Hello everyone!
Introduction (feel free to skip):
I have just spent the last 2 weeks non-stop reading on various amazing foam board/XPS projects created by xkr971, built both the 0.4x and 0.53x Karlsonators with TC9FD and built Nautaloss II Reference Monitors. Many thanks to all who contributed too! They are all awesome, but I really like the Nautaloss the most and I plan to rebuild them into a more interesting shape - S shaped. I have been also experimenting with the DML speakers which seem to be a very good way how to support my electronic piano. As neither Nautaloss nor DML go low enough, I would like to build some sub to support the low end and run it in the FAST system. Atm. I run the 0.53x Karlsonator as a sub which is sub-optimal.
This slot loaded band pass sub looks very good! And I would like to give it a try as it offers smooth response up to 200 Hz, unlike tapped horns I tried to experiment with. Unfortunately, the mcm 55-2421 is not available in Europe and it would be a bit too much anyway. I would like to keep a lower form factor. Atm. I have the Tang Band W6-1139 and W5-1138 in my disposal and I would like to test if they could work in this sub. I also have set of 4 6.5” Poly Woofers for the 6 USD, but they are not suitable for this design.
Question:
I tried to load the script to Akabak (version 317b91), but I cannot get it running. I guess it is meant for the old legacy Akabak 2.xx version? Did perhaps someone try to run it in the new version and has the project/script available and could provide it? Do you possibly have an experience with Tang Band W6-1139 and W5-1138 drivers in this sub design? I am a Newbie in Akabak and so any help would be appreciated! Any other recommendations for suitable woofers and designs are also welcome.
Introduction (feel free to skip):
I have just spent the last 2 weeks non-stop reading on various amazing foam board/XPS projects created by xkr971, built both the 0.4x and 0.53x Karlsonators with TC9FD and built Nautaloss II Reference Monitors. Many thanks to all who contributed too! They are all awesome, but I really like the Nautaloss the most and I plan to rebuild them into a more interesting shape - S shaped. I have been also experimenting with the DML speakers which seem to be a very good way how to support my electronic piano. As neither Nautaloss nor DML go low enough, I would like to build some sub to support the low end and run it in the FAST system. Atm. I run the 0.53x Karlsonator as a sub which is sub-optimal.
This slot loaded band pass sub looks very good! And I would like to give it a try as it offers smooth response up to 200 Hz, unlike tapped horns I tried to experiment with. Unfortunately, the mcm 55-2421 is not available in Europe and it would be a bit too much anyway. I would like to keep a lower form factor. Atm. I have the Tang Band W6-1139 and W5-1138 in my disposal and I would like to test if they could work in this sub. I also have set of 4 6.5” Poly Woofers for the 6 USD, but they are not suitable for this design.
Question:
I tried to load the script to Akabak (version 317b91), but I cannot get it running. I guess it is meant for the old legacy Akabak 2.xx version? Did perhaps someone try to run it in the new version and has the project/script available and could provide it? Do you possibly have an experience with Tang Band W6-1139 and W5-1138 drivers in this sub design? I am a Newbie in Akabak and so any help would be appreciated! Any other recommendations for suitable woofers and designs are also welcome.
I use legacy Akabak and it requires an old 32 bit computer. My virtual machine on Win 10 died and so no access to Akabak at the moment.
You might be able to simulate this is HornResp also. I have not used the new Akabak but it should be backwards compatible. You might ask in the Akabak thread.
I have not tried the TB drivers you ask about - I have other larger 10in designs using cad audio Alpine subwoofers that are proven.
https://www.diyaudio.com/community/threads/pp-slot-loaded-sub-with-alpine-swr-12d2.264737/
You might also look into the XKi subwoofer that has great upper mids reach.
https://www.diyaudio.com/community/...tio-karlson-6th-order-bandpass.268524/page-66
You might be able to simulate this is HornResp also. I have not used the new Akabak but it should be backwards compatible. You might ask in the Akabak thread.
I have not tried the TB drivers you ask about - I have other larger 10in designs using cad audio Alpine subwoofers that are proven.
https://www.diyaudio.com/community/threads/pp-slot-loaded-sub-with-alpine-swr-12d2.264737/
You might also look into the XKi subwoofer that has great upper mids reach.
https://www.diyaudio.com/community/...tio-karlson-6th-order-bandpass.268524/page-66
Hello Xrk, and thank you for the answer. Unfortunately, I do not have any 32-bit machine in my disposal and I could not figure out how to run the scripts in the 3.x version.
On the other hand, I managed to simulate the TB W5-1138 in Hornresp using the tapped horn model with a vented front chamber. The first horn segment is set to 0.1 cm (min allowed) with the second and third set both to 10 cm. The chamber size is 7 l and the went is 16x1.5 cm2, 58 cm long (if I fit it to the box). My idea was to have the box as tall as possible with the smallest form factor.
The results look quite nice for such a small driver - corner loaded at 1W. However, there are some significant spikes higher up. Could these be a real problem or are these just features of Hornresp? There are no filters applied, but the sub certainly needs HP around 35 hz and LP around max 150 Hz.
As I understand it, adding the second driver in the pull configuration reduces THD and increases the output. Does it have some more advantages? It seems to be a bit of an overkill to add a second driver for low listening levels.
I also found your post #74 with Push-Pull ML-TransFlex design and it looks very interesting.
Have you tried to build the sub or do you at least have some sketch?
What does the extended length of the chamber to support the 1/4-wave action improve?
What were the approximate dimensions of the duct?
On the other hand, I managed to simulate the TB W5-1138 in Hornresp using the tapped horn model with a vented front chamber. The first horn segment is set to 0.1 cm (min allowed) with the second and third set both to 10 cm. The chamber size is 7 l and the went is 16x1.5 cm2, 58 cm long (if I fit it to the box). My idea was to have the box as tall as possible with the smallest form factor.
The results look quite nice for such a small driver - corner loaded at 1W. However, there are some significant spikes higher up. Could these be a real problem or are these just features of Hornresp? There are no filters applied, but the sub certainly needs HP around 35 hz and LP around max 150 Hz.
As I understand it, adding the second driver in the pull configuration reduces THD and increases the output. Does it have some more advantages? It seems to be a bit of an overkill to add a second driver for low listening levels.
I also found your post #74 with Push-Pull ML-TransFlex design and it looks very interesting.
Have you tried to build the sub or do you at least have some sketch?
What does the extended length of the chamber to support the 1/4-wave action improve?
What were the approximate dimensions of the duct?
Those peaks are part of the design optimization and you want to move them high so your low pass filter can catch them. That’s what the stub on the trans flex is for. It absorbs that peak somewhat. I have not built that - it’s MMJ’s design so you might ask him.
Opposing dual drivers cancel vibration too and double air movement. Bass is all about air - check cone excursion for SPL you need. If not high one can work of course especially of corner loaded in a room.
Opposing dual drivers cancel vibration too and double air movement. Bass is all about air - check cone excursion for SPL you need. If not high one can work of course especially of corner loaded in a room.
Thank you for the answer again. I just found out that the sharp peaks were port resonances so increasing the volume to 8l and shortening the port shifted the peaks higher up. Enlarging the slot then broadened the peaks so they are less prominent. Here is 4th order HP at 33 Hz and 4th order LP at 140 which should be OK with Nautaloss II.
The maximum SPL is very clear and thanks for the clarification with the vibrations. I suppose a proper, heavy construction would decrease the vibrations too. Please, correct me if wrong.
What do you mean by “the stub on the trans flex”? Is it the black brick on the thin part of the port?
Stub is a 1/4 wave snubber much like a 50ohm terminator on an electrical coax cable. If you have say a 300Hz peak, calculate the 1/4 wave length and make closed end channel of that length heavily stuffed with glass wool etc. it will absorb some of the peak. I am not sure what you are referring to as the brick in the diagram, sounds like the 1/4 wave stub above the vent. Your sim looks good - yes short ports are better than long ones. But short ones tend to be smaller so watch for max velocity in the port and keep below 15 m/sec.
Thank you for the clarification! I just found you mentioning it in another topic. I may try to incorporate the stub in the design. I am getting velocities at 22 m/s at full power, which is less than ideal. Increasing the port area moves the resonance even lower and so having the stub may be the way to go. If it does not work, making the full, double-speaker version and running each part with a lower power will solve the problem.