sounds system project. need help with numbers

[subwoffer]

hi . i would like to know if anybody have the knowledge to tell me what amplifier i should buy to feed 12 inch subwoofer , and what Woltage of the speakers should come with it ? ( i'd  like it pretty loud, not the " built in mirrors" sound

[Cortez]

hi . i would like to know if anybody have the knowledge to tell me what amplifier i should buy to feed 12 inch subwoofer , and what Woltage of the speakers should come with it ? ( i'd  like it pretty loud, not the " built in mirrors" sound

Oh my, this will get a lot more complex then you ever imagined.

First of all, the terms are "Voltage" and "Wattage", the latter being the power and probably what
you're asking about.

The size of the woofer tells you absolutely nothing about it's power requirements.
You can find the rated power of a loudspeaker usually on the back of it or on the
package. For a 12" woofer, it can be anything from 30W to over 500W. It will also
have a certain resistance value, between 2 and 8 ohms.

When looking at an amplifier, it's power will be rated something like 100W/ch@8ohm,
meaning you get an output of 100 watts per channel (if you have 2 speakers which
is a normal stereo setup) if the loudspeaker is an 8 ohm speaker. To get things even
more complicated, the speakers always changes it's resistance depending on the
tone frequency (read: it can be 2 ohm at low tones and 10 at high tones).

If this value varies more, you need a stronger and more stable (usually more expensive,
not just more watts) amplifier.

And now forget all of this since it has nothing to do with quality or even how loud a
loudspeaker will play.

That's determined by the speaker's efficiency/sensitivity value given in a number like
90dB/W/m, which means it'll play 90dB loud with 1W of power at 1 meter away.

In short, this means a speaker with high sensitivity can play louder with just 1 watt
then some will with 100 watts.

Considering how you put the question together, I'm gonna say you're screwed.
 

...but feel free to ask if something needs more explaining, if my english is good
enough I'll try..

[subwoffer]

thanks for the explanation .
but i think i'll be able to simplify this a bit .
take a car for example . minimum stereo setup (with sub and AMP) . sounds loud enough .
now lets be more specific,i'd like to hear it loud enough while driving at 0-90 kmh(considering that's on the bike )  . ( the 90 kmh speed with music might be in my dreams only, but i dont care , i'll be happy enough to listen to it on "parking" or 20 kmh . )

so,even more simple , what setup should i buy that will be balanced enough to fit bike's electricity , and be loud enough .

saw a millions of those on youtube, i think this will  be simple enough as long as i'll know the specific of the products that will do the job
(this is the "super-extreme system)

(and thats more stabilized )


(and another one , kind of how to )

[zombie]

A few check points will make this easier... The size of the speaker is mandated by the size of the enclosure. Use some cardboard to rough in the area for your speaker(s) Use a cubic foot box filled w/ styrofoam noodles to gauge the air space inside your box. Match your speaker(s) to that.
The amp does not need to be rated at 100,000,000watts. A good 20 watt amp will work great with 2, 4" subs in a cubic foot of air space.With one 4 chanel 40 watt amp you can run 6 speakers, w/ crossovers, and still draw less than 20amps at the battery. The battery would benefit from a surge capacitor as well. 300. - 400.00 could set you up killer. No need for a "head unit" either. Use your phone/mp3/bluetooth.
Sound stream makes some of the best stuff. These will drive you nuts... http://www.soundstream.com/AudioProducts/Subwoofers/stealth.htm

[subwoffer]

all i need is 1 sub and 2 speakers .
can you please help me choose the right products? ( btw i cant get this amazing sub,because i havent found this on a local sites, and if i'll do it'll cost a fortune, so i'll be satisfied enough with a regular one , i'll make a nice box for him inside the seat)

so things i need:
1.sub
2. pair of speakers
3.amp
4.surge capacitor


the sub will be 12 or 10 , fits perfect under the seat . now if the amp is 200 w , what sub should i get ?

[zombie]

What battery are you going to use? What is the out put of you stator?

[subwoffer]

im going to use the stock downtown battery,and of course turn the system on only when the engine works .
please explain about the out put of the stator?

[whiteknight]

im going to use the stock downtown battery,and of course turn the system on only when the engine works .
please explain about the out put of the stator?

in basic terms, the stator will be playing tug of war with the "sound system" you need to be getting enough charge to the battery to be able to supply a powerful enough spark for the engine and power your system. Did i get that right Zombie?

[Vivo]

First to ask is "what type of music do you listen to?" RnB? Jazz? Different types requires different sound set up.

Second question is how much space are you willing to suffer or give up?

Speakers performance depends a lot on the enclosure (box). Would you prefer a bandpass or sealed enclosure system? With the speakers specification, one can compute a matching enclosure. You have to consult a shop for this or   http://www.bcae1.com/spboxnew2.htm     Efficiency is the key word and not power. An efficient system will sound good with low power and with the right equipment.

Typical Class AB amps are less efficient (around 50-60%) thus eats a lot of power. Get a class D amp with a higher efficiency at 90%. This consumes a lot less power.

Also, don't be misled by bike super sound set-ups in the net. A lot of these are for "show" and attach them to external power supplies when parked. Most of these are not being used while riding.










For your scoot, I would suggest.

1. an 8" subwoofer and a set of 6" separates

2. a Class D Digital four channel speaker maybe a 40x4 RMS  (use 2 channel for a set of separates and bridge the other two for your sub)

3. a 1 farad capacitor


As to sound quality, forget about it because the acoustics would be at it's worst. It's a scooter.

Last thing, consult a pro if you want to do things right. This is not a D.I.Y. thing.

[Cortez]

I won't get into specifics (re exact products since I have knowledge only about hi-end home audio stuff, and I
wouldn't even invest money into a car system since it all sounds like crap, being it's inside a car), but I will say
+1 to the D class amp recommendations, and make sure you don't kill the electrics on the scoot.

That's the first thing to take care of.

And again, all this talk about 20W or 40W or whatever watts being loud enough, you don't know that, it depends
on the loudspeakers.

Some will punch out 80dB, some over 100dB with the same amplifier, and that's night and day difference.

I used to have a home audio setup with high sensitivity speakers that could play at live even levels (think jazz club etc)
with just a 18W amplifier.

I've got a friend who can have his own private Rolling Stones concert in the room with a 8W per channel amp and
some freakish loudspeakers with over 100dB/w/m efficiency.

On the other hand, a KRELL 300W amp (popular choice among the deaf) with some electrostatic Martin Logan speakers
of the same price level (read: very expensive) will not be able to play even half as loud.

[subwoffer]

im giving up the whole underseat space . i have to think about an idea how to make the speakers go in and out the "storage" under the seat, and still be fixed enough , for avoiding vibrations and stuff .

anyway .correct me if i wrong

speakers:

http://www.caraudiodirect.co.uk/jbl-gt5-502.html

amp

http://www.ebay.com/itm/MOTORCYCLE-AMP-NITRO-SMALL-MINI-4-CH-300W-AMPLIFIER-NEW-/130546681380?pt=Car_Amplifiers&hash=item1e65304624&vxp=mtr#ht_4540wt_1163


sub

http://www.crutchfield.com/S-PZz8w4GuiW3/p_109GTO804/JBL-GTO804.html#details-tab

[Cortez]

That'll work, just don't expect anyone to tell you how good it'll sound.
No one will know.

That's all cheap stuff.

[subwoffer]

I'm not trying to impress the media with the super awesome audio system design you know . Btw , I have this "cheap" Logitech 5.1 speakers In my room
, an I'm pretty satisfied . Sure, I'm not the sound master , but as long as it has a clear sound , and deep enough bass, I'll be damn happy .


And what's wrong with " cheap" jlb speakers ? Does they sound like sh**ty Chinese kind of "koss" products ?
And the sub that I've mentioned also, not some unknown malfunction .
The only thing that is cheap and not that popular is that amp , that I'll be very thankfull if you'll point me to the right direction of those amps .

[whiteknight]

Does they sound like sh**ty Chinese kind of "koss" products ?

i'll be careful about what you say man. being as we ride chinese/taiwanese scoots......just saying.

[Vivo]

Do some more researches, I know you'll find something that will suit your need.

I would suggest you get marine speakers instead of conventional ones. These are more water resistant in case you encounter some rain.