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Topic with many replies

Create your own festival stereo


Author Message
Written on: 10.05.2009 18:53
Jim Daggerthuggert
Posts: 637
Cos skrev:

Thought it would be nice to show you guys a picture of the the project as it stands now, it's still not done but it's beginning to look like somethingicon_biggrin.gif
http://img5.imageshack.us/img5/1135/dsc00050btk.th.jpg


You need to pimp it maaaan, pimp it goooood!
Written on: 10.05.2009 19:09
Saturnus
Posts: 3047
Jim Daggerthuggert skrev:

Cos skrev:

Thought it would be nice to show you guys a picture of the the project as it stands now, it's still not done but it's beginning to look like somethingicon_biggrin.gif
http://img5.imageshack.us/img5/1135/dsc00050btk.th.jpg


You need to pimp it maaaan, pimp it goooood!


Damn, that big. About 3-4 times the size of my boominator ... and with the same drivers ... I think you may have miscalculated the internal volume gravely.

[This article was edited 1 times, at last 10.05.2009 at 19:10.]
Written on: 10.05.2009 20:58
Cos
Posts: 39
Well inside it's devided into 3 seperate rooms so it should be okayicon_smile.gif We always planned on making it big because we wanted it to function as a bench type furniture, we are also gonna add a back rest and some sort of beer dispensing device but we haven't really gotten to that part yet and it's gonna be on wheels too, but that's kind of a given with the size and what noticon_smile.gif
Written on: 11.05.2009 23:19
DarkCity
Posts: 162
Jim Daggerthuggert skrev:

Cos skrev:

Thought it would be nice to show you guys a picture of the the project as it stands now, it's still not done but it's beginning to look like somethingicon_biggrin.gif
http://img5.imageshack.us/img5/1135/dsc00050btk.th.jpg


You need to pimp it maaaan, pimp it goooood!

Nobody can pimp a festivalstereo like i DOOOOOOO! icon_cool.gif
This years bling-bling: Back & front lid kevlar speakers! PIMPING & PUMPING!
Just sitting back in my camping chair with the remote and surfing my ipod icon_razz.gif
http://i40.tinypic.com/219rhw5.jpg
Written on: 12.05.2009 12:57
ThokN
Posts: 77
Hello again Saturnus.

I've been reading everything posted about the Boominator here, on DIYAudio and 41hz, and in a post you give a link to your CAD files, but youshare.com is not working properly. I'm not able to download the zip file. Is there some way that you can share the cad files with me? We are beginning the build of a boominator this friday, and it would be so much easier with some detailed drawings of the external and internal dimensions icon_smile.gif

We've almost build the Amp6Basic, and are going to order the speakers now, so we're quite excited about the build.

We don't have access to a CNC cutter, but I suppose that we will be able to make our own adjustments to the CAD drawings so that we can build it by hand, right?

Thank you very much for the inspiring work you have done with the Boominator!
Written on: 19.05.2009 20:44
Cos
Posts: 39
Hey Saturnus, you aren't answering on your mail so i thought I'd try to reach you hereicon_smile.gif
are you still up for our arangement?
Written on: 20.05.2009 02:18
Deleted user The more I think about it, the more I reckon it's time to build one myself. Mainly so I can blast Wagner at 8:00 every morning when I get up. Just to let the neighboring camps know that Emilius is up...


I will compile a 'Roskilde boombox for retards' tutorial if I get around to acquiring the knowledge, money and time to build one this year. Basically unlike Saturnus' tutorial, it will be mainly about where the wires go, etc.

[This article was edited 1 times, at last 20.05.2009 at 02:22.]
Written on: 20.05.2009 22:50
Sune
Posts: 37
Is there anyone who can recommend any other amplifiers working well with mp3 players? The Amp6 sound like a good choice, but I haven't got the skills or equipment to solder anything myself. Isn't it possible to order them "ready to go" somewhere?

What else than battery, speakers, amplifier and power/speaker wires should be on the shopping list? any other electronic stuff, fuses of some kind of anything else?

Emilius: Good idea, would be nice with a tutorial with the basics for all us electronic-dummies icon_smile.gif
Written on: 20.05.2009 23:28
Saturnus
Posts: 3047
Sune skrev:

Is there anyone who can recommend any other amplifiers working well with mp3 players? The Amp6 sound like a good choice, but I haven't got the skills or equipment to solder anything myself. Isn't it possible to order them "ready to go" somewhere?


I can recommend the hlly t-amp ready made board. It's larger and has more ordinary "run-of-the mill" components compared to the "hi-end quality" components in the amp6basic. But with the current price cut, it's almost the same price as the amp6basic

http://www.hllyelectronics.com/html/fm_transmitter_1_97.html

Written on: 20.05.2009 23:33
Saturnus
Posts: 3047
Cos skrev:

Hey Saturnus, you aren't answering on your mail so i thought I'd try to reach you hereicon_smile.gif
are you still up for our arangement?


You got mail (earlier) ... just wanted to wait until I had the components in hand before making any solid commitments.
Written on: 21.05.2009 00:50
Christian Bøggild
Posts: 1
Hey Saturnus

I've been following your posts with great interest and have just ordered some of the vital parts you've recommended (4x hp10w, tweeters, amp etc)... thanks so far. I noticed one of the other guys in here talking about some cad drawings of your boominator - do you have such? If not, would you have any tips and recommendations on the dimensions, sectioning of the chassis etc?

Last but not least the magnet-to-magnet thing - how is that practically done?

Regards,
Christian
Written on: 21.05.2009 14:04
Simon B.
Posts: 44
Hi Guys..

Simply wanted to let other rookies know that you don't have to be a total electronics-genius to build your own stereo.. I built my boombox back in early 2008 without that much help (Carsound in Roskilde helped a bit with the crucial wiring).. I just made up my mind not to settle with a crappy little radio that played more static than music.. The following pictures include the front and back + a view of the interior electronics ("indmaden" - in danish).. The last picture was before i redesigned the whole box - I made it smaller + mounted the rear speakers.. I hadn't heard or read about Saturnus' Boominator beforehand - if i had i might have chosen a more clever energy-efficient design with the right materials.. Have faith people.. It's doable even though you have little knowledge of anything.. icon_biggrin.gif (Hope i know how to paste pictures)

http://img40.imageshack.us/img40/7108/29212450.th.jpg
http://img40.imageshack.us/img40/7636/98069250.th.jpg
http://img40.imageshack.us/img40/6712/92843435.th.jpg
Written on: 21.05.2009 15:24
Deleted user Dude, where'd you get that kart?
Written on: 21.05.2009 15:32
Simon B.
Posts: 44
Emilius skrev:

Dude, where'd you get that kart?


Hehe.. I modified it a bit, but here you go:

http://www.harald-nyborg.dk/merinfo.asp?varenr=9977&n=60100
Written on: 21.05.2009 15:35
Deleted user
Simon B. wrote:

Emilius wrote:

Dude, where'd you get that kart?


Hehe.. I modified it a bit, but here you go:

http://www.harald-nyborg.dk/merinfo.asp?varenr=9977&n=60100



I've actually been looking at that before, but the wheels appear a lot smaller and crappier in the advertisement than it does in your photos.
Written on: 21.05.2009 15:39
Simon B.
Posts: 44
Emilius skrev:

Simon B. skrev:

Emilius skrev:

Dude, where'd you get that kart?


Hehe.. I modified it a bit, but here you go:

http://www.harald-nyborg.dk/merinfo.asp?varenr=9977&n=60100



I've actually been looking at that before, but the wheels appear a lot smaller and crappier in the advertisement than it does in your photos.

They are actually quite sturdy and can stand being abused.. Last year when going home i had my boombox, two car batteries, tent, clothes and so on on it.. icon_smile.gif
Written on: 21.05.2009 18:43
Kenneth Jensen
Posts: 6
Yup, been using that one last year and its joining the festival this year too.
Written on: 25.05.2009 20:29
Deleted user Out of knowledge, money and time, it appears that money is the limiting factor this year. : (

I'll have to wait with my project, peeps will have to wait for the 'Roskilde Boombox for Retards' tutorial, and some people will unknowingly not have to suffer through Flight of the Valkyries every morning.

It's gonna be tough getting this project out of my head... what a bummer.

Can anyone come up with a better name for me than Boom Raider?
Written on: 26.05.2009 01:13
Robin
Posts: 13
I plan to build my own boombox and wonder if i use the amp6basic,
2x http://www.ljudia.no/hyttalerelementer-s82124/bass-s97514/10-tomme-c96816/paudio-hp-10w-p78414/
2x http://www.ljudia.no/hyttalerelementer-s82124/piezo-c78561/mgr-ch-5-a-p78563/

How will the sound be and should i go for P.audio HP-10W 4 ohms instead of 8?

I dont need anything els? except a carbattery.
Written on: 26.05.2009 10:59
Deleted user Since it looks like Saturnus is taking a break from helping us noobs out, I'll answer this with my limited theoretical knowledge (no practical experience yet).

First of all, you need a couple of power resistors to be able to match the total impedance for each channel. The way Saturnus describes the setup earlier in the thread means that the power will be distributed so that the tweeter gets much less than the woofers. I'm only assuming that this is desirable.

To calculate equivalent total impedance, use linear addition for the resistors (and speakers) in series, and the following variation of Ohm's law for parallel connections:

Rtot=(1/R1+1/R2+...)^-1

I get around 3.5 Ohms per channel if I understood Saturnus' suggestion correctly earlier, where a 47Ohm power resistor is connected in series with each tweeter. That should answer your question of whether to get the 4 or 8 Ohms woofer. I think that as long as you get the equivalent total impedance right, and the power is balanced correctly, Bob's your uncle.

Also make sure you are using wires that are able to handle the current you're drawing through them.

You might also think about getting a potentiometer to mod your amp6 with, as far as I have understood on this thread, it doesn't come with gain control. I'm not the one to ask on how to do that though.

You can also get a filter for your tweeters (crossover?) so that they only get the desired range on the frequency spectrum.

I can't think of anything else for now, but do keep in mind that I'm a noob as well.


Cheers.
Written on: 26.05.2009 11:00
Sune
Posts: 37
Logically thinking I would assume that the sensivity of the tweeters should be as close to the sensivity of the drivers as possible, or doesn't this matter? And in case it does, is it better to get tweeters with a higher or lower sensivity if an exact match isn't possible?

I am looking at the HP10W drivers at 96db and either Piezo MPT-005 or MPT-177 at 94 and 99db respectively.

http://www.ts-audio.biz/tsshop2/WGS/869/PRD/MPT-005/Piezo-Hochtoener.htm
http://www.ts-audio.biz/tsshop/WGS/869/PRD/MPT-177/Piezo-Hochtoener.htm
Written on: 26.05.2009 11:15
Deleted user Unfortunately I can't answer this question. In the setup that's been described earlier, the tweeters get way less power than the woofers, even though they are around the same sensitivity. I have to assume that this has something to do with tweeters generally being more audible, which I know nothing about. If someone finds a link to somewhere that can explain this, I'd be grateful.
Written on: 26.05.2009 11:32
Saturnus
Posts: 3047
Damnit!

That's the second time I accidentally press "delete" instead of "edit" ... how about a "confirm delete"-option?

Anyways, I'll retype the vital points.

Piezos are not regular tweeters. They are capacitive loads and not resistive loads, so you need a completely different set of equations to calculate filters for them.

If you want to decrease the level of a piezo, you add a series capacitor, not a series resistor.

A series resistor on a piezo has 2 functions;

a) it makes the amp see a resistive load preventing the amp from being fried by positive feedback

b) it acts as a series capacitor would on a normal speaker, ie. as a highpass filter. The value depends on the desired x-over frequency and the piezo itself.

A HP10W has an average sensitivity of about 94.5 dB/w/m in a box, any piezo with a rated sensitivty of 94 or 95 will do, even higher or lower is possible as piezos generally aren't very linear speakers, and output often varies more than 12 dB over their frequency range.

The Zomax HP100 piezo I use are very high quality ones, that with the suggested series resistor has a x-over frequency at 3.6 KHz and varies less than 3 dB from 3 KHz to 13 KHz after which the level declines. Remember MP3-players generally do not produce sound over 13 KHz unless you use an uncompressed format since cutting everything above 13 KHz is a vital part of reducing the datastream.

[This article was edited 1 times, at last 26.05.2009 at 11:36.]
Written on: 26.05.2009 11:36
Deleted user Excellent. This is the post I've been wanting to find in the forums. Thanks.
Written on: 26.05.2009 11:46
Saturnus
Posts: 3047
Oh, btw, for all question regarding the amp6basic, I refer to the www.41hz.com forum ... all possible questions you might have is already asked and answered there.

Btw, sorry if my previous post came of as lecturing and arrogant but I had typed it twice before each time explaining the different things to consider, and accidentally deleted my post both times instead of editing it. I was even more mad at the forum than usual.

[This article was edited 2 times, at last 26.05.2009 at 11:51.]


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