Thanks a bunch just a guy, looks like im ready to build!
Tested the amp powering it over a cheap pc power supply and sub sounds way better free air than it did when i just plugged it in some random stereo speaker outputs with high and low pass filters EQed in. I guess without enough amps to back it up everything will sound bad! I did keep it quiet since its just a "8 amp 12v rail" at best but oh boy it got me pumped. It might sound like something i tell ya.
About the port, ill try to find something easiest to make which would be a pipe but here closest i can find is a tin metal 150mm diameter pipe made for wood stove chimneys, id have to reinforce it somehow to stop it from vibrating and ringing but i dont think that would be a problem. Its diameter however...
Thats gives area of about 176.715 cm2 which is a bit short than your recommendation. There are 160mm diameter pvc pipes everywhere used for toilet plumbing and its really cheap as well but that would give an area of 201.062 cm2 which is even more than your four 3 inch port solution. Unless there is an easy solution around this like making it longer or shorter i will build a slotted port. More work but if that is what it takes thats the least i can do for you guys out of respect.
Small question, port has to have its own volume? What i mean is if my port has a volume of lets say 10 liters would that make the box 240 liter?
if that is the case i would need to build the port on the outside?
It wont be a major issue im just asking.
About the software High pass, i can easily make curves steep as much as i want or a nice slow slope, as i understand the program just cuts the sound on digital level and it doesnt even exit the DAC/AMP if eq under certain threshold - tested on sub 20hz and it worked.
Here is a GREATLY over exaggerated example of what someone could do,
sharp as a knife or soft as a pillow. on the low side we see the high pass in the middle we see i can go funky and make it look like a wave easily and on the higher side lets imagine my headphones have a ear killing peaks at 5, 7 and 10 kHz so i tame it.
About the low pass on my eq, that isnt possible because my DAC/AMP only has 1 stereo output so even though software allows to configure every singe speaker im able to connect to it and to a custom eq on it just as detailed as this one; im short on the hardware side so i will be running my standard stereo speakers along this sub im building to give it bass where this thing has not. Im happy with its mids and highs honestly and that is coming from a guy that doesnt find highs on superlux hd668b too rough.
But we all know audio. It will never stop. Ill just think of something else when im in a better monetary situation.
This thing will be so ghetto ill be proud of it.
In the end it is getting powered by a $30 led strip power supply thats rated 480W 12V@40A
Making it frugal just makes it so much more enjoyable for me you know?
If my mentioned port issue can be sorted by gluing sponge on every inner wall of the enclosure or something easly like that let me know please!
Thank you again just a guy!
Tested the amp powering it over a cheap pc power supply and sub sounds way better free air than it did when i just plugged it in some random stereo speaker outputs with high and low pass filters EQed in. I guess without enough amps to back it up everything will sound bad! I did keep it quiet since its just a "8 amp 12v rail" at best but oh boy it got me pumped. It might sound like something i tell ya.
About the port, ill try to find something easiest to make which would be a pipe but here closest i can find is a tin metal 150mm diameter pipe made for wood stove chimneys, id have to reinforce it somehow to stop it from vibrating and ringing but i dont think that would be a problem. Its diameter however...
Thats gives area of about 176.715 cm2 which is a bit short than your recommendation. There are 160mm diameter pvc pipes everywhere used for toilet plumbing and its really cheap as well but that would give an area of 201.062 cm2 which is even more than your four 3 inch port solution. Unless there is an easy solution around this like making it longer or shorter i will build a slotted port. More work but if that is what it takes thats the least i can do for you guys out of respect.
Small question, port has to have its own volume? What i mean is if my port has a volume of lets say 10 liters would that make the box 240 liter?
if that is the case i would need to build the port on the outside?
It wont be a major issue im just asking.
About the software High pass, i can easily make curves steep as much as i want or a nice slow slope, as i understand the program just cuts the sound on digital level and it doesnt even exit the DAC/AMP if eq under certain threshold - tested on sub 20hz and it worked.
Here is a GREATLY over exaggerated example of what someone could do,
sharp as a knife or soft as a pillow. on the low side we see the high pass in the middle we see i can go funky and make it look like a wave easily and on the higher side lets imagine my headphones have a ear killing peaks at 5, 7 and 10 kHz so i tame it.
About the low pass on my eq, that isnt possible because my DAC/AMP only has 1 stereo output so even though software allows to configure every singe speaker im able to connect to it and to a custom eq on it just as detailed as this one; im short on the hardware side so i will be running my standard stereo speakers along this sub im building to give it bass where this thing has not. Im happy with its mids and highs honestly and that is coming from a guy that doesnt find highs on superlux hd668b too rough.
But we all know audio. It will never stop. Ill just think of something else when im in a better monetary situation.
This thing will be so ghetto ill be proud of it.
In the end it is getting powered by a $30 led strip power supply thats rated 480W 12V@40A
Making it frugal just makes it so much more enjoyable for me you know?
If my mentioned port issue can be sorted by gluing sponge on every inner wall of the enclosure or something easly like that let me know please!
Thank you again just a guy!
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Talking about multiple ports i found some interesting info you might like!
I do not know if you incorporated it into your calculation but if not it might be something we both learn today!
Also i forgot to comment about me liking boomy bass. I thought that high bass we hear in wallmart and cheap tiny sub boxes tuned only to be loud are boomy. I do listen to strong bass oriented music but i usually EQ 80-120Hz down and from 80-20Hz gradualy EQ up (talking about my headphones here, current speakers can only dream of 40Hz let alone 20). So i dont know maybe i do like boomy bass if thats what it is. My analysis show songs i like hang from 22 to 40Hz and dip into 80s only in bassline variations.
Not too proud to share what my main music taste is like since i also listen to other genres but
give your system this a listen https://soundcloud.com/korosu/lurk#t=2:20
A minute will be enough and you will get the idea of what i mean. Deep strong bass that occasionally slides into mid and high bass but is mainly situated down low.
Not a perfect example but it will do, i find pitched percussion in that genre more than kicks
but bassline has to be there.
Cheers man, wish we were closer so i could buy you a beer or a whole case!
I do not know if you incorporated it into your calculation but if not it might be something we both learn today!
Also i forgot to comment about me liking boomy bass. I thought that high bass we hear in wallmart and cheap tiny sub boxes tuned only to be loud are boomy. I do listen to strong bass oriented music but i usually EQ 80-120Hz down and from 80-20Hz gradualy EQ up (talking about my headphones here, current speakers can only dream of 40Hz let alone 20). So i dont know maybe i do like boomy bass if thats what it is. My analysis show songs i like hang from 22 to 40Hz and dip into 80s only in bassline variations.
Not too proud to share what my main music taste is like since i also listen to other genres but
give your system this a listen https://soundcloud.com/korosu/lurk#t=2:20
A minute will be enough and you will get the idea of what i mean. Deep strong bass that occasionally slides into mid and high bass but is mainly situated down low.
Not a perfect example but it will do, i find pitched percussion in that genre more than kicks
but bassline has to be there.
Cheers man, wish we were closer so i could buy you a beer or a whole case!
No, I don't like that at all. It's incorrect. It's very wrong. If you follow those guidelines you will end up with a MUCH lower tuning than expected, and if you put the multiple ports in the corners of the boxes like the example then the tuning will be even lower than if the ports were clustered in the center.
A quick search shows that info came from here - Port Design
- but it's been copied and pasted to other places on the internet.
This is garbage, you should pay it no attention and ideally it should be wiped off the face of the internet.
Yes, that's exactly what I thought you were listening to. And I think you want the low bass to be much heavier than the higher bass. In that case, this cheap woofer in a huge box should work out pretty well for you.
3 and 6 inch pipes come from a variety of sources and you should be able to find them locally. PVC or ABS is fine. 176 sq cm is only 4 sq cm less than the 180 I spec'ed, this will make no practical difference.
Also, later today I'll run the sim using your PEQ instead of the amp's 40 hz high pass filter to protect the driver below tuning. That will be a bit better use of what you have available.
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Hah okay, sorry then.
So glad to hear that.
Here in europe i might find 1/4, 1/2, 3/4 and 1 inch things, everything else is metric. Ive searched for 152mm as well but closest thing to 6 inch is dn150 standard which i cant find any of in my country. 160mm plastic for toilet plumbing or 150mm 1mm tin tube for chimney will have to do unless i decide to get fancy with slot port with space i have beneath the port shown in my short video below.
Here is how im planning it right now in my mind so let me know if you see any major flaws.
https://streamable.com/bvo7
btw that port is hilarious, almost as wide as it is long.
Ran out of time to edit unfortunately so here it goes copy paste:
edit: Just googled some more, it would be 5 times cheaper to go with 160mm pvc pipe than 150 tin one, let alone how much easier it would be to glue it and cut it. I did some noob calculations on some port calc site app and it tells me my 160mm diameter port would have to be 8.94 inches or 22.71 centimeters long. Is that correct? I dont know which parameters you used so with this calc i guessed 26.5Hz tuning frequency, inputed 250 liters for enclosure and of course put 6.3 inches for port diameter (160mm).
If it is even possible to do it with 160mm please let me know, im sure there is more to it than just its proportions so i dont know if it is even possible but it would be A LOT easier and cheaper.
160 mm diameter tube is fine, if my calculations are correct that's about 201 sq cm.
It's a bit odd to have an empty chamber below the box that the port fires into but if you want to do that, it's fine. It will be a bandpass chamber but the effect is likely way too high in frequency to worry about for a subwoofer so I've neglected it in the sim.
These sims show a variety of different situations, a couple of different filters and a couple of different tunings.
All sims shown at 250 watts.
Image 1 - hornresp inputs
2 - t/s parameters (make sure I didn't make any mistakes or change anything since I started)
3 - schematic drawing - the port should be simulated inside the enclosure with volume subtracted but that would require different software and it hardly matters
4 - frequency response with a 20 cm port and 40 hz 12 db/oct high pass
5 - displacement with 20 cm port and 40 hz 12 db/oct high pass
(velocity for this port length and high pass is low, maybe 12 m/s IIRC)
6 - frequency response with a 20 cm port and 20 hz 24 db/oct high pass
7 - displacement with a 20 cm port and 20 hz 24 db/oct high pass
(this high pass would have to be done with your parametric eq, velocity for this high pass is high, maybe 27 m/s IIRC)
8 - frequency response with a 40 cm port and 17 hz 24 db/oct high pass
9 - displacement with a 40 cm port and 17 hz 24 db/oct high pass
(this high pass would have to be done with your parametric eq, velocity with this high pass is moderate/high at about 22 m/s IIRC)
This shows that port length isn't that critical - the difference between a 20 and 40 cm port length drops tuning from about 27 hz to 21 hz and the bump in response shifts a bit lower in frequency and smooths out a bit in amplitude (a few less db) with the lower tuning. BUT the lower tuning comes at the expense of higher excursion for the same output level.
This also shows that you can control the bump in response with a high pass filter or with eq - but with the type of music you listen to you might enjoy a really fat bass line. Personally I like a bit of a bump at the lowest frequencies especially with this type of electronic music. It will sound different in different rooms, room modes may be as strong as +/- 15 db and could occur at any frequency in the subwoofer passband so it's hard to say what response to target and what you will prefer.
It's easy to do the high pass as shown with the parametric eq. Just use the eq to cut the DIFFERENCE between the blue line and red line in the frequency response graphs shown.
This gives a pretty good idea of what different port lengths are going to do, what different filters are going to do, and what velocity will be like for these situations.
After this if you have any general questions I will answer them but for the most part I'm done with this. You really should download a simulator and play with it. I recommend Hornresp but most people start out with WinISD.
It's a bit odd to have an empty chamber below the box that the port fires into but if you want to do that, it's fine. It will be a bandpass chamber but the effect is likely way too high in frequency to worry about for a subwoofer so I've neglected it in the sim.
These sims show a variety of different situations, a couple of different filters and a couple of different tunings.
All sims shown at 250 watts.
Image 1 - hornresp inputs
2 - t/s parameters (make sure I didn't make any mistakes or change anything since I started)
3 - schematic drawing - the port should be simulated inside the enclosure with volume subtracted but that would require different software and it hardly matters
4 - frequency response with a 20 cm port and 40 hz 12 db/oct high pass
5 - displacement with 20 cm port and 40 hz 12 db/oct high pass
(velocity for this port length and high pass is low, maybe 12 m/s IIRC)
6 - frequency response with a 20 cm port and 20 hz 24 db/oct high pass
7 - displacement with a 20 cm port and 20 hz 24 db/oct high pass
(this high pass would have to be done with your parametric eq, velocity for this high pass is high, maybe 27 m/s IIRC)
8 - frequency response with a 40 cm port and 17 hz 24 db/oct high pass
9 - displacement with a 40 cm port and 17 hz 24 db/oct high pass
(this high pass would have to be done with your parametric eq, velocity with this high pass is moderate/high at about 22 m/s IIRC)
This shows that port length isn't that critical - the difference between a 20 and 40 cm port length drops tuning from about 27 hz to 21 hz and the bump in response shifts a bit lower in frequency and smooths out a bit in amplitude (a few less db) with the lower tuning. BUT the lower tuning comes at the expense of higher excursion for the same output level.
This also shows that you can control the bump in response with a high pass filter or with eq - but with the type of music you listen to you might enjoy a really fat bass line. Personally I like a bit of a bump at the lowest frequencies especially with this type of electronic music. It will sound different in different rooms, room modes may be as strong as +/- 15 db and could occur at any frequency in the subwoofer passband so it's hard to say what response to target and what you will prefer.
It's easy to do the high pass as shown with the parametric eq. Just use the eq to cut the DIFFERENCE between the blue line and red line in the frequency response graphs shown.
This gives a pretty good idea of what different port lengths are going to do, what different filters are going to do, and what velocity will be like for these situations.
After this if you have any general questions I will answer them but for the most part I'm done with this. You really should download a simulator and play with it. I recommend Hornresp but most people start out with WinISD.
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Thanks a bunch dude!
If you believe there could be any kind of anomalies with port firing down i will change the design and make port fire forward as shown:
if not then i can play with a longer port since i have plenty room in that axis.
I like the graphs you provided very much and before cutting the tube to final i will experiment with various lengths first since 40cm ports simulation looks very interesting down low.
Nothing is 100% untill we hear it right?
If you believe there could be any kind of anomalies with port firing down i will change the design and make port fire forward as shown:
if not then i can play with a longer port since i have plenty room in that axis.
I like the graphs you provided very much and before cutting the tube to final i will experiment with various lengths first since 40cm ports simulation looks very interesting down low.
Nothing is 100% untill we hear it right?
The bottom firing port should be just fine, it's just a little odd.
You can experiment with port lengths even longer than 40 cm if you want, tuning will continue to go down and the response hump will continue to get smaller as port length increases. But it will cost you max spl, as the lower tuning uses up your available excursion faster. And of course the lower tuning would need a different filter setting to protect the driver and let through as much power above tuning as possible.
You can experiment with port lengths even longer than 40 cm if you want, tuning will continue to go down and the response hump will continue to get smaller as port length increases. But it will cost you max spl, as the lower tuning uses up your available excursion faster. And of course the lower tuning would need a different filter setting to protect the driver and let through as much power above tuning as possible.
Hi goa604,
where are you from? Don't use tin pipes that are designed for chimneys as they are too thin and might rattle. You can find pvc pipes used for drains from 10 cm in diameter up to 25 or more cm in stores like jax, bauhaus, or any other store that sells building materials. I like low powerful bass too, and just recently built sub for a car with 4 alpine type r that destroys in low 20s.
where are you from? Don't use tin pipes that are designed for chimneys as they are too thin and might rattle. You can find pvc pipes used for drains from 10 cm in diameter up to 25 or more cm in stores like jax, bauhaus, or any other store that sells building materials. I like low powerful bass too, and just recently built sub for a car with 4 alpine type r that destroys in low 20s.
hey IceTorch! Sorry for the late reply but yes i will definitely use some kind of pvc pipe made for toilet plumbing, i also think tin chimney ones will rattle.
There is a 160mm standard and i believe i will use those. Im from Zagreb btw, you? Where can i see your alpine build? Low bass is best bass
There is a 160mm standard and i believe i will use those. Im from Zagreb btw, you? Where can i see your alpine build? Low bass is best bass
I'm from Rijeka. Sadly I don't record and upload stuff I make, just not that kind of person, so you can only see it in person, and honestly it's not much to see. It was made as a test box just to see what it will sound like and if I actually want 4 alpines in my car, and if I recorded it you will hear rattle and distortion and see whole car vibrating and there is a lot videos of just that on youtube. But in person it's kinda awesome, clear powerful low bass but I'm still not sure if it's worth destroying whole car just to have that much bass...
This thread took a turn for the better over the last handful of posts
I promise imma make it a bit better when i start the build, something unexpected ate a huge portion of my wallet so i will have to wait a tiny bit for now. I already got the audio splitter cable, preamp, amp, 4 side pieces for the box, now i just need a tiny bit more for front and back 32mm thick mdf pieces, one of them with sub cutout. Some minor things like silicone sealant i already bought, speaker wires imma make myself from magnet wire and only thing thats left to buy are screws. Ill use scrap material i got left from front and back panels to cut it into triangles and make that whole thing sturdier, including bracing for those 4 sides i already got to reduce vibration.
Pvc pipe i found is 160mm in diameter and 500mm long so i will start experimenting with port lenght before i cut it to calculated 222mm, i wont seal it with silicone right away since there will be changes but i will think of something with a putty or something stupid like that.
Big thanks to all.
Small update. Ordered front and back panels couple of days ago but they have legal right to deliver them up to 15 work days so thats gonna probably take a while.
In the mean time i decided to take another cabinet and re-purpose it
for this kind of thing because panels in those dimensions i showed earlier were in the neighborhood of $150, these are about 65 cutting included.
While waiting for the most important panels i decided to build some basic bracing inside, It is all glued first then screwed after the glue has hardened a bit so i dont get any squeaky noises. there is still one horizontal one to install but i will do that after im sure i have subwoofer clearance.
I also put between the panels some pva glue to fill the small gaps and after it dried i put silicone over all the edges i currently can silicone.
Im thinking about bracing front to back but i dont know how will i manage to drill the holes exactly where those braces would be once the box is closed so im thinking about just seriously thickening the sh!t outa those front and back panels with some nice planks. It might even be needed since im not sure about my port clearance from the inside at 40cm long and 16cm diameter it leaves me with just 6cm to the back side, dont know if that would be a problem so im planning on making a thicker front side and have port stick out but id hate to have it like that, I might find an 160mm pvc elbow but im not sure how lenght of port would be calculated then, imput is appreciated!
Could use some planks from an old shed that look cool and aged, would sand them on one side and glue them on with some epoxy glue or other that has great shear strength and that way all flex would be held by the glue layer.
Not to mention its more difficult to move more mass so that will help with efficiency of the box as well.
Anyway i know i jump from subject to subject but everything is getting close and last minute changes are still possible.
Components are waiting
Cheers guys and i cant wait for your comments!
In the mean time i decided to take another cabinet and re-purpose it
for this kind of thing because panels in those dimensions i showed earlier were in the neighborhood of $150, these are about 65 cutting included.
While waiting for the most important panels i decided to build some basic bracing inside, It is all glued first then screwed after the glue has hardened a bit so i dont get any squeaky noises. there is still one horizontal one to install but i will do that after im sure i have subwoofer clearance.
I also put between the panels some pva glue to fill the small gaps and after it dried i put silicone over all the edges i currently can silicone.
Im thinking about bracing front to back but i dont know how will i manage to drill the holes exactly where those braces would be once the box is closed so im thinking about just seriously thickening the sh!t outa those front and back panels with some nice planks. It might even be needed since im not sure about my port clearance from the inside at 40cm long and 16cm diameter it leaves me with just 6cm to the back side, dont know if that would be a problem so im planning on making a thicker front side and have port stick out but id hate to have it like that, I might find an 160mm pvc elbow but im not sure how lenght of port would be calculated then, imput is appreciated!
Could use some planks from an old shed that look cool and aged, would sand them on one side and glue them on with some epoxy glue or other that has great shear strength and that way all flex would be held by the glue layer.
Not to mention its more difficult to move more mass so that will help with efficiency of the box as well.
Anyway i know i jump from subject to subject but everything is getting close and last minute changes are still possible.
Components are waiting
Cheers guys and i cant wait for your comments!
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