Hi! For a while now, I have been on the mission of creating the ultimate battery powered outdoor speaker, and this has almost become an obsession of mine. As I have sourced information, I have become accutely aware of the limitations that physics presents regarding small portable builds. Now I need to ask for some inputs.
The goal is to reach 60-65hz and 120 db in a maximum 89 liter (externally) enclosure, icluding tweeter, horn, battery, bracing and so on. The idea for now is to make use of the BMS 4594HE coaxial with a passive crossover, paired with RCF hf950 horn and crossed over to two parallel woofers around 650hz. Similar to Peter morris "double 10" and horn" build. Double 10 and Horn | Sound Forums
I really dont want the dimensions to exceed 30x35x85cm (11"x13.5"x35"), because this is the limit of what I am comfortable carrying and still call it portable (gonna build two). I am aware this isnt real subwoofer duty per se, but I feel this is the right forum, since the aim is to get as low as possible within these restraints. Plan is to compensate for low frequencies below 60hz using maxbass or other "missing fundamentals" algorithms via a sigmaDSP platform. Maybe also do FIRcorrections with Rephase for flat phase if I have the patience to learn it.
I will use a 12v 50ah lifepo4 battery, and a 4 four channel car amplifier. Or maybe 36v and Wondom amp, if I am able to find a lifepo4 battery with right size.
I am looking for a suitable driver that will do 60-65hz and 120db @100-150W for two in parallel. I have been simming around with hornresp, but havent really found a good match.
#1 Do you think this is realistic goals to have for this build?
#2 Do you know a driver that have the sensitivy, low fs and high xmax to meet these requierments as close as it gets?
#3 Another thing I could not find relevant information on is the effect of tilting the woofers some degrees in direction of each other to save some height. Any one know the effect of this specially regarding phase cancellations and directivity?
Thanks in advance!
The goal is to reach 60-65hz and 120 db in a maximum 89 liter (externally) enclosure, icluding tweeter, horn, battery, bracing and so on. The idea for now is to make use of the BMS 4594HE coaxial with a passive crossover, paired with RCF hf950 horn and crossed over to two parallel woofers around 650hz. Similar to Peter morris "double 10" and horn" build. Double 10 and Horn | Sound Forums
I really dont want the dimensions to exceed 30x35x85cm (11"x13.5"x35"), because this is the limit of what I am comfortable carrying and still call it portable (gonna build two). I am aware this isnt real subwoofer duty per se, but I feel this is the right forum, since the aim is to get as low as possible within these restraints. Plan is to compensate for low frequencies below 60hz using maxbass or other "missing fundamentals" algorithms via a sigmaDSP platform. Maybe also do FIRcorrections with Rephase for flat phase if I have the patience to learn it.
I will use a 12v 50ah lifepo4 battery, and a 4 four channel car amplifier. Or maybe 36v and Wondom amp, if I am able to find a lifepo4 battery with right size.
I am looking for a suitable driver that will do 60-65hz and 120db @100-150W for two in parallel. I have been simming around with hornresp, but havent really found a good match.
#1 Do you think this is realistic goals to have for this build?
#2 Do you know a driver that have the sensitivy, low fs and high xmax to meet these requierments as close as it gets?
#3 Another thing I could not find relevant information on is the effect of tilting the woofers some degrees in direction of each other to save some height. Any one know the effect of this specially regarding phase cancellations and directivity?
Thanks in advance!
Alternatives First.
Meeting your mission statement, if at all possible (without relaxing the constraints imposed by it), will be all about reproducing the low end of the audio spectrum with extreme efficiency in order to conserve battery energy.
A better tack, would be to implement a three/four unit solution, consisting of (2) small stereo satellites plus one subwoofer.
In this setting, I would set the c/o frequency at say 120 Hz.
Note: to facilitate portability, two co-located bass units could be deployed as an array.
By centralizing bass reproduction you may expect a 6 dB improvement in efficiency over that of other bifurcated arrangements.
I would use a passive radiator implementation of a reflex enclosure.
Large excursion drivers are not going to present a friendly load to your battery power source, so to get the maximum VD you will be looking for, you want to maximize active/passive radiator SD.
Where efficiency is at issue, a driver with under-hung voice coil should be used.
With the outdoor venue, there will be no room gain to help out with the bass and the drivers will need to be moisture resistant as well.
If you cannot find a stock driver to handle the bass requirement, you can get a custom build Flex Units from Audio Technology, if they are still in business.
Use an active crossover and dedicated amplifier for the bass drive. Passives filters simply waste too much precious electrical energy.
There may be alternate design strategies that will deliver an optimal solution as well; but these are the ones that come to mind at the moment.
Meeting your mission statement, if at all possible (without relaxing the constraints imposed by it), will be all about reproducing the low end of the audio spectrum with extreme efficiency in order to conserve battery energy.
A better tack, would be to implement a three/four unit solution, consisting of (2) small stereo satellites plus one subwoofer.
In this setting, I would set the c/o frequency at say 120 Hz.
Note: to facilitate portability, two co-located bass units could be deployed as an array.
By centralizing bass reproduction you may expect a 6 dB improvement in efficiency over that of other bifurcated arrangements.
I would use a passive radiator implementation of a reflex enclosure.
Large excursion drivers are not going to present a friendly load to your battery power source, so to get the maximum VD you will be looking for, you want to maximize active/passive radiator SD.
Where efficiency is at issue, a driver with under-hung voice coil should be used.
With the outdoor venue, there will be no room gain to help out with the bass and the drivers will need to be moisture resistant as well.
If you cannot find a stock driver to handle the bass requirement, you can get a custom build Flex Units from Audio Technology, if they are still in business.
Use an active crossover and dedicated amplifier for the bass drive. Passives filters simply waste too much precious electrical energy.
There may be alternate design strategies that will deliver an optimal solution as well; but these are the ones that come to mind at the moment.
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Neo Dan, from what I understand about peter morris thread, it was designed to be crossed over at 110 to meet subwoofer, and not intended for stand alone use. Please correct me if Im wrong. Also using it as a battery powered speaker raised some questions.
Robwells, thank you, I will definetely look into BP4.
Chris, the 10fh520 looks really promising! I will hold my attention on this one. Thanks!
whgeiger, thank you so much for that in depth design strategy! I will investigate this route also.
Robwells, thank you, I will definetely look into BP4.
Chris, the 10fh520 looks really promising! I will hold my attention on this one. Thanks!
whgeiger, thank you so much for that in depth design strategy! I will investigate this route also.
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