My buddy, who isn't the brightest one i my mind, is building a new box for
his subs. 10" Alpine type E, and a 10" JL W3. The box will be sealed with NO
divider. Of what I know, one of the subs will wreck, right away. I've ben
told this, and have seen it happen to two very cheap woofers. I've also
heard that it's never a good idea to have two different woofers in the boot.
Any feedback?

If sub construction os the same there will not be any issues if hes running
them in mono together. Although by the sounds of this its unlikely. I wont
say that they will damage one another but at some point they will be
fighting each other reducing output.
Hell, if they are that cheap give it a go and post your results. Do a
Mythbusters on my theory.


Scotty


"Kirby" wrote in message
news:XTToe.1584174$8l.800068@pd7tw1no...
My buddy, who isn't the brightest one i my mind, is building a new box for
his subs. 10" Alpine type E, and a 10" JL W3. The box will be sealed with
NO
divider. Of what I know, one of the subs will wreck, right away. I've ben
told this, and have seen it happen to two very cheap woofers. I've also
heard that it's never a good idea to have two different woofers in the
boot.
Any feedback?

"Kirby" wrote in message
news:XTToe.1584174$8l.800068@pd7tw1no...
My buddy, who isn't the brightest one i my mind, is building a new box for
his subs. 10" Alpine type E, and a 10" JL W3. The box will be sealed with
NO
divider. Of what I know, one of the subs will wreck, right away. I've ben
told this, and have seen it happen to two very cheap woofers. I've also
heard that it's never a good idea to have two different woofers in the
boot.
Any feedback?


Just ask him which is cheaper... 2 new subs or an extra piece of wood?

I fail to see how they're in danger of blowing with such a setup. How
exactly are they going to be "fighting each other?"

"Kirby" wrote in message
news:XTToe.1584174$8l.800068@pd7tw1no...
My buddy, who isn't the brightest one i my mind, is building a new box for
his subs. 10" Alpine type E, and a 10" JL W3. The box will be sealed with
NO
divider. Of what I know, one of the subs will wreck, right away. I've ben
told this, and have seen it happen to two very cheap woofers. I've also
heard that it's never a good idea to have two different woofers in the
boot.
Any feedback?

"MZ" wrote in message
...
I fail to see how they're in danger of blowing with such a setup. How
exactly are they going to be "fighting each other?"

"Kirby" wrote in message
news:XTToe.1584174$8l.800068@pd7tw1no...
My buddy, who isn't the brightest one i my mind, is building a new box
for
his subs. 10" Alpine type E, and a 10" JL W3. The box will be sealed with
NO
divider. Of what I know, one of the subs will wreck, right away. I've ben
told this, and have seen it happen to two very cheap woofers. I've also
heard that it's never a good idea to have two different woofers in the
boot.
Any feedback?





Bass responce from Subs are specific to design. While one sub may be
designed to propell itself 1inch forward and the other is tighter and only
designed for 1/2 inch, the tighter sub will be effectively sucked in with
the airflow. Try it with a shoe box and plastic wrap. You can see when ones
pushed in further (The double layered side to act as the tighter sub) the
other will distort somewhat.

Sheeeit, for the sake of a small extra peice of timber divede the damn
things. Problem solved.

Bass responce from Subs are specific to design. While one sub may be
designed to propell itself 1inch forward and the other is tighter and only
designed for 1/2 inch, the tighter sub will be effectively sucked in with
the airflow. Try it with a shoe box and plastic wrap. You can see when
ones pushed in further (The double layered side to act as the tighter sub)
the other will distort somewhat.

What? How is the "tighter" one going to be "sucked in"? The force driving
equilibrium won't be stronger than the force pushing the speaker out (from
the amp). And even if what you said was true, how is that going to blow the
sub?

The driver with the lower BL will get pushed around by the driver with the
higher BL this in turn will lead to back EMF and cause the load to become
quite inductive. The amplifier will see a more difficult load and the
frequency response will suffer from the increased reactance.

Chad


"MZ" wrote in message
...
I fail to see how they're in danger of blowing with such a setup. How
exactly are they going to be "fighting each other?"

"Kirby" wrote in message
news:XTToe.1584174$8l.800068@pd7tw1no...
My buddy, who isn't the brightest one i my mind, is building a new box
for
his subs. 10" Alpine type E, and a 10" JL W3. The box will be sealed with
NO
divider. Of what I know, one of the subs will wreck, right away. I've ben
told this, and have seen it happen to two very cheap woofers. I've also
heard that it's never a good idea to have two different woofers in the
boot.
Any feedback?

So what you're saying is that this may go lower than 2 ohms, and possibly
ruin the amp?


"Chad Wahls" wrote in message
...
The driver with the lower BL will get pushed around by the driver with the
higher BL this in turn will lead to back EMF and cause the load to become
quite inductive. The amplifier will see a more difficult load and the
frequency response will suffer from the increased reactance.

Chad


"MZ" wrote in message
...
I fail to see how they're in danger of blowing with such a setup. How
exactly are they going to be "fighting each other?"

"Kirby" wrote in message
news:XTToe.1584174$8l.800068@pd7tw1no...
My buddy, who isn't the brightest one i my mind, is building a new box
for
his subs. 10" Alpine type E, and a 10" JL W3. The box will be sealed
with
NO
divider. Of what I know, one of the subs will wreck, right away. I've
ben
told this, and have seen it happen to two very cheap woofers. I've also
heard that it's never a good idea to have two different woofers in the
boot.
Any feedback?

The driver with the lower BL will get pushed around by the driver with the
higher BL this in turn will lead to back EMF and cause the load to become
quite inductive. The amplifier will see a more difficult load and the
frequency response will suffer from the increased reactance.

Of course. But my question is how will this destroy one, or as the other
poster said, both speakers?

"MZ" wrote in message
...
The driver with the lower BL will get pushed around by the driver with
the
higher BL this in turn will lead to back EMF and cause the load to become
quite inductive. The amplifier will see a more difficult load and the
frequency response will suffer from the increased reactance.

Of course. But my question is how will this destroy one, or as the other
poster said, both speakers?



Nah it's unlikely to trash speakers but it could sound like ass, make the
amp run hot, or at WORST cause the weaker speaker to mechanically fail at
the voice coil/cone bonding point.

What's wrong with just putting a chunk 'o wood in there?

Chad

Nah it's unlikely to trash speakers but it could sound like ass, make the
amp run hot, or at WORST cause the weaker speaker to mechanically fail at
the voice coil/cone bonding point.

But that's what I'm getting at. How is it going to cause the weaker speaker
to mechanically fail? Even if it was left unhooked, it would be acting
almost like a passive radiator. Now unless the stronger speaker is pushing
so much air that the passive (unhooked) speaker was exceeding its xmax, I
don't see how you're going to blow it. You'd have to have quite the
disparity for that to happen. And I don't think that disparity exists
between the two subs he listed.

What's wrong with just putting a chunk 'o wood in there?

What's wrong with just using one of the subs?

My friend likes all the bass he can handle, and is plainly too dumn to put a
divider in. However I know that I have seen someone do this with two *very*
cheap woofers, and the surroung tore off of the weaker one for lack of a
better term.



"MZ" wrote in message
...
Nah it's unlikely to trash speakers but it could sound like ass, make
the
amp run hot, or at WORST cause the weaker speaker to mechanically fail
at
the voice coil/cone bonding point.

But that's what I'm getting at. How is it going to cause the weaker
speaker
to mechanically fail? Even if it was left unhooked, it would be acting
almost like a passive radiator. Now unless the stronger speaker is
pushing
so much air that the passive (unhooked) speaker was exceeding its xmax, I
don't see how you're going to blow it. You'd have to have quite the
disparity for that to happen. And I don't think that disparity exists
between the two subs he listed.

What's wrong with just putting a chunk 'o wood in there?

What's wrong with just using one of the subs?

My friend likes all the bass he can handle, and is plainly too dumn to put
a
divider in. However I know that I have seen someone do this with two
*very*
cheap woofers, and the surroung tore off of the weaker one for lack of a
better term.

If they were cheap woofers, how do you know it was the lack of a divider
that tore the surround? How do you know it wasn't simply blown by the
amplifier? Why would the woofer face more excursion indirectly from the
other woofer than with the very same signal directly?? I'm just asking for
a "how", not anecdotal evidence.

Well it may be hard for me to explain, but I think it comes down with a
sealed box, and of where the air comes from when the sub moves out. I
figured that it made its way through the surround and the cone. and the amp
wasnt doing it cuz it was getting 50 watts, when it could handle 150.


"MZ" wrote in message
news
My friend likes all the bass he can handle, and is plainly too dumn to
put
a
divider in. However I know that I have seen someone do this with two
*very*
cheap woofers, and the surroung tore off of the weaker one for lack of a
better term.

If they were cheap woofers, how do you know it was the lack of a divider
that tore the surround? How do you know it wasn't simply blown by the
amplifier? Why would the woofer face more excursion indirectly from the
other woofer than with the very same signal directly?? I'm just asking
for
a "how", not anecdotal evidence.

Well it may be hard for me to explain, but I think it comes down with a
sealed box, and of where the air comes from when the sub moves out. I
figured that it made its way through the surround and the cone.

What? Are you saying air passed through the surround and cone?

and the amp
wasnt doing it cuz it was getting 50 watts, when it could handle 150.

Power out can't be greater than power in. In other words, if 50 watts can't
blow the sub directly, it's not going to do it indirectly through another
subwoofer. Basically, what this means is that if subwoofer A, driven by 50
watts, causes subwoofer B to move 1 cm (just makin' up numbers here), then
subwoofer B, driven by 50 watts directly, will move more than 1cm. Direct
indirect. The caveat here is if the two woofers are vastly different - such
that subwoofer A's excursion is much greater than 1cm.

Like I said in my last post, you don't know why the sub blew. Just because
the amp says 50 watts on the package and the sub says 150 doesn't make it
true. In fact, it's impossible to judge a speaker's true power handling in
isolation, because it's dependent on enclosure size, enclosure type, crest
factor of the music, how much the amplifier is being overdriven, etc.
Manufacturers just estimate these numbers. Sometimes, especially when you
look at tweeters, power handling numbers aren't actually power handling -
they're estimates on recommended amplifier size. Unfortunately, many
manufacturers neglect to include this tidbit of information.

Basically, what I'm saying is that you don't have enough evidence to suggest
that the sub blew because there wasn't a divider. It was a cheap sub. They
blow. That's what makes a cheap sub a cheap sub.

"MZ" wrote in message
news
Bass responce from Subs are specific to design. While one sub may be
designed to propell itself 1inch forward and the other is tighter and
only designed for 1/2 inch, the tighter sub will be effectively sucked in
with the airflow. Try it with a shoe box and plastic wrap. You can see
when ones pushed in further (The double layered side to act as the
tighter sub) the other will distort somewhat.

What? How is the "tighter" one going to be "sucked in"? The force
driving equilibrium won't be stronger than the force pushing the speaker
out (from the amp). And even if what you said was true, how is that going
to blow the sub?


I never said that it would BLOW anything! Reduce output and sound like ****
yes, blow a sub, no.

The only way I can see that a sub could be damaged ("Blown") would be that
the sub that had teh longest excursion would move heaps and the other not
much in comparison, the one that was being fought if it was an air cooled
coild would over heat with prolonged use. Based on the initial posting I
seriously doubt that the guys gear would likey be anything that would affect
the thermal cooling properties of any sub.

I think that "sucked in" was maybe an incorrect (or poorly described)
analergy. Maybe restricted in movement....?

"MZ" wrote in message
...
Nah it's unlikely to trash speakers but it could sound like ass, make the
amp run hot, or at WORST cause the weaker speaker to mechanically fail at
the voice coil/cone bonding point.

But that's what I'm getting at. How is it going to cause the weaker
speaker to mechanically fail? Even if it was left unhooked, it would be
acting almost like a passive radiator. Now unless the stronger speaker is
pushing so much air that the passive (unhooked) speaker was exceeding its
xmax, I don't see how you're going to blow it. You'd have to have quite
the disparity for that to happen. And I don't think that disparity exists
between the two subs he listed.

What's wrong with just putting a chunk 'o wood in there?

What's wrong with just using one of the subs?


Or whats wrong with getting creative and building a bandpass box so that the
weaker sub can at least do some good. Or maybe this guy should get off his
butt and buy two matching subs, seperate the box and seal like a gophers
arsehole. Do the job once, do it right!

Can I get an amen?!?


"Scotty" wrote in message
u...

"MZ" wrote in message
...
Nah it's unlikely to trash speakers but it could sound like ass, make
the
amp run hot, or at WORST cause the weaker speaker to mechanically fail
at
the voice coil/cone bonding point.

But that's what I'm getting at. How is it going to cause the weaker
speaker to mechanically fail? Even if it was left unhooked, it would be
acting almost like a passive radiator. Now unless the stronger speaker
is
pushing so much air that the passive (unhooked) speaker was exceeding
its
xmax, I don't see how you're going to blow it. You'd have to have quite
the disparity for that to happen. And I don't think that disparity
exists
between the two subs he listed.

What's wrong with just putting a chunk 'o wood in there?

What's wrong with just using one of the subs?


Or whats wrong with getting creative and building a bandpass box so that
the
weaker sub can at least do some good. Or maybe this guy should get off his
butt and buy two matching subs, seperate the box and seal like a gophers
arsehole. Do the job once, do it right!

What I'm saying is that the surround started to detach from the cone,
letting air pass through.


"MZ" wrote in message
...
Well it may be hard for me to explain, but I think it comes down with a
sealed box, and of where the air comes from when the sub moves out. I
figured that it made its way through the surround and the cone.

What? Are you saying air passed through the surround and cone?

and the amp
wasnt doing it cuz it was getting 50 watts, when it could handle 150.

Power out can't be greater than power in. In other words, if 50 watts
can't
blow the sub directly, it's not going to do it indirectly through another
subwoofer. Basically, what this means is that if subwoofer A, driven by
50
watts, causes subwoofer B to move 1 cm (just makin' up numbers here), then
subwoofer B, driven by 50 watts directly, will move more than 1cm. Direct

indirect. The caveat here is if the two woofers are vastly different -
such
that subwoofer A's excursion is much greater than 1cm.

Like I said in my last post, you don't know why the sub blew. Just
because
the amp says 50 watts on the package and the sub says 150 doesn't make it
true. In fact, it's impossible to judge a speaker's true power handling
in
isolation, because it's dependent on enclosure size, enclosure type, crest
factor of the music, how much the amplifier is being overdriven, etc.
Manufacturers just estimate these numbers. Sometimes, especially when you
look at tweeters, power handling numbers aren't actually power handling -
they're estimates on recommended amplifier size. Unfortunately, many
manufacturers neglect to include this tidbit of information.

Basically, what I'm saying is that you don't have enough evidence to
suggest
that the sub blew because there wasn't a divider. It was a cheap sub.
They
blow. That's what makes a cheap sub a cheap sub.

"MZ" wrote in message
...
Nah it's unlikely to trash speakers but it could sound like ass, make the
amp run hot, or at WORST cause the weaker speaker to mechanically fail at
the voice coil/cone bonding point.

But that's what I'm getting at. How is it going to cause the weaker
speaker to mechanically fail? Even if it was left unhooked, it would be
acting almost like a passive radiator. Now unless the stronger speaker is
pushing so much air that the passive (unhooked) speaker was exceeding its
xmax, I don't see how you're going to blow it. You'd have to have quite
the disparity for that to happen. And I don't think that disparity exists
between the two subs he listed.

It would not happen if the speaker were left unhooked. When it is hooked is
the VC is presented a controlled low impedance load. The coil will do
whatever it can to do it's job. so we have two coils trying to do their
job. Lets say one coil can move 9 MM and the other can move 5 MM within the
magnetic gap. The cone attached to the speaker trying to move 5 MM will see
the load of the speaker trying to move 9MM but the coil is only designed for
5MM, this is where the mechanical problem occurs. Also remember that air
has inertia as does the cone, this compounds the problem.

I have seen countless pro drivers wasted when people smoke an 18 in a dual
18 enclosure. They replace one of the 18's with an off brand and it or the
other mysteriously fails mechanically although the coil looks great on
inspection. Granted this is an extreme example and it does happen on
drivers with more surface area but it is proof that it is a bad idea to mix
drivers in the same enclosure, hell it's bad in my eyes to use different
drivers in the same passband.



What's wrong with just putting a chunk 'o wood in there?

What's wrong with just using one of the subs?

Ha! Agreed!

Chad

Then that would have been an already defective speaker.


"Kirby" wrote in message
news:5Hape.1590136$8l.889631@pd7tw1no...
What I'm saying is that the surround started to detach from the cone,
letting air pass through.


"MZ" wrote in message
...
Well it may be hard for me to explain, but I think it comes down with a
sealed box, and of where the air comes from when the sub moves out. I
figured that it made its way through the surround and the cone.

What? Are you saying air passed through the surround and cone?

and the amp
wasnt doing it cuz it was getting 50 watts, when it could handle 150.

Power out can't be greater than power in. In other words, if 50 watts
can't
blow the sub directly, it's not going to do it indirectly through another
subwoofer. Basically, what this means is that if subwoofer A, driven by
50
watts, causes subwoofer B to move 1 cm (just makin' up numbers here),
then
subwoofer B, driven by 50 watts directly, will move more than 1cm.
Direct

indirect. The caveat here is if the two woofers are vastly different -
such
that subwoofer A's excursion is much greater than 1cm.

Like I said in my last post, you don't know why the sub blew. Just
because
the amp says 50 watts on the package and the sub says 150 doesn't make it
true. In fact, it's impossible to judge a speaker's true power handling
in
isolation, because it's dependent on enclosure size, enclosure type,
crest
factor of the music, how much the amplifier is being overdriven, etc.
Manufacturers just estimate these numbers. Sometimes, especially when
you
look at tweeters, power handling numbers aren't actually power handling -
they're estimates on recommended amplifier size. Unfortunately, many
manufacturers neglect to include this tidbit of information.

Basically, what I'm saying is that you don't have enough evidence to
suggest
that the sub blew because there wasn't a divider. It was a cheap sub.
They
blow. That's what makes a cheap sub a cheap sub.

It took time for this to take place... its not like it happened right away,
actually it was a couple of months after he purchased the woofer.



"scott johnson" (net) wrote in message
...
Then that would have been an already defective speaker.


"Kirby" wrote in message
news:5Hape.1590136$8l.889631@pd7tw1no...
What I'm saying is that the surround started to detach from the cone,
letting air pass through.


"MZ" wrote in message
...
Well it may be hard for me to explain, but I think it comes down with
a
sealed box, and of where the air comes from when the sub moves out. I
figured that it made its way through the surround and the cone.

What? Are you saying air passed through the surround and cone?

and the amp
wasnt doing it cuz it was getting 50 watts, when it could handle 150.

Power out can't be greater than power in. In other words, if 50 watts
can't
blow the sub directly, it's not going to do it indirectly through
another
subwoofer. Basically, what this means is that if subwoofer A, driven
by
50
watts, causes subwoofer B to move 1 cm (just makin' up numbers here),
then
subwoofer B, driven by 50 watts directly, will move more than 1cm.
Direct

indirect. The caveat here is if the two woofers are vastly different -
such
that subwoofer A's excursion is much greater than 1cm.

Like I said in my last post, you don't know why the sub blew. Just
because
the amp says 50 watts on the package and the sub says 150 doesn't make
it
true. In fact, it's impossible to judge a speaker's true power
handling
in
isolation, because it's dependent on enclosure size, enclosure type,
crest
factor of the music, how much the amplifier is being overdriven, etc.
Manufacturers just estimate these numbers. Sometimes, especially when
you
look at tweeters, power handling numbers aren't actually power
handling -
they're estimates on recommended amplifier size. Unfortunately, many
manufacturers neglect to include this tidbit of information.

Basically, what I'm saying is that you don't have enough evidence to
suggest
that the sub blew because there wasn't a divider. It was a cheap sub.
They
blow. That's what makes a cheap sub a cheap sub.

sounds like it was a junk speaker to begin with.



"Kirby" wrote in message
news:uAbqe.1632442$6l.288238@pd7tw2no...
It took time for this to take place... its not like it happened right
away,
actually it was a couple of months after he purchased the woofer.



"scott johnson" (net) wrote in message
...
Then that would have been an already defective speaker.


"Kirby" wrote in message
news:5Hape.1590136$8l.889631@pd7tw1no...
What I'm saying is that the surround started to detach from the cone,
letting air pass through.


"MZ" wrote in message
...
Well it may be hard for me to explain, but I think it comes down
with
a
sealed box, and of where the air comes from when the sub moves out.
I
figured that it made its way through the surround and the cone.

What? Are you saying air passed through the surround and cone?

and the amp
wasnt doing it cuz it was getting 50 watts, when it could handle
150.

Power out can't be greater than power in. In other words, if 50 watts
can't
blow the sub directly, it's not going to do it indirectly through
another
subwoofer. Basically, what this means is that if subwoofer A, driven
by
50
watts, causes subwoofer B to move 1 cm (just makin' up numbers here),
then
subwoofer B, driven by 50 watts directly, will move more than 1cm.
Direct

indirect. The caveat here is if the two woofers are vastly
different -
such
that subwoofer A's excursion is much greater than 1cm.

Like I said in my last post, you don't know why the sub blew. Just
because
the amp says 50 watts on the package and the sub says 150 doesn't make
it
true. In fact, it's impossible to judge a speaker's true power
handling
in
isolation, because it's dependent on enclosure size, enclosure type,
crest
factor of the music, how much the amplifier is being overdriven, etc.
Manufacturers just estimate these numbers. Sometimes, especially when
you
look at tweeters, power handling numbers aren't actually power
handling -
they're estimates on recommended amplifier size. Unfortunately, many
manufacturers neglect to include this tidbit of information.

Basically, what I'm saying is that you don't have enough evidence to
suggest
that the sub blew because there wasn't a divider. It was a cheap sub.
They
blow. That's what makes a cheap sub a cheap sub.