10-inch-diameter speakers

[[email protected]]

I've always wanted some 10-inch (or 12-inch speakers for my home
stereo system. My receiver is only about 100 watts or so, and I've got
one 8-inch, and one 10-inch speaker.

There's this deal over at Pep Boys - a pair of 10-inch *car* speakers
for $40 ($50, with $10 rebate).

I was about to buy them for my Onkyo home receiver, but a fellow
shopper warned me that car speakers can't be interchanged with home
audio. I thought he was BS-ing me, but then I thought I should check
over here just to make sure.

They're 4-ohm, 600W (peak?) speakers. Non-major-brand-name... thought
I'd try them, and if they don't sound right, just return them.

So... can car audio speakers be interchanged with home audio speakers?
Or is this a fire-hazard waiting to happen?

Michael

 

[Pooh Bear]

I've always wanted some 10-inch (or 12-inch speakers for my home
stereo system.

Why ?

My receiver is only about 100 watts or so, and I've got
one 8-inch, and one 10-inch speaker.

There's this deal over at Pep Boys - a pair of 10-inch *car* speakers
for $40 ($50, with $10 rebate).

I was about to buy them for my Onkyo home receiver, but a fellow
shopper warned me that car speakers can't be interchanged with home
audio. I thought he was BS-ing me, but then I thought I should check
over here just to make sure.

They're 4-ohm, 600W (peak?)

Joke car audio rating.

speakers. Non-major-brand-name... thought
I'd try them, and if they don't sound right, just return them.

If you can.

So... can car audio speakers be interchanged with home audio speakers?
Or is this a fire-hazard waiting to happen?

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

 

[[email protected]]

Why ?

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

Joke car audio rating.

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

If you can.

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

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.

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...

Graham

Michael

 

[Richard Henry]

I've always wanted some 10-inch (or 12-inch speakers for my home
stereo system. My receiver is only about 100 watts or so, and I've got
one 8-inch, and one 10-inch speaker.

There's this deal over at Pep Boys - a pair of 10-inch *car* speakers
for $40 ($50, with $10 rebate).

I was about to buy them for my Onkyo home receiver, but a fellow
shopper warned me that car speakers can't be interchanged with home
audio. I thought he was BS-ing me, but then I thought I should check
over here just to make sure.

They're 4-ohm, 600W (peak?) speakers. Non-major-brand-name... thought
I'd try them, and if they don't sound right, just return them.

So... can car audio speakers be interchanged with home audio speakers?
Or is this a fire-hazard waiting to happen?

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

 

[Richard Henry]

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.


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

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.

 

[[email protected]]

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?

 

[[email protected]]

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

Not sure what those are...
http://www.google.com/search?hl=en&q=spinal+tap+speakers&btnG=Google+Search

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.

 

[Pooh Bear]

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

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.

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

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.

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


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

That helps !

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

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

 

[Pooh Bear]

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?

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

Graham

 

[Pooh Bear]

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

He was having a joke.

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.

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

Just not sufficiently impressed to spend $2,000 on a set of speakers.

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

Graham

 

[[email protected]]

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

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..." ?

 

[[email protected]]

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.

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

Thanks,

Michael

 

[Pooh Bear]

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..." ?

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

 

[Pooh Bear]

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

In that area.

Graham

 

[Boris Mohar]

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..." ?

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.

 

[[email protected]]

I've always wanted some 10-inch (or 12-inch speakers for my home
stereo system. My receiver is only about 100 watts or so, and I've got
one 8-inch, and one 10-inch speaker.

There's this deal over at Pep Boys - a pair of 10-inch *car* speakers
for $40 ($50, with $10 rebate).

I was about to buy them for my Onkyo home receiver, but a fellow
shopper warned me that car speakers can't be interchanged with home
audio. I thought he was BS-ing me, but then I thought I should check
over here just to make sure.

They're 4-ohm, 600W (peak?) speakers. Non-major-brand-name... thought
I'd try them, and if they don't sound right, just return them.

So... can car audio speakers be interchanged with home audio speakers?
Or is this a fire-hazard waiting to happen?

Michael

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

 

[GregS]

I've always wanted some 10-inch (or 12-inch speakers for my home
stereo system. My receiver is only about 100 watts or so, and I've got
one 8-inch, and one 10-inch speaker.

There's this deal over at Pep Boys - a pair of 10-inch *car* speakers
for $40 ($50, with $10 rebate).

I was about to buy them for my Onkyo home receiver, but a fellow
shopper warned me that car speakers can't be interchanged with home
audio. I thought he was BS-ing me, but then I thought I should check
over here just to make sure.

They're 4-ohm, 600W (peak?) speakers. Non-major-brand-name... thought
I'd try them, and if they don't sound right, just return them.

So... can car audio speakers be interchanged with home audio speakers?
Or is this a fire-hazard waiting to happen?

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

 

[John Fields]

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..." ?

 

[John Fields]

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

---
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
4 ohm load can be driven, we can say:


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".

 

[Spehro Pefhany]

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

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




Best regards,
Spehro Pefhany