Hello everyone!
I am planning to upgrade my self made portable "boombox" with some better speakers and amplifier, and i already have quite a good idea on what to get but i'd like some opinions from who wants to help me with some advice 😀
First of all, the box is already built (attached picture). It's a 10 litre bass reflex box with two, let's say full-range, speakers that share the said 10L, and two ports that tune the box to 58Hz IIRC (i made it some years ago). The speakers were salvaged and are just some random "eongchang" 4 inch 5W drivers that came off an AIWA LCX110 microHiFi, so nothing fancy really.
The box already has a 4s li-ion battery, so 14.4V nominal.
For the amplifier i'm gonna use a tpa3116 based aiyima board with tone controls and bluetooth. This means that the maximum power going to the speakers will be around 30 watts at 1% THD+N, plus i'll have some sort of EQ.
As for the drivers, what i'm looking for is a pair of woofers and tweeters, keeping the budget a bit low (possibly less than 100€ for everything, crossover included) but still managing to get a good sounding system. The woofers can be both 4" or 5" and i need a good compromise between sensitivity and bass extension, as the speaker is battery powered.
Speaking of the woofers, my best bet for this enclosure are the Sb Acoustics sb12pfcr25-4, as they have an acceptable 87.5 dB sensitivity and are quite cheap. I've simulated them in Speakerboxlite with my box specifications (so two drivers into a single 10L ported enclosure, Fb being 58Hz) and the frequency response shows an F3 of 57, F6 of 50 and F10 of 44Hz. How do you think that would sound? I personally am new to speaker modelling so i don't know how these numbers translate to actual listening, if these would have good bass or be a bit lacking.
I've also simulated the sb13pfcr25-4 but it looks like the bass would be worse on these in the same box.
I checked some other drivers as well, but the SB12 look to be the best compromise between sensitivity and bass extension.
For the tweeters my possible choice are the LaVoce tn100.70: they're cheap and with a second order crossover (and maybe a 1.5dB L-pad as they're 89dB) they should do well with the SB midwoofers, or at least it looks like so from my simulations with XSiM and the crossover calculator spreadsheet.
I already tried designing the crossover but i'll wait until i decide myself on the components to purchase before asking you further information 🙂
So, in the end this is what i have in mind for now, and i hope to hear some opinions from anyone willing to help in this upgrade project. I hope i didn't violate any forum rules in the post (if so, please let me know!)
Thanks in advance to everyone 🙂
I am planning to upgrade my self made portable "boombox" with some better speakers and amplifier, and i already have quite a good idea on what to get but i'd like some opinions from who wants to help me with some advice 😀
First of all, the box is already built (attached picture). It's a 10 litre bass reflex box with two, let's say full-range, speakers that share the said 10L, and two ports that tune the box to 58Hz IIRC (i made it some years ago). The speakers were salvaged and are just some random "eongchang" 4 inch 5W drivers that came off an AIWA LCX110 microHiFi, so nothing fancy really.
The box already has a 4s li-ion battery, so 14.4V nominal.
For the amplifier i'm gonna use a tpa3116 based aiyima board with tone controls and bluetooth. This means that the maximum power going to the speakers will be around 30 watts at 1% THD+N, plus i'll have some sort of EQ.
As for the drivers, what i'm looking for is a pair of woofers and tweeters, keeping the budget a bit low (possibly less than 100€ for everything, crossover included) but still managing to get a good sounding system. The woofers can be both 4" or 5" and i need a good compromise between sensitivity and bass extension, as the speaker is battery powered.
Speaking of the woofers, my best bet for this enclosure are the Sb Acoustics sb12pfcr25-4, as they have an acceptable 87.5 dB sensitivity and are quite cheap. I've simulated them in Speakerboxlite with my box specifications (so two drivers into a single 10L ported enclosure, Fb being 58Hz) and the frequency response shows an F3 of 57, F6 of 50 and F10 of 44Hz. How do you think that would sound? I personally am new to speaker modelling so i don't know how these numbers translate to actual listening, if these would have good bass or be a bit lacking.
I've also simulated the sb13pfcr25-4 but it looks like the bass would be worse on these in the same box.
I checked some other drivers as well, but the SB12 look to be the best compromise between sensitivity and bass extension.
For the tweeters my possible choice are the LaVoce tn100.70: they're cheap and with a second order crossover (and maybe a 1.5dB L-pad as they're 89dB) they should do well with the SB midwoofers, or at least it looks like so from my simulations with XSiM and the crossover calculator spreadsheet.
I already tried designing the crossover but i'll wait until i decide myself on the components to purchase before asking you further information 🙂
So, in the end this is what i have in mind for now, and i hope to hear some opinions from anyone willing to help in this upgrade project. I hope i didn't violate any forum rules in the post (if so, please let me know!)
Thanks in advance to everyone 🙂
Attachments
You've picked good woofers, ether the 12PFC or the 13PFC will be OK, but you should be prepared to re-tune the box a bit lower. I'd aim for an F3 below 50Hz. You may be able to make the ports a bit longer by gluing a piece of pipe to the inside end of the port.
Hello, thanks for the quick response! Retuning will not be a problem as i will probably change the ports anyways and make new ones (or a single one, if i'll put the tweeters where the ports are now).
I tried simulating both the sb12 with a 50Hz box tuning (green line in attachment) and the sb13 with that very same tuning (blue line). Somehow the sb13 does look like it has worse bass, that's why i chose the smaller one in the first place; only by increasing internal volume the simulator gives me better bass with the sb13. The red line represents the sb12 with the current 58Hz tuning.
Do you think the 50Hz tuning will sound better?
Attachments
re"two drivers into a single 10L" - I missed this bit, 13PFC will need ~ 10L each
IIRC, to get the most low end out of a 12PFC, you'll need 7 or 8 L per driver
IIRC, to get the most low end out of a 12PFC, you'll need 7 or 8 L per driver
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Just did a quick sim in Unibox for 12PFC in 5 L; best I could get was tuned to 52Hz gave an F3 of 50Hz
Maybe this could be of interest if you choose the coax SB13...
https://www.wagneronline.com.au/attachments/Audio-Speakers-PA/sbacoustics/SB-PFC-COAX_Crossover.pdf
https://www.wagneronline.com.au/attachments/Audio-Speakers-PA/sbacoustics/SB-PFC-COAX_Crossover.pdf
thank you! I guess that's really the best i can get out of the sb midwoofers in such an enclosure. Those 10 litres are the max i can get without redoing the whole box, whic has a small room in the back for all the electronics; those 10 litres are only shared with the two reflex ports.
By simulating the driver in unibox i somehow get the cone excursion to go past the 5mm xmax approximately in the 80-100Hz region, while speakerboxlite showed me it didn't exceed xmax in that region: is this concerning?
I had seen the coaxial and in terms of ease of implementation it would be a great choice, but it's a bit expensive for me, i think i'll go with the LaVoce tweeters, putting them where the two reflex tubes are and redoing the port entirely (maybe making a single one in the back).
I have tried designing a 2nd order crossover for the sb12 woofer and LaVoce tn100.70 tweeter, what do you think about the frequency response? They're approximately crossed at 3KHz.
Component values are the following:
Woofer: Sb acoustics sb12pfcr25-4 (4 ohm)
Low-pass: L2 0.5mH, C2 15uF
Tweeter: LaVoce tn100.70 (8 ohm)
High-pass: C9 4.7uF, L9 0.5uF
L-pad: R series 1.51 ohm, R parallel 17 ohm
I attached varous graphs, does anyone know what the "power response" line means and why it drops off for the tweeter? Is this related to the LPAD?
Attachments
What do you think of the Dayton Audio tcp115-4 instead of the sb acoustics midwoofer? I had a look in WinISD and it looks like it has a more peaky frequency response if put in the same enclosure (5L tuned to 50Hz), similar F10 but lower F3 thanks to the peak. Xmax is 1mm lower, and SPL should be similar (WinISD estimated a higher sensitivity for the sb acoustics midoofer, while on paper the difference shuldn't be more than 1dB).
I don't know if this kind of response is acceptable or it would be noticeably peaky around 50Hz. If i wanted a more linear frequency response i'd need a smaller enclosure, but that would lead to less bass as well.
In the attached screenshots, sb12 is brown and dayton tcp is blue. Power is set to 30W for both as that's the maximum power the amplifier is going to put out.
I don't know if this kind of response is acceptable or it would be noticeably peaky around 50Hz. If i wanted a more linear frequency response i'd need a smaller enclosure, but that would lead to less bass as well.
In the attached screenshots, sb12 is brown and dayton tcp is blue. Power is set to 30W for both as that's the maximum power the amplifier is going to put out.
Attachments
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I also experimented an extended bass alignment with the tcp115-4 by tuning the box lower, around 42Hz; it basically shows a constant -3dB until 43Hz, but i'm concerned abpout group delay, which i didn't consider before: it's about 21ms at 39Hz, is this going to make the bass sound bad/boomy/slow? I read someone saying it's not a problem if the product frequency*delay is below 400, while in my case it would be of 800; others say it can be ignored under 80Hz. I don't know who to trust honestly 😀
Attached pics show the tests done in WinISD.
Attached pics show the tests done in WinISD.
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better go dayton?
I got some experience with Vituixcad2 and designed a crossover for the dayton audio tcp115-4 alongside a dayton audio nd16fa-6. It's a second order + zobel on the woofer and a third order + LPad on the tweeter. What do you think about the plot?
The box is still modeled as 10L for two drivers, tuned at 50Hz.
I got some experience with Vituixcad2 and designed a crossover for the dayton audio tcp115-4 alongside a dayton audio nd16fa-6. It's a second order + zobel on the woofer and a third order + LPad on the tweeter. What do you think about the plot?
The box is still modeled as 10L for two drivers, tuned at 50Hz.
Attachments
...and dayton it is!
In the end i decided to choose dayton audio speakers as they would be more "confortable" in such an enclosure, as it's bigger than what these drivers need, while the sb acoustics needed more like 6-7 litres for each driver.
I chose the dayton audio tcp115-4 woofer and the dayton audio nd16fa-6 tweeter, connected to a series crossover inspired by the "dayton 4" build i foundHERE. I attached the crossover for reference, i went for this setup as it only required 4 components for each driver (i initially intended to use a 2nd order+zobel on the woofer and a 3rd order+lpad on the tweeter, but this led to 9 components per speaker, but also a flatter midrange response in theory).
What i can say is these woofers are really good for their price, and put out a lot of deep bass, obviously not as deep as a proper subwoofer but they can get down to the 40s with good SPL, with the box tuned at 50Hz; they can get pretty loud with a battery powered tpa3116 (powered with a 4s li ion battery, so 14.4V nominal) but they're not very efficient at just 86.5dB at 2.83V/1M.
The nd16fa-6 are great little tweeters as well. They're really tiny (perfect for tight fitments like mine) but they sound amazing, they're crystal clear but not too sharp (even though i left them a bit bright in the crossover). Crossed over at around 4.5HKHz they complement the woofers really well.
I attached some pictures of the finished speaker to show you how it came out. The only thing i'm not convinced by are the reflex ports, i had to cut them and make elbows as bending them was impossible even with hot air. Maybe i'll change them for proper curved ports later on, but for now they'll do. They're 3.5mm in diameter (basically bare minimum for these drivers, and they tend to chuff a bit, but that's always covered by music unless i try to use the speaker as a subwoofer).
The grills i used are monacor cbr-100sgp, not quite adequate for these drivers as mounting holes will overlap with the woofer basket (i did a workaround by mounting the screws at an angle), but it came out nice anyways. Putting the driver between the plastic lip and the metal grill is impossible, the grills are intended to be put above the speakers (actuallt, these are automotive grills...)
I hope this will be a reference for anyone looking to make something similar with these drivers 🙂 and thanks to everyone who helped.
In the end i decided to choose dayton audio speakers as they would be more "confortable" in such an enclosure, as it's bigger than what these drivers need, while the sb acoustics needed more like 6-7 litres for each driver.
I chose the dayton audio tcp115-4 woofer and the dayton audio nd16fa-6 tweeter, connected to a series crossover inspired by the "dayton 4" build i foundHERE. I attached the crossover for reference, i went for this setup as it only required 4 components for each driver (i initially intended to use a 2nd order+zobel on the woofer and a 3rd order+lpad on the tweeter, but this led to 9 components per speaker, but also a flatter midrange response in theory).
What i can say is these woofers are really good for their price, and put out a lot of deep bass, obviously not as deep as a proper subwoofer but they can get down to the 40s with good SPL, with the box tuned at 50Hz; they can get pretty loud with a battery powered tpa3116 (powered with a 4s li ion battery, so 14.4V nominal) but they're not very efficient at just 86.5dB at 2.83V/1M.
The nd16fa-6 are great little tweeters as well. They're really tiny (perfect for tight fitments like mine) but they sound amazing, they're crystal clear but not too sharp (even though i left them a bit bright in the crossover). Crossed over at around 4.5HKHz they complement the woofers really well.
I attached some pictures of the finished speaker to show you how it came out. The only thing i'm not convinced by are the reflex ports, i had to cut them and make elbows as bending them was impossible even with hot air. Maybe i'll change them for proper curved ports later on, but for now they'll do. They're 3.5mm in diameter (basically bare minimum for these drivers, and they tend to chuff a bit, but that's always covered by music unless i try to use the speaker as a subwoofer).
The grills i used are monacor cbr-100sgp, not quite adequate for these drivers as mounting holes will overlap with the woofer basket (i did a workaround by mounting the screws at an angle), but it came out nice anyways. Putting the driver between the plastic lip and the metal grill is impossible, the grills are intended to be put above the speakers (actuallt, these are automotive grills...)
I hope this will be a reference for anyone looking to make something similar with these drivers 🙂 and thanks to everyone who helped.
