Hi,
I'm new to this forum, but definitely smitten by the DIY after making a pair of Troels Gravesen studio 101s.
Now I'm building a subwoofer to extend the frequency of the setup. I have a Volt B2549. I'm thinking to go with the manufacturers specs and make a 100 l ported with a 10 cm ø x 6,5 cm vent. With the internal dimensions of about. 60h x 40,9d x 40,9w cm.
I'm thinking if using 36(?) mm bamboo for the front and 22 mm mdf for the rest, no bracing.
Question is if anyone's got any recommendations or experiences to share, I'll be interested. If not, I'll simply go with the outline as above and post some pics and experiences here.
I'll be using a balanced external amp, so if somebody has some recommendations for a two way active filter under 500€, don't be shy.
Peace, love and happiness, Thor
I'm new to this forum, but definitely smitten by the DIY after making a pair of Troels Gravesen studio 101s.
Now I'm building a subwoofer to extend the frequency of the setup. I have a Volt B2549. I'm thinking to go with the manufacturers specs and make a 100 l ported with a 10 cm ø x 6,5 cm vent. With the internal dimensions of about. 60h x 40,9d x 40,9w cm.
I'm thinking if using 36(?) mm bamboo for the front and 22 mm mdf for the rest, no bracing.
Question is if anyone's got any recommendations or experiences to share, I'll be interested. If not, I'll simply go with the outline as above and post some pics and experiences here.
I'll be using a balanced external amp, so if somebody has some recommendations for a two way active filter under 500€, don't be shy.
Peace, love and happiness, Thor
It's a 100L@18Hz alignment, not bad.
What was the int. volume for the Troels Gravesen studio 101s (13-18L)?
The port was way too small for a good design (driver power). It would need a 9/10cm diameter. Alignments for this would be 13L@47Hz, 18L@40Hz. The 18L (or 22L) would be better to work standalone (no sub) because of less excursion and extension in LF.
If making an appropriate port it will take a lot of internal space but you won't need it with subs probably.
A box shape that has dimensions 60 centimeters by 40.9 centimeters by 40.9 centimeters has a volume of: 100.37 liters/3.5445 cubic feet
A cylindrical shape that has a diameter of 10.5 centimeters and a depth of 65 centimeters has a volume of: 5.6284 liters/0.19876 cubic feet
B2549 (10″) Volume Displaced (Litres): 1.2
(100-7=93)
Using one or two ports (5.7 cm/40 cm length) gives you a good sub speaker tuned low (~18/19Hz).
Xlim Maximum Excursion (mm): @18mm makes the sub work well good to the infras 14Hz (@max power/excursion limit).
F-12 dB 15 Hz
F-24 dB 11 Hz
Nice project.
You would need a power amp 250/300W 8 Ohms (RMS).
Volt B2549 (10″)
ScanSpeak Classic 18W/8542 7"
Troels Studio-101
What was the int. volume for the Troels Gravesen studio 101s (13-18L)?
The port was way too small for a good design (driver power). It would need a 9/10cm diameter. Alignments for this would be 13L@47Hz, 18L@40Hz. The 18L (or 22L) would be better to work standalone (no sub) because of less excursion and extension in LF.
If making an appropriate port it will take a lot of internal space but you won't need it with subs probably.
A box shape that has dimensions 60 centimeters by 40.9 centimeters by 40.9 centimeters has a volume of: 100.37 liters/3.5445 cubic feet
A cylindrical shape that has a diameter of 10.5 centimeters and a depth of 65 centimeters has a volume of: 5.6284 liters/0.19876 cubic feet
B2549 (10″) Volume Displaced (Litres): 1.2
(100-7=93)
Using one or two ports (5.7 cm/40 cm length) gives you a good sub speaker tuned low (~18/19Hz).
Xlim Maximum Excursion (mm): @18mm makes the sub work well good to the infras 14Hz (@max power/excursion limit).
F-12 dB 15 Hz
F-24 dB 11 Hz
Nice project.
You would need a power amp 250/300W 8 Ohms (RMS).Volt B2549 (10″)
ScanSpeak Classic 18W/8542 7"
Troels Studio-101
Attachments
Thanks Inductor!
As for the 101s, I should make a separate thread for it. They're just great. Mine are close to the original specs, about 12-13 litres. Bigger volume and or different ports would make them go deeper for sure, but maybe there would be some sacrifice of the mids, which in mine are pretty good, if I may say so myself ;-) I may do another cabinet for them later though...
Measuring up my ideal sub of 100L I am tempted to reduce to 70L, just so they don´t take over the world. WinISD (don´t laugh) Says that F3 would be around 24 Hz.
Also I like the idea of using smaller ports. A 65 cm port in a 60x40x40 box would mean an angle, and thats maybe less than ideal?
I plan to use a bridged Electrocompaniet AW 60 FFT on the sub, I think that it means around 240w? I usually listen at moderate levels, so I´m not too concerned about loudness.
Hope to start building in a week or two
As for the 101s, I should make a separate thread for it. They're just great. Mine are close to the original specs, about 12-13 litres. Bigger volume and or different ports would make them go deeper for sure, but maybe there would be some sacrifice of the mids, which in mine are pretty good, if I may say so myself ;-) I may do another cabinet for them later though...
Measuring up my ideal sub of 100L I am tempted to reduce to 70L, just so they don´t take over the world. WinISD (don´t laugh) Says that F3 would be around 24 Hz.
Also I like the idea of using smaller ports. A 65 cm port in a 60x40x40 box would mean an angle, and thats maybe less than ideal?
I plan to use a bridged Electrocompaniet AW 60 FFT on the sub, I think that it means around 240w? I usually listen at moderate levels, so I´m not too concerned about loudness.
Hope to start building in a week or two
Ports dimensions for VOLT B2549
Yes, for the 101s, as I said already basically the same thing.
In your case, as sreten said already the speakers between 70-60L makes a very enjoyable sub tuned to between 20 and 23Hz.
In the first case (you asked) 60L@20Hz ports are 9.4 cm x 79.5 cm,
In the case of a 70L@23Hz, 2x ports of 7.4 cm x 58.5 cm. Distance between ports 16 cm.
or 3x ports 5.7 cm x 55.8 cm. Distance between ports 12.5 cm.
Finally, in the case of a (VOLT B2549) VB = 65.0 L, FB = 22.0 Hz
1x port of 9.4 cm x 59 cm.
Yes, for the 101s, as I said already basically the same thing.
In your case, as sreten said already the speakers between 70-60L makes a very enjoyable sub tuned to between 20 and 23Hz.
In the first case (you asked) 60L@20Hz ports are 9.4 cm x 79.5 cm,
In the case of a 70L@23Hz, 2x ports of 7.4 cm x 58.5 cm. Distance between ports 16 cm.
or 3x ports 5.7 cm x 55.8 cm. Distance between ports 12.5 cm.
Finally, in the case of a (VOLT B2549) VB = 65.0 L, FB = 22.0 Hz
1x port of 9.4 cm x 59 cm.
Attachments
Last edited:
Coolio, thanks!
It seems like the 70L box will give the best response below 80hz. I already have a 10 cm port lying around. Hoping to use it for this project. It seems like a length of 49.17 cm will give me a F3 of about 24 Hz. Based on this calculator
Will using an 90 degrees angle on the port in order to reduce box size affect the performance in a big way?
-T
It seems like the 70L box will give the best response below 80hz. I already have a 10 cm port lying around. Hoping to use it for this project. It seems like a length of 49.17 cm will give me a F3 of about 24 Hz. Based on this calculator
Will using an 90 degrees angle on the port in order to reduce box size affect the performance in a big way?
-T
Attachments
Measure the internal diameter in mm to be accurate.
Larger diameter the bigger the length...
Hi,
just chiming in with some pics of the sub, I'm afraid I can't tell you how it sounds as I haven't a proper x-over yet. I have ordered a DBX 223, but wondering if an upgrade to a Marchand Electronics would be worth it....
The materials used are 19mm MDF for top and bottom and 22mm MDF for the sides and finally 40mm Bamboo for the front. I had ALOT of help from a friend CNCing and gluing the parts
All the best!
Thor
just chiming in with some pics of the sub, I'm afraid I can't tell you how it sounds as I haven't a proper x-over yet. I have ordered a DBX 223, but wondering if an upgrade to a Marchand Electronics would be worth it....
The materials used are 19mm MDF for top and bottom and 22mm MDF for the sides and finally 40mm Bamboo for the front. I had ALOT of help from a friend CNCing and gluing the parts
All the best!
Thor
hi,
it is one of my worries. The picture is a test-assembly. I chopped off a bit of the tube before the final assembly, so hopefully it is good....(But the resonance freq ended up higher than I wanted it to be) The perspective on some of the pictures are warped too.
Eventually I might consider a port with smaller diameter and thus shorter length. I simply went with the manufacturers recommendation on port diameter not realizing that the wide diameter equaled such a long tube. Beginners mistake.
Are there any benefits from having a wider tube, as opposed to a narrower or even several narrow ones? Ideally I'd have one or more short ports in the front.
Cheers
-Thor
it is one of my worries. The picture is a test-assembly. I chopped off a bit of the tube before the final assembly, so hopefully it is good....(But the resonance freq ended up higher than I wanted it to be) The perspective on some of the pictures are warped too.
Eventually I might consider a port with smaller diameter and thus shorter length. I simply went with the manufacturers recommendation on port diameter not realizing that the wide diameter equaled such a long tube. Beginners mistake.
Are there any benefits from having a wider tube, as opposed to a narrower or even several narrow ones? Ideally I'd have one or more short ports in the front.
Cheers
-Thor
Ok,
I've had the sub up and running for a couple of weeks now. I'm using a DBX 223 crossover and an Abrahamsen bridged amp. I use my setup for composing and mixing. Adding the sub really helps to make decisions in the lower register, ie drums and synth/bass type sounds.
But there are some issues still. Running a sweep/test tone the responce is good down to about 33-34 hz. In that area there is a bump, and going in tho the 20ies there is no sound, I can just register that the membrane is moving. Im thinking to alter or change the port. The port I use today is 10cm in diameter, but I couldn't really fit the desired length into the box. Duh, beginners mistake...
Also my findings might as well be due to the room form and size. The peak at 33 hz is very present some places and almost not there in other areas if I move around in the room.
My options as far as I can tell is to extend the port with another bend in the bottom. Or I could go with a 7,5 cm diameter port in the front. But then I read that ports should be at least 1/3 as wide as the driver. Any tip's anyone?
I've had the sub up and running for a couple of weeks now. I'm using a DBX 223 crossover and an Abrahamsen bridged amp. I use my setup for composing and mixing. Adding the sub really helps to make decisions in the lower register, ie drums and synth/bass type sounds.
But there are some issues still. Running a sweep/test tone the responce is good down to about 33-34 hz. In that area there is a bump, and going in tho the 20ies there is no sound, I can just register that the membrane is moving. Im thinking to alter or change the port. The port I use today is 10cm in diameter, but I couldn't really fit the desired length into the box. Duh, beginners mistake...
Also my findings might as well be due to the room form and size. The peak at 33 hz is very present some places and almost not there in other areas if I move around in the room.
My options as far as I can tell is to extend the port with another bend in the bottom. Or I could go with a 7,5 cm diameter port in the front. But then I read that ports should be at least 1/3 as wide as the driver. Any tip's anyone?
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