Collective Custom Boombox Project?

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caution

Member (SA)
Reli said:
Also, if it has some kind of phone cradle, it should be on the top or the back, instead of the front. Nothing looks dumber than a box with a phone stuck on the front. Put it on top or on the back where it can't be seen. Hell I wouldn't even bother creating a cradle, as it would require complex tooling to create.
How about a rear compartment like the Wheely has, then you'd have a place to stash your phone, memory sticks, tapes, cables, whatever. Maybe even stick a USB port and DC plug in there.
 
I think you guys are starting to drift from the original concept. This box is going to be huge. Just to fit a 10 inch driver, a 6.5 inch mid and a 2.5 inch tweeter will require this project box to be bigger than a wheely. So any thoughts of carrying this thing any distance with 24 D cells on board is pure fantasy.

It would be the ultimate blaster though if Superduper is allowed to work his magic. :-) As with all these types of builds, the external casing is the hard bit. Norm's original concept did not require this box to look like a vintage box and for good reason. Unless members here suddenly get free access to an industrial 3D printer, this box has little chance of having the vintage look we'd all like.

So try and be realistic about the look of this thing and it may have some chance of turning into a reality. :-)

James...... :-)
 

Reli

Boomus Fidelis
caution said:
How about a rear compartment like the Wheely has, then you'd have a place to stash your phone, memory sticks, tapes, cables, whatever. Maybe even stick a USB port and DC plug in there.
Or on top. Just a simple indentation is probably enough. People could stick some Velcro in there if they want.
 

Lasonic TRC-920

Moderator
jimmyjimmy19702010 said:
I think you guys are starting to drift from the original concept. This box is going to be huge. Just to fit a 10 inch driver, a 6.5 inch mid and a 2.5 inch tweeter will require this project box to be bigger than a wheely. So any thoughts of carrying this thing any distance with 24 D cells on board is pure fantasy.

It would be the ultimate blaster though if Superduper is allowed to work his magic. :-) As with all these types of builds, the external casing is the hard bit. Norm's original concept did not require this box to look like a vintage box and for good reason. Unless members here suddenly get free access to an industrial 3D printer, this box has little chance of having the vintage look we'd all like.

So try and be realistic about the look of this thing and it may have some chance of turning into a reality. :-)

James...... :-)
I have done the math before when it comes to speaker cabinets. In regards to the classic radio's we all love, a radio with 8" woofers would require a cabinet WAY bigger than a J1. 10" woofers would be WAYYYYY bigger than a Wheely.

You can play with the numbers here: http://www.bcae1.com/spboxnew2.htm

It's tough to satisfy everyone's personal tastes. I think the more realistic approach is for Norm to just build what he wants and it's Take it or Leave it after that. Enzo Ferrari was a man with a vision, Ferdinand Lamborghini was a man with a vision, Henry Ford was a man with a vision. None of these people were surrounded by yes men or bean counters. The envisioned it and they built it.

Also remember, in the 80's before Amar Bose figured out enclosure parameters, these radio's were just open cases with amplifiers. Super Low Tech. To improve upon that AND with using the new electrical components Norm is suggesting, this should be "SHOULD BE" leaps forward on our classic blasters. But in order to calculate the correct enclosure for the speaker size (which was never done on the classic radios) it's going to have to be BIG just for 8" speakers, let alone 10's.

It may not be a radio you can huff down the street, or even power on batteries small enough to carry. But there is only one way to find out.
 

Reli

Boomus Fidelis
I'd add a black rectangular grill or duct in the middle, along the bottom.........For the subwoofer (assuming there is one).
 
For what it's worth, IMHO, this is the setup sweet spot for a mid weight portable boomer:

1. Very sensitive 8 inch drivers
2. Silk dome tweeters of a suitable loudness to keep up with the drivers
3. Sealed and separated left and right cabinets
4. Efficient, powerful (50+ real watts RMS per channel) D class amp
5. A cabinet material of a suitable thickness to avoid a sing along cabinet situation (thick plastic, carbon fibre etc) - metal cabinets are to be avoided!!
6. A clean and high SQ program source.

Trust me, 8 inch drivers well driven by a powerful amp in a sealed, solid cabinet will produce all the deep bass you will ever want! (No sub required) :-) Forget about the bass level of an M90, C100F, Master Blaster - etc - they are not even close to what Norms box will be capable of with a pair of 8s.

A 10 inch driver has to have a mid speaker to cover those frequencies so combined, the required cabinet size grows massive!
 

redbenjoe

I Am Legend
no chris --need not be that wide -
my version of the dual jvc 550 in STEREO had full 10" woofs within a 29 1/2" wide canbinet ( exact same as the c100f )
 
Lasonic TRC-920 said:
If your talking about a sealed cabinet with 8" speakers, it will be BIG!

Have a look here: http://www.bcae1.com/spboxnew2.htm
My V2.0 box - (8 inch drivers) was the exact same size as a C100F (slightly deeper). The bass was massive. I very rarely turned the bass up past the mid position as it would shake the glasses in the kitchen cabinet (next room over)! :-) - it was hilarious! And that was with only 20 watts RMS per channel.
 

redbenjoe

I Am Legend
ok chris -
and btw // off topic.... can anybody here post a few pix from my old dual 550 stereo thread - i cant find them here -
and lost them all in a computer crash - thanks ..
 

hardmen

Member (SA)
Just for an Idea as well...

CAM01453.jpgCAM01454.jpg

Cheap items, cheap cobstruction, massives (not really "heavier") and sounds nice!

Cheers.
 

Reli

Boomus Fidelis
The thing is, how many MODERN home hifi setups have 10" woofers? Very few. They're just not necessary in this day & age, unless you're going for a certain look.
 

Superduper

Moderator
Staff member
I think James understands the situation best. When I first thought about making up a batch, (all the same in case anyone is listening), I thought then that I'll probably get 10 guys wanting 10 different boomboxes. We want it big, grail size, we want it medium. We don't listen to CD, I listen to CD almost exclusively if possible. FM only is fine, but I want AM. We want it classic looking, but we want it modern looking. We want subs but we don't need subs. We want a pocket for personal audio devices but it must be invisible. Needs to use sealed lead acid batteries, but why can't we use power tool batteries -- all we need is the socket, yeah it's different for every battery and they are expensive but just the socket. Ok but where do we get the socket and do we take orders for different brands for different guys? Oh and it needs 50 wpc true power but to do that means it needs high voltage. This can either be accomplished by lots of batteries in series. But then 12 volts should be consididered which means a DC-DC buck converter which is fine except it needs high amperage batteries (in parallel instead of series, at least same number of cells). Oh yeah and we want touch screen and etc etc etc. So true to form, you guys didi not disappoint for there truly is as many requirements as there are members, lol.

Guys, while I would love to work on designing something that incorporates all the features you guys want into a single board, at 50 times the cost of buying the ready made modules that are made in china, then in the end, we make up what, 10 of them? Seriously, to get this off the ground, we need to compromise and accept that we aren't going to get everything we "want" or else the project will never get past the discussion dreamin phase.

Now, I proposed something huge. Why not medium you say? Well, we got medium boxes left and right. Why go through all this to make a medium box? M70's are on eBay every single day of the year. New offerings are available, ala TDK and the rest. But how many guys have a Wheely in great working condition? Very few. You know, the wheely, the huge empty box with decks that don't work, fake spectrum analyzer display, amp that promises huge sound except it farts and stutters when you want it to assertive and show it's prowess,.... yeah THAT wheely. And for that, a nice looking one sets you back probably at least a grand? My plan was not to make a boombox that is another boombox. I want to make THE boombox. The one that says THIS is what I listen to, the others are for collecting. The one that tells everyone that enters a man cave that this is the one to try first, and that this one is special. The one that gets all the attention. Why fake an M90 by imitating all the features.... just get an M90 already.

I started collecting audio gear some 30 years ago. Well some even 35 years ago. Started out with home audio gear and if you guys saw my collection (they are all boxed now), you guys would be in heaven. But at some point, being the packrat that I am, space became an issue. I could no longer setup and play with my gear. I could not even get to my gear much less assemble a stack. You know, the one where you place the amp on the bottom, stack a tape deck on top, then preamp, then equalizer, tuner, etc. All the while connecting charlottes web behind. Of course moving the whole shebang was out of the question. Mellymelsr and Reli knows best, they saw my home and knows what I am talking about regarding space. So I went all-in-ones. You know, boomboxes. Now, when I want to move something, just carry the whole thing. I'm at a different place now, and do have some space to play with home audio gear. But now, I can no longer lift them. Too heavy to do without help anymore and nobody in my house cares about sound except me.

Anyhow, to me, very few boomboxes out there can offer sound that even approaches home audio gear. The best boombox is a total wimp when compared to the bottom of the rung audio gear in my home, so not trying to replace the home stereo. There is no way to put the bang of a 80 pound 1200 watts (mains consumption) piece of gear with the washing machine sized speakers into a small handheld box and use batteries too, aint gonna happen. BUT I thought wouldn't it be cool to have a piece that can technically use batteries if someone hold stock in duracell, and wants a full all-in-one setup that you can move from room to room. Hence comes this project.

As for why off the shelf products.... I believe James has already done this. Take it from someone who knows.... there is no reason to try to build an amp or preamp or MP3 player, with bluetooth, from scratch. Not when the ones from China, ready built, can be acquired for cheaper than it costs you just to accumulate the parts locally. It makes no friggen sense to spend hours, weeks or more, to draw up the plans, engineer it into the PCB cad program to output the files that the PCB manufacturers require, wire $250 to China to make up 10 bare PCB's and then we haven't even begun to buy all the components to populate the boards yet. And what if a problem manifests, an error in the PCB design that shows up after building it and requires a redo? So let's just say I have already spent many hours looking through lots of already built (or kit) modules that are available, considered the features, and while a few years ago, China put out lots of junk, today, they put out stuff that we can't touch for the price they charge already done. The downside is that we are limited to whatever features that particular module was built with. Can we custom make a preamp board with wide mode when no current kit or ready made project has that feature? Of course we can! But at what cost? So, I think we should keep it simple, and accept the limitations of the modules that are currently available. If those features become available later -- add it! That's what so great about modular. So if there is a feature you guys want, search for it and see if a module exists and we will see if it can be implemented into the project. But please don't ask me to build in touch screen controls. I mean, who is offering a diy module like that right now and if not, should I then build it for these 5 or 10 units?

More thoughts:
8" or 10" woofers have one thing going for them... they can put out sound quite effortlessly compared to small drivers. The sound seems natural whereas small drivers seem to strain. Larger drivers also have much higher SPL sensitivity. So you can get larger sound without resorting to larger amps to compensate for lower speaker sensitivity. Subwoofers: They are nice to have, but they require lots of power to run them. So in a portable device, that means they don't nibble cookies, they are the cookie monster. Still you might say the big ben has one and so does the kaboom right? Ok, but how long does the kaboom lasts on batteries and does it produce equivalent sound while portable? And the big ben does sound nice at moderate sound levels. But this blaster is going to kick it's azzz and the SPL's will be huge. Basically if you put a big ben next to this completed project, you won't hear the big ben... it'll be like it isn't even there. Therefore, in order for the big ben system to work, the sub will need 100wpc to match the 50wpc of the fulll range setup. Going back to battery life here..... Of course an option is to have a sub that can be setup to work only when on AC. That might be doable but of course does add to the cost. Might be OK, but I guess we will need to see if we want to build that level of complexity into our first boomer attempt.

Cosmetics: Hardmen's two ideas look pretty good and does indeed have a "classic" look. And it appears to accomplish that with just a rectangular box without complicated design elements. Just some smartly placed cosmetic panels. It might be worth some consideration.

Joe: Give me some time on the box design. I need input from you though on what is too comlex and what is feasible. Initially I thought that maybe a large sheet can be cut in a manner so that once bent on a brake, could end up with a rectangular chassis. Add front and rear panels and we are done, but as I piece this together in my mind, I'm thinking the precision to accomplish that is so hard to do that the end result might not look too good. Will likely be gaps in the seams and stuff that will be unsightly. However, yesterday, I saw a show on REV'n TV where a guy was building a custom console for some sort of truck. They built it using angle metal that was welded to the shape of the desired console. Then aluminum panels were cut to cover the gaps in the welded frame. The frame was copper color, probably powder coated, and the aluminum was natural finish, edge screwed to the frame with decorative screws. To prevent the ugly seam syndrome, the aluminum panels were cut slightly smaller than the frame so that it covers up the openings but some of the frame showed along the edges. The results was very attractive indeed. Do you think that is doable?

In time, I might acquire a hobby CNC lathe and maybe even a laser cutter. Either or both of those would change the game entirely but I don't have the funds for those toys right now. Maybe after selling off some of my grails, it can be a reality. However, that's not going to be a tommorow thing.... probably talking years away. Sigh, on the one hand, I wish time would slow down so I can milk the rest of my days for all it's worth. On the other hand, it would be plenty nice to have those machines here right now.
 

redbenjoe

I Am Legend
jimmyjimmy19702010 said:
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jimmy - THANKS alot
 

redbenjoe

I Am Legend
NICE post norm

no need to consume months and several months saving up for a cnc lathe or a laser cutter .. just for TEN boxes -
unless you truly live 100 miles from nowhere --you will find local machine shops with much better than ' hobby ' priced
machines

the ONE choice that most of us posters agree on is the ' classic ' look -
while none of us will object to creating a ' modern classic '

also - to make your goal less lofty --i suggest this group can design THE WORLDS GREATEST BOOMER --
that does NOT need to blow away an m90 by making its sound 10 times louder and 5 times more clear/defined

just think how good just TWICE as good as an m90 will sound
----------------

so my suggestion is to relax about the ' utopia ' box --
and ' simply ' set out to make the slam-dunk BEST BOX
 

Superduper

Moderator
Staff member
Very true Ira. Yesterday, I have already tested a chinese amp that I purchased about a year ago but never used, with no preamp tone control, using only my ipod classic as source and carefully turning volume down to nothing before connecting to the amp, and hooking up to a set of EPI 6.5" 2-way bookshelf speakers with no surrounds (yeah, they need to be refoamed). The volume and midrange clarity was astounding. No M90 in my collection can match it, and the bass was hard and stiff. Incredible considering the speakers had no surrounds, so I would've thought that they would be farting and vibrating but they did not. I can only imagine what the bass would've sounded like had the speakers had intact surrounds and therefore sealed to the enclosure. Oh yeah, I had it powered using the internal PS of my portable suitcase lab kit. I have no idea how robust or not it is, but it does have variable output and I did test it at 15, 18, 20 volts and didn't observe any discernible differences even though technically higher voltage should yield higher output. Also, the output was quite linear and there was no sagging of the sound until I cranked it to near max output (using ipod's volume control) but I suspect that the sag was from the ipod output signal and not from the amp itself (at the time, the battery bar was blinking red and shutdown was probably imminent). I started with a full charge and it only lasted 30 minutes at high volumes so either it takes a lot of juice to power the amp at full ipod output, or more likely as the ipod is over 8 years old with the orig batteries, it's about time to chuck or replace the battery. The dynamic headroom is astounding. I would not say that it gets 5 times louder than an M90. But anyone that has heard an M90 at full tilt knows that even if we are talking about the same volume as an M90, we are talking loud. Sound quality wise, this little amplifier module will blow away the M90 or C100 (with the EPI 6.5" I had them connected to). If I had to compare it to a hot rod car engine, I would describe it like it pulls hard from start all the way to redline without any observable signs of flat spots. I'm not sure about detail because I was pushing it hard for about 30 minutes straight and my ears were literally hurting. But it was pleasing to listen to even at such high levels because it was pretty much distortion free. I can not push the M90 past 70 or 80% because distortion makes it sounds like explosion is imminent. The C100 is even worse, that raw sound to me is total crap. So how loud did it go with the 6.5" surround-less 8-ohm bookshelf speakers? I would say maybe 1.5 x's as loud without any of the distortion associated with any boomer at near max volume settings. Higher powered versions of this little amp are available as well but then I wonder if power supply issues will become an issue. Also at approx 1.5x M90 power, this little amp module probably isn't near max yet. Again, there was some crapping out when source was near max volume but it sounded more like either the PS was sagging or the ipod could not push clean signal at max due to low battery level. I will need more tests to determine which but in any event, the results look promising.

In short, I have high hopes and expectations for this project and hope it all interfaces without any major hurdles. Perhaps I should build one first and do a traveling boombox type of thing. Have it travel the USA from member to member, each participant must pay their own shipping costs, and anyone interested to can have a personal test drive for, say a week?
 
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