Closure:
Take a look at this reseller: Svebry Electronics AB
I live in Skövde and always buy my electronics from them. The box i have is the G-111 Aluminiumbox Grå 115 x 65 x 55mm. Its perfect in size BUT you have to grind of / (dremla bort) two protruding rails.
The box also have mounting holes for screwes but they wont fit the holes on the card, i solved this by adding some plastic washers.
Where do you live? would be interesting to listen to a bigger version. You can find my build at:
SFS-V2 Aka Festivalstereobygge #2 - Minhembio forum
Good luck!
By the way to you all: Is there any news or progress in the LiFePO4 batteries?
Take a look at this reseller: Svebry Electronics AB
I live in Skövde and always buy my electronics from them. The box i have is the G-111 Aluminiumbox Grå 115 x 65 x 55mm. Its perfect in size BUT you have to grind of / (dremla bort) two protruding rails.
The box also have mounting holes for screwes but they wont fit the holes on the card, i solved this by adding some plastic washers.
Where do you live? would be interesting to listen to a bigger version. You can find my build at:
SFS-V2 Aka Festivalstereobygge #2 - Minhembio forum
Good luck!
By the way to you all: Is there any news or progress in the LiFePO4 batteries?
Cool build, and as far as I can prata svensk, great documentation
I know a tiny little bit about them, in general - what are you thinking specifically? (I may have missed an earlier discussion in the thread ...)
Hello Euforia!
The box is now ordered!
By now you've probably already read my post in your thread. I wrote some more questions in there.
I live near Stockholm. I will gladly upload a movie when the box is completed, otherwise pherhaps we will meet at some festival 2011
I hope it will play louder then the HP10W version, thanks to the higher sensitivity of the 12" drivers.
Thank you!
I have made something kind of similar with the exactly same bass drivers (2 of them) and piezos.
It's 33kg with 130liters of volume. Ported. I'm using 10kg car battery and 25wx2 car amp
It's huge, it looks funny as I have installed two wheels under it.
Im having serious problem with the piezos, they are way too loud, and the crossovers (12db) are not steep enough. Plus the port has resonance frequency somewhere near 50hz wich is far from optimal, when plugged to 80w amp xmax is not sufficient.
It's 33kg with 130liters of volume. Ported. I'm using 10kg car battery and 25wx2 car amp
It's huge, it looks funny as I have installed two wheels under it.
Im having serious problem with the piezos, they are way too loud, and the crossovers (12db) are not steep enough. Plus the port has resonance frequency somewhere near 50hz wich is far from optimal, when plugged to 80w amp xmax is not sufficient.
Thanks man.. Im really happy with it..
I started out with 150ohm series resistors on the tweeters and then tried out 120 and 100 aswell and the sound wasnt that great.. The tweeters couldnt really match the hp-10w's and it sounded a bit hollow..
But when i removed the resistors and just hooked up the tweeters with full signal it sounded great, so thats the config im sticking with now.. It might be because the spl of the tweeters is 95 and the woofers is 96.. I dont know - someone more knowledgeable might be able to clarify this
I have the HP-10W's with 93dB piezos.
I'd be interested in Saturnus's (or others') replies.I thought you needed the resistors to remove the piezo's bottom end harshness? Will their removal give greater output from the tweeters?
thanks
Paul
Update of the 4 x 12" Boominator.
An update of the 12" Boominator!
We have been manufacturing during some weekends for some time now, wich so far have resulted in an mock-up of the cabinet (no glue added, except on the vent assembly).
An exploded view of the vent. This design makes the box to peak with 4 dB @ 115 Hz. The tuning frequency is approximately 55 Hz. Tuning it higher would make the peak even louder...
A look from the inside. We found a piece of PVC tubing that fitted the holes made by the saw-drill near perfect.
Outside look. We plan to add fillets (a rounded chamfer?) to the inside edges of the holes.
The same piezos as Phaedras. Unfortunately, three times as expensive here in Sweden compared to Dejlige Denmark...
As you can see I haven't added any high pass filters yet. I plan to cut the frequency at around 80 - 100 Hz to extend the life of the elements beyond the first night of battering... I have some resistors for the tweeters, but after reading about Phaedras box, I'm not sure that I'll use them.
So, what's left to do?
Playing it in the open air made me realize that compared to its predecessor, it's loud as hell!
Thats all for now!
/ Daniel
An update of the 12" Boominator!
We have been manufacturing during some weekends for some time now, wich so far have resulted in an mock-up of the cabinet (no glue added, except on the vent assembly).
An externally hosted image should be here but it was not working when we last tested it.
An exploded view of the vent. This design makes the box to peak with 4 dB @ 115 Hz. The tuning frequency is approximately 55 Hz. Tuning it higher would make the peak even louder...
An externally hosted image should be here but it was not working when we last tested it.
A look from the inside. We found a piece of PVC tubing that fitted the holes made by the saw-drill near perfect.
An externally hosted image should be here but it was not working when we last tested it.
Outside look. We plan to add fillets (a rounded chamfer?) to the inside edges of the holes.
An externally hosted image should be here but it was not working when we last tested it.
The same piezos as Phaedras. Unfortunately, three times as expensive here in Sweden compared to Dejlige Denmark...
An externally hosted image should be here but it was not working when we last tested it.
As you can see I haven't added any high pass filters yet. I plan to cut the frequency at around 80 - 100 Hz to extend the life of the elements beyond the first night of battering... I have some resistors for the tweeters, but after reading about Phaedras box, I'm not sure that I'll use them.
So, what's left to do?
- The design will probably be Tuborg-inspired...
- The hinge for the hatch to the middle compartment will be looking like this, and hidden inside the box:
- The corners will be fitted with aluminium profiles.
- Some kind of LED-lighting will be added.
- One power switch and one lighting switch will be added.
- Eventually a photovoltic panel will be added.
Playing it in the open air made me realize that compared to its predecessor, it's loud as hell!
Thats all for now!
/ Daniel
Hey guys
I've been browsing this and other forums for a while and little more than a month ago i decided to build my own boombox.. The boominator was an excellent inspiration and i've built something quite similar..
I shot some pictures while making it.. Enjoy
Hi there phaedras. How did you dimension your relex ports and where did you get those plastic tubes for i? i saw in an earlier post that could not figure out to do so, but maybe knowledge came your way?
Hi there phaedras. How did you dimension your relex ports and where did you get those plastic tubes for i? i saw in an earlier post that could not figure out to do so, but maybe knowledge came your way?
Hey mate, I used a free program called WinISD.. Its mentioned several times in this thread and its an excellent ressource!
I bought the reflex ports at a place called CC Pro Shop here in Denmark, they wern't that expensive, but im sure you can find some cheaper on the internet.. I paid approx 10$ for each of them!
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I'm creating a mono boominator that is designed be to lightweight and "extremely loud", and want feedback about the feasibility of the design.
The design philosophy is to use neo woofers for lightness, to keep the overall weight below 15 kilos. I've done a fair amount of searching for drivers with enough efficiency to be "extremely loud", during peaks, which I define as over 90 db at the lister's position and ~110 dB at one meter.
Before I list the driver, let me say I figure that an 8 ohm low frequency driver with about 95db sensitivity will be able to reach 110db with an sure 100 watt amp, which can deliver 32 watts in 8 ohms and should roughly provide 15 db of amplification over the 1w/meter baseline.
This may seem like a lot of wattage for a portable battery operated device, but I figure the 32 watts will only be used on peaks, and the rest of the time it will be used at much lower wattages. I'm using two 5 ah/12 v SLA AGM packs and am planning on getting a 24 v solar charger with two 12v panels totaling over 10-15 watts.
Given these weight and loudness design goals, I've purchased this driver to build a mono boominator:
The Faital Pro 8PR200
FaitalPRO - Neodymium Professional Drivers
It weights only 2.5 kilos, it has about 95db efficiency. The frequency response looks fairly smooth up to 1.5 kHz. Since I like bass, i was impressed that the Fs was a reasonable 58 Hz, the Xmax is reasonably large, and and the Vas is only 18 liters. The low Vas means that I can use a ported design to get some deep bass from the driver (in theory). I'll need over 14 liters of space, and currently am planning on using a crossbraced aluminum suitcase (see The BoomCase By Mr. SiMo for similar cabs). With a lot of space, I can tune the port lower and down to 58 Hz.
I haven't looked at the acoustical limits of this driver yet, but am going to use bassbox software to see where the driver breaks up and protect it. I'm planning on using a 24db electronic crossover at 50 hz to protect the woofer.
Any thoughts on the feasibility of getting ~110 db with 32 watts and with one of these drivers?
The design philosophy is to use neo woofers for lightness, to keep the overall weight below 15 kilos. I've done a fair amount of searching for drivers with enough efficiency to be "extremely loud", during peaks, which I define as over 90 db at the lister's position and ~110 dB at one meter.
Before I list the driver, let me say I figure that an 8 ohm low frequency driver with about 95db sensitivity will be able to reach 110db with an sure 100 watt amp, which can deliver 32 watts in 8 ohms and should roughly provide 15 db of amplification over the 1w/meter baseline.
This may seem like a lot of wattage for a portable battery operated device, but I figure the 32 watts will only be used on peaks, and the rest of the time it will be used at much lower wattages. I'm using two 5 ah/12 v SLA AGM packs and am planning on getting a 24 v solar charger with two 12v panels totaling over 10-15 watts.
Given these weight and loudness design goals, I've purchased this driver to build a mono boominator:
The Faital Pro 8PR200
FaitalPRO - Neodymium Professional Drivers
It weights only 2.5 kilos, it has about 95db efficiency. The frequency response looks fairly smooth up to 1.5 kHz. Since I like bass, i was impressed that the Fs was a reasonable 58 Hz, the Xmax is reasonably large, and and the Vas is only 18 liters. The low Vas means that I can use a ported design to get some deep bass from the driver (in theory). I'll need over 14 liters of space, and currently am planning on using a crossbraced aluminum suitcase (see The BoomCase By Mr. SiMo for similar cabs). With a lot of space, I can tune the port lower and down to 58 Hz.
I haven't looked at the acoustical limits of this driver yet, but am going to use bassbox software to see where the driver breaks up and protect it. I'm planning on using a 24db electronic crossover at 50 hz to protect the woofer.
Any thoughts on the feasibility of getting ~110 db with 32 watts and with one of these drivers?
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New Boombox
I'm back with another build. My goals were: Smaller, lighter, more sensitive/efficient, and louder. To achieve this, the last variable unfortunately went up... Price.
Went with a single 10" design:
Single very sensitive 10" from Faital Pro
And the CTS piezo KSN-1141
Went with the TI-600 amp from ClassDaudio.com which is based on the new Texas Instruments TAS5630 chip. With 3 x 12v 9ah = 36v SLA batteries, it will put out about 150W before clipping. At that volume, there wouldn't be more than 2-3 hours of runtime, but on occasion its nice to have the 122db+ headroom.
I modeled the box in bassbox for this curve.
And when putting my cheap SPL meter to work, the real results looked like this:
I've read that this piezo tends to be more sensitive than its 92db rating, but that doesn't appear to be the case in my testing. I'm about 5db lower than the woofer which is rated at 97db.
Question: Is there any way to pad a woofer or does this end up being a complete disaster? I would think it would throw away a good bit of energy through heat. Assuming this is the case, my only option is to find a more sensitive piezo or try to find a way to add a second one to bring my 1.8k+ up by 3db. Any other options?
Here's the new beast. Pre-laminate...
I'm back with another build. My goals were: Smaller, lighter, more sensitive/efficient, and louder. To achieve this, the last variable unfortunately went up... Price.
Went with a single 10" design:
Single very sensitive 10" from Faital Pro
And the CTS piezo KSN-1141
Went with the TI-600 amp from ClassDaudio.com which is based on the new Texas Instruments TAS5630 chip. With 3 x 12v 9ah = 36v SLA batteries, it will put out about 150W before clipping. At that volume, there wouldn't be more than 2-3 hours of runtime, but on occasion its nice to have the 122db+ headroom.
I modeled the box in bassbox for this curve.
An externally hosted image should be here but it was not working when we last tested it.
And when putting my cheap SPL meter to work, the real results looked like this:
An externally hosted image should be here but it was not working when we last tested it.
I've read that this piezo tends to be more sensitive than its 92db rating, but that doesn't appear to be the case in my testing. I'm about 5db lower than the woofer which is rated at 97db.
Question: Is there any way to pad a woofer or does this end up being a complete disaster? I would think it would throw away a good bit of energy through heat. Assuming this is the case, my only option is to find a more sensitive piezo or try to find a way to add a second one to bring my 1.8k+ up by 3db. Any other options?
Here's the new beast. Pre-laminate...
An externally hosted image should be here but it was not working when we last tested it.
Sounds like you are looking to build what I just completed... I was looking for 120db+ though which meant a different amp and 3 batteries to drive it...
Take a look at the 10" from Faital Pro. W10N4-200. It comes in a 4ohm version which will get you a clean 65-75W out of that sure board. And it is rated at 97db. I spent a lot of time plotting all of their woofers in the 8-12" range. Here is the 8 in a .5 cu ft box and the 10 in a 1cu ft box. or 14 liters and 28 liters.
The 8" is 109-112db at 35w and 10" is 112-115db.
The 4ohm 10" with the sure board should get you a clean 116-119db at 1 meter. And since the sure board has two channels, you could build yourself a second "slave" box without batteries or amp and drive it from your first one. Then you'd be at 119-122db.
The 10" was $50 cheaper too.
An externally hosted image should be here but it was not working when we last tested it.
A upgrade to a more sensitive tweeter would be a easy enough fix. Piezos are considered low on the audio food chain and need a x-over or processing to sound good.
Piezos, in general, are low on the foodchain, but some are actually extremely high end. The beauty of piezos is that you don't need a crossover. They present themselves as a capacitor and only kick in at higher frequencies.
The tricky part is finding a piezo that can handle 150W and can cover 2Khz up.
The tricky part is finding a piezo that can handle 150W and can cover 2Khz up.
Saulty, considering your design goals of "Smaller, lighter, more sensitive/efficient, and louder", I think you kicked some butt.
With the way you ported the W10N4-200, it looks like it gets freakin loud.
How much does the box weight? I'm also going to use birch plywood, and since price is not a big a deal I plan on adding some $20 wheels from parts express.
I think in theory you could get some added efficiency for about $100 more, with the addition of an active crossover and dsp module.
I remember being told from an old audio engineer that amplifiers still try to power the ranges of the spectrum of a speaker that the speaker cannot reasonably play, so if you cross over the speaker using an active crossover then it adds efficiency.
The catch is you have to use an active crossover instead of a passive one.
There is this 3x3 inch MiniDsp for $100 which runs on 12 v-24v (if you are using more than 12 v, I would consider getting a 15v regulator at a place like Mouser electronics). The dsp also can pad the woofer and has an EQ that could possibly tame some peaks in they very bumpy (but high efficiency) Faital. It is here: MiniDSP
A horn might help your design. I toyed with the idea of using the $35 D250-X down to about 600 Hz with the $5 exponential horn that goes to ~600Hz. It has about 107 db/watt.
I think this MiniDSP thing will really improve the efficiency of the system and also has the side benefit of allowing skewed and bumpy drivers to be used. I used an iphone app called "RTA" to measure the frequency response of my last portable speaker. That could be used to figure out where the bumps are since the resolution is pretty high, and then use the MiniDSP software to tame the peaks.
In any case, since I like deep bass so much, I could maybe use the Faital you mentioned but tune it deeper. It has almost 6mm of xmax. Most of the kick beats in music are from around 70-110 Hz, and I'm not convinced bass is not possible outside in a small speaker. I mean, the bass can bounce off the ground and the speaker might be put inside or in a corner. Given how much raw output you are getting, if I were making a box like yours I would trade off some output and tune it deeper so it sounded more thunderous and gigantic.
By the way, if you are using 36v, did you eliminate the solar panels? I haven't seen solar charging systems for that type of setup.
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Saulty, very nice looking response but the cabinet is still way too large to be considered really compact enough for a portable build.
The Faitals are quite good for the price, and had there not been lots of other requirements to the woofers I used in the Boominator they would have been high on my list for a replacement. However, they're not deep enough (physically) to couple the speakers together to make that all important (in the Boominator) mechanical connection between front and back plate so that thinner ply (12mm) could be used instead of the otherwise necessary 15mm minimum.
I also have to agree with you on the piezos. Usually they're considered utter crap, and rightfully so, but there are gems among them that can easily compete with even the best dome tweeters on the market. Since the Zomax HP100s that I used in the Boominator isn't produced anymore, I'm also leaning towards a CTR one. But I also have my eye on a P.audio tweeter horn.
bluewhale, if you don't believe deep bass is unimportant for this purpose outdoors, I suggest you try it. Even though you have 1 reflecting surface you have to remember that indoors you have 6 reflecting surfaces. In principle you need at least 4 times the output outdoors than indoors to be percieved equally loud in the deep bass range.
The Faitals are quite good for the price, and had there not been lots of other requirements to the woofers I used in the Boominator they would have been high on my list for a replacement. However, they're not deep enough (physically) to couple the speakers together to make that all important (in the Boominator) mechanical connection between front and back plate so that thinner ply (12mm) could be used instead of the otherwise necessary 15mm minimum.
I also have to agree with you on the piezos. Usually they're considered utter crap, and rightfully so, but there are gems among them that can easily compete with even the best dome tweeters on the market. Since the Zomax HP100s that I used in the Boominator isn't produced anymore, I'm also leaning towards a CTR one. But I also have my eye on a P.audio tweeter horn.
bluewhale, if you don't believe deep bass is unimportant for this purpose outdoors, I suggest you try it. Even though you have 1 reflecting surface you have to remember that indoors you have 6 reflecting surfaces. In principle you need at least 4 times the output outdoors than indoors to be percieved equally loud in the deep bass range.
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Saturnus, I built a truly portable battery operated speaker one year ago with a bass response that cut off around 80-90Hz.. We used it at Burningman. It had an eminence 8cx, and we found that for dance music it was quite nice. In fact, people said it boomed even though part of the beat was cut off.
I do recognize that indoors you can get a gradual 15db or so boost down to 20 Hz with all the surfaces in a typical room, but it is graduated. Room response curves show that the effect increases as the bass gets deeper. At around 70 Hz, where the kick beat in most music ends, there isn't that much of a boost. I'd have to check to make sure, but I don't believe it will be 4 times the output.
Interesting. Could they be coupled with a piece of wood and some glue somehow?
Bluewhale, thanks for the ideas. I didn't know about that iphone app to measure frequency response. I will definitely give it a try. As matter of fact, when I did my testing the manual way (with a test tone CD and radio shack spl meter) I was in my garage with the door open. Not exactly outdoor conditions. I did test with various box tunings and noticed a definite difference in the frequency response, but I haven't actually listened to music with the various tunings to see if I can tell a difference. I will do this in the coming days along with another frequency response test with the RTA app. I'll let you know if a lower F3 has any noticeable effect outdoors. Without increasing box size, a lower F3 will be at the expense of a flatter response and elimination of that slightly higher bump at 100hz.
Also reading about that minidsp module. pretty neat idea and would give a ton of control.
Saturnus, you are right about it not being super portable. But it is much more portable than my previous one which came in at about 65lbs. With a shoulder strap, it wouldn't be a big deal to throw it in the back of any car and haul it down to the beach or anywhere else. I do anticipate another build to fill that extremely portable need.
After doing a little more listening, I don't actually notice a problem with the slightly less sensitive piezo. I think I may have gotten too caught up in the response curve and forgot to actually listen to the result. I'll fire it up next to my other build (that I've grown to love) this weekend to see how much they differ.
Oh and Bluewhale, I didn't go the solar panel route at all. No need when carrying this much battery. 3 x 9ah batteries and this level of sensitivity gives me more runtime than I'll ever need. Unless I'm actually playing these things wide-open. But in the 108db range (15W), I've got well over 20hrs of runtime. And if I am pushing this thing with 150W, solar panels aren't going to help me anyhow.
Also reading about that minidsp module. pretty neat idea and would give a ton of control.
Saturnus, you are right about it not being super portable. But it is much more portable than my previous one which came in at about 65lbs. With a shoulder strap, it wouldn't be a big deal to throw it in the back of any car and haul it down to the beach or anywhere else. I do anticipate another build to fill that extremely portable need.
After doing a little more listening, I don't actually notice a problem with the slightly less sensitive piezo. I think I may have gotten too caught up in the response curve and forgot to actually listen to the result. I'll fire it up next to my other build (that I've grown to love) this weekend to see how much they differ.
Oh and Bluewhale, I didn't go the solar panel route at all. No need when carrying this much battery. 3 x 9ah batteries and this level of sensitivity gives me more runtime than I'll ever need. Unless I'm actually playing these things wide-open. But in the 108db range (15W), I've got well over 20hrs of runtime. And if I am pushing this thing with 150W, solar panels aren't going to help me anyhow.
Okay, I just got Bass Box Pro, and after putting in the normalized frequency response of some of these professional drivers, it seems they don't have any bass below 100 even with a ported design. This is considering the actual frequency response of the driver in a ported enclosure. Could this be correct?