Assembly of box for 15 inch subwoofer, help me please

[brazilanlittlebass]

Where can I get more information about box construction and response frequency? Thanks everyone for the tips

[Joe X]

On 1/23/2023 at 4:09 PM, brazilanlittlebass said:

@Joe X So, in reality, I like rebassed-style music, with this frequency that I chose between 38 and 40 hz, will it not be possible to play music at approximately 30 hz, play it loud? because I believe that this speaker will not last a long time playing at 25hz. I wanted something like rap but with sound pressure, or is this system I have not ideal for doing it? I redid the measurements in my car and managed to reach the following measurements: Length 88 cm, height 47 cm and width 45 cm, this is the maximum, even putting the back seat forward because of the battery. Do you think it's possible to play low and strong with this setup? I appreciate it if you can give me the links on the content, thanks a lot buddy

 

I take note of your new maximum dimensions but I would like to know brand and model of your sub, amp, head unit, other components you may have like equalizer, DSP or any other device you may have.

 

Also how is your electrical spec, battery, alternator, wiring, etc.

 

Also check this video on what is cliipping and why you need to avoid it, it's meant to be short and simple, I will post other links later:

 

 

[Joe X]

So here is a second suggestion, power: to sub rated, amp subsonic filter to 28Hz, minimum port clearance 9 cm, figure is just an assembly guide:

 

NOTE: Tuning down to 34Hz and F3 of 26Hz, will be adequate for low tuned, music, net volume up to 4 cubic feet.

 

NOTE: If building outside you need to build a cardboard dummy box to test fit in it's way inside.

 

 

 

 

[brazilanlittlebass]

@Joe XThe subwoofer is a Protech model Competition 2k Double coil 2+2 15 inches (Brazil) the two coils connected in parallel generated me 1.1 ohm in the multimeter, amplifier is a Lil Wonder series 3 2600W, Soundstream. Front radio is a pioneer 6800, I have an Expert audio processor model PX-1 (Brazil). I have a 40 amp battery in the vehicle safe my car usually stays at 12.8 ~ 13.5 volts with the stereo on, one in the back of 200 amps, alternator I believe to be 60 amps. I will install together a bank of capacitors of approximately 80 farads. For the amplifier will go 4 cables of 70mm² positive and negative, my car has big 3 and the cables that come from the alternator to the rear are 20mm², The box will have the subwoofer facing the rear door, in this case the 47cm measurement will be the height, and the 45cm measurement will be the depth , thank you very much for your help

Edited January 26, 2023 by brazilanlittlebass

[Joe X]

So before anything I would like to know your situation, do you have a working system that is not performing well and you want to improve it?

 

If the sub has currently an enclosure, do you have specs?

 

Do you have any pics of your system you would like to share?

 

 

Edited January 30, 2023 by Joe X

[brazilanlittlebass]

@Joe XUntil a certain moment I had it, but I crashed my vehicle and then I removed the system, at the moment I only have the front device and the door speakers, but all the equipment is in good condition, The box I had was sold to another friend, but I didn't like the sound much less the power, I believe it was designed the wrong way. So I decided to make mine myself. 

[Joe X]

So I just wanted to see how is your system and I must say that your system is pretty nice and you do have a mulltimeter and a portable scope which should be enough for you to get it to work perfectly, the areas of concern that I see and may hurt your output are the following:

1) In the past system you show in the pics there seems to be no space for rear batteries so apparently you were running the system on the front battery only.

2) the enclosure you show there is no port visible and if there is a port on either side it wouldn't have enough clearance to work properly so yes a new ported enclosure should help you to get louder.

3) The stock alternator you mention of 60A could have a hard time recharging your batteries and could get damaged over time if you play your system loud for anything more than a few minutes a day and you would need to play your system a low level for a big while the alternator recharges your batts, you need to either get an aftermarket a high output alternator or use an external charger to keep your batts charged and help your current alternator from overworking .

 

4) Don't know if your amp actually puts out the claimed power, many soundstream amps put out much lower power than they claim, if so you could be losing output there.

5) Don't know of you went through a proper gain settings procedure BUT your DSP have an amplitude limiter function which should ensure that once it's setup you will not experience clipping as long as your head unit does not clip.

 

Please read carefully the above points and seek to address the issues to get better performance in your current system.

[Joe X]

Also you can check the following vids to see how much performance other people have managed with your same sub, review their system specs and maybe ask some questions?

 

Since these guys use and know brazilian components you can get better answers on stuff available in your country.

 

 

 

 

 

 

Edited February 3, 2023 by Joe X

[brazilanlittlebass]

@Joe X Thanks for the help, so in this old system the battery was standing, it's a slim model. It was behind the back door, I have an external battery charger to charge them, here in Brazil it's complicated, instead of people helping each other they deny information, they prefer to sell a service to helping another human being, I wanted to learn more about which frequency generates which type of result, what changes a larger literage, or a narrow duct and a longer but larger duct, you know? I want to learn about the subject, I also wanted to know what software you use to design your speakers, the one you designed in 3D, the Bass box doesn't seem very interesting to me or I could be wrong, thanks for everything

[Joe X]

You can learn a lot just from reading older posts, I guess almost any questions you may have has been addressed at some point in these forums, for example if you want a discussion on how narrow your port should be read this:

 

 

If you want to figure out the effects of tuning, I can tell you that the best tool you already have which is the bassbox software, but if you actually want o find out how it actually sounds, you cannot be told that, you need to experience it by building and testing enclosures.

 

The software to draw the figures is called sketchup, kind of hard to use at first but it's free to use.

 

let us know your progress on your build, you will learn a lot just by getting it to perform well, that's why I posted those two vids, get your system to perform better than them and you will know you are getting good at designing systems. recheck all the concerns I had with your system and see what you can come up with.