Hello!
I am building a speaker/sound trailer for my bicycle, to use at events/large rides/etc. And I enjoy EDM and techno and bass and want it to succeed at that.
I asked a question about what to build (with photo and description of build) on reddit (www.reddit.com/r/SoundSystem/comments/1eia1kb/looking_to_upgrade_my_bike_sound_system_with/) and got several recommendations for a tham15. (And similar responses in the 12v sound system Facebook group) Details of my setup in the Reddit thread but I have a 2x300, 1x500w amp with the 500w channel unused
I read a bunch of things (references below) and have the below plan - and am hoping someone will chime in if it's a bad idea!
I'll buy:
1 sheet 3/4 ply:
https://www.homedepot.com/p/SANDEPL...ual-0-709-in-x-48-in-x-96-in-454559/203414066
Standard wood glue
15" driver (see questions)
Then using the the plans below cut everything out with table saw and miter saw (except for the horn baffle), glue together all but the side panel... and then pray.
Question:
1) Does this plan make sense? Would you recommend a different speaker or plan for my setup? My focus is on using my unused 500W channel to have a good sound at 50hz, and then being lightweight, small, and cheap - with about equal importance for those three.
2) I'm debating on what drivers to use. Looking through recommendations on the forums, what is currently available, and is less than $350 I see the below drivers, and would be curious which you would recommend? I know these aren't the features I need to look into - but I'm not sure how to read the other specs well enough to make a determination myself.
Dayton Audio 15LF: $150, 22lb
Eminence Kappalite 3015LF: $289, 10lb
Eminence Kappa Pro-15LF: $209, 25lb
PRV 15SW2000: $189, 30lb
B&C 15NDL88L: $350, 15lb
3) Is the finishing/paint/seal on the outside important to the sound? What do you recommend doing? (I'm looking for fun, not professional, look)
4) would getting a dsp be essential?
Thanks!
References and what I got out of them:
The design and discussion, people have strong opinions on reflectors but as a newb i shouldn't do them:
https://www.diyaudio.com/community/threads/tham15-a-compact-15-tapped-horn.175658/
Wood glue is fine:
https://www.diyaudio.com/community/threads/what-is-the-best-adhesive-glue-for-speaker-boxes.312142/
Ideas for drivers:
https://www.diyaudio.com/community/...or-tham15-x4-from-a-single-20a-outlet.385960/
I probably shouldn't do 1/2in ply but maybe it's ok especially if I do a cubo?
https://www.diyaudio.com/community/threads/tham-15-cutsheet.408349/page-2
Maybe I could do a cubo
https://autoconfig.freespeakerplans.com/plans?view=article&id=44:cubo15
https://forum.speakerplans.com/cubo15-vs-tham15-measured_topic104372.html
https://www.diyaudio.com/community/...uper-scoop-and-folded-horn-subwoofers.231894/
What is a folded horn, tapped horn, scoop (post 12 especially)
Cutsheet:
https://forum.speakerplans.com/uploads/12282/Cutting_Diagram_for_THAM15_MK1.pdf
General discussion of tham15:
https://forum.speakerplans.com/martinson-tham-15_topic53906_page1.html
Reference drawing of tham15:
https://www.martinsson.cc/blog/index.php?entry=entry090721-180410 - the horn mouth baffle is the only one that needs to be cut
I am building a speaker/sound trailer for my bicycle, to use at events/large rides/etc. And I enjoy EDM and techno and bass and want it to succeed at that.
I asked a question about what to build (with photo and description of build) on reddit (www.reddit.com/r/SoundSystem/comments/1eia1kb/looking_to_upgrade_my_bike_sound_system_with/) and got several recommendations for a tham15. (And similar responses in the 12v sound system Facebook group) Details of my setup in the Reddit thread but I have a 2x300, 1x500w amp with the 500w channel unused
I read a bunch of things (references below) and have the below plan - and am hoping someone will chime in if it's a bad idea!
I'll buy:
1 sheet 3/4 ply:
https://www.homedepot.com/p/SANDEPL...ual-0-709-in-x-48-in-x-96-in-454559/203414066
Standard wood glue
15" driver (see questions)
Then using the the plans below cut everything out with table saw and miter saw (except for the horn baffle), glue together all but the side panel... and then pray.
Question:
1) Does this plan make sense? Would you recommend a different speaker or plan for my setup? My focus is on using my unused 500W channel to have a good sound at 50hz, and then being lightweight, small, and cheap - with about equal importance for those three.
2) I'm debating on what drivers to use. Looking through recommendations on the forums, what is currently available, and is less than $350 I see the below drivers, and would be curious which you would recommend? I know these aren't the features I need to look into - but I'm not sure how to read the other specs well enough to make a determination myself.
Dayton Audio 15LF: $150, 22lb
Eminence Kappalite 3015LF: $289, 10lb
Eminence Kappa Pro-15LF: $209, 25lb
PRV 15SW2000: $189, 30lb
B&C 15NDL88L: $350, 15lb
3) Is the finishing/paint/seal on the outside important to the sound? What do you recommend doing? (I'm looking for fun, not professional, look)
4) would getting a dsp be essential?
Thanks!
References and what I got out of them:
The design and discussion, people have strong opinions on reflectors but as a newb i shouldn't do them:
https://www.diyaudio.com/community/threads/tham15-a-compact-15-tapped-horn.175658/
Wood glue is fine:
https://www.diyaudio.com/community/threads/what-is-the-best-adhesive-glue-for-speaker-boxes.312142/
Ideas for drivers:
https://www.diyaudio.com/community/...or-tham15-x4-from-a-single-20a-outlet.385960/
I probably shouldn't do 1/2in ply but maybe it's ok especially if I do a cubo?
https://www.diyaudio.com/community/threads/tham-15-cutsheet.408349/page-2
Maybe I could do a cubo
https://autoconfig.freespeakerplans.com/plans?view=article&id=44:cubo15
https://forum.speakerplans.com/cubo15-vs-tham15-measured_topic104372.html
https://www.diyaudio.com/community/...uper-scoop-and-folded-horn-subwoofers.231894/
What is a folded horn, tapped horn, scoop (post 12 especially)
Cutsheet:
https://forum.speakerplans.com/uploads/12282/Cutting_Diagram_for_THAM15_MK1.pdf
General discussion of tham15:
https://forum.speakerplans.com/martinson-tham-15_topic53906_page1.html
Reference drawing of tham15:
https://www.martinsson.cc/blog/index.php?entry=entry090721-180410 - the horn mouth baffle is the only one that needs to be cut
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I suppose my concern would be if you have the legs to tow it? Can you pull a 100 lb trailer keeping up to the pack for an entire event?
12vx2x300W+1x500W amp sounds like up to 100A current draw, but let's say it's 30 on average while listening / riding.
How long do you want it to last? 100A/h LiFrPo4 battery maybe goes 3 hours, weighing in at ~25 lbs. Dont even ask what the equivalent A/h in lead acid weighs...
The concerns are legs is valid, but is one I'm willing to work on (notably building up an ebike to help). I do want to keep it under 120lb ideally.
RE battery I already have them - several 48V 15ah batteries.
The actual usage is also below the wattage of the amp - it gets a lot of distortion as you approach full power. But yeah there's a theoretical max of 50a but I think it's closer to 5a
What would you suggest I do?
RE battery I already have them - several 48V 15ah batteries.
The actual usage is also below the wattage of the amp - it gets a lot of distortion as you approach full power. But yeah there's a theoretical max of 50a but I think it's closer to 5a
What would you suggest I do?
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Sounds like you have the battery / amp sorted. What amp takes 48 VDC and makes 2X 300 + 1X 500W? Curious.
Since weight is your "enemy", I'd suggest an opposed driver design for the sub. Ordinarily the force of the cone pushing on air has a lot of weight behind it (combined driver / cabinet weight) as a heavy, stationary mass to push against. With the opposed design, two speakers push in opposite directions and the reactionary force cancels out between them mechanically through the cabinet structure..
Intuitively, one could then use a lighter structure. Whether this is so in practice, or it ends up just as heavy anyway because of two drivers, is beyond my knowledge. One would think you could use such a trick to your advantage, given your situation.
Since weight is your "enemy", I'd suggest an opposed driver design for the sub. Ordinarily the force of the cone pushing on air has a lot of weight behind it (combined driver / cabinet weight) as a heavy, stationary mass to push against. With the opposed design, two speakers push in opposite directions and the reactionary force cancels out between them mechanically through the cabinet structure..
Intuitively, one could then use a lighter structure. Whether this is so in practice, or it ends up just as heavy anyway because of two drivers, is beyond my knowledge. One would think you could use such a trick to your advantage, given your situation.
The amp is: https://www.parts-express.com/Sure-...dio-Amplifier-Board-T-Amp-320-3351?quantity=1 . It's ok.
Thread moved to Subwoofer forum. If that doesn't seem the most appropriate then it can always moved again 🙂
When there's a will, there's a way - how about 400lb 🫠
https://www.instagram.com/p/C4p2OP_xNMI/?igsh=ZTQxZTZzaXFsZHBp
Thank you! I tried putting it there originally, but as a new member I couldn't post there yet.
Thread moved to Subwoofer forum. If that doesn't seem the most appropriate then it can always moved again 🙂
Bitsmasher - Rik's trailer was actually my inspiration and what finally got me to work on it! Getting to something like that is honestly probably an end goal... in several years... and once I've moved to somewhere bigger. I literally wouldn't be able to fit those at my apartment. My speakers currently live piled in a stack on my nightstand when not in use 🙂 .
Also I'm guessing Atlanta, where I am, is hillier than his location 🙁
I'd say 1/2 inch is definitely OK for the majority of the enclosure as long as weight is more important to you than getting the best sound quality. Weight seems far more important for this application to me, but it's not my build.
The "Lite" versions of these take it even farther, though the construction details will matter more, and the curved panels are obviously different than the THAM. It's just an idea of what can be done on a lightweight build.
https://billfitzmaurice.info/Jack.html
https://billfitzmaurice.info/forum/viewtopic.php?t=21516
That's going to depend on the type of plywood you use and the chances of it getting wet.
Of course 1/2” is enough here. It’s not like the cabinet has to tolerate 3000 watts. The 3015LF has its limits too because of the light cone, but chances are you will be well within them. Limited by the energy density you can carry.
Is this thing going to RAGBRAI next year? One can keep a 2nd set of batteries on the bus, and have them ready to swap out.
Is this thing going to RAGBRAI next year? One can keep a 2nd set of batteries on the bus, and have them ready to swap out.
No plans for it to go on RAGBRAI... especially not when it's not yet working 🙂
So would using something like https://www.homedepot.com/p/19-32-in-x-4-ft-x-8-ft-BC-Sanded-Pine-Plywood-201427/100007300 work in my application - where i'm willing to sacrifice some quality for weight?
I'd say the chances of it getting wet are... medium. Humidity is likely at times.
One additional question - what connector/connection method would you recommend, and where/how should I place it? By connection method I mean "how you plug the speaker into the amp once it's built".
Thanks!
So would using something like https://www.homedepot.com/p/19-32-in-x-4-ft-x-8-ft-BC-Sanded-Pine-Plywood-201427/100007300 work in my application - where i'm willing to sacrifice some quality for weight?
I'd say the chances of it getting wet are... medium. Humidity is likely at times.
I'm not a fan of those for two reason - they don't have the bass response i'm looking for (based on my uninformed reading of the graphs), and more importantly i don't think I have the skills for the lite version of those - though love the idea and if this first speaker goes well... could see me replacing my existing speakers (which covers the rest of the range) with them.
No such plans at the moment. I only vaguely know of them.
One additional question - what connector/connection method would you recommend, and where/how should I place it? By connection method I mean "how you plug the speaker into the amp once it's built".
Thanks!
If your budget can handle it, something like this should have fewer voids, smoother surfaces, etc.
https://www.homedepot.com/p/Columbi...-8-ft-PureBond-Birch-Plywood-833185/100020218
With any chance of moisture exposure, paint is a good idea for any typical wood surface that might get wet. There are textured, durable paints made specifically for speakers, or you could use an exterior grade paint or varnish of your liking.
Neutrik SpeakON connectors are one common way to connect the amp and speaker if they are going to be separate.
https://www.homedepot.com/p/Columbi...-8-ft-PureBond-Birch-Plywood-833185/100020218
With any chance of moisture exposure, paint is a good idea for any typical wood surface that might get wet. There are textured, durable paints made specifically for speakers, or you could use an exterior grade paint or varnish of your liking.
Neutrik SpeakON connectors are one common way to connect the amp and speaker if they are going to be separate.
As an updated plan: I am going to build a tham12 because I realized I don't have enough space to store a tham15 (i live in a small apartment).
I'm going to build out of 1/2 in plywood https://www.homedepot.com/p/Columbi...-8-ft-PureBond-Birch-Plywood-833185/100020218
I'll put in this driver https://www.parts-express.com/B-C-12NDL76-12-Neodymium-Woofer-294-570
I'll put these in the corners https://www.parts-express.com/Plastic-Stacking-Corner-16-Pcs.-262-834
And i'll use this for input: https://www.parts-express.com/Speaker-Terminal-Cup-Gold-Insulated-5-Way-Binding-Post-260-242
(I don't have speakon anywhere so would have to get amp to speakon, speakon cable, in addition to the port... which is a bit much.)
I'll get a brightly colored exterior paint for it.
Am I forgetting anything in this? And does anyone have a 1/2 (.453 actual) in cutlist/cutsheet? Otherwise i'll have to adapt martinsson's drawings which I can do.
I'm going to build out of 1/2 in plywood https://www.homedepot.com/p/Columbi...-8-ft-PureBond-Birch-Plywood-833185/100020218
I'll put in this driver https://www.parts-express.com/B-C-12NDL76-12-Neodymium-Woofer-294-570
I'll put these in the corners https://www.parts-express.com/Plastic-Stacking-Corner-16-Pcs.-262-834
And i'll use this for input: https://www.parts-express.com/Speaker-Terminal-Cup-Gold-Insulated-5-Way-Binding-Post-260-242
(I don't have speakon anywhere so would have to get amp to speakon, speakon cable, in addition to the port... which is a bit much.)
I'll get a brightly colored exterior paint for it.
Am I forgetting anything in this? And does anyone have a 1/2 (.453 actual) in cutlist/cutsheet? Otherwise i'll have to adapt martinsson's drawings which I can do.
Have you looked at the single sheet TH project ?
The Jbell SS15? Single 1/2" ply cabinet designed for the 3015LF.
Also there are the 2' cubes from the same thread , basically is a smaller SS15 just measuring 2' per side but is not the CUBO ,is still a TH.
I think I got the plans for em all, cut sheet can be made easily with a cut list optimizer web app,it even make the order of the cuts sequentially in a list , so you optimize your cut time
if you need help let me know I will be happy to lay a hand.
The Jbell SS15? Single 1/2" ply cabinet designed for the 3015LF.
Also there are the 2' cubes from the same thread , basically is a smaller SS15 just measuring 2' per side but is not the CUBO ,is still a TH.
I think I got the plans for em all, cut sheet can be made easily with a cut list optimizer web app,it even make the order of the cuts sequentially in a list , so you optimize your cut time
if you need help let me know I will be happy to lay a hand.
SS15 is even bigger than THAM15, so if cycrev has settled on a THAM12 to meet size constraints then it'd be a suggestion in the wrong direction...
The enclosure volumes are 260L, 187L and 82L respectively. The THAM15 being 2.2x the size of THAM 12, the SS15 being 3.2x the size of THAM12 and 1.4x the size of THAM15
A single SS15 would be as big as I'd want to carry on a bicycle trailer before things get serious, but that doesn't allow any space for battery, amp or tops 😳
And a even a THAM15 is a bit large for lugging up/down stairs and in to an apartment
As for the redesign around 12mm ply, with some clever resources available to us a helpful forum member might be able to adapt the design to fit your specific size constraints (ie, going a bit larger to gain output without getting too big to fit in your space)
https://www.diysubwoofers.org/sheets/
https://freeloudspeakerplan.rf.gd/?i=1 (discussion here)
The enclosure volumes are 260L, 187L and 82L respectively. The THAM15 being 2.2x the size of THAM 12, the SS15 being 3.2x the size of THAM12 and 1.4x the size of THAM15
A single SS15 would be as big as I'd want to carry on a bicycle trailer before things get serious, but that doesn't allow any space for battery, amp or tops 😳
And a even a THAM15 is a bit large for lugging up/down stairs and in to an apartment
As for the redesign around 12mm ply, with some clever resources available to us a helpful forum member might be able to adapt the design to fit your specific size constraints (ie, going a bit larger to gain output without getting too big to fit in your space)
https://www.diysubwoofers.org/sheets/
https://freeloudspeakerplan.rf.gd/?i=1 (discussion here)
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Do THs really offer any advantage over straight BR when you start making them tiny? That NDL76 is like 97-98 dB/W natively, which is probably plenty. Small ish cabinet, low tuned so as not to run out of excursion, high pass at 50 (all you can realistically expect from batteries). A TH of the same size may not give any more 50 Hz output - can’t beat Hoffman.
Is BR short for Bass Reflex? Do you have any resources you recommend for learning about it?
Looking into it https://www.parts-express.com/B-C-1...UkMnqUs9KHP036fvhzLP7uGSap9WvBU8KHyNzYNwBq2F2 it says a 3.5' cube box with a vent. The dimensions don't matter as long as thebox is that volume right? Does the vent dimensions matter?
Thanks,
Benjamin
Looking into it https://www.parts-express.com/B-C-1...UkMnqUs9KHP036fvhzLP7uGSap9WvBU8KHyNzYNwBq2F2 it says a 3.5' cube box with a vent. The dimensions don't matter as long as thebox is that volume right? Does the vent dimensions matter?
Thanks,
Benjamin
Box dimensions and vent area interact together to change the tuning of the cabinet (Fb)
if you change one or the other or both the tuning change
Box volume interacts with the vent. Aspect ratio not as much. Model it in B&C’s recommended 3.5 CF, and play with the tuning. Going up a bit might help if you’re limiting response to say 50 Hz. You’d probably be hard pressed to make a 3.5 CF net TH play any louder at 50 Hz with that driver, and yiu can sure as hell cross the mains over higher with an ordinary reflex box. THs get their “gain” from increased cubic footage, and you pay for it by having a limit on upper end useability.