See my edit ^....GuyPanico said:
Basically it's a bit of a PITA right now, but I should figure some way of charging all the cells at once somehow...
MikeHunt79 said:
I wouldn't worry about it. Those are nice coaxials, which I naturally like better than 3-ways. They are created for infinite baffles, and it will not matter what you do to them. You cannot make them into home audio, so don't worry about it. It's not worth the time.
My honest advice would be to forget about venting them. Remember, you are in England. My Dad was once stationed at Lakenheath on TDY for a little over a year, and Mom and I followed. I know all about your weather. If you vent the box, not only can water get in, but moisture surely will. It will cause the innards to rust or grow all sorts of molds and mildew. I never figured out how England could grow all that stuff so readily. Try to keep it sealed if possible. You will not regret it. 😉
😱 The worst thing is I actually live in Bristol, so I recognise most of the places in that Daily Mail article.Thankfully I don't recognise any of the people tho... 😀
I am starting to get to that age where I'm up not up all hours, but that being said, I'm off out again in a minute...
I think it is built into your(third person plural) genes. Not to worry. We all get over it eventually. 😀
Anyway, back on topic, I managed to get you a pic of some 18650 Li-ion cells and a laptop battery pack that has just been ripped openThe flash screwed up the exposure a bit tho... 🙁
EDIT: The black thing of the left is a DSD charger - it will charge cells at about 800ma when combines with a Nokia ACP-12x mobile phone charger. 🙂
I plan to use 3 x DSD chargers... I charge cells 1,3,5, then when they are fully charged, I charge cells 2,4,6.
I keep meaning to make a multi-core cable to make this quicker to do, or get some sort of pack charger. 🙂 [/B]
Neat, I have already talked to a computer friend from Canada, who is down here on vacation. He is going to gather up some and take them apart just to make a nice battery array. This should be a great way to provide portable power.
If weather resistant is what you want you definantly dont want to go ported! 🙂 Also, I think any driver that has a rubber surround and a plastic or metal cone is inherantly weather resistant. Although in the long term, moisture and UV light from the sun my take its toll on rubber. You could look into marine speakers. Although I think your Kappas will work great. Another great thing about car speakers is they seem to be more efficient then home speakers. Or is that just me?
I will be recieving my speakers amongst some other items Tuesday. I went with the 4, TB 871's, and a Dayton SD215. And powering them with a sure electronics 4ch amp. Decent power, although I will be feeding it 19v, not 24v. Who knows when I'll get the amplifier in.
I recieved my iphone crade with remote on Friday. Unfortunantly it picks up interference from the phone anytime there is activity. Similiar to setting your phone down next to PC speakers. So I cant use the line out, i'll have to use the headphone jack afterall. But at least I can retain the remote control functionality.
I will be recieving my speakers amongst some other items Tuesday. I went with the 4, TB 871's, and a Dayton SD215. And powering them with a sure electronics 4ch amp. Decent power, although I will be feeding it 19v, not 24v. Who knows when I'll get the amplifier in.
wimdehaan said:
I recieved my iphone crade with remote on Friday. Unfortunantly it picks up interference from the phone anytime there is activity. Similiar to setting your phone down next to PC speakers. So I cant use the line out, i'll have to use the headphone jack afterall. But at least I can retain the remote control functionality.
Is infinite baffle the same thing as open baffle? I'm still learning the jargon... 😱John L said:
I think the rain saves us the need to water the plants ourselves. 😎 It is raining right now as I'm typing this - I think I'm going to have to invest in some waterproof varnish or paint.John L said:
As far as the box goes, I think I'll go sealed. Also I guess box size won't really matter either with sealed. Would some sort of high pass active crossover be a good idea to stop over excursion?
You're not wrong - I'm starting to feel quite old when I'm in a club and you're outnumbered by people that look 10 years younger than you. 😱John L said:
Nice - just be careful and don't short out the cells. Also, have a look into some sort of low-voltage-cutoff circuit. They should'nt go below 3v per cell otherwise they won't recharge.John L said:
😎GuyPanico said:
That amp is awesome for boombox use - It's basically a pre-built 41hz.com amp9 kit... When teamed up with 4 ohm loads is sounds great, I've even used it for powering subs! 🙂
The cone on these Kappa's are plastic looking, and rubber surrounds, the only thing that looks a little fragile is the tweeter part. I'm gonna use the grills tho, which should things a bit. I'm tempted to make this modular - IE:
Have each speaker in a separate box.
Also have the amp and batteries in a third box.
Maybe have banana plugs or speakons connecing the boxes.
Have some sort of clip of a ratchet strap if I keep the boxes together.
Then I'll also have the option of taking the speakers off and having them further apart if I want to...
Any thoughts on this?
Let me offer one word of caution here. This is going to be a portable boom box that operates via battery. It is not to be like some home audio equipment that requires a great deal of current. You have to keep this in mind.
I just went to Sure's site and checked up on his amp offering. He has some tiny amp which is not what you want. Also he has that 4 X 100 watt and a 2 X 100 watt amplifier. However, if you use these, you will be able to enjoy your music on the 'fly' for perhaps an hour or so, before the batteries give up their ghosts. Not great for long usage away from any plug-ins.
However, there is this little puppy. It is 15 watts/channel into 4 ohms, and it does not draw anywhere the current those other two do. And 15 watts is more than enough to run your boom box very well thank you. No need to go totally out on a limb. and if this does not work, then you can graduate up to another more powerful amplifier, and not be out of a lot of cash.
My 2c here.
Yes.
I just went to Sure's site and checked up on his amp offering. He has some tiny amp which is not what you want. Also he has that 4 X 100 watt and a 2 X 100 watt amplifier. However, if you use these, you will be able to enjoy your music on the 'fly' for perhaps an hour or so, before the batteries give up their ghosts. Not great for long usage away from any plug-ins.
However, there is this little puppy. It is 15 watts/channel into 4 ohms, and it does not draw anywhere the current those other two do. And 15 watts is more than enough to run your boom box very well thank you. No need to go totally out on a limb. and if this does not work, then you can graduate up to another more powerful amplifier, and not be out of a lot of cash.
My 2c here.
Yes.
IB and OB are not the same. IB has the back wave totally contained (i.e. a super large box) classic examples would be a subwoofer built into the attic, crawl space or a wall shared with a sizable room. If the volume of the enclosure is about 10 times Vas you have IB. Given the rather small Vas of most car speakers the trunk or even the door panel can qualify as an infinite baffle.
OB is a driver mounted on a baffle with the rear side not enclosed such that the rear wave will come around the edge of the baffle and combine with the front wave. This will cause a rolloff at some frequency determined by the baffle size. Using a driver with a total Q greater than .7 or so will compensate somewhat for the rolloff. OB gives you an approximately figure 8 radiation pattern which definitely affects the quality of sound and imaging.
mike
OB is a driver mounted on a baffle with the rear side not enclosed such that the rear wave will come around the edge of the baffle and combine with the front wave. This will cause a rolloff at some frequency determined by the baffle size. Using a driver with a total Q greater than .7 or so will compensate somewhat for the rolloff. OB gives you an approximately figure 8 radiation pattern which definitely affects the quality of sound and imaging.
mike
MikeHunt79 said:
I doing something along these lines, but for a different purpose. My full rangers are in the top portion of the enclosure, and the subwoofer is in an independant (although passive) enclosure below. My hopes are that I can simply place the boombox on top of the subwoofer, fasten the two latches be on my way. I'm using bananna plugs for power and a few dowels to get perfect alignment when the two mate together. This gives me the option of having a much smaller and easily transported device.
These will be disassembled and flush mounted on the bottom of the boombox. http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=260-301
This will be mounted on the top of the subwoofer enclosure. http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=090-460
Then a pair of these draw latches to hold the two together. http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=262-210 I think two should be plenty.
I like your idea of being able to seperate the speakers. That gets it another step closer to home hifi quality sound!
I thought I would just throw this out for all you IPod junkies, who want that ultimate boom-box to go along with it. Try Thodio: Exquisite Wooden iPod Docks
Is this what you had in mind? 😀 😉
Is this what you had in mind? 😀 😉
GuyPanico said:
I thought about building exactly this sort of thing, but how are you going to handle the crossover?
I was going to use 2 Hi-Vi B3Ss and an elemental designs 7kv2 for the sub powered by a 4 ch sure-electronics amp. It all looked good to go, but the crossovers look like they will cost a ton.
b3s x 2 = $21
7kv2 = $30 (bought used off of a forum)
sure-elect. amp = $57
amp psu = $25
that makes the total about $125 give or take. I started to look at crossover solutions and making my own in line crossovers would have cost me $120 to $175 just for the crossovers 😱 Did you figure out a way around this?
actually after some more research I could do more budget oriented 12db crossovers for about $80 which isn't horrible...but i'm still wondering how you're going to handle the crossovers/filters
I'm going to use a PLLXO http://www.diyaudio.com/forums/showthread.php?s=&threadid=114294 . This keeps the components small and much cheaper. I'm only filtering the subwoofer.
The thing is, I've already made up the battery pack to 24v. Also, I won't be running this flat-out, I just like to have some headroom...John L said:
I already have the 4 channel amp, and tested it with my Li-ion pack, and it works a treat... I doesn't use much more than 1 amp when turned up very loud with my 6x9's. As my battery pack it 4800mah, it should do almost 5 hours very loud, or say 10 hour less loud. I'm happy with this. 🙂
That sounds like it will work well, I may try some similar sort of clip system. Dowels are a great idea also. 🙂GuyPanico said:
I pretty much have all the parts, apart from the HPF... I'm tempted to try it all without a HPF for now.
I think I'm gonna go for 55Hz HPF with 12db/oct, using the design on this page:
http://sound.westhost.com/project09.htm#download_esp_lr
Anyone else know if this design is any good? It's an active crossover, so it will go after my volume control, but before my amp.
Here's an amp6 based boombox project to look at-
http://metku.net/index.html?path=mods/ghettoblaster/index_eng
...and mine-
http://www.flickr.com/photos/47642593@N00/483423821/in/set-72157600117133010/
...which I'm VERY happy with, but the drivers aren't available any more.
I'll be interested to see what you do with the 871's, I still have four kicking around...
http://metku.net/index.html?path=mods/ghettoblaster/index_eng
...and mine-
http://www.flickr.com/photos/47642593@N00/483423821/in/set-72157600117133010/
...which I'm VERY happy with, but the drivers aren't available any more.
I'll be interested to see what you do with the 871's, I still have four kicking around...
My shure electronics amp arrived and I think it's going to work perfectly. I tried a single B3N speaker on one channel and it played quite loud. Since the drivers i'll actually be using are 6dB more efficient, and i'm using 4 of them in a 4ohm configuration, it should be very loud.
I'll start construction pretty soon!
I'll start construction pretty soon!
Slight change of plan... I'm rebuilding my battery packs to 11.1v and going for the amp6 basic. 🙂 AMP9 is now in the car.
This is much easier, as the amp6 shuts off below 9v, so it won't kill my unprotected cells if I leave it on (in theory).
For XO's, look into using op-amps for an active crossover. Cheap, and should give good sound as well.
I'm gonna get back to it now, I'll have something worth photographing at some point! 🙂
EDIT: AMP6 is burning in 😀
This is much easier, as the amp6 shuts off below 9v, so it won't kill my unprotected cells if I leave it on (in theory).
For XO's, look into using op-amps for an active crossover. Cheap, and should give good sound as well.
I'm gonna get back to it now, I'll have something worth photographing at some point! 🙂
EDIT: AMP6 is burning in 😀
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