I was a bass player ages ago (lol, 25ish years?) and just recently ordered one for Father’s Day.
I’ve been a tinkerer forever and have been eyeballing all the lovely and inexpensive new gear out there now… class D amps, and inexpensive subs and DML speakers and all this fun stuff I never knew I needed. ;-p
I want to shove a 10-12” sub (or maybe a 4 8” ones?) into a slightly beefed up bass guitar case, along with a few hundred watts of Class D amp and with some of the Dayton audio exciters to use one of the panels as a flat panel speaker. Ideally it would also have an AC and DC option. It also hopefully holds the guitar when it’s not being used. ;-p The intent is to jam with friends, maybe getting a little rowdy but not bringing down the house.
Not asking for much? lol. Anyway, I’m still in the ideas stage and have a few guidance questions.
Which is likely to work best, a single larger sub or several smaller ones? The “Enclosure” volume is likely to be 1.75-2 cubic feet. But some at least will be padded/felt lined which will eat some space. 16x48x5 or 6-ish inches.
Layout wise I’m debating between smaller subs and/or full range speakers on either side of the neck firing to the “back” or bottom, or a larger shallow mount sub with the neck literally sitting on foam padding on the speaker magnet when the bass is stored. The mids I’m not as worried about space wise, but I’m planning to at least try a DML flat panel soloution and see how far I get.
There’s obviously a lot of challenges, not the least of which is designing for a poor “enclosure” and just physically figuring out where and what to fit in there. It also can’t be toooo heavy, and still needs to protect the guitar in travel. Let me know if I’m missing something obvious as to why it’s a total no-go.
So… TLDR if you were thinking of making a bass amp that is also a bass case would you pick multiple smaller drivers or one as big as you can manage? (Ignore mids for now.)
I’ve been a tinkerer forever and have been eyeballing all the lovely and inexpensive new gear out there now… class D amps, and inexpensive subs and DML speakers and all this fun stuff I never knew I needed. ;-p
I want to shove a 10-12” sub (or maybe a 4 8” ones?) into a slightly beefed up bass guitar case, along with a few hundred watts of Class D amp and with some of the Dayton audio exciters to use one of the panels as a flat panel speaker. Ideally it would also have an AC and DC option. It also hopefully holds the guitar when it’s not being used. ;-p The intent is to jam with friends, maybe getting a little rowdy but not bringing down the house.
Not asking for much? lol. Anyway, I’m still in the ideas stage and have a few guidance questions.
Which is likely to work best, a single larger sub or several smaller ones? The “Enclosure” volume is likely to be 1.75-2 cubic feet. But some at least will be padded/felt lined which will eat some space. 16x48x5 or 6-ish inches.
Layout wise I’m debating between smaller subs and/or full range speakers on either side of the neck firing to the “back” or bottom, or a larger shallow mount sub with the neck literally sitting on foam padding on the speaker magnet when the bass is stored. The mids I’m not as worried about space wise, but I’m planning to at least try a DML flat panel soloution and see how far I get.
There’s obviously a lot of challenges, not the least of which is designing for a poor “enclosure” and just physically figuring out where and what to fit in there. It also can’t be toooo heavy, and still needs to protect the guitar in travel. Let me know if I’m missing something obvious as to why it’s a total no-go.
So… TLDR if you were thinking of making a bass amp that is also a bass case would you pick multiple smaller drivers or one as big as you can manage? (Ignore mids for now.)
It’s so subjective, lol.
Maybe something like a 100 to 150 watt combo amp. Enough to be heard playing with, well maybe not an angry drummer but at least a slightly annoyed one. ;-p
Just jamming with buddies in the basement, but a maybe a little loudly. Enough low tones for the low B to feel “full” but not shake windows too much.
Maybe something like a 100 to 150 watt combo amp. Enough to be heard playing with, well maybe not an angry drummer but at least a slightly annoyed one. ;-p
Just jamming with buddies in the basement, but a maybe a little loudly. Enough low tones for the low B to feel “full” but not shake windows too much.
Ok, here’s the update. I’ve got some parts on the way, starting with the audio exciters. I plan to start with these, and if nothing else I’ll turn them into some funky speakers for the house.
https://www.parts-express.com/Dayto...m-2-Hole-Exciter-24W-4-Ohm-295-225?quantity=1
I picked up 4.
The plan is to stick them on 1/4 birch ply and see what it can do and if it sounds like it has enough “presence” to work in conjunction with a sub. I got the screw on mounting plug design because it looks easier to experiment with.
I also have this Class D amp, currently to be used with the headphone out from a little headphone practice amp.
https://a.co/d/06U2tYJU
I liked this one because its watt output ranges well with voltage input, so I can start out at low input voltage and work my way up.
This is the headphone amp, if anyone was interested. I like that it hooks to Bluetooth so I can look up songs on YouTube and jam with them. I don’t really use effects on it with bass so no feel on that front.
https://a.co/d/0iXLh8jx
https://www.parts-express.com/Dayto...m-2-Hole-Exciter-24W-4-Ohm-295-225?quantity=1
I picked up 4.
The plan is to stick them on 1/4 birch ply and see what it can do and if it sounds like it has enough “presence” to work in conjunction with a sub. I got the screw on mounting plug design because it looks easier to experiment with.
I also have this Class D amp, currently to be used with the headphone out from a little headphone practice amp.
https://a.co/d/06U2tYJU
I liked this one because its watt output ranges well with voltage input, so I can start out at low input voltage and work my way up.
This is the headphone amp, if anyone was interested. I like that it hooks to Bluetooth so I can look up songs on YouTube and jam with them. I don’t really use effects on it with bass so no feel on that front.
https://a.co/d/0iXLh8jx
Probably better as funky speakers for the house, they want lightweight material like foam core to make much noise.
For bass, you want a stiff, airtight (other than bass reflex ports) enclosure.
Plywood ATA (Airline Transit Authority) cases fit that general requirement:
It is possible to DIY a case like that, but the valence material has to be sized for the plywood you use, preferably at least 3/8", bass enclosures are usually 3/4".
Any air leaks will make noise and waste considerable amounts of your limited power.
Don't waste time on a small power supply, get 36volts and ~6 amps.
Since you have a five string bass (32Hz low B), and limited cabinet volume, sealed would be the easy choice. Bass reflex (ported) would be more efficient, but fitting the very long ports required inside the cabinet more challenging. That said, using plumbing pipe, the ports could be carried in the case and fitted outside when playing. An example here:
https://www.diyaudio.com/community/threads/hot-rod-8-2-way-pa-studio-monitor.343215/
To make any appreciable output down low, the drivers need to "move a lot of air", so you are looking for the best displacement vs cost ratio. Displacement = cone area (Sd) times Xmax (linear excursion).
Multiple smaller drivers will be easier to fit in your bass case than a single large driver of equal displacement, and will generally have better sound in the upper range.
Art
Right now, I’m eyeballing this speaker:
https://a.co/d/09cpSMED
In conjunction with the DML panel IF the DML experiments work out. Sealed enclosure, no ports (the low end bump isn’t worth the effort for this use.) I’m actually reaching “up” with this sub, not down lol. I’d use a woofer if I could find similar shallow mounts but the industry doesn’t really “do” that. This “sub” has specs and user reviews that place it as higher frequency than some of its peers, which is better in my use case. winISD shows it falling off around 40 but close enough. Top end should reach the 200-400hz rollover expected to match the DML’s.
There’s some examples of using the ply effectively as a DML surface, but I’m hardly married to ply as the surface. It’s just cheap, available and EZ place to start testing. The foam core is possible too, or as a tougher alternative I do the foam core with a layer of CF or fiberglass and see how that works. Actually, another alternative I’ve considered is just cardboard. Throw a cool looking light cloth and resin on it and see how it plays. In the end, that’s just an excuse to play with that tech, lol.
The case will be a custom construct, with additional bracing if needed and sealed air tight, or at the least as close to that as I can get, lol. 1/4-3/8 birch ply with thicker on the edges (support and sealing surfaces) was the thought. I haven’t played with fiberglass in a couple of years, but it may come in to play.
If the DML experiments works out the lid will be… well, I have some ideas lol. If it doesn’t I’ll probably fall back to adding some smaller midbass/full range drivers and call it a day.
https://a.co/d/09cpSMED
In conjunction with the DML panel IF the DML experiments work out. Sealed enclosure, no ports (the low end bump isn’t worth the effort for this use.) I’m actually reaching “up” with this sub, not down lol. I’d use a woofer if I could find similar shallow mounts but the industry doesn’t really “do” that. This “sub” has specs and user reviews that place it as higher frequency than some of its peers, which is better in my use case. winISD shows it falling off around 40 but close enough. Top end should reach the 200-400hz rollover expected to match the DML’s.
There’s some examples of using the ply effectively as a DML surface, but I’m hardly married to ply as the surface. It’s just cheap, available and EZ place to start testing. The foam core is possible too, or as a tougher alternative I do the foam core with a layer of CF or fiberglass and see how that works. Actually, another alternative I’ve considered is just cardboard. Throw a cool looking light cloth and resin on it and see how it plays. In the end, that’s just an excuse to play with that tech, lol.
The case will be a custom construct, with additional bracing if needed and sealed air tight, or at the least as close to that as I can get, lol. 1/4-3/8 birch ply with thicker on the edges (support and sealing surfaces) was the thought. I haven’t played with fiberglass in a couple of years, but it may come in to play.
If the DML experiments works out the lid will be… well, I have some ideas lol. If it doesn’t I’ll probably fall back to adding some smaller midbass/full range drivers and call it a day.
The Infinity reference-1200sm looks like a good choice for the project.
Just going off it's published specs, you can expect to reach Xmax at 99dB at 30Hz (low B), 104dB at 40Hz (low E) with it in a sealed cabinet.
The cabinet suggestions response seems reasonable:
At 2.83volts, (2 watts @4ohm) the sealed does ~80dB @30Hz, 85dB @40hz.
With 200 watts, 100dB@30Hz, 105dB @40hz.
100dB@30Hz sounds about equal loudness to ~50dB at 1kHz, a quiet conversation.
The driver could take more than 200watts, but will be above 10% distortion, and when driven past Xmax, the mids start to sound "gargly".
At 2.83volts, (2 watts @4ohm) the 33Hz Fb ported does 89dB @30Hz, 92dB @40hz.
With 200 watts, 109dB@30Hz, 112dB @40hz.
It would be +5dB louder @30Hz, +7dB louder @40hz than the sealed.
Given just 1/4 the power it would be near the level of the sealed woofer.
When you consider equal loudness contours, +4dB @30Hz sounds around "twice as loud".
And consider these are one meter levels- an orchestral kick drum can do ~115dB at three meters, snare ~108dB. Rock drummers tend to do those kinds of levels when "restrained" 😉
Anyway, since you potentially have the cabinet volume for the bass reflex, I'd suggest using it, you can always adjust the low/high balance with tone controls, but when you can't hear the low end at full power, nothing you can do about it except distort 😢.
Art
Left turn, Clyde!
lol, OK, DML was fun but I’m dropping it for this build anyway.
Enter a stupid quantity of 6.5" "subs"
https://www.parts-express.com/GRS-6LPSW-4-6-1-2-Low-Profile-Subwoofer-4-Ohm-292-461?quantity=1
OK, I was poking around at various speaker/sub combo's and throwing them at WinISD to see what stuck. I saw these small subs and expected not to get a lot from them, but WinISD is telling me something different. I did use 8 of them, though... LOL
I fully expect I've just got things wrong in WinISD BUT... in these snips, green is 8x of these 6.5" subs in a ported enclosure, blue in just a sealed box. I also think it would be way easier to stuff it in a bass case, because the depth is only 2 inches. It's not as "low" as the big sub, but the SPL is way higher and the freq is more focused in the ranges that seem to be "usefull" in a bass amp. (At least, it replicates a lot of what I found for big name bass cabs.)
I did need to put a "high pass" filter on it to keep 20Hz from blowing the speaker up, based on the numbers. Is that real world concern? Would the amp even pass along 20Hz info, and if so as a practical thing do I need to somehow keep that frequency away from the signal? If so.. any cheap/effective way to "Brick wall" under 30 Hz?
This isn't a "cheaper" solution but it seems like it may be overall better in terms of SPL, useable freq, and fitting the physical limitations and doing with them the best it can.
Thanks for any insight!
lol, OK, DML was fun but I’m dropping it for this build anyway.
Enter a stupid quantity of 6.5" "subs"
https://www.parts-express.com/GRS-6LPSW-4-6-1-2-Low-Profile-Subwoofer-4-Ohm-292-461?quantity=1
OK, I was poking around at various speaker/sub combo's and throwing them at WinISD to see what stuck. I saw these small subs and expected not to get a lot from them, but WinISD is telling me something different. I did use 8 of them, though... LOL
I fully expect I've just got things wrong in WinISD BUT... in these snips, green is 8x of these 6.5" subs in a ported enclosure, blue in just a sealed box. I also think it would be way easier to stuff it in a bass case, because the depth is only 2 inches. It's not as "low" as the big sub, but the SPL is way higher and the freq is more focused in the ranges that seem to be "usefull" in a bass amp. (At least, it replicates a lot of what I found for big name bass cabs.)
I did need to put a "high pass" filter on it to keep 20Hz from blowing the speaker up, based on the numbers. Is that real world concern? Would the amp even pass along 20Hz info, and if so as a practical thing do I need to somehow keep that frequency away from the signal? If so.. any cheap/effective way to "Brick wall" under 30 Hz?
This isn't a "cheaper" solution but it seems like it may be overall better in terms of SPL, useable freq, and fitting the physical limitations and doing with them the best it can.
Thanks for any insight!
So for sensitivity usually normal live sound speakers
are used for MI ( Musical instrument) duty.
For instance the now abandoned 12" sub
before hit 99 dB at xmax. with alot of power
As with most typical 15" bass drivers
they do 98 to 100 dB with 1 watt
If your enclosure is 1.75 to 2 cubic feet.
This is basically what a live sound 12"
needs.
A common 15" bass driver be
3 to 4 cubic feet.
Most people weasel them into
3 cubic feet.
Unless you find something with
low Qts like classic EV 15L or 15B
they do fine in 3 cubic feet.
Otherwise most use Kappalite
Eminence for typical bass cab
3012 for 12" or 3015 for 15"
they have LF version for more power
or xmax. tradeoff is less high end
so often do a 2way with a 6.5" for mid.
Budget bass guitar rig
usually celestion pulse
or eminence CB158
are used for MI ( Musical instrument) duty.
For instance the now abandoned 12" sub
before hit 99 dB at xmax. with alot of power
As with most typical 15" bass drivers
they do 98 to 100 dB with 1 watt
If your enclosure is 1.75 to 2 cubic feet.
This is basically what a live sound 12"
needs.
A common 15" bass driver be
3 to 4 cubic feet.
Most people weasel them into
3 cubic feet.
Unless you find something with
low Qts like classic EV 15L or 15B
they do fine in 3 cubic feet.
Otherwise most use Kappalite
Eminence for typical bass cab
3012 for 12" or 3015 for 15"
they have LF version for more power
or xmax. tradeoff is less high end
so often do a 2way with a 6.5" for mid.
Budget bass guitar rig
usually celestion pulse
or eminence CB158
Typical bass guitar amplifiers yes
now days do brick wall over excursion
with a high pass filter.
Usually around 35 Hz
would be 4th order highpass.
You can use linkwitz or butterworth
in Winisd. Specify 4th order.
numerous highpass filter pedals real world
and run this in you amplifiers effects loop
GRS subs are 83 dB
when normal MI speakers in 12"
range are 94 to 97 dB
which would be one watt compared
to likely 60 to 100 watts for home audio subs.
Something budget for good SPL
and overall sound be
PRV Audio 12W800A
Dayton Audio PA310-8
since they likely model in typical1.75 to 2 cubic feet and port freq
would just be Fs or no more than
3 to 5 Hz higher than Fs
other than more expensive
neos such as kappalite 3012
Thank you! I’m starting to clue in to some of these specs and what they really mean, lol. I’m sure I’m still only seeing a percent of the picture, lol.
General (I think?) question…. Given a cramped box situation, would one ideal(ish) speaker be better than 2 “overstuffed” ones? Ohh, and next generality… one badass driver, or two decent-ish ones?
I’m currently eyeballing this driver, higher SPL, reasonable mounting depth with smaller neo magnet, and I think I can squeeze in two. It’s also cheap, but that’s not the only factor. Honestly 2x10 was more than I expected to be able to do so I’m probably over engineering lol.
https://www.parts-express.com/NE1230-8-12-Paper-Cone-Neodymium-Woofer-8-Ohm-299-2261?quantity=1
I’m also not entirely clear on SPL vs rated power…. Like, if a speaker is hitting Xmax it’s putting out the most SPL it can, right? So why is a “300w RMS” speaker hitting XMAX at 120w?
It’s all a learning experience anyway, so even if it ends up sucking I’ll have learned what not to do. ;-p
General (I think?) question…. Given a cramped box situation, would one ideal(ish) speaker be better than 2 “overstuffed” ones? Ohh, and next generality… one badass driver, or two decent-ish ones?
I’m currently eyeballing this driver, higher SPL, reasonable mounting depth with smaller neo magnet, and I think I can squeeze in two. It’s also cheap, but that’s not the only factor. Honestly 2x10 was more than I expected to be able to do so I’m probably over engineering lol.
https://www.parts-express.com/NE1230-8-12-Paper-Cone-Neodymium-Woofer-8-Ohm-299-2261?quantity=1
I’m also not entirely clear on SPL vs rated power…. Like, if a speaker is hitting Xmax it’s putting out the most SPL it can, right? So why is a “300w RMS” speaker hitting XMAX at 120w?
It’s all a learning experience anyway, so even if it ends up sucking I’ll have learned what not to do. ;-p
Ohh wait, realized I said 2x10 was more than I thought I could do, that’s a 12 I posted. So 2x12.
2 “overstuffed” may produce no more low bass, but more upper bass.
You really need to compare drivers in relation to what you want them to do.
Two of those have less displacement than one Infinity reference-1200sm. More mid bass, less low bass.
https://www.parts-express.com/NE1230-8-12-Paper-Cone-Neodymium-Woofer-8-Ohm-299-2261?quantity=1
Xmax is the extent of linear excursion, a speaker can be driven past Xmax, but will distort more.
300 watts is just a bit more than +3dB over 120watts.
Four times the displacement (excursion) is required for each halving of frequency to maintain the same SPL in a sealed cabinet.
The average power used may be a fraction of the peak power, a speaker hitting 300 watt peaks may average under 40 watts.
Not to quibble about it but 300W peak ≠ 300W RMS.
Wish some people understand what a paragraph can do to your writing.
https://eminence.com/blogs/blog/understanding-loudspeaker-power-ratings
And a few other tidbits.
https://eminence.com/pages/support__understanding-loudspeaker-data
https://www.talkbass.com/attachments/jbl-technical-note-vol-1-no-16-pdf.789624/
Wish some people understand what a paragraph can do to your writing.
https://eminence.com/blogs/blog/understanding-loudspeaker-power-ratings
And a few other tidbits.
https://eminence.com/pages/support__understanding-loudspeaker-data
https://www.talkbass.com/attachments/jbl-technical-note-vol-1-no-16-pdf.789624/
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Mechanically a speaker in all simplicity moves back and forth.
It can only move so far forward and so far back before it reaches 10 % distortion.
So this is the Xmax rating.
A speaker can be driven past Xmax
Distortion will be higher of course.
Eventually it will hit Xlim
Xlim is actual mechanical damage. Forward motion usually will damage
or distort the cone or surround.
Rearward there is a magnet plate and the voice coil will actually physically strike
it.
More often than not the manufacture rating for Xlim would be based on when
the voice coil will strike the rear plate.
Some speakers have a " bumped back" plate
Sometimes visible as a bump on the magnet.
They increase the distance of the rear plate / magnet so the coil
wont hit it as quickly
Low frequency is the main cause to hit Xmax faster.
Next sim you do in winisd.
Look at cone excursion screen and apply power
You will see quickly how below, say 100 Hz
Speaker can reach Xmax quickly.
Power rating such as 300 watts
is a thermal rating how much heat it can handle
before damage.
In the old days most the thermal issues was the glue
used to glue the wire to the coil.
Once it gets too hot the glue fails.
So its why you see large diameter coils for high power
like 2.5 inches to 3 inches so the can dissipate heat better.
Also they use aluminum or kapton coil forms to glue the wire
too. Since they dissipate heat better.
Then of course modern epoxy glue has much much higher
thermal rating before it melts and fails.
Very old basic speakers used paper bobbins for coils
you wont get much more than 20 to 30 watts from those
paper doesn't dissipate heat very well.
With most modern high power drivers, the suspension "soft parts", either the surround or spider(s) limit excursion prior to the voice coil former striking the back plate.
Though a driver may be driven to Xmax with far less power than it's thermal (burn) rating, surround limitations (Xlim or Xmech) are progressive and usually require considerably more power than the driver is rated for to reach.
Always a good idea to verify by hand what the limitations are, the voice coil former striking the back plate may cause instant damage, while hitting the suspension limits may take quite some time before damage.