10-inch-diameter speakers

Why ?

Joke car audio rating.

If you can.

Car speakers are designed to operate in a different environment and may not function optimally in a normal loudspeaker enclosure and also may be more robust. Other than that, there's no big difference.

What youd need to watch is the impedance. Car speaker are normally 4 ohms to get more watts from a limited voltage source. Hi-fi loudspeakers are typically 8 ohms. Just be sure your receiver's happy with driving 4 ohms.

Graham

Oh, to hear the bass. There are a few tracks on my Keiko Matsui jazz CDs that have bass.

eh... so, if I really ran 600W through them, they'd melt the coils?

Good point... I'll double-check.

get

How would I know if my receiver's happy with 4 ohms? Is lack of smoke a good indication? ;)

The receiver's a 20-year-old or thereabouts Onkyo. Still works... ;)

Michael

I would get some of those Spinal Tap model 11-inch speakers.

not

more

ohms to get

typically 8

Take your 2 8-ohm speakers and connect them in parallel across one of the outputs. Do you get good sound? Even when it's turned all the way up?

Now try the other channel.

No can do... the receiver won't run *any* speakers unless *both* left and right speaker are connected. (I wonder why they designed the receiver that way...)

But I'm sure I was missing the point of your reply. Are you saying the sound might sound funny at higher volumes when powering a 4-ohm speaker?

Not sure what those are...

Are you saying that 10-inch / 12-inch speakers are obsolete?

You know, I had the experience of wandering into a Bose factory outlet store once, and I was impressed by how much bass those little (4-inch or so) speakers could put out. Just not sufficiently impressed to spend $2,000 on a set of speakers.

I suspected as much.

Just be aware that the mid range and treble may suffer as much as the bass improves.

In fact a large cone isn't *essential* for bass but it does help do it efficiently. On the the other hand a smaller cone is almost invariably better for mid and treble.

Certainly. Car audio 600W peak probably translates closer to 75W RMS. The most powerful 'PA' 10 inch speakers I know are rated about 200-250W RMS.

get

That helps !

It may possibly be a little unhappy with 4 ohms in that case. I'd err on the safe side if I were you.

Graham

And make sure it doesn't get too hot either. A party is a good test !

Graham

He was having a joke.

Yeah. Dr Amar Bose has rewritten the laws of physics didn't you know ? ;~)

Very wise. Bose is 90% marketing and the other 10% is hype. I won't say lies for legal reasons.

Graham

for

Speaking of which... how can any speaker company get away with such outrageous claims for peak wattage? Or is the legal defense "Well, they can provide 600 watts safely for a MILLIsecond..." ?

get

Oh yeah... limited voltage source. So, from V=IR, is it typically about 24V or so driving hi-fi loudspeakers?

Thanks,

Michael

for

Abou that. The US FTC actually made some legislation called the 'amplifier rule' to stop misleading claims about hi-fi etc audio but car audio slipped through the net.

The same misleading statements are made about computer powered speakers typically too. You see these tiny cabinets claiming to be 100W or more !

Graham

get

In that area.

Graham

for

For the same reason thy get away with advertising 8hp air compressors that run in 115 volts and use 3/4hp motor. No one cares.

A couple of points not already covered by other posts:

It's not clear from your post exactly what the situation is. Car speakers are often sold as raw drivers, without enclosures Those are intended to be placed in cutouts in the car, such as in the trunk or door panels. You need *some* sort of enclosure or baffle to prevent the back wave from leaking around to the front and cancelling out the sound... a driver in free air has very limited output, and that gets worse at lower frequencies.

So if you are indeed contemplating raw drivers, you'll need to put them

in an enclosure. The enclosure should be designed according to the properties of the driver. If you just plop an arbitrary driver in an arbitrary box you may not be satisfied with the results. The design process can be enjoyable and there are lots of books and articles on the topic, but you must be prepared for a bit of a project.

Another issue that most folks don't recognize is that the bass in car systems usually seems much stronger than you can get in your living room. The reason for this is that (with the windows rolled up) the car is a sealed pressure vessel. In the ideal situation with the speaker mounted so the back space is isolated from the passenger area (typically the trunk), the bass response can theoretically be flat down to just about DC. (If you made everything airtight, you could hit DC... but that wouldn't be very important after the first few minutes without air!) So, you are not going to get that kind of performance in your home system.

Best regards,

Bob Masta

The way it works. if you need bass, you have to first know what the frequency is. You take the woofers parameters and build a proper box. In those calculations, the low frequenct limit is given. Most of todays amps do not support 4 ohms.

greg

get

--- Depends on how much power your receiver can pump out.

Assuming it's a voltage source and is rated to put 100 watts into 8 ohms means that the voltage it needs to supply into across that impedance will be:

E = sqrt(PR) = sqrt (100W * 8R) ~ 28VRMS

And the current:

E 28V I = --- = ----- ~ 3.5ARMS R 8R

Since the current the amp can supply is what will limit how hard the

P = I²R = 3.5A² * 4R = 50W

It's 50 watts instead of 49 because of the rounding we did earlier, but the point is that with a load of 4 ohms instead of 8 ohms you can only get half the rated power from the amp. There are a few more things to consider, like how much voltage headroom the amp has and how hard you can overdrive it before you hurt it, but with a 4 ohm load you should start hearing distortion with the volume control cranked to a little over "5".

-- John Fields Professional Circuit Designer

lies for

rule' to

net.

typically too.

Like my '200W' amplified speakers that run off a 9VDC 200mA wall wart? ;-)

Best regards, Spehro Pefhany