Hi everyone.
Not sure if this is the correct forum but i,ll start here 🙂
I have an ide about building a "full range" boombox, small enough to bring to the beach, travels and so on.
Something like 1,5" - 2" full range drivers with passive radiators, bluetooth and rechargeable. Nothing unusual here.
Now, When at home i would like to "dock" it to a larger subwoofer module built around a 5" woofer to keep size somewhat still small but getting the extra thump and umph 🙂
How can this be done? The 2 modules by them self is no problem however i would like the boom box to be full range when used by it self.. and when docked to the sub module engage a high pass filter to keep it of low bass duty.
Has anyone built something like this? Am i a complete fool thinking of building it? 🙂
Any input is very much appreciated
Best regards
Joakim
Not sure if this is the correct forum but i,ll start here 🙂
I have an ide about building a "full range" boombox, small enough to bring to the beach, travels and so on.
Something like 1,5" - 2" full range drivers with passive radiators, bluetooth and rechargeable. Nothing unusual here.
Now, When at home i would like to "dock" it to a larger subwoofer module built around a 5" woofer to keep size somewhat still small but getting the extra thump and umph 🙂
How can this be done? The 2 modules by them self is no problem however i would like the boom box to be full range when used by it self.. and when docked to the sub module engage a high pass filter to keep it of low bass duty.
Has anyone built something like this? Am i a complete fool thinking of building it? 🙂
Any input is very much appreciated
Best regards
Joakim
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Hello, you could do that with the right car audio head unit with HP and LP filters and a Pre-out for the subwoofer. Anyway, how much midbass would you expect from a 2" fullrange, not much I guess. I am thinking of a recent idea on building a 2 way boombox, powered either by a higher quality 50W/8ohm AB class amplifier or a head unit. The 3.5" midbass is a Peerless SLS-85S25CP04-04 and tweeter Peerless XT25SC40-04.
This combo would have produced plenty midbass rendering additional woofer unnecessary and I fancy not thin sounding fullrange units.
This combo would have produced plenty midbass rendering additional woofer unnecessary and I fancy not thin sounding fullrange units.
Attachments
The problem is not " how much bass you expect from a pair of 2 inches speaker" but how to eliminate the bass frequencies so they don't overload them.
There are some ways to eliminate it ( well, just some dB's )
passive or active filters.
Active is mandatory for the subwoofer, so an Op-Amp based circuitry before the amplifier
It accomplishes the job of mixing Left and Right channels into one channel, then a lowpass filter, generally two second order filters cascaded.
The highpass filter is also better done at line level. You can use input capacitor value to determine Fcut, but also, if the amplifier is a regular class B-AB amp with single supply rail and not BTL, the output capacitor. The input resistance of the amplifier and the impedance of the speaker will determine the value (....).
So for the satellites, a simple switch to change input capacitor.
Example: 100 nF OR 1 uF ( also 10 nF OR 0.22 uF )
For ouput cap: 220 uF OR 1000 uF ( for 4 Ω load )
There are some ways to eliminate it ( well, just some dB's )
passive or active filters.
Active is mandatory for the subwoofer, so an Op-Amp based circuitry before the amplifier
It accomplishes the job of mixing Left and Right channels into one channel, then a lowpass filter, generally two second order filters cascaded.
The highpass filter is also better done at line level. You can use input capacitor value to determine Fcut, but also, if the amplifier is a regular class B-AB amp with single supply rail and not BTL, the output capacitor. The input resistance of the amplifier and the impedance of the speaker will determine the value (....).
So for the satellites, a simple switch to change input capacitor.
Example: 100 nF OR 1 uF ( also 10 nF OR 0.22 uF )
For ouput cap: 220 uF OR 1000 uF ( for 4 Ω load )
Hi
Thanx for the advice Lojzek. Your suggestions is good and will certainly work however they will be more stationary then what i had in mind.
I am of course well aware that the sound quality and SPL from a 2" driver not going to be high..
I thinking good enough for travels,, background musik when working etc.
And when at home using the "docking" function for getting more SPL and low end and maybe charging.
Thank you Picowallspeaker for your input !
Thanx for the advice Lojzek. Your suggestions is good and will certainly work however they will be more stationary then what i had in mind.
I am of course well aware that the sound quality and SPL from a 2" driver not going to be high..
I thinking good enough for travels,, background musik when working etc.
And when at home using the "docking" function for getting more SPL and low end and maybe charging.
Thank you Picowallspeaker for your input !
The problem is how to build a bluetooth portable that would be better than commercial offerings in terms of battery, bluetooth connectivity, sound quality on the go, etc.
If it were for me and actual portability was a concern, I'd use a sony xr-b30 which is a fairly decent bluetooth speaker and then build a "sub" dock. The signal would go to the dock and from there to the speaker analog input. I'd use fairly steep analog high and low pass filters.
I'm busy btw building a small kit using that Peerless SLS-85S25CP04-04 in about 1l.
If it were for me and actual portability was a concern, I'd use a sony xr-b30 which is a fairly decent bluetooth speaker and then build a "sub" dock. The signal would go to the dock and from there to the speaker analog input. I'd use fairly steep analog high and low pass filters.
I'm busy btw building a small kit using that Peerless SLS-85S25CP04-04 in about 1l.
That is a very nice kit 00940🙂
Sure i could just use a commercial boombox and work from there..
Buuuuut... where is the fun in that? 🙄
I do not expect the build to be cheaper or better then commercial.. its just more fun to build it.. And i get something to do in the evenings 🙂
/JZ
Sure i could just use a commercial boombox and work from there..
Buuuuut... where is the fun in that? 🙄
I do not expect the build to be cheaper or better then commercial.. its just more fun to build it.. And i get something to do in the evenings 🙂
/JZ
2p/2c
For efficiency's sake, have a look at Faital PRO 3FE25. these are quite/very efficient and don't need many watts to push them. Build them sealed into your BB. Depending on source, can add bass via EQ/DSP. It won't go deep AND loud but it will manage some depth and will go very loud if bass is attenuated.
J.
For efficiency's sake, have a look at Faital PRO 3FE25. these are quite/very efficient and don't need many watts to push them. Build them sealed into your BB. Depending on source, can add bass via EQ/DSP. It won't go deep AND loud but it will manage some depth and will go very loud if bass is attenuated.
J.
Not that much of a problem. One can literally size the boombox to whatever quality standard one wanted meaning a larger and heavier product.
Parts Express is selling a decent boombox kit with Dayton Audio PC 83-4 drivers and I think they would have made a good decision if they offered it through ebay store as well.
60 Watt Powered Bluetooth Speaker Package with 3" Full-Range Drivers
And you end up with something too big, too heavy, too fragile, not practical enough to carry with you. I do agree that we can do better if accept larger and heavier products but something "to bring to the beach, travels and so on" was the initial request. With 1.5" or 2" drivers, it's going to be real hard to have something worth building. Commercial bluetooth speakers (at least the best ones) are making use of quite a bit of engineering (hardware and software) to offer decent sound in a practical and rugged package. Unless one's ready to use 3D printing or CNC machining and lay out his own pcb for a whole bluetooth+dsp+amp solution...
I really do get the pride in building your own stuff. I'm just pointing out that it's not very useful to design the best ever boombox if it ends up staying on a desk.
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