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The ultimate small speaker - final design peer review thread


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#21 lowerFE

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Posted 11 August 2016 - 03:49 PM

Hey LowerFe...Have you looked at any of the Aurum Cantus drivers? They have a couple which may work better than the SEAS for this type of project.

 

Any chance you would increase the enclosure size to 6.5x6.5 or maybe 7x7? That opens up a lot of more driver choices with a bit more SD. Also can you really fit the 3.5" mid and tweet in between the two drivers on a 14x6 baffle?

 

Been very busy lately, so I haven't been able to spend time to digest SME's suggestions and give a proper response, and won't be able to for a few more days. I also have some substantial improvements in mind, but don't have time to flesh out the details yet. But I can respond to yours quickly.

 

Yes, I actually did look at them, specifically the AC120, and the specs are unreal. However, when I asked opinions of them, multiple people chimed in to say the woofers measure *extremely* off spec, like Qts of 0.55 instead of 0.18. 

 

14x6x6 is already bigger than I want and at the edge of what I'd consider to be a small speaker. Increasing it further will no longer make it a small speaker and becomes dangerously close to the size of a bookshelf speaker. I'd say 80% of the fun is the challenge of keeping it small and the satisfaction of being able to claim "mine is smaller and sounds way better". Unfortunately at 14x6x6 it is already bigger than most sound docks. I absolutely want it noticeably smaller than the Sonos Play 5, by far the best sounding lifestyle speaker on the market, and be able to claim "mine is smaller and sounds way better". You built the M.A.U.L. to be the coolest kid on the block, I'm sure you'd understand where I'm coming from  :D The value factor on this project is a solid 0, but the fun factor is 12/10.

 

And yes, I can fit the 2 woofers, mid and tweeter on the 14x6 baffle if I machine off the frame for every driver. I'm trying extremely hard to keep the box size small! Without doing this, the dimensions would have to increase by 2'' in width and 1'' in height. 



#22 Ricci

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Posted 12 August 2016 - 02:01 PM

Yes, I actually did look at them, specifically the AC120, and the specs are unreal. However, when I asked opinions of them, multiple people chimed in to say the woofers measure *extremely* off spec, like Qts of 0.55 instead of 0.18. 

 

  :D The value factor on this project is a solid 0, but the fun factor is 12/10.

 

That's the exact driver I was thinking of and the first I've heard of that. I guess those specs are too good to be true. :(

Do you have any links to measurements or discussion? I was thinking about using the AC165 in a compact bookshelf design but not if its a fairy tale driver.



#23 lowerFE

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Posted 12 August 2016 - 09:25 PM

That's the exact driver I was thinking of and the first I've heard of that. I guess those specs are too good to be true. :(

Do you have any links to measurements or discussion? I was thinking about using the AC165 in a compact bookshelf design but not if its a fairy tale driver.

 

 

Here's the thread

 

http://techtalk.part...um-cantus-ac120

 

I wanna announce several improvements I plan on incorporating. First, the woofer, since this is data-BASS :P .

 

I found a much better woofer for my application - the little known Wavecor WF152BD05. This is the driver I was hoping for, sacrifice Fs to tighten the suspension and drop the Vas. It has a nice low Qts of 0.29 and a lot of motor strength. The Q in a sealed 5L enclosure for a pair of them is 0.69! In a PR enclosure, it delivers around 2dB more output than the SEAS L16RNX from 40-55Hz with the same input power because the PR's actually boost output. This is very close to an ideal specially designed small subwoofer driver like the Tangband W5-1138SMF that brings around 3dB more. I've attached simulations for a comparison between the Wavecor and the SEAS L16RNX. One person mentioned that the sound quality is extremely good and comparable to a Scanspeak Revelator 15W (!), and behaves very well when pushed very hard. Looks like this is about as good of a woofer for my speaker. Bass, sound quality, non crazy price, check check check. 

 

Next, I'm going to try an internally amplified design. I'm thinking of trying my hands on some electronics and put a 4 channel amplifier and power supply right into the speaker. Both components are small enough to just fit in the speaker, and would massively declutter the need for 2 external amps and 2 power bricks for *each* speaker.

 

http://www.parts-exp...508-(t--320-335

http://hifimediy.com...PS300R-28V-110V

 

Unfortunately the amp won't be as powerful, 64W vs 125W per channel (1% THD), but this is close enough to the 70W power rating on the woofers. However, even if the woofers can take the 125W, after power compression the difference is probably around 1dB. So I'll sacrifice 1dB for the massive convenience from 4 less boxes and 4 pairs less wires. One other advantage is that this amp could help to thermally protect the speaker. It has a temperature sensor that'll throttle power if it gets too hot, I believe at >80C. If it gets this hot inside the speaker, the woofer's voice coil is probably straining as well, and it would be good to limit power. While this is not the ideal amp, this is more than enough when I have no experience with DIY electronics. An ideal amp would be a really nice sounding mid powered amp like the TPA3116 for the tweeter and midrange, and a powerful amp like the TDA7498E for the woofers, but that would be too much of a challenge for a first time electronic DIY. Maybe next time.

 

After much thought, it may not be worth chasing the 1/4'' wavelength crossover with the midrange and tweeter. So I want to try something else - an cylindrical midrange chamber. In my last speaker, the midrange chamber is essentially a cube, the least ideal enclosure shape. This time, I will use a stuffed cylindrical midrange chamber to better deal with standing waves and resonances. Because of the cylindrical shape, the midrange and tweeter cannot be in the same chamber as it will take up too much internal volume because there's no way of reclaiming the internal volume behind the tweeter like I can do with wood. This results in an increase in the distance between the mid and tweeter to a point where the crossover frequency will be infeasibly low for the tweeter.  However, I do expect a noticeably cleaner midrange with this change. 

 

Man, I keep thinking this is about as good as it gets, but I keep proving myself wrong. I like it!

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#24 SME

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Posted 14 August 2016 - 07:54 AM

...

 

After much thought, it may not be worth chasing the 1/4'' wavelength crossover with the midrange and tweeter. So I want to try something else - an cylindrical midrange chamber. In my last speaker, the midrange chamber is essentially a cube, the least ideal enclosure shape. This time, I will use a stuffed cylindrical midrange chamber to better deal with standing waves and resonances. Because of the cylindrical shape, the midrange and tweeter cannot be in the same chamber as it will take up too much internal volume because there's no way of reclaiming the internal volume behind the tweeter like I can do with wood. This results in an increase in the distance between the mid and tweeter to a point where the crossover frequency will be infeasibly low for the tweeter.  However, I do expect a noticeably cleaner midrange with this change. 

 

...

 

The standing wave resonances of the inside of a cylinder are only slightly less bad than in a cube with all sides equal but still worse than if you just used a box with dissimilar dimensions.  The curved sides don't have any kind of magic standing-wave suppressing properties.  Any shaped interior with have standing waves.  Shapes with symmetry are worse because there you see multiple resonances with different geometry but the same frequency.  Besides, good absorber inside the box will suppress almost all the interior standing wave resonances.

 

Of course, the wood panels and box itself also have standing wave resonances, but these are different and depend more on the plywood thickness, the bracing scheme, and any damping that's present, than the shape.



#25 lowerFE

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Posted 16 August 2016 - 08:57 PM

The standing wave resonances of the inside of a cylinder are only slightly less bad than in a cube with all sides equal but still worse than if you just used a box with dissimilar dimensions.  The curved sides don't have any kind of magic standing-wave suppressing properties.  Any shaped interior with have standing waves.  Shapes with symmetry are worse because there you see multiple resonances with different geometry but the same frequency.  Besides, good absorber inside the box will suppress almost all the interior standing wave resonances.

 

Of course, the wood panels and box itself also have standing wave resonances, but these are different and depend more on the plywood thickness, the bracing scheme, and any damping that's present, than the shape.

 

 

You're right. I mistakenly remembered that cylindrical midrange enclosures are significantly better than rectangular enclosures. I remember this from the Linkwitz LXmini, but the use of a cylindrical enclosure was for optimal diffraction instead of internal standing waves. I will stick with rectangular midrange enclosures as they can act as a brace and allow a closer midrange and tweeter placement. I might try one with non parallel walls depending on difficulty. 

 

After some thought, it doesn't seem there is a nice way to deal with the group delay problem without serious sacrifices of real world performance. The bass will be significantly boosted, there's no doubt about it for a satisfying listening experience. The use of a steep high pass slightly below tuning is necessary to prevent PR over excursion. On top of that, the compressor is going to increase the group delay as well. So either way the group delay around tuning is going to be bad. Honestly, I probably will enjoy the fat sounding ringing bass like how I enjoy my Logitech Z-5500 (it actually measures extremely well, much better than it's reputation). I don't actually like the sound of most high end subwoofers using heavy duty drivers from the likes of JL, Martin Logan, Paradigm, or DIY like the Dayton UM woofers that people say as "tight" (I unfortunately own two of these kind of subs). I much prefer the thicker sounding bass from subs like JTR or the PA style subs. But this is another (long) story. 

 

On the other hand, I found a much more suitable amplifier. 4 channels, much higher power (100W @ 0.05% THD), integrated power supply, small form factor, low price. Unfortunately, I have to buy a minimum of 10 units when I only need 2. I'm trying to figure out if there is a way around the MOQ. 

 

http://www.aliexpres..._460608255.html

 

I've also updated the first post with the upgrades.



#26 lowerFE

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Posted 19 August 2016 - 10:44 PM

Another update: I found a suitable tweeter to address the low sensitivity issue of the Scanspeak D3004/6020 tweeter I was originally planning on using. 

 

TW030WA03_04-250ps.jpg

 

I will be using the Wavecor TW030WA04. This is a 1.2'' tweeter flangeless 4 Ohm tweeter. This tweeter has a sensitivity of 94dB @ 2.83V, which is 7-8dB higher than the Scanspeak. Wavecor's specs are known to be very accurate, so I believe the 94dB sensitivity is real. The 57% larger Sd also means the tweeter will likely to play a lot lower with less distortion at high volumes. Since this is flangeless, I don't have to butcher an expensive tweeter's frame to reduce size, and it will make it easier for me to get very tight CTC spacing and a much better chance of getting the 1500Hz crossover for the 1/4'' wavelength crossover to work. While a few users have commented on the excellent sound quality of this tweeter, I don't know if it'll sound as good as the Scanspeak as they are the benchmark small format tweeter. I do expect it to sound very close, and the benefit of the vastly higher sensitivity for dynamics and higher peak SPL should outweigh the slight sound quality advantage of the Scanspeak. 

 

There is a non ferro fluid version of this tweeter, and the sensitivity is 1dB higher. Should I consider it?



#27 lowerFE

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Posted 22 August 2016 - 09:51 PM

More updates:

 

Let's get the bad news out of the way first. It looks like I won't be able to fit this on a 14'' x 6'' baffle. I will need 14.5'' x 6'' if I want to rear mount all the drivers. I am considering reducing the side wall thickness of the enclosure and midrange chamber by half to 1/8'', so I'll save 4 x 1/8'' = 1/2'' to bring the dimension back down to 14'' x 6''. The other walls will remain 1/4''. While mechanical vibrations won't be a problem due to the dual opposed design, I'm not sure of the possibly consequences of reducing the side wall thickness to 1/8'' for cabinet resonances. 

 

Now for the good news!

 

The amplifier is getting a significant upgrade. I will be using the ICEpower 50ASX2 for the midrange and tweeter, which will provide 50W for each driver. The two woofers will be powered by the ICEpower 125ASX2, which will deliver 125W per channel to the woofers. The ICEpower amps should sound much better than most of the class D amplifiers on eBay and Alibaba. I never knew ICEpower made lower power units until now. They have integrated power supplies, the dimensions are incredibly small and they're not horribly expensive. That said, they are still more than double the price of the previous amp I was considering. However, there will be no doubts on the excellent sound quality, power output, and build quality of ICEpower amps. 

tw030wa13_14_front.jpg

 

I'm changing the tweeter to the Wavecor TW030WA13, which seems to be an upgraded version of the TW030WA04 with a nice chambered tweeter. The driver is very good at playing low with 60% more Sd and over 3x higher Xmax than the Scanspeak tweeter. Someone mentioned using this tweeter with a 1000Hz crossover and it had no problems even with volume in the high 90dB's. The only downside is the larger physical size. Even with the flange perfectly cut, it is still 7mm larger, requiring an even lower crossover frequency.



#28 SME

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Posted 23 August 2016 - 06:53 AM

I don't think 1/8" thickness will be satisfactory if you are using ply or MDF.  It will most likely be very lossy.  Even hardboard is quite floppy at 1/8" thick.  I'd be concerned about 1/4" being to be too thin, but it depends on the length and width of the unbraced spans.  IIRC, stiffness roughly increases by 8X every time you double thickness, so you give up a lot when you reduce thickness.



#29 Ricci

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Posted 23 August 2016 - 01:12 PM

I don't think 1/8" thickness will be satisfactory if you are using ply or MDF.  It will most likely be very lossy.  Even hardboard is quite floppy at 1/8" thick.  I'd be concerned about 1/4" being to be too thin, but it depends on the length and width of the unbraced spans.  IIRC, stiffness roughly increases by 8X every time you double thickness, so you give up a lot when you reduce thickness.

 

Agreed. Not to mention it will also become quite fragile to shocks or other unintended incidents. Getting enough material to seal all of the joints well could be tough also.



#30 lowerFE

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Posted 24 August 2016 - 09:19 PM

I just got an interesting thought:

 

I based my enclosure design on BBC's research on cabinet thickness, and how they reached the conclusion that thinner walls are better for midrange than thicker walls because thinner walls pushes the panel resonance down to a lower frequency - about ~100Hz for a 1/4'' thickness wall. So that has me thinking: what thickness and what dimensions does the walls have to be to push the resonance down to 40-50Hz where it would be beneficial to have the box resonate and add bass output to a small speaker where every bit of bass output is needed. 

 

Are there simulations or formulas to predict box resonance?



#31 SME

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Posted 24 August 2016 - 09:53 PM

I just got an interesting thought:

 

I based my enclosure design on BBC's research on cabinet thickness, and how they reached the conclusion that thinner walls are better for midrange than thicker walls because thinner walls pushes the panel resonance down to a lower frequency - about ~100Hz for a 1/4'' thickness wall. So that has me thinking: what thickness and what dimensions does the walls have to be to push the resonance down to 40-50Hz where it would be beneficial to have the box resonate and add bass output to a small speaker where every bit of bass output is needed. 

 

Are there simulations or formulas to predict box resonance?

 

If you dig around, you might be able to find formulas for resonances of single panels in isolation, but they won't be convenient to use and will fail to fully describe of a completely cabinet consisting of multiple panels and whatever bracing scheme is used.  A more accurate solution for full cabinets is to use FEM solid mechanics modelling, but this will be even less convenient to use and more sensitive to input parameters that you most likely have no easy way to measure or determine.

 

I'd rather not go into the BBC study here and in fact, the subject of cabinet design is very complex and fraught with controversy over "which way is best".  I will say, however, that if the box walls are resonating enough to substantially alter the response, it will almost certainly do more harm than good.  You will have a hard time predicting how it will behave.  If you are that desperate for extra bass output, I think the time would be better spent developing custom rectangular drivers and/or passive radiators.  Serious.  If that sounds like a pain (and it does to me), then it's probably best to stick with what is known to work.



#32 lowerFE

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Posted 24 August 2016 - 11:19 PM

If you dig around, you might be able to find formulas for resonances of single panels in isolation, but they won't be convenient to use and will fail to fully describe of a completely cabinet consisting of multiple panels and whatever bracing scheme is used.  A more accurate solution for full cabinets is to use FEM solid mechanics modelling, but this will be even less convenient to use and more sensitive to input parameters that you most likely have no easy way to measure or determine.

 

I'd rather not go into the BBC study here and in fact, the subject of cabinet design is very complex and fraught with controversy over "which way is best".  I will say, however, that if the box walls are resonating enough to substantially alter the response, it will almost certainly do more harm than good.  You will have a hard time predicting how it will behave.  If you are that desperate for extra bass output, I think the time would be better spent developing custom rectangular drivers and/or passive radiators.  Serious.  If that sounds like a pain (and it does to me), then it's probably best to stick with what is known to work.

 

That's probably true -- if box resonance is audibly contributing, that probably won't sound good. I was initially excited by the idea of squeezing even more bass out of a small speaker. So far the driver and passive radiators are contributing to the bass. It would be cool if the box also contributed to the bass output. 

 

I am curious what the box resonance frequency for the speaker I will be building is though. Is there any way to measure that? Any behaviour that could be seen though a CSD or something?

 

I actually researched about some pretty crazy things to do to get as much bass as possible in a small speaker. The most promising one was the use of gases less compliant than air to make the internal volume larger than it is. I remember increasing by a factor of 2 was quite achievable. In a speaker this small, I'm mostly limited by the power input as most small drivers cannot handle more than 100W of power. By reducing power requirements by a factor of 4, I could have gained 6dB more output either through the drivers able to use more of their excursion or doubling up on drivers. Unfortunately, gases leak over time, and even if the box can be completely sealed, the gas will leak through the driver cones and surround, and this idea was abandoned. 

 

So on things that I could realistically do, I will be making my own passive radiator by butchering the very high excursion Tang Band W5-1138SMF that will have at least twice the excursion than the off the shelf Peerless passive radiator. This is necessary to support the active woofers since each active driver only gets one passive radiator of the same Sd. 



#33 SME

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Posted 24 August 2016 - 11:41 PM

There will be multiple resonances.  And note that the cabinet resonances are entirely separate from the resonances of the air within the cabinet.  For an ideal single panel, the resonances are harmonically related and analogously similar to what you see with air space cabinet resonance and room modes.  For a completed cabinet, the resonances will not be harmonic and will be more difficult to predict.  The best way to measure cabinet resonances is with an accelerometer and maybe a CSD of that data.  Of course, you have to choose where to put the accelerometer for each measurement, and need multiple measurements to get a good idea of what's going on.  And of course, this still doesn't tell you how radiation from the cabinet impacts the acoustic response.



#34 lowerFE

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Posted 27 August 2016 - 10:15 PM

Some more updates, starting with bass:

 

I measured my previous design to see what kind of group delay I was getting. The speaker is tuned to 47Hz, high passed at 40Hz, with ~12dB of bass boost that makes it perfectly flat to 45Hz. Unfortunately, the speaker can reach 2 - 2.5 cycles at and below tuning. This is clearly not good, at least by the textbook definition.

 

EDIT: One complication is that the SMSL amp I used to power the woofers seem to have a built in bass boost. The model shows I need up to 12dB of boost, but I only applied 9dB on the miniDSP to achieve it. This might have made the group delay a lot worse as the results are a lot worse than what WinISD predicted. One explanation could be that there were a total of 5 filters used (4 on the miniDSP, 1 in the amp) to shape the bass response. Would using 4 filters instead of 1 in the miniDSP worsen the group delay? I used 4 when I could have just used 2 (boost and high pass) because I was anal on getting the bass to be literally ruler flat. However, if more filters cause more delays, I will reduce the number of filters. 

 

That said, my subjective opinion of the bass quality is excellent. Maybe it's because I might prefer a boomier sounding bass, because I don't like the sound of many well regarded SQ subwoofers from the likes of JL, Martin Logan or Paradigm. Because of this finding, I will continue my previous plan to boost the bass flat despite the group delay problems. 

 

The second update is on the tweeter: Originally I switched out the Scanspeak tweeters because SME pointed out that their very low 85.9dB test bench sensitivity will hold back the performance. However, after some research, it turns out that it seems every tweeter that Medley's Musings test has 4-6dB lower sensitivity than the manufacturer's rating. Scanspeak is known to have accurate, if not conservative specs even with Klippel testing. Two other tests for two different tweeters in the same tweeter family showed that Scanspeak's sensitivity rating is actually 1dB conservative. Therefore I believe the D3004/602010 tweeter I previously used does have an honest 90dB sensitivity.

 

As for the Wavecor tweeter, I noticed the sensitivity rating is an average between 5-20KHz. However, the tweeter exhibits a rising top end, which means that the actual sensitivity is actually 1-2dB lower because of the lower 2-5KHz band. Therefore, the Wavecor tweeter is only at most 2dB more sensitive instead of 7dB that I previously thought. The Wavecor tweeter also has poorer off axis response partly due to the bigger Sd. The sound quality is also a gamble. The tweeter is also 10mm bigger, increasing CTC distance. Therefore, the Wavecor lost of its advantage in sensitivity and the disadvantages now overwhelm the advantages. The Scanspeak tweeter is back because it is smaller, better off axis dispersion, better sound quality, and having a protective grill. 

 

Because the Scan is back in the game, now the question is, should I do a true Ricci style build and upgrade to the beryllium version of the tweeter? :P What do you guys think? The price is $120 vs $280 for each tweeter. However, I just read a measurement of the Be tweeter and the measurements and especially the distortion data is simply outstanding. It would have no problem handling the 1500Hz crossover. The tester also mentioned that besides having less sensitivity, it measures and sounds essentially the same as the $450-$520 normal sized Scanspeak beryllium tweeter as they share the same diaphragm, just a weaker motor on the small one.

 

The devil's advocate side of me is saying no, at ~$2500, this silly speaker is already stupid expensive and way more expensive than expected. I also want to hear the difference between the old and the new and how audible the difference between the two are when they share the same mid and tweeter, but this one will have an improved crossover, diffraction control, DSP, amp, midrange damping and construction. 

 

Link to the Scanspeak small Be tweeter measurements

 

This is the distortion measured at 98dB at 1 meter, barely any distortion even at 1000Hz.

red-D3004-604010_II_dist_-12.2_96dB-1m.g



#35 Ricci

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Posted 29 August 2016 - 01:52 PM

 

The devil's advocate side of me is saying no, at ~$2500, this silly speaker is already stupid expensive and way more expensive than expected.

 

 

 

:o  :blink: That's one expensive micro speaker!

 

Since the budget is blown out already, was there any thought to using exotic materials like perhaps aluminum plate for the enclosure?



#36 SME

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Posted 29 August 2016 - 05:19 PM

Indeed.  With some kind of sheet metal, you can probably achieve sufficient enclosure stiffness with much thinner walls, but if you do this, you really need to be sure that the first resonant frequency is high enough that you won't hit it because sheet metal is very poorly damped.  Or you can try using some damping sheet with it, of which there are many products designed specifically for sheet metal.  This may require testing to ascertain what works and what's acceptable.

 

Edit: Note that the sheet metal still has to be sufficiently thick for adequate stiffness.  Most products are very thin and may not be stiff enough.  You're pretty much on your own here if you go this way though.


Edited by SME, 29 August 2016 - 05:39 PM.


#37 Contrasseur

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Posted 29 August 2016 - 07:44 PM

Metal would require lots of tooling. Folding, welding, maybe even casting, just way too much for probably no net benefit.

 

If wood won't cut it for you, then you need composites. 1/4" carbon fiber or fiberglass with epoxy is damn tough. Even 1/8" will go a long way. They can be laid up in the final shape, with virtually no tooling required. Adding bracing would be elementary. Some people even consider it easier than woodworking once you get the hang of it. Just carve out a foam mold, glass the whole thing, then remove your foam. Cost is quite reasonable also. For such a small enclosure, the materials cost will be miniscule compared to your current $2.5k electronics and transducers budget.

 

Useless in the workshop? Draw it in Solidworks or SketchUp and send that bitch to a 3D printer. You can brace it within an inch of its life for no extra work or money. Put gussets on top of gussets inside your gussets. You only pay per gram in 3D printing. You'll probably be using ABS or something. Fiber reinforced plastics can be stronger than many metals, but I don't know if they're printable.


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#38 lowerFE

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Posted 29 August 2016 - 08:40 PM

:o  :blink: That's one expensive micro speaker!

 

Since the budget is blown out already, was there any thought to using exotic materials like perhaps aluminum plate for the enclosure?

 

Yeah it is nuts! Every component is top notch. It is essentially taking the drivers of a very high end 3 way speaker, choose the smaller diameter driver in the same family, and cramming them into this tiny box. I wasn't kidding when I said the value factor is a -1. And you guys aren't helping me with fiscal responsibility! :P That said, if things turn out well, it should be able to compete toe to toe against some very high end "Hi-Fi" style loudspeakers. Now that would be nuts!

 

The main reason is because I couldn't reuse any of my previous components. Originally I thought cost wise this is not gonna be so bad because I can reuse the miniDSP, amp, and the mid and tweeters. But then the HD version of the miniDSP came out and it is priced far too high (should have replaced the 6 year old 2x4 instead of charging double the price as a higher end model), but I gotta have it for the digital input, FIR filters and impulse correction. Then I decided to use 4 of the pricey ICEpower amps to clean up the clutter and a properly designed amp, so I couldn't use the 4 amps I already bought. SME mentioned I should get the 4 ohm midrange to get more out of the amp, so I couldn't reuse the 8 ohm midrange in the previous speaker. So I thought, screw it, might as well keep the old speaker for comparison and sentimental reasons and put it in another room. The miniDSP's and the 4 ICEpower amps represent nearly half the cost of the build. 

 

Fuck it, I'm gonna get the beryllium tweeters. It's *THE* ultimate small speaker, right? :lol: I better not screw up when I cut the face plate off of these!

 

I could make an enclosure out of aluminum, but I cannot put a nice fancy finish on it, and I want this speaker to have a very nice finish to it. 



#39 Ricci

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Posted 30 August 2016 - 01:56 PM

Useless in the workshop? Draw it in Solidworks or SketchUp and send that bitch to a 3D printer. You can brace it within an inch of its life for no extra work or money. Put gussets on top of gussets inside your gussets. You only pay per gram in 3D printing. You'll probably be using ABS or something. Fiber reinforced plastics can be stronger than many metals, but I don't know if they're printable.

 

You could 3d print them but the cheaper FDM machines, which produce the cheap parts don't finish that well on parts that big. The materials aren't all that strong without some thickness either. any more than 30% fill can cause huge issues with parts warping / pulling on bigger pieces. SLS or SLA would be a LOT better but the money goes way up too.



#40 SME

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Posted 31 August 2016 - 05:30 AM

This looks interesting: https://www.sculpteo.com/en/. I have no idea what it would cost, but they do have a variety of material choices.






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