit of advice. If doing a side woofer like that, I'd cross quite low. Typical FASTs cross at the baffle step F3, but in this case there are two different baffle step points. The side baffle is quite large and the baffle step point will be very low. Because of this, I'd cross where the woofer remains radiant in full space. Likely less than 100hz.
Also, plan on pushing them up against the back wall to keep the woofer distance to wall within 1/4 max wavelength. So of crossing at 80hz, that'll mean less than a meter or what ever the length is. Half a meter would be even better. This raises some issues with the full ranger though. It'll have a weak range of about 100hz to 500hz. Thankfully your dsp can take care of that if needed. The other is that a slightly higher XO might be woofer for the A7. At least its not an A6 or FF85 or something that should be crossed higher.
I have a little bit of advice. If doing a side woofer like that, I'd cross quite low. Typical FASTs cross at the baffle step F3, but in this case there are two different baffle step points. The side baffle is quite large and the baffle step point will be very low. Because of this, I'd cross where the woofer remains radiant in full space. Likely less than 100hz.
Also, plan on pushing them up against the back wall to keep the woofer distance to wall within 1/4 max wavelength. So of crossing at 80hz, that'll mean less than a meter or what ever the length is. Half a meter would be even better. This raises some issues with the full ranger though. It'll have a weak range of about 100hz to 500hz. Thankfully your dsp can take care of that if needed. The other is that a slightly higher XO might be woofer for the A7. At least its not an A6 or FF85 or something that should be crossed higher.
#2 works better for me if only because of an assumed deeper response from the full range driver which would enable you to blend in the woofer at a lower point.
Thank you for the great feedback ... a new area for me to look at and for messing about with numbers.
I'd like to keep the side placement of the woofer, so adjustments to baffle width can be made. However, probably not to a point where the respective f3 can be matched, so the goal would be to minimise the difference. Currently f3's are roughly 490Hz and 255Hz
On both boxes, the woofer baffle free air radiance is around ~94Hz. So if I XO at this point, I'd need to either compensate the fullrange driver with the DSP or design the FR enclosure to help. Even if I go with a higher XO, I'd still need to utilise the DSP and/or better FR enclosure design to better integrate the two drivers.
Though, placing both drivers on the same baffle would make integration easier?
Lots to think on. Thanks
Paul.
I'd like to keep the side placement of the woofer, so adjustments to baffle width can be made. However, probably not to a point where the respective f3 can be matched, so the goal would be to minimise the difference. Currently f3's are roughly 490Hz and 255Hz
On both boxes, the woofer baffle free air radiance is around ~94Hz. So if I XO at this point, I'd need to either compensate the fullrange driver with the DSP or design the FR enclosure to help. Even if I go with a higher XO, I'd still need to utilise the DSP and/or better FR enclosure design to better integrate the two drivers.
Though, placing both drivers on the same baffle would make integration easier?
Lots to think on. Thanks
Paul.
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Hi,
FWIW tapered enclosures (or rooms) aren't as non resonant
as some believe, as simple reflection gets you to back to to
a rectilinear shape. However you can vary the stuffing density
along a tapered rear enclosure, which can help the rearwave.
rgds, sreten.
FWIW tapered enclosures (or rooms) aren't as non resonant
as some believe, as simple reflection gets you to back to to
a rectilinear shape. However you can vary the stuffing density
along a tapered rear enclosure, which can help the rearwave.
rgds, sreten.
Will the full range driver produce enough low frequencies in its enclousure to meet the subwoofer? I have not seen any sims to know if this will work well.
Thank you Dave 🙂
Utilising 18mm board, outer dimensions (H,W,D)cm = 101.9, 23.6, 43.6 ... This would sit nicely in the space available and the FR driver would be at ear height when seated.
Internal FR enclosure dimensions (W,D)cm = 20, 40, Height = 15cm tapering down to 1cm or could make it 16cm down to 0cm ...
Paul
Utilising 18mm board, outer dimensions (H,W,D)cm = 101.9, 23.6, 43.6 ... This would sit nicely in the space available and the FR driver would be at ear height when seated.
Internal FR enclosure dimensions (W,D)cm = 20, 40, Height = 15cm tapering down to 1cm or could make it 16cm down to 0cm ...
Paul
Hi Godzilla,
Let me see if I get this bit right [can post pic' from WinISD in the morning]...
WinISD plots the FR enclosure's f3 at ~93Hz, manually working out the baffle's f3 is 490Hz. For the Woofer baffle, f3 is 266Hz and upper point of free air radiance is ~96Hz. If I do the XO at 95Hz & with a quick layman's working out, the FR driver should be about 6db down at the XO point, 3dB down at 150hz, level by 490Hz and then gaining 3dB above that. Real world will no bought be very different & my maths very wrong 🙂
Paul
Let me see if I get this bit right [can post pic' from WinISD in the morning]...
WinISD plots the FR enclosure's f3 at ~93Hz, manually working out the baffle's f3 is 490Hz. For the Woofer baffle, f3 is 266Hz and upper point of free air radiance is ~96Hz. If I do the XO at 95Hz & with a quick layman's working out, the FR driver should be about 6db down at the XO point, 3dB down at 150hz, level by 490Hz and then gaining 3dB above that. Real world will no bought be very different & my maths very wrong 🙂
Paul
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WinISD plot for A7.3 in a sealed 6.41L enclosure, f3 marked ... Response is near identical down to a 5L sealed box.
Could start playing with a vented enclosure for the full range driver, and tuning it to provide a boost at the XO point. Or, move both drivers onto the same baffle with a slightly higher XO. hmm ...
Paul
Could start playing with a vented enclosure for the full range driver, and tuning it to provide a boost at the XO point. Or, move both drivers onto the same baffle with a slightly higher XO. hmm ...
Paul
Attachments
It appears your design will work.
I found blending ported enclosures with subs doesn't sound as good as sealed. Are you using a sub amp to power the woofer?
I found blending ported enclosures with subs doesn't sound as good as sealed. Are you using a sub amp to power the woofer?
Sealed it is, and an easy looking build to 🙂
I'll be using a 'The Wire' Class A/AB Power Amp, which can be from 1Watt to 400Watt dependant on power supply.
The woofer is an 8Ohm, 89dB 2.83V/1m, 70/150Watt. Will be two in a small room and would like to EQ for ~90dB peak SPL at the listening position. So was thinking something like 15dB gain would be enough to recover any losses and have an extra ~9dB to play with during EQ.
I'm not after excess, just enough to do the job 🙂
Paul
I'll be using a 'The Wire' Class A/AB Power Amp, which can be from 1Watt to 400Watt dependant on power supply.
The woofer is an 8Ohm, 89dB 2.83V/1m, 70/150Watt. Will be two in a small room and would like to EQ for ~90dB peak SPL at the listening position. So was thinking something like 15dB gain would be enough to recover any losses and have an extra ~9dB to play with during EQ.
I'm not after excess, just enough to do the job 🙂
Paul