sound system for velomobile - help needed

[wojtek]

yes the problem is, 5v usb powered speakers won't sound great. I'd decide for 12vdc. And just cut the 12vdc cable and connect to 3s Lipo pack. Or main battery via the Dc to Dc converter. Got some from Edward [Lyen] on ES.

Powering is not a problem , just finding small speakers that sound great.

Now i changed my priorities. I just want clear and crispy sound more than powerful boom boom. I gave up idea of making outdoor parties

Read a lot of reviews, the logitech s715i might have superior sound quality than supertooth disco. I may order both on amazon, test them and return one.
But surely i want to run them at 12v power and with attached batteries!

All your music equipment needs power usually 5V or 12V DC. No one believes that you can run most of these 120V AC adapters, off your DC bicycle battery. It does work. I tested a bunch of them with my 48V battery. They all worked. Look what Fechter figured out.
Cheap DC-DC converters for over 60v input.

I don't know if this adapter will have enough amps for what you want to do? Need to ask the electricity experts that.

 

[wojtek]

http://qlshifi.com/en/wzcapi/qa350_mod_v2.htm
QA350 MOD V2

Hifiman HM-602
http://news.cnet.com/8301-13645_3-20021179-47.html

they sound to be far better than ipod...

 

[John in CR]

Many car speakers don't require a box, just separation between the front and rear output so the bass waves don't cancel each other. Also, you are looking for high efficiency speakers, then you only need a few watts to play extremely loud on very little power. There are tiny digital amps that have great sound and are extremely efficient too. Some of my tube amps only have 2 watts of power, but paired with my higher efficiency speakers they'll play concert level loud. I also have several cheap but great sounding digital amps of less than 8 watts that would blow you out of a velomobile with good speakers. One of those is isn't much bigger than a credit card.

It's all in the first watt with good rigs. Unfortunately the public has been sold on watts as the measure of importance, so the manufacturers come out with cheap high power and match it with very inefficient speakers, just to get the same sound output we were getting in the 70's before the only amps with more than 30-40 watts didn't exist except in professional sound systems.

Here's a good one for under $30 that weighs less than half a kg and can easily run off of batteries.
http://www.amazon.com/Lepai-Tripath-TA2020-Class-T-Amplifier/dp/B0049P6OTI/ref=dp_cp_ob_e_title_1
Speakers are a very personal choice, but you'd be surprised the good sound possible from some super cheap factory replacement car speakers found at electronics and car parts warehouses.

 

[wojtek]

thanks John! and i agree with you. I am looking for a nice clear and rich sound now.

it does look good and i think i can plug MP3 player directly into this amp and connect to speakers.

I gave up the car radio idea and want to get a mp3 player connected to amp connected to speakers

So speakers are the last missing link..

 

[marty]

http://qlshifi.com/en/wzcapi/qa350_mod_v2.htm
QA350 MOD V2
I DON'T KNOW WHAT THIS IS?

Hifiman HM-602
http://news.cnet.com/8301-13645_3-20021179-47.html
$790 WONDER IF IT SOUNDS BETTER BECAUSE IT COSTS MORE?

they sound to be far better than ipod...

Did you look here?
Music Storage and Playing Equipment
http://endless-sphere.com/forums/viewtopic.php?f=1&t=27568

Speakers will sound different in a house, shop, car, velomobile, or outside. I would go to a car radio place and ask for advise. Take a look here http://www.the12volt.com/

I am old. When CDs came out, people said vinyl record albums sounded better. When MP3s came out. people said CDs sound better. My cassette tapes sound good to me.

 

[Erogo]

Hey John, good hifi philosophy there. I built up one of those tripath digital amps (are they kinda PWM amps?!) for my kitchen radio, as described in DeeJays boombox thread. I was keen to get v high efficiency speakers - it's the dB/wm figure, isn't it? Often times that's not specified, or not trustworthy, until you get into quite high-end drivers, isn't it? Can you link to any exceptions? - I won't hold you to them as recommendations

also, the separation between front and back of speaker is the theoretical "infinite baffle", isn't it? Approximated by car door panel, parcel tray or - what in a velomobile? Can't mount it in the bodyshell, or it'll get wet on one side or tother. So then some custom structure inside, which may or may not be fully closed, but is either way a box, and then to approximate the infinite baffle, the bigger the better, and internally damped, no?

Unless you're going to start talking open baffle designs designed around the drivers specific characteristic parameters, coupling with the cavity of the velmobile shell, and by then I think we're overkill

cheers, and - if you can point me to some cheap high efficiency drivers I'd be real interested!
Eric

 

[John in CR]

Eric,

Speaker building was my hobby before hot air engines, which was before ebikes, so I've been out of it for a while sitting on a stockpile of drivers and speakers of my own design from horns to line arrays and everything in between, but primarily open alignments of different types. My favorite is a modified U baffle single driver speaker with a significant portion of the bass frequencies captured by a Helmholtz slot filter and sent through a rear bass horn.

You'd need to define cheap and how high efficiency. The only really high efficiency stuff that can be found cheap is pro audio drivers. Combine a 15" lower line pro woofer and a bullet tweeter seen in car audio (tweaked of course but easily done), and 98 or 99db on 1 watt is pretty simple. That's not practical for a velo though unless it's something for burning man. The only route to cheap and high efficiency for a velo is going to me something like a mini line array.

I ran a line array on my desk for years. I went to all the electronics shops I could find, and listened to every small cheap drive I could find. The kind that are hidden behind the grill of TV's, clock radios, whatever. We're talking $1-2 speakers. I bought a pair of a few that sounded ok at the shop with just a piece of cardboard I brought as a baffle. I tested 4-5 different ones at home. The ones I liked best, I picked up a case of 100 for something under $100, I don't recall exactly. I made all kinds of line arrays with those speaker drivers.

With weight being a concern with a velo definitely get a round speaker then you can use a lightweight tube like a piece of PVC to make your enclosure. Efficiency isn't much of a concern, because you're in a more constant position relative to the vehicle, even more so than at your desk. That means you can put the speakers closer to you. Most are junk, but some actually sound pretty nice, so a favorite set of computer speakers might be a good source for small speakers to put in a velo, and if you needed more bass dig that subwoofer driver out too and build the same volume box and port size but using a cylinder.

I should stop now before this turns into a book.

 

[sk8norcal]

saw this at Fry's

jawbone bluetooth speakers.
would be nice on my little scooter..

http://thecoolgadgets.com/jambox-jawbones-bluetooth-speaker-system-8-hours-of-battery-life/

 

[wojtek]

this lepai is great amp! lightweight and cheap! and should sound great

they have also other good looking products, some of you may be interested:
http://cgi.ebay.com/ebaymotors/Motorcycle-Scooter-Audio-MP3-waterproof-speaker-Alarm-/250875838912?pt=Motorcycles_Parts_Accessories&hash=item3a695d81c0

jawbone bluetooth speakers are nice but according to the reviews Soundmatters foxLv2 are better.
http://www.soundmatters.com/foxl/technology.html

I would either go for soundmatters or for the lepai amp and some (???) speakers.

 

[John in CR]

Also, for those who like bass heavy music there's software, MaxxBass is one example, that enhances the bass frequencies without the speaker having to play them. What it does is uses an algorithm to enhance the harmonics of the bass notes, and this causes the brain to hear the notes without them actually played back by the speakers. This system is used on a lot of today's music, and that's why a lot of it sounds WAY too bass heavy when played back through a system capable of reproducing the lowest octave. The recording industry has gone this route because of the trend toward small speakers that simply can't reproduce full range. I've heard it used and the sound is quite natural, though the physical sensation is missing. If you're a bass head and need to really feel the bass, a good option would be to attach a tactile transducer to your seat.
http://www.parts-express.com/wizards/searchResults.cfm?srchExt=CAT&srchCat=634

Another interesting approach in a velo, though I've never heard one is to use an "exciter", which attaches to a surface of the vehicle turning that surface into a speaker. Years ago I remember hearing about one of these types of units that apparently could turn a FedEx box into a decent sounding speaker.

Unfortunately I'd never give up my sense of sound while riding. As much as I love music, being able to hear is too important for safety. Otherwise I'd have some proven solutions for you. I think you're on the right track with that little T-amp.

When Altec Lansing first broke into the computer speaker market their little 4.1 system had some sweet sounding tiny speakers. Unfortunately they later went toward all the gimmickry like the rest instead of sound quality. The speakers from that system would be perfect for your velo.

 

[sk8norcal]

^ still got my aliens...

 

[wojtek]

http://www.amazon.com/Dayton-Quadpod-Exciter-anything-Speaker/product-reviews/B004AR5G9O/ref=dp_top_cm_cr_acr_txt?ie=UTF8&showViewpoints=1

never heard of exciter to be honest. Not available in Europe so i will have to get it from USA. Interesting!

the volomobile chasis:
Self supporting fiber composite chassis, manufactured from finest epoxy resins (certified for building aircrafts) and fabrics
glossy and polishable white gel-coat surface

Can i plug all at the same time?
- exciter x1
- speakers x2
- bass shaker x1

i would need many outputs.

That would be great!

Im not that into listening while riding. it is more a cool feature while NOT riding or riding in no traffic.

 

[John in CR]

A pair of the exciters would replace speakers, not in addition. Really just something interesting I through out there, not something I'd try in my nice new expensive velo. That little amp and a pair of small speakers is how I'd go for a permanent(ish) install. Then for occasions where more sound might be needed have something bigger to bring along...maybe as simple as another one of those amps and a couple of coaxials mounted in PVC to keep it light with some long wires to set up for listening while parked. How you plan to use them should dictate what you build.

When I do my ocean to ocean ride in a few months, I'll definitely have some rockin good sound aboard using 2 of these little amps based on the same T-amp in the one I linked above. One will drive one of my pairs of high efficiency small Fostex full rangers, and the other some kind of bass tube to round out the bottom end.

 

[Dee Jay]

When Altec Lansing first broke into the computer speaker market their little 4.1 system had some sweet sounding tiny speakers. Unfortunately they later went toward all the gimmickry like the rest instead of sound quality.

I wanted to mention this too..back in the 90's Harman Kardon and I think even Yamaha PC speakers shipped out in package deals like Gateways and Compaq. You should find them at junk shop and garage sales now.

EDIT: Oh BTW, those were the days when they called PCs with speakers "multimedia PCs" well duh! LMFAO!

 

[wojtek]

http://www.dynamatstore.com/index.php?l=product_detail&p=114
Dynamat SuperLite
expensive and bit heavy 2kg for 12 square feet
and it may look terrible inside velomobile
http://www.google.com/search?hl=en&q=Dynamat+SuperLite&gs_sm=d&gs_upl=437l2718l1l2889l2l2l0l0l0l0l162l162l0.1l1l0&bav=on.2,or.r_gc.r_pw.&biw=1280&bih=599&um=1&ie=UTF-8&tbm=isch&source=og&sa=N&tab=wi

i will try with the foam instead

 

[marty]

http://www.dynamatstore.com/index.php?l=product_detail&p=114
Dynamat SuperLite
expensive and bit heavy 2kg for 12 square feet
and it may look terrible inside velomobile
http://www.google.com/search?hl=en&q=Dynamat+SuperLite&gs_sm=d&gs_upl=437l2718l1l2889l2l2l0l0l0l0l162l162l0.1l1l0&bav=on.2,or.r_gc.r_pw.&biw=1280&bih=599&um=1&ie=UTF-8&tbm=isch&source=og&sa=N&tab=wi

i will try with the foam instead

Are you building a coffin? Think you are getting a bit heavy? Buy some small USB powered computer speakers and a iPod or a cell phone to hold your music. And or that HD Radio player I mentioned earlier. To keep it simple all these things are powered by 5V DC. I know nothing about these speakers but they have a good rating on Amazon. I am happy with my iPod, although it is a bit expensive.

Logitech Stereo Speakers Z120, USB Powered (980-000524)

 

[Pure]

6. Velomobile as such is not the best place for music quality. Even with best speakers and players, the sound might not be great at all.
I could cover the interior with a special lightweight sound enhancing material?

I skimmed through the thread and didn't see anyone mention this. I apologize is someone did and I missed it. But a cheap solution to this problem would be to use what we call poor mans dynomat. Go get several cans of spray on undercoating from an automotive store. Spray it on all the inside surfaces of your velo's body (minus the windshield of course) and it will really help absorb the road \noise echoing off of the interior panels and help make your music sound better. You do need a pretty thick coat, but as long as you don't go too crazy it shouldn't add too much weight.

 

[wojtek]

some reviews about this Poor mans dynomat:

Prepare to have your car smell like tar when the sun shines nice and bright all summer.

DONT DO IT plain and simple. You WILL regret it. It wont work well, it will smell like ass year round and prolly start seaping out of panels and shit in the summer. If you are really that cheap look into some Brown Bread. Same shit is dynomat but wayyy cheaper.

 

[Pure]

Interesting, we've never had any issues with it. And here it gets so hot in a car you can actually bake cookies in it. I can see how that might be possible with certain brands but think about it. If those statements where 100% true for all brands of undercoating, it would never stay on any vehicle, and to best of my knowledge, it's used on every production vehicle sold in the USA.

It does take it a wile to cure, but once it does it shouldn't be an issue. Either way, if it works it's worth it. Def worth getting a couple of brands that you have available to you and experimenting on several test sheets. Lay them out in the sun, etc, and see what happens. At worse, your out a lil $ for the test samples.

Edit: Real Dynomat or even brown bread would be very weight prohibitive in your application. That shit starts adding on pounds once you really start covering some real square inches.

You are basically just wanting to deaden the echoing effect the plastic shell/body has. There are plenty of other ways to do this. You could even just put a thin coat of pure silicone caulk on the interior of the body. Use rollers and brushes to apply a thin coat. Any rubber like material adhered to the body panels will do the job.

 

[wojtek]

thanks for your advice!
which brand exactly would you recommend to test?

how about acoustic foam?

Interesting, we've never had any issues with it. And here it gets so hot in a car you can actually bake cookies in it. I can see how that might be possible with certain brands but think about it. If those statements where 100% true for all brands of undercoating, it would never stay on any vehicle, and to best of my knowledge, it's used on every production vehicle sold in the USA.

It does take it a wile to cure, but once it does it shouldn't be an issue. Either way, if it works it's worth it. Def worth getting a couple of brands that you have available to you and experimenting on several test sheets. Lay them out in the sun, etc, and see what happens. At worse, your out a lil $ for the test samples.

Edit: Real Dynomat or even brown bread would be very weight prohibitive in your application. That shit starts adding on pounds once you really start covering some real square inches.

You are basically just wanting to deaden the echoing effect the plastic shell/body has. There are plenty of other ways to do this. You could even just put a thin coat of pure silicone caulk on the interior of the body. Use rollers and brushes to apply a thin coat. Any rubber like material adhered to the body panels will do the job.

 

[Pure]

I'll have to get with my buddies who are into this sort of thing and ask them if there are any particular brands to stay away from. It's literally been years since I used it. I was a teen at the time and FWIW I just went and bought what my local auto parts store had on hand..

I have to admit the more I think about it, the silicone idea is a pretty good one. As long as it's pure silicone, like what you would use to seal a fish tank. Once cured it has 0 odor to it, and will withstand some pretty high temps. Not to mention it cures clear so as long as you don't have a 2 inch thick coat, it will hardly be noticeable. Also it's one of the few things that will stick to coroplast (often used for velomobile body panels) So if you ever go lightweight coroplast panels, there you go!

 

[marty]

No gooey undercoating in a velomobile please. Seems like a horrible mess to me. Glue on some Speaker Box / Automotive Trunk lining Carpet. Use contact cement. Will have to cut the carpet to fit. Use a sharp knife. Take your time. Make paper patterns if needed. Contact cement smells like brain damage.
Here is a picture of how I put a woofer in my car where the spare tire used to be.

More pictures of my car audio project here http://voltev.com/03sx/
Car sounds great with a whole bunch of sound proofing stuff.

 

[bzhwindtalker]

When we rode across the US in our custom velomobiles with my friend Chase, we had cheap wallmart USB speakers running of external batt that we charged from solar panels. Some of those usb speakers will do 10w, way enough for a VM ! its also quite cheap a 12$ a set. you could power them from any cell phone charger used as DC/DC (if you have a battery onboard) otherwise they run fine on 1S lipo :wink:

 

[wojtek]

i ordered 2x little low V powered amplifiers and speakers [Lepai 2020a+ and one more powerful with Bose components] but f**** EU wants to destroy them as they don't have CE.

Can't believe it.

Those speakers would be perfect: http://www.soundscience-corp.com/qsb.html
but they don't have 3.5mm jack inbuilt.

 

[thedarlington]

can anyone elaborate on marty's post about using switcher WALL AC Power Bricks to step down currents? im really interested in this concept but how do you connect it to the battery circuit? do you just hookup one metal wall tab to batt+ and the other to batt- ?

All your music equipment needs power usually 5V or 12V DC. No one believes that you can run most of these 120V AC adapters, off your DC bicycle battery. It does work. I tested a bunch of them with my 48V battery. They all worked. Look what Fechter figured out.
Cheap DC-DC converters for over 60v input.

USB TRAVEL CHARGER
http://www.allelectronics.com/make-a-store/item/PS-223/USB-TRAVEL-CHARGER/1.html
I don't know if this adapter will have enough amps for what you want to do? Need to ask the electricity experts that.