Need help from audio experts!

[48Rob]

I'm trying to put together a sound system for my motorcycle, and need help.

The radio I've chosen is a Boss Audio 2080
http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... 0129863328
It is rated at 80 Watts x 4, or, in my understanding, 80 Watts to each speaker.

I plan to mount two 4" non amplified speakers on the bike.
http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... 0147523849
Using my logic, I'll have two speakers that the radio will send 80 Watts each of power to.

In looking for a good setup, I've found that many motorcycle speakers are amplified, both internal and external.

Most are rated at 50 Watts x 2.

So the confusion is; if my radio sends 80 Watts to the two speakers I'll have connected, why would I want to buy a set of amplified speakers that are rated at 50 Watts?

Some of the amplified speakers are rated at 100 Watts x 2, still, only 20 Watts more than the radio already produces?

Am I comparing apples to apples?

Besides a hefty price difference in amplified versus non amplified speakers, I'll have yet another draw on the bikes electrical system, and one more component to hide/protect from the weather.

I have a windshield, and have a factory exhaust, not the loud rattle your windows (and patience) so overall at reasonable speeds, there isn't a lot of noise to overcome.

<img src="http://w48rob.wik.is/@api/deki/files/489/=nomad_in_the_black_hills.jpg">

Thanks for any help!

Rob

[xrover]

First off, I must proclaim I am not an expert, just someone who has been through a number of different set ups over the years.

My take on it is this. Your source of power will come from your stereo and it is this source and how clean it is will impact how clean your sound will be in your speakers. If your stereo sends out a signal with distortion, an amplified speaker will only boost that distortion. You also need to take into consideration, the more things being powered to get sound out of a speaker, the more chance of picking up other noises from the engine.

Based on these, I would recommend a non-amplified speakers, since you have enough power from your receiver to push the speaker, and it will then only give you one source to focus on getting clean power to it. If you get alternator whine, then you can get a ground loop hooked up to your stereo.

The last comment I would make, your speakers should be rated close to the power your stereo can give out, as having too little of a speaker will result in the speaker creating distortion, and too much speaker power will require you to push more volume out of your stereo which will potentially result in distorted sound coming from it (and amplification of engine noise to boot).

Let the opinions vary as there are some good electrical theory folks on the board.

[48Rob]

The last comment I would make, your speakers should be rated close to the power your stereo can give out, as having too little of a speaker will result in the speaker creating distortion, and too much speaker power will require you to push more volume out of your stereo which will potentially result in distorted sound coming from it

Makes perfect sense, thank you!

The speakers are rated as below;
35 Watts RMS, 105 Peak per Speaker; Total System Rating: 70 Watts RMS, 210 Watts

The stereo though, doesn't offer this type of info, only that it is 80 Watts x 4.

Are these numbers close enough?

?

Rob

[Elumia]

you can find the intallation manual here:
http://www.bossaudio.com/support/index. ... itemid=332

They don't give you any distortion specs on the built in amp. It does look like the unit will function as a pre-amp (bypass the internal amp) if you connect to an auxillary amplifier. That way you don't multiply distortion, or could choose an amplifier with better distortion specifications.

If you have the unit, hook it up and see what it sounds like before you install everything. It will probably be suffcient as you will be suject to lots of other noise on a motorcycle.

I guess the question is, How many watts are needed to overcome a Harley?

Mark

[Walt M]

Rob, it has alwaye been my understandiing that you just don't have to turn up the stereo all the way. you want the amplifier to be more powerful than the speakers. the more watts the speakers can handle just means that they can be turned up loud without distortion. I hope this helps. Walt

[Elumia]

Walt, Rob,

What you want is to do get all the volume you want to hear by turning the unit up to about 1/2 volume or so. The more you turn the knob to full volume, the more the distortion increases. That is the reason for having lots of watts of power. Most distortion happens at the max power.

Better speakers will better reproduce the signal sent to them. You certainly don't want them overpowered, but underpowered can also be a problem.

Mark

[48Rob]

Mark and Walt,

Thank you!

The radio is ordered, but I'm still considering my choices regarding speakers.
I prefer not to buy amplified speakers.
Now I just have to choose non powered speakers that can handle the power without cleaning out my wallet...
Anything that has the word "motorcycle" or marine" in the description is priced accordingly...

I'm not sure how many Watts it takes to overcome a Harley...mostly because I don't have a Harley (its a Kawasaki) but I understand the thought

I appreciate the time you spent working on my question!

Rob

[xrover]

Speakers are very much a personal choice, however I recommend looking at Polk Audio Momo series. They are essentially a marine speaker, but priced for the car market. I have them in my truck, which is a loud Landrover Defender, and they work great and won't kill your wallet. Polk figured that anything going in a vehicle is going to need more protection than a home speaker. They have quite a few sizes to choose from since your spacing will be limited.
www.polkaudio.com

One of the best product I bought, which is no longer available new, was the Polk Midock10 which is a portable ipod system. I purchased it for offroading as the ipod loads in like a sideways cassette, so it is held well in place. And it has great sound! People are very impressed, especially considering it was sold by Radio Shack for $199.
http://www.polkaudio.com/homeaudio/prod ... /midock10/

Yea, I like Polk!

[PaulC]

Can't help you with the audio thing but it's nice to find another Kawasaki Rider on the forum. I've got a 96 Vulcan myself.

Cheers
Paul

[asianflava]

I'd stay away from Boss, but since you already ordered it then we'll stick with it. I worked at a stereo store that sold Boss and a lot of them came back. Hopefully they've gotten better over the years.

Anyway, Boss says that the head is 80X4 but they tend to inflate their figures. Most (if not all) head units actually put out 25W continuous and 50W peak power. That peak power is the rating that they plaster all over the unit, it is a short burst of power that the radio can produce. It can be very distorted and very short, pretty much useless for listening purposes. Consider an outboard 80X4 amp, it is probably 3 to 4 times the size of a DIN sized radio. There is no way they can fit the guts of an 80X4 amp, the tuner, the CD mechanism in a DIN sized package.

Speaker power handling is a different issue. You can put speakers rated for 35W on an amp that puts out 75W, you just won't be able to use all 75W. This situation would actually be better because the amp will have more headroom (reserve capacity) before going into distortion.

Since you have a built-in amp inside the head unit, you don't need powered speakers. They are probably best suited to low or un-powered heads.

If the head doesn't have high pass crossover outputs you can put a 100µF capacitor on the positive lead of each speaker. What this does is prevent most frequencies under 400hz from coming out (assuming that they are 4Ω speakers). A 4in speaker wouldn't be able to reproduce those frequencies but they will try, when they do it will just make more distortion. The speakers will play louder with more clarity. If you think you need more bottom end, you can remove the cap or try a different size.

Check out this chart: http://www.carstereo.com/help/Articles.cfm?id=1

[48Rob]

Well...

If the head unit really isn't a "real" 80 Watts, then choosing a speaker won't be so difficult...

Darn twisted advertising

So I suppose this means that the 60 Watt x 4 unit that I passed on (which was cheaper...) would have sounded just as good?

Thanks for giving me the truth.

Thanks for the advice on the capacitors.
I have capacitors on the door speakers in my truck, had to install them after putting big speakers behind the seat.
The door speakers kept trying to kick out bass to keep up with the rear speakers, and sounded horrible.
Now they only produce mid range and higher sound.

This is the same concept you're trying to show me for the 4" speakers, right?

Rover, thanks for the link!
I'll consider Polk as well.
Waterproof and decent sound is the main goal.

Thanks all for the help.
One would never guess it can be so complicated...just to listen to the radio now and then while riding...


Rob

[48Rob]

Can't help you with the audio thing but it's nice to find another Kawasaki Rider on the forum. I've got a 96 Vulcan myself.

Cheers
Paul

Paul,

I've a 2006 Vulcan Nomad, best bike I've ever owned!

Happy trails!


<img src="http://w48rob.wik.is/@api/deki/files/269/=bike_out_West_5.jpg">

[Creamcracker]

I'm trying to put together a sound system for my motorcycle, and need help.

The radio I've chosen is a Boss Audio 2080
http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... 0129863328
It is rated at 80 Watts x 4, or, in my understanding, 80 Watts to each speaker.

I plan to mount two 4" non amplified speakers on the bike.
http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... 0147523849
Using my logic, I'll have two speakers that the radio will send 80 Watts each of power to.

In looking for a good setup, I've found that many motorcycle speakers are amplified, both internal and external.

Most are rated at 50 Watts x 2.

So the confusion is; if my radio sends 80 Watts to the two speakers I'll have connected, why would I want to buy a set of amplified speakers that are rated at 50 Watts?

Some of the amplified speakers are rated at 100 Watts x 2, still, only 20 Watts more than the radio already produces?

Am I comparing apples to apples?

Besides a hefty price difference in amplified versus non amplified speakers, I'll have yet another draw on the bikes electrical system, and one more component to hide/protect from the weather.

I have a windshield, and have a factory exhaust, not the loud rattle your windows (and patience) so overall at reasonable speeds, there isn't a lot of noise to overcome.

<img src="http://w48rob.wik.is/@api/deki/files/489/=nomad_in_the_black_hills.jpg">

Thanks for any help!

Rob

Hey Rob, the rule of thumb is that speakers should be about 20% higher than the watt out put from the radio.....so if your radio has an output of 80Watts then the speakers need to be about 100 watts otherwise the radio will blow the speakers. (On re-reading I might have misunderstood your question)
Philip

[48Rob]

Hi Philip,

Actually, I was asking several questions at once...

Your rule of thumb is one I've heard elsewhere, and will try to follow.


Currently, the radio is rated at 80 Watts x 4, and the speakers I'm considering are 35 Watts RMS 105 peak.

The radio doesn't list power in RMS, only Watts, and I don't know how to convert.

Other advice suggests that though it claims 80 Watts, actual radio output is closer to 25.
If this is the case, then 35 Watt speakers will handle 25 Watt output of the stereo...if we're still comparing the same version of Watts?

Rob

[Trackstriper]

Rob,

You'll probably be just fine with the speakers you are looking at. I wouldn't spend too much time trying to analyze the watts issue. Asianflava is right about the output of your head unit. Last night I was guessing 20-25 watts rms, on a good day, downhill. It's about advertising. Without getting too technical, you don't need all that much power to have some good tunes.

The speaker manufacturer lists both rms values and peak values, so they are at least a little forthcoming. But, over what frequency range? What is the efficiency? What is the typical impedance of the speaker? etc. That they don't talk about. However, it's not critical for you. These are only 4" speakers and you can only do so much with a small cone. The speaker drivers were chosen by the manufacturer of the package to be a good fit with a decent car stereo head unit. The speakers should be be efficient enough to get the required volume that you need. If they don't work rather generically, I wouldn't think they would sell many... not good for business. I don't know if you would need the capacitors to roll-off the lower frequencies or not. I'd just try 'em like they sold them to you. Sounds like you can return the speakers if they don't sound good.

The really big question is...do they look like they belong on your bike!

You have a great natural sense about that.

Bruce