Subwoofer for portable boombox

MVK

Member
2018-10-16 4:00 pm
Hi,

I got a pair of Focal EC 165 Coaxial car speakers i don't use and i want to use them in a portable boombox build, but i want to make a 2.1 enclosure with a sub.
Which sub would work for this project? I will run it all from a TDA7498E 2.1 bluetooth 5.0 amplifier board 160Wx2+220W sub (AIYIMA TDA7498E Subwoofer Amplifier Audio Board 160Wx2+220W 2.1 Amplificador Power Amplifier Speaker Home Sound Theater DIY BTL on AliExpress) and a 29.4v battery i have made with the spot welder.

It needs to be
- 4ohm
- Need no more than about 15 liter because i dont want the boombox to be too
big. 6-8 inches would be enough.
- Need to be able to be used with 200w or less.
- go down to 35hz or lower.

Is this possible, any suggestions?
 

MVK

Member
2018-10-16 4:00 pm
I already got the Executive 200 watt portable on. But its not good at loud volumes even with a 21v battery.

Does it matter if the enclosure size for the coaxial car speakers are much smaller than recommended enclosure size when i add a sub with correct volume and a passive radiator?
 
Thank you for the feedback on the executive! Can you give more detail about the results? I've been planning to build one for someone else and I hoped that long excursion tang-band with the passive radiator would have been enough. Do you think it is underamplified, and/or are you hitting excursion limits? As a fallback from an outdoor party speaker, would it at least do well as an indoor, medium size room stereo?

I would think your mids would be fine in a smaller box but it would raise the f3 and you'd want to raise their high pass filter (and raise the subs low pass) to compensate, or else you'd end up with a hole in the response between the two.
 
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MVK

Member
2018-10-16 4:00 pm
It will work alright for a small/medium sized. The sub starts rattling at high volumes and the speakers just sounds to bright and harsh at high volumes. But i still think it is better compared to anything else on the market at this time. Would recommend making a bigger battery pack if you consider building one.
 

MVK

Member
2018-10-16 4:00 pm
So i got the Wavecor SW182BD03 Subwoofer and a passive radiator which should work in a 12 liter enclosure.

How do i raise the high pass filter and the subwoofers low pass? The Speakers has built in crossover, and the amplifier also got som adjustments on it aswell.