Hello DIYaudio communty!
My name is Max and I'm a 2nd year electronic engineering student. I am trying to combine some of my hobbies in a project. Being a novice when it comes to building speakers i am seeking for your wisdom. I try to look up as much info as i can before asking questions but i'm afraid i cant find a clear answer for this problem.
As the title says am building "portable" 2.1 Bluetooth speaker. To avoid dealing with tweeter crossovers i am using 2 Tangband W4-1337 SDF full range drivers and a ScanSpeak 5.5" driver as a Mid/Low bass woofer. This will be connected to a TPA 3116 2.1 Class D amp with a build in adjustable crossover for the bass. I plan on using 2 passive radiators to keep ik sealed. I would like to avoid getting stuff inside while using it outside.
I think that my speakers and amp are a bit too overpowered but i already have it so... yeah.. Cant change that anymore
My dilemma is:
I am trying to combine these speakers in 1 relatively small enclosure. Right now i have them all not separated like most commercial Bluetooth speakers do. Will this be a problem or would it be wise to put the Tangband drivers each in a separate enclosure? If i separate them it will end up being a small sealed enclosure for each driver, maybe even so small that it would be worse than leaving them all in one space. So.... what to do?
I have included pictures of my design. The boxes etc are space holders for batteries and electronics. The two holes in the rear is for the two 6.5 inch radiators
I hope you guys can give me a good advice. If you have other things that i can improve on (probably everything) please do tell!
Ow and the entire enclosure will be 3d printed. Total size will be 405mm wide 170mm high and 240mm deep.
My name is Max and I'm a 2nd year electronic engineering student. I am trying to combine some of my hobbies in a project. Being a novice when it comes to building speakers i am seeking for your wisdom. I try to look up as much info as i can before asking questions but i'm afraid i cant find a clear answer for this problem.
As the title says am building "portable" 2.1 Bluetooth speaker. To avoid dealing with tweeter crossovers i am using 2 Tangband W4-1337 SDF full range drivers and a ScanSpeak 5.5" driver as a Mid/Low bass woofer. This will be connected to a TPA 3116 2.1 Class D amp with a build in adjustable crossover for the bass. I plan on using 2 passive radiators to keep ik sealed. I would like to avoid getting stuff inside while using it outside.
I think that my speakers and amp are a bit too overpowered but i already have it so... yeah.. Cant change that anymore
My dilemma is:
I am trying to combine these speakers in 1 relatively small enclosure. Right now i have them all not separated like most commercial Bluetooth speakers do. Will this be a problem or would it be wise to put the Tangband drivers each in a separate enclosure? If i separate them it will end up being a small sealed enclosure for each driver, maybe even so small that it would be worse than leaving them all in one space. So.... what to do?
I have included pictures of my design. The boxes etc are space holders for batteries and electronics. The two holes in the rear is for the two 6.5 inch radiators
I hope you guys can give me a good advice. If you have other things that i can improve on (probably everything) please do tell!
Ow and the entire enclosure will be 3d printed. Total size will be 405mm wide 170mm high and 240mm deep.
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Hi, I'm not sure how is this stereo amp chip configured as a 2.1 system. Tang Band units are capable of 70 Hz/-3dB in about 4,5 litre cabinet, so I would rather keep the boombox simpler without the added midwoofer. This chip gives 2*8 W/8 ohm with a 12V battery so in that sense it's more than enough for casual listening.
Separating speaker boxes is common sense if you want the best out of these with an appropriate PR. TB radiators seem not to be. Simulate the response of these.
Frequency response on-axis according to manufacturer would suffice, but it wouldn't off-axis. That's a compromise one has to accept.
If I were to build myself one, I'd try to find a co-axial unit and work some kind of a crossover or at least use car audio units with just a cap on tweeter.
Separating speaker boxes is common sense if you want the best out of these with an appropriate PR. TB radiators seem not to be. Simulate the response of these.
Frequency response on-axis according to manufacturer would suffice, but it wouldn't off-axis. That's a compromise one has to accept.
If I were to build myself one, I'd try to find a co-axial unit and work some kind of a crossover or at least use car audio units with just a cap on tweeter.
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Have yo looked thru the Boominator thread?
http://www.diyaudio.com/forums/clas...imate-party-machine.html?highlight=boominator
There is likely a lot of info there to help you.
http://www.diyaudio.com/forums/clas...imate-party-machine.html?highlight=boominator
There is likely a lot of info there to help you.
Hi Lojzek Thanks for your response!
The board uses 2 chips. One for 2x 50w (max) and one for 100w (max). I plan to drive it between 12v to 21v depending on what works best.
I thank you for the advice on using just 2 drivers and no sub. I kinda already have the drivers and amp so i will try it first before i buy other components such as coax speakers and stereo amp. The cost of printing the enclosure is almost 0 for me.
I have made a sealed version with bigger room for the Tang Band drivers. (see include picture) By looking at the boominator thread it would be a good idea to fill it these with light padding am i right? I have also angled the drivers a couple degrees outwards to give it a better stereo representation.
Thanks alot for this! I will have a look.
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Hey Sonic, absolutely! A good measure of lining on the walls should do the trick with some space left to freely pass the sound to a radiator. Here is simulated pics of the ideal radiator parameters with added 12 g of extra weight (Seas SP 18R). This is respectable performance for such a small midwoofer, although cranked up and the voice coil is out of the magnetic gap at lower tones. Best to play some music and see. If only you could add a steep high pass electronic filter at say 50Hz in order to protect the unit from overexcursion, that would be an awesome feature.
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That is the same idea that I'm going with right now. A pair of 3.5" car coax speakers in a 2 liter (net) closed box. The coax speakers have an in-line cap on the tweeter (courtesy of the manufacturer). Portability won out over bass extension on my coax project.
A dedicated woofer with attention to bass, acoustic isolation and treatment, and an appropriate crossover can definitely yield higher sound quality.
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Exactly, good thinking Dave. If there ever arises the need to complement the Tang Band wide band units with a tweeter, I'd first consider adding one like in a sketch, before spending additionally on coaxial stuff. Dayton has got ND 16 FA-6 driver with just 32,5 mm overall diameter and crossed at 4-5 kHz should perform well.
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Hi Lojzek,
Thanks for your reply. I am thankful for you running that sim. I have to be honest that for a novice like learning curve is steep so thanks for helping me out.
I see you ran a sim with a passive radiator. The way i am planning to use them is to have the left and right driver (the Tangbands) sealed. Only the center woofer will be having 2 passive radiators. Else all 3 drivers would have to share the same air.
I will set the crossover to the center 5.5" Scanspeak between 200 and 300hz(?) for the low's. I forgot to mention the specific type of amp im using. This is the one: https://www.aliexpress.com/item/Blu...32783356333.html?spm=2114.13010608.0.0.TRrICF
It can set treble, bass and a "subwoofer" crossover
Anyways, i have printed the front. Everything fits as intended. Looking good so far
Max.
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The pots are for Volume, Treble, Bass and Crossover for lows. It basicly allows you to use 2 channels for mid / high and one for the lows. You need to add your own crossover if you have tweeters.
I have ordered these radiators : https://www.aliexpress.com/item/2pc...32662734685.html?spm=2114.13010608.0.0.twaQGF
It should be easy to mod it with more weight but I'm not sure if i will use them. I might end up making radiators out of some old sony speakers.
I have ordered these radiators : https://www.aliexpress.com/item/2pc...32662734685.html?spm=2114.13010608.0.0.twaQGF
It should be easy to mod it with more weight but I'm not sure if i will use them. I might end up making radiators out of some old sony speakers.
Thanks, I'll sim the drivers in a box as if in free space to see what happens when you low pass electronically. PCD allows to change from Butterworth, LR to Bessel. The woofer would have to be elevated in level for the midrange gets boosted with baffle step. That's good. Can I assume the sealed cabinet volume at about 2 litres?
In case it wouldn't work with your PR's, 2 of the dayton audio 6,5" should, although pricier. The simulated spl is under assumption of being in an infinite baffle and when in free space then the total spl drops by 6dB. There is a discrepancy between Scan Speak specification of sensitivity being 87 dB/2,83V/1m and the one calculated from T/S parameters of 89,8 dB/2,83V/1m. Anyway, that won't be an issue meaning you'll only have to raise the woofer level to a lesser value than i said before (6dB).
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Small update,
Once again thanks for the usefull data Lojzek
I have finished the rear and have fitted parts needed for it to work. Batteries and other stuff still has to be fitted later. This is just to test it. I used black tape to make it sealed for now.
I think it works great! High and Mids are Bass is good according to my untrained ears BUT at higher volumes the Scanspeak woofer cant keep up for the lows. It doesnt have enough throw? ( i dont know the proper term). The woofer moves too far back and forth and distorts. I turn down the subwoofer channel to prevent damage. This only happens at high volumes and bass heavy music. Even with the subwoofer channel turned down a bit it still sounds good.
A buddy of mine happens to have a Tang Band W5-1138SMF that i could use. Would you reckon that this will improve the the low tones at higher volumes? The design of the driver certainly seems better suited...
Thanks,
Max
Once again thanks for the usefull data Lojzek
I have finished the rear and have fitted parts needed for it to work. Batteries and other stuff still has to be fitted later. This is just to test it. I used black tape to make it sealed for now.
I think it works great! High and Mids are Bass is good according to my untrained ears BUT at higher volumes the Scanspeak woofer cant keep up for the lows. It doesnt have enough throw? ( i dont know the proper term). The woofer moves too far back and forth and distorts. I turn down the subwoofer channel to prevent damage. This only happens at high volumes and bass heavy music. Even with the subwoofer channel turned down a bit it still sounds good.
A buddy of mine happens to have a Tang Band W5-1138SMF that i could use. Would you reckon that this will improve the the low tones at higher volumes? The design of the driver certainly seems better suited...
Thanks,
Max
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