[amdx]

My 16 yr old daughter bought an Insignia IS-PCSS101-Two 12" 8 Ohm speakers
and amp, 200 Watts into 4 ohms. This is a subwoofer system. Dad's job- Get
the most thump from what she's got. I will build a cabinet for the trunk.
Some options- #1-combine L+R (sub freqs) and bridge amp into parallel
speakers. (500W into 4 ohms) one cabinet (no partition) two speakers. Option
#2-Build cabinet with partition , drive each 8 ohm speaker with L or R side
amp, I think that's 100 watts times two speakers. So now I think I'm
comparing 500 watts to 200 watts. Feedback? I've measured
Qms,Qes,Qts,Cms,and calculated a Vas of 2.32cuft for each speaker. Do I just
double the cabinet size if I put two speakers in with no partition? (mono)

Thanks, Mike

[Peter Larsen[_3_]]

amdx wrote:

My 16 yr old daughter bought an Insignia IS-PCSS101-Two 12" 8 Ohm
speakers and amp, 200 Watts into 4 ohms. This is a subwoofer system.

Please rephrase, is this about plural or is it not?

Kind regards

Peter Larsen

[amdx]

"Peter Larsen" wrote in message
...
amdx wrote:

My 16 yr old daughter bought an Insignia IS-PCSS101-Two 12" 8 Ohm
speakers and amp, 200 Watts into 4 ohms. This is a subwoofer system.

Please rephrase, is this about plural or is it not?

Kind regards

Peter Larsen

That's a desision to be determined. I believe the two channels are pretty
much the same below 150 hertz ( correct me if you like ).
So I can combine the two channels (low freqs only) and bridge the amp if
needed for max audio output.
Thanks for your help,
Mike

[jakdedert]

amdx wrote:
My 16 yr old daughter bought an Insignia IS-PCSS101-Two 12" 8 Ohm speakers
and amp, 200 Watts into 4 ohms. This is a subwoofer system. Dad's job- Get
the most thump from what she's got. I will build a cabinet for the trunk.
Some options- #1-combine L+R (sub freqs) and bridge amp into parallel
speakers. (500W into 4 ohms) one cabinet (no partition) two speakers. Option
#2-Build cabinet with partition , drive each 8 ohm speaker with L or R side
amp, I think that's 100 watts times two speakers. So now I think I'm
comparing 500 watts to 200 watts. Feedback? I've measured
Qms,Qes,Qts,Cms,and calculated a Vas of 2.32cuft for each speaker. Do I just
double the cabinet size if I put two speakers in with no partition? (mono)

Thanks, Mike

Just my $.02...while it's admirable that you want to do a project
for/with your daughter, it might be more important to preserve her ears,
not to mention the sanity of the neighborhood.


That said, subs are mono. There will be no left/right info detected
from the listeners POV if you separate the channels.

That leaves building the most efficient box utilizing those two speakers
as the best option...including powering it in the most efficient way,
which is usually a bridged configuration.

All the above assuming you have a suitable electronic x-over (usually
built into the amp?) to direct only sub frequencies to the amp.

There are newsgroups devoted to autosound which might give you more
specific information concerning your particular car and equipment.

jak

[amdx]

"jakdedert" wrote in message
...
amdx wrote:
My 16 yr old daughter bought an Insignia IS-PCSS101-Two 12" 8 Ohm
speakers and amp, 200 Watts into 4 ohms. This is a subwoofer system.
Dad's job- Get the most thump from what she's got. I will build a cabinet
for the trunk. Some options- #1-combine L+R (sub freqs) and bridge amp
into parallel speakers. (500W into 4 ohms) one cabinet (no partition) two
speakers. Option #2-Build cabinet with partition , drive each 8 ohm
speaker with L or R side amp, I think that's 100 watts times two
speakers. So now I think I'm comparing 500 watts to 200 watts. Feedback?
I've measured Qms,Qes,Qts,Cms,and calculated a Vas of 2.32cuft for each
speaker. Do I just double the cabinet size if I put two speakers in with
no partition? (mono)

Thanks, Mike

Just my $.02...while it's admirable that you want to do a project for/with
your daughter, it might be more important to preserve her ears, not to
mention the sanity of the neighborhood.


That said, subs are mono. There will be no left/right info detected from
the listeners POV if you separate the channels.

That leaves building the most efficient box utilizing those two speakers
as the best option...including powering it in the most efficient way,
which is usually a bridged configuration.

All the above assuming you have a suitable electronic x-over (usually
built into the amp?) to direct only sub frequencies to the amp.

There are newsgroups devoted to autosound which might give you more
specific information concerning your particular car and equipment.

jak

So, it sounds like you agree with a mono system, paralleled speakers and
bridged amp?
I haven't found any newsgroups devoted to autosound, any names?
Thanks, Mike

[Trevor Wilson[_2_]]

"amdx" wrote in message
...
My 16 yr old daughter bought an Insignia IS-PCSS101-Two 12" 8 Ohm speakers
and amp, 200 Watts into 4 ohms. This is a subwoofer system. Dad's job- Get
the most thump from what she's got. I will build a cabinet for the trunk.
Some options- #1-combine L+R (sub freqs) and bridge amp into parallel
speakers. (500W into 4 ohms) one cabinet (no partition) two speakers.
Option #2-Build cabinet with partition , drive each 8 ohm speaker with L
or R side amp, I think that's 100 watts times two speakers. So now I think
I'm comparing 500 watts to 200 watts. Feedback? I've measured
Qms,Qes,Qts,Cms,and calculated a Vas of 2.32cuft for each speaker. Do I
just double the cabinet size if I put two speakers in with no partition?
(mono)

**Oh great! Just what this planet needs - ANOTHER deaf, stupid 16 year old,
annoying everyone around her, with stupid music, played at stupid levels.

Spend the money and time on a decent education, an appreciation of how
valuable her hearing is and respect for those around her.

Trevor Wilson

[Peter Larsen[_3_]]

jakdedert wrote:

Just my $.02...while it's admirable that you want to do a project
for/with your daughter, it might be more important to preserve her
ears, not to mention the sanity of the neighborhood.

Indeed. Car stereo is bad news for the sense of hearing.

jak


Kind regards

Peter Larsen

[GregS[_3_]]

In article , "amdx" wrote:
My 16 yr old daughter bought an Insignia IS-PCSS101-Two 12" 8 Ohm speakers
and amp, 200 Watts into 4 ohms. This is a subwoofer system. Dad's job- Get
the most thump from what she's got. I will build a cabinet for the trunk.
Some options- #1-combine L+R (sub freqs) and bridge amp into parallel
speakers. (500W into 4 ohms) one cabinet (no partition) two speakers. Option
#2-Build cabinet with partition , drive each 8 ohm speaker with L or R side
amp, I think that's 100 watts times two speakers. So now I think I'm
comparing 500 watts to 200 watts. Feedback? I've measured
Qms,Qes,Qts,Cms,and calculated a Vas of 2.32cuft for each speaker. Do I just
double the cabinet size if I put two speakers in with no partition? (mono)

Thanks, Mike

I don't think the partition will matter, but somehow a partition seems safer.
L and R are essentially the same thing. I never see any point in summing, just use
one channel for the bass. it will also insure there is no phase difference.


Might as well go for 500 watts or 250 per driver, but its not going to matter.
Double cabinet size should work. Is there a port ?

grge

[Arny Krueger]

"amdx" wrote in message

"jakdedert" wrote in message
...
amdx wrote:
My 16 yr old daughter bought an Insignia IS-PCSS101-Two
12" 8 Ohm speakers and amp, 200 Watts into 4 ohms. This
is a subwoofer system. Dad's job- Get the most thump
from what she's got. I will build a cabinet for the
trunk. Some options- #1-combine L+R (sub freqs) and
bridge amp into parallel speakers. (500W into 4 ohms)
one cabinet (no partition) two speakers. Option
#2-Build cabinet with partition , drive each 8 ohm
speaker with L or R side amp, I think that's 100 watts
times two speakers. So now I think I'm comparing 500
watts to 200 watts. Feedback?

Mono, particularly in a car.


I've measured
Qms,Qes,Qts,Cms,and calculated a Vas of 2.32cuft for
each speaker. Do I just double the cabinet size if I
put two speakers in with no partition? (mono)

Yes. Do the mental experiment - two subs in a 2 x large box, with and
without a partition running down the middle. The force on each side of the
partition will be equal and opposite, so it matters not whether the
partition is there or not.

That said, subs are mono. There will be no left/right
info detected from the listeners POV if you separate the
channels.

Agreed.

That leaves building the most efficient box utilizing
those two speakers as the best option...including
powering it in the most efficient way, which is usually
a bridged configuration.

Agreed.

All the above assuming you have a suitable electronic
x-over (usually built into the amp?) to direct only sub
frequencies to the amp.

Agreed. Also important - *not* allowing subwoofer signals to get into the
upper-range drivers.

There are newsgroups devoted to autosound which might
give you more specific information concerning your
particular car and equipment.

You can start with rec.audio.car

So, it sounds like you agree with a mono system,
paralleled speakers and bridged amp?

Agreed.

I haven't found any newsgroups devoted to autosound, any
names? Thanks, Mike

http://www.speakerplans.com/forum/fo...pics.asp?FID=5

http://www.hometheaterhifi.com/forum....php/f-30.html

and more generally about subwoofers:

http://www.hometheatershack.com/forums/

[GregS[_3_]]

In article , "amdx" wrote:

"jakdedert" wrote in message
.. .
amdx wrote:
My 16 yr old daughter bought an Insignia IS-PCSS101-Two 12" 8 Ohm
speakers and amp, 200 Watts into 4 ohms. This is a subwoofer system.
Dad's job- Get the most thump from what she's got. I will build a cabinet
for the trunk. Some options- #1-combine L+R (sub freqs) and bridge amp
into parallel speakers. (500W into 4 ohms) one cabinet (no partition) two
speakers. Option #2-Build cabinet with partition , drive each 8 ohm
speaker with L or R side amp, I think that's 100 watts times two
speakers. So now I think I'm comparing 500 watts to 200 watts. Feedback?
I've measured Qms,Qes,Qts,Cms,and calculated a Vas of 2.32cuft for each
speaker. Do I just double the cabinet size if I put two speakers in with
no partition? (mono)

Thanks, Mike

Just my $.02...while it's admirable that you want to do a project for/with
your daughter, it might be more important to preserve her ears, not to
mention the sanity of the neighborhood.


That said, subs are mono. There will be no left/right info detected from
the listeners POV if you separate the channels.

That leaves building the most efficient box utilizing those two speakers
as the best option...including powering it in the most efficient way,
which is usually a bridged configuration.

All the above assuming you have a suitable electronic x-over (usually
built into the amp?) to direct only sub frequencies to the amp.

There are newsgroups devoted to autosound which might give you more
specific information concerning your particular car and equipment.

jak

So, it sounds like you agree with a mono system, paralleled speakers and
bridged amp?
I haven't found any newsgroups devoted to autosound, any names?
Thanks, Mike

rec.audio.car

and the FAQ
http://www.mobileaudio.com/rac-faq/

[GregS[_3_]]

In article , jakdedert wrote:
amdx wrote:
My 16 yr old daughter bought an Insignia IS-PCSS101-Two 12" 8 Ohm speakers
and amp, 200 Watts into 4 ohms. This is a subwoofer system. Dad's job- Get
the most thump from what she's got. I will build a cabinet for the trunk.
Some options- #1-combine L+R (sub freqs) and bridge amp into parallel
speakers. (500W into 4 ohms) one cabinet (no partition) two speakers. Option
#2-Build cabinet with partition , drive each 8 ohm speaker with L or R side
amp, I think that's 100 watts times two speakers. So now I think I'm
comparing 500 watts to 200 watts. Feedback? I've measured
Qms,Qes,Qts,Cms,and calculated a Vas of 2.32cuft for each speaker. Do I just
double the cabinet size if I put two speakers in with no partition? (mono)

Thanks, Mike

Just my $.02...while it's admirable that you want to do a project
for/with your daughter, it might be more important to preserve her ears,
not to mention the sanity of the neighborhood.


That said, subs are mono. There will be no left/right info detected
from the listeners POV if you separate the channels.

That leaves building the most efficient box utilizing those two speakers
as the best option...including powering it in the most efficient way,
which is usually a bridged configuration.

All the above assuming you have a suitable electronic x-over (usually
built into the amp?) to direct only sub frequencies to the amp.

I always like using bandpass boxes because they don't need a crossover, and you
can change the range of the driver for which its designed, like extending
range at the expense of SPL, or getting more output SPL at the expense of Q.

greg


There are newsgroups devoted to autosound which might give you more
specific information concerning your particular car and equipment.

jak

[amdx]

"Trevor Wilson" wrote in message
...

"amdx" wrote in message
...
My 16 yr old daughter bought an Insignia IS-PCSS101-Two 12" 8 Ohm
speakers and amp, 200 Watts into 4 ohms. This is a subwoofer system.
Dad's job- Get the most thump from what she's got. I will build a cabinet
for the trunk. Some options- #1-combine L+R (sub freqs) and bridge amp
into parallel speakers. (500W into 4 ohms) one cabinet (no partition) two
speakers. Option #2-Build cabinet with partition , drive each 8 ohm
speaker with L or R side amp, I think that's 100 watts times two
speakers. So now I think I'm comparing 500 watts to 200 watts. Feedback?
I've measured Qms,Qes,Qts,Cms,and calculated a Vas of 2.32cuft for each
speaker. Do I just double the cabinet size if I put two speakers in with
no partition? (mono)

**Oh great! Just what this planet needs - ANOTHER deaf, stupid 16 year
old,



Not to brag, but you called her stupid, she's carrying a 4.538 grade point
average.





annoying everyone around her, with stupid music, played at stupid levels.

Spend the money and time on a decent education, an appreciation of how
valuable her hearing is and respect for those around her.

Trevor Wilson

[AZ Nomad]

On Wed, 30 Jan 2008 19:48:14 GMT, GregS wrote:
In article , "amdx" wrote:
My 16 yr old daughter bought an Insignia IS-PCSS101-Two 12" 8 Ohm speakers
and amp, 200 Watts into 4 ohms. This is a subwoofer system. Dad's job- Get
the most thump from what she's got. I will build a cabinet for the trunk.
Some options- #1-combine L+R (sub freqs) and bridge amp into parallel
speakers. (500W into 4 ohms) one cabinet (no partition) two speakers. Option
#2-Build cabinet with partition , drive each 8 ohm speaker with L or R side
amp, I think that's 100 watts times two speakers. So now I think I'm
comparing 500 watts to 200 watts. Feedback? I've measured
Qms,Qes,Qts,Cms,and calculated a Vas of 2.32cuft for each speaker. Do I just
double the cabinet size if I put two speakers in with no partition? (mono)

Thanks, Mike

I don't think the partition will matter, but somehow a partition seems safer.
L and R are essentially the same thing. I never see any point in summing, just use
one channel for the bass. it will also insure there is no phase difference.

That's a terrible idea. Bass isn't always monophonic. If the mix has more
bass on one side (such as a bass player who isn't in the middle of the mix),
the bass level will depend on which channel you selected.

Mix the channels together then amplify, or use one channel per speaker.


Might as well go for 500 watts or 250 per driver, but its not going to matter.
Double cabinet size should work. Is there a port ?

[amdx]

"GregS" wrote in message
...
In article , "amdx"
wrote:
My 16 yr old daughter bought an Insignia IS-PCSS101-Two 12" 8 Ohm speakers
and amp, 200 Watts into 4 ohms. This is a subwoofer system. Dad's job- Get
the most thump from what she's got. I will build a cabinet for the trunk.
Some options- #1-combine L+R (sub freqs) and bridge amp into parallel
speakers. (500W into 4 ohms) one cabinet (no partition) two speakers.
Option
#2-Build cabinet with partition , drive each 8 ohm speaker with L or R
side
amp, I think that's 100 watts times two speakers. So now I think I'm
comparing 500 watts to 200 watts. Feedback? I've measured
Qms,Qes,Qts,Cms,and calculated a Vas of 2.32cuft for each speaker. Do I
just
double the cabinet size if I put two speakers in with no partition? (mono)

Thanks, Mike

I don't think the partition will matter, but somehow a partition seems
safer.
L and R are essentially the same thing. I never see any point in summing,
just use
one channel for the bass. it will also insure there is no phase
difference.


Might as well go for 500 watts or 250 per driver, but its not going to
matter.
Double cabinet size should work. Is there a port ?

grge

The design at this point is a sealed box.
Mike

[GregS[_3_]]

In article , AZ Nomad wrote:
On Wed, 30 Jan 2008 19:48:14 GMT, GregS wrote:
In article , "amdx"
wrote:
My 16 yr old daughter bought an Insignia IS-PCSS101-Two 12" 8 Ohm speakers
and amp, 200 Watts into 4 ohms. This is a subwoofer system. Dad's job- Get
the most thump from what she's got. I will build a cabinet for the trunk.
Some options- #1-combine L+R (sub freqs) and bridge amp into parallel
speakers. (500W into 4 ohms) one cabinet (no partition) two speakers. Option
#2-Build cabinet with partition , drive each 8 ohm speaker with L or R side
amp, I think that's 100 watts times two speakers. So now I think I'm
comparing 500 watts to 200 watts. Feedback? I've measured
Qms,Qes,Qts,Cms,and calculated a Vas of 2.32cuft for each speaker. Do I just
double the cabinet size if I put two speakers in with no partition? (mono)

Thanks, Mike

I don't think the partition will matter, but somehow a partition seems safer.
L and R are essentially the same thing. I never see any point in summing, just
use
one channel for the bass. it will also insure there is no phase difference.

That's a terrible idea. Bass isn't always monophonic. If the mix has more
bass on one side (such as a bass player who isn't in the middle of the mix),
the bass level will depend on which channel you selected.


I can just see(hear) it now, with the bass player on the left side of the back seat.

If its less than 70 Hz you can't tell. With a good sub you can't tell direction.

greg


Mix the channels together then amplify, or use one channel per speaker.


Might as well go for 500 watts or 250 per driver, but its not going to matter.
Double cabinet size should work. Is there a port ?

[AZ Nomad]

On Thu, 31 Jan 2008 14:56:35 GMT, GregS wrote:
In article , AZ Nomad wrote:
On Wed, 30 Jan 2008 19:48:14 GMT, GregS wrote:
In article , "amdx"
wrote:
My 16 yr old daughter bought an Insignia IS-PCSS101-Two 12" 8 Ohm speakers
and amp, 200 Watts into 4 ohms. This is a subwoofer system. Dad's job- Get
the most thump from what she's got. I will build a cabinet for the trunk.
Some options- #1-combine L+R (sub freqs) and bridge amp into parallel
speakers. (500W into 4 ohms) one cabinet (no partition) two speakers. Option
#2-Build cabinet with partition , drive each 8 ohm speaker with L or R side
amp, I think that's 100 watts times two speakers. So now I think I'm
comparing 500 watts to 200 watts. Feedback? I've measured
Qms,Qes,Qts,Cms,and calculated a Vas of 2.32cuft for each speaker. Do I just
double the cabinet size if I put two speakers in with no partition? (mono)

Thanks, Mike

I don't think the partition will matter, but somehow a partition seems safer.
L and R are essentially the same thing. I never see any point in summing, just
use
one channel for the bass. it will also insure there is no phase difference.

That's a terrible idea. Bass isn't always monophonic. If the mix has more
bass on one side (such as a bass player who isn't in the middle of the mix),
the bass level will depend on which channel you selected.


I can just see(hear) it now, with the bass player on the left side of the back seat.

If its less than 70 Hz you can't tell. With a good sub you can't tell direction.
no ****, sherlock.

Read what I wrote. I wasn't talkinig about stereo imaging and suggested
mixing to mono. I was talking about the idea of using just one channel.
In your situation, if the bass player was on the left, and the right channel
was selected to drive the sub, the bass would be distorted and attenuated
as hell.

[GregS[_3_]]

In article , AZ Nomad wrote:
On Thu, 31 Jan 2008 14:56:35 GMT, GregS wrote:
In article , AZ Nomad
wrote:
On Wed, 30 Jan 2008 19:48:14 GMT, GregS wrote:
In article , "amdx"
wrote:
My 16 yr old daughter bought an Insignia IS-PCSS101-Two 12" 8 Ohm speakers
and amp, 200 Watts into 4 ohms. This is a subwoofer system. Dad's job- Get
the most thump from what she's got. I will build a cabinet for the trunk.
Some options- #1-combine L+R (sub freqs) and bridge amp into parallel
speakers. (500W into 4 ohms) one cabinet (no partition) two speakers.
Option
#2-Build cabinet with partition , drive each 8 ohm speaker with L or R side

amp, I think that's 100 watts times two speakers. So now I think I'm
comparing 500 watts to 200 watts. Feedback? I've measured
Qms,Qes,Qts,Cms,and calculated a Vas of 2.32cuft for each speaker. Do I
just
double the cabinet size if I put two speakers in with no partition? (mono)

Thanks, Mike

I don't think the partition will matter, but somehow a partition seems
safer.
L and R are essentially the same thing. I never see any point in summing,
just
use
one channel for the bass. it will also insure there is no phase difference.

That's a terrible idea. Bass isn't always monophonic. If the mix has more
bass on one side (such as a bass player who isn't in the middle of the mix),
the bass level will depend on which channel you selected.


I can just see(hear) it now, with the bass player on the left side of the back
seat.

If its less than 70 Hz you can't tell. With a good sub you can't tell
direction.
no ****, sherlock.

Read what I wrote. I wasn't talkinig about stereo imaging and suggested
mixing to mono. I was talking about the idea of using just one channel.
In your situation, if the bass player was on the left, and the right channel
was selected to drive the sub, the bass would be distorted and attenuated
as hell.

Find one modern song like that. Let me know what it is.


greg

[dizzy]

amdx wrote:

Not to brag, but you called her stupid, she's carrying a 4.538 grade point
average.

I thought 4.0 was the highest possible.

Is an "A" worth 10 points these days? 8)

[Arny Krueger]

"GregS" wrote in message


That's a terrible idea. Bass isn't always monophonic.

Depends what you call bass. Judging by comments below, bass can be construed
to mean response below 70 Hz.

If the mix has more bass on one side (such as a bass
player who isn't in the middle of the mix), the bass
level will depend on which channel you selected.

As a rule, musical instruments that play bass notes do not produce pure sine
waves. True even for electronic basses and synths. the sad truth about
instruments like pipe organs and other more common bass instruments is that
they typicall produce more harmonics than fundamentals. The situation is so
extreme that the fundamental is often smaller than any of the first few
harmonics.

I can just see(hear) it now, with the bass player on the
left side of the back seat.

If its less than 70 Hz you can't tell. With a good sub
you can't tell direction.

The point here being that if you reproduce 70 Hz cleanly, it is hard to
localize in most rooms. If the room is the passenger compartment of some
automotive vehicle, the room is generally so small that you won't localize
70 Hz for sure.

Per my comments above, a clean 70 Hz is only going to come from a test tone,
not from general music.

[dizzy]

amdx wrote:

My 16 yr old daughter bought an Insignia IS-PCSS101-Two 12" 8 Ohm speakers
and amp, 200 Watts into 4 ohms. This is a subwoofer system. Dad's job- Get
the most thump from what she's got. I will build a cabinet for the trunk.

I tried putting subs in the trunk, once. I was not pleased with the
coloration that resulted from shooting the sound through the back
seats.

[AZ Nomad]

On Thu, 31 Jan 2008 15:42:07 GMT, GregS wrote:
In article , AZ Nomad wrote:
On Thu, 31 Jan 2008 14:56:35 GMT, GregS wrote:
In article , AZ Nomad
wrote:
On Wed, 30 Jan 2008 19:48:14 GMT, GregS wrote:
In article , "amdx"
wrote:
My 16 yr old daughter bought an Insignia IS-PCSS101-Two 12" 8 Ohm speakers
and amp, 200 Watts into 4 ohms. This is a subwoofer system. Dad's job- Get
the most thump from what she's got. I will build a cabinet for the trunk.
Some options- #1-combine L+R (sub freqs) and bridge amp into parallel
speakers. (500W into 4 ohms) one cabinet (no partition) two speakers.
Option
#2-Build cabinet with partition , drive each 8 ohm speaker with L or R side

amp, I think that's 100 watts times two speakers. So now I think I'm
comparing 500 watts to 200 watts. Feedback? I've measured
Qms,Qes,Qts,Cms,and calculated a Vas of 2.32cuft for each speaker. Do I
just
double the cabinet size if I put two speakers in with no partition? (mono)

Thanks, Mike

I don't think the partition will matter, but somehow a partition seems
safer.
L and R are essentially the same thing. I never see any point in summing,
just
use
one channel for the bass. it will also insure there is no phase difference.

That's a terrible idea. Bass isn't always monophonic. If the mix has more
bass on one side (such as a bass player who isn't in the middle of the mix),
the bass level will depend on which channel you selected.


I can just see(hear) it now, with the bass player on the left side of the back
seat.

If its less than 70 Hz you can't tell. With a good sub you can't tell
direction.
no ****, sherlock.

Read what I wrote. I wasn't talkinig about stereo imaging and suggested
mixing to mono. I was talking about the idea of using just one channel.
In your situation, if the bass player was on the left, and the right channel
was selected to drive the sub, the bass would be distorted and attenuated
as hell.

Find one modern song like that. Let me know what it is.

Sorry, I don't listen to rap. I can name a thousand songs where the
bass isn't smack center.

Do you really want a file listing of my jazz collection, 60s-90s rock
collection, and classical collections?

[Arny Krueger]

"dizzy" wrote in message
news
amdx wrote:

Not to brag, but you called her stupid, she's carrying
a 4.538 grade point average.

I thought 4.0 was the highest possible.

There are such things as A+ grades at some schools. Their numeric value is
often given as 4.3

[Arny Krueger]

"AZ Nomad" wrote in message


Sorry, I don't listen to rap. I can name a thousand
songs where the bass isn't smack center.

A spectral analysis will probably show that the perception of being
off-center comes from harmonics 70 Hz.

[Arny Krueger]

"dizzy" wrote in message
news
amdx wrote:

My 16 yr old daughter bought an Insignia IS-PCSS101-Two
12" 8 Ohm speakers and amp, 200 Watts into 4 ohms. This
is a subwoofer system. Dad's job- Get the most thump
from what she's got. I will build a cabinet for the
trunk.

I tried putting subs in the trunk, once. I was not
pleased with the coloration that resulted from shooting
the sound through the back seats.

That's often a pretty effective low-pass filter.

One friend of mine cut out the back of the well the rear arm rest folded
into. You just popped it down for critical listening. ;-)

[amdx]

"dizzy" wrote in message
news
amdx wrote:

Not to brag, but you called her stupid, she's carrying a 4.538 grade
point
average.

I thought 4.0 was the highest possible.

Is an "A" worth 10 points these days? 8)

I knew that was coming, I wondered that for a while myself. She is taking
4- Advanced Placment (AP) classes
and 1- dual (HS/college) enrollment class. These classes are weighted higher
than regular classes.
Proud Dad

[jakdedert]

Arny Krueger wrote:
"dizzy" wrote in message
news
amdx wrote:

My 16 yr old daughter bought an Insignia IS-PCSS101-Two
12" 8 Ohm speakers and amp, 200 Watts into 4 ohms. This
is a subwoofer system. Dad's job- Get the most thump
from what she's got. I will build a cabinet for the
trunk.

I tried putting subs in the trunk, once. I was not
pleased with the coloration that resulted from shooting
the sound through the back seats.

That's often a pretty effective low-pass filter.

One friend of mine cut out the back of the well the rear arm rest folded
into. You just popped it down for critical listening. ;-)


If one has speakers in the rear deck area (between the seats and back
window) with the rear of the cones exposed, there's a possibility of
serious modulation of those cones by the pressure waves from the subs.

jak

[GregS[_3_]]

In article , "Arny Krueger" wrote:
"dizzy" wrote in message
news
amdx wrote:

My 16 yr old daughter bought an Insignia IS-PCSS101-Two
12" 8 Ohm speakers and amp, 200 Watts into 4 ohms. This
is a subwoofer system. Dad's job- Get the most thump
from what she's got. I will build a cabinet for the
trunk.

I tried putting subs in the trunk, once. I was not
pleased with the coloration that resulted from shooting
the sound through the back seats.

That's often a pretty effective low-pass filter.

One friend of mine cut out the back of the well the rear arm rest folded
into. You just popped it down for critical listening. ;-)

If the sub is only low bass, there should be no coloration except for possible resonance
effects. I built one system with a bandpass, with the port entering the passenger
compartment with the box in the trunk. That gets rid of any possible effect. You
can also use that on ported boxes, if the bass is limited in range.

greg

[Peter Larsen[_3_]]

AZ Nomad wrote:

If its less than 70 Hz you can't tell. With a good sub you can't
tell direction.

no ****, sherlock.

Read what I wrote. I wasn't talkinig about stereo imaging and
suggested mixing to mono. I was talking about the idea of using just
one channel.

In your situation, if the bass player was on the left, and the right
channel was selected to drive the sub, the bass would be distorted
and attenuated as hell.

First of all: what he said was to put both subs in the same box and then
wire each sub to each amplifier channel. With a standard panpot ... ie. a 4
dB compromise boost of what is panned to one side only ... the loss of level
would be 2 dB. So attenuated as hell does not apply. Distorted as hell also
not, it is good enough in this context to consider the unused sub to
constitute cabinet wall if it is connected to an active amplifier channel,
not a perfecly rigid wall, but better than just flapping around.

Next: Not to worry, masterman has the plug in that fixes the sound if
mixerman panned a low bass instrument to one side only. It costs some USD 50
and - as I recall this - is called "Mono".


Kind regards

Peter Larsen

[Arny Krueger]

"jakdedert" wrote in message

Arny Krueger wrote:
"dizzy" wrote in message
news
amdx wrote:

My 16 yr old daughter bought an Insignia IS-PCSS101-Two
12" 8 Ohm speakers and amp, 200 Watts into 4 ohms. This
is a subwoofer system. Dad's job- Get the most thump
from what she's got. I will build a cabinet for the
trunk.

I tried putting subs in the trunk, once. I was not
pleased with the coloration that resulted from shooting
the sound through the back seats.

That's often a pretty effective low-pass filter.

One friend of mine cut out the back of the well the rear
arm rest folded into. You just popped it down for
critical listening. ;-)
If one has speakers in the rear deck area (between the
seats and back window) with the rear of the cones
exposed, there's a possibility of serious modulation of
those cones by the pressure waves from the subs.

Agreed. They make plastic buckets that address this problem.

[Arny Krueger]

"GregS" wrote in message

In article
, "Arny
Krueger" wrote:
"dizzy" wrote in message
news
amdx wrote:

My 16 yr old daughter bought an Insignia IS-PCSS101-Two
12" 8 Ohm speakers and amp, 200 Watts into 4 ohms. This
is a subwoofer system. Dad's job- Get the most thump
from what she's got. I will build a cabinet for the
trunk.

I tried putting subs in the trunk, once. I was not
pleased with the coloration that resulted from shooting
the sound through the back seats.

That's often a pretty effective low-pass filter.

One friend of mine cut out the back of the well the rear
arm rest folded into. You just popped it down for
critical listening. ;-)

If the sub is only low bass, there should be no
coloration except for possible resonance
effects.

Agreed - if you cross the sub over low enough.

I built one system with a bandpass, with the
port entering the passenger
compartment with the box in the trunk. That gets rid of
any possible effect.

You keep talking about bandpass speakers this way, which forces me to
mention that some bandpass alignments are very dependent on a good
electrical low pass filter, because the FR of the port's output is very
rough in the upper bass and/or lower midrange.

You probably picked an alignment with well-controlled port radiation - mazel
tov!

[Peter Larsen[_3_]]

amdx wrote:

"dizzy" wrote in message
news
amdx wrote:

Not to brag, but you called her stupid, she's carrying a 4.538
grade point
average.

I thought 4.0 was the highest possible.

Is an "A" worth 10 points these days? 8)

I knew that was coming, I wondered that for a while myself. She is
taking 4- Advanced Placment (AP) classes
and 1- dual (HS/college) enrollment class. These classes are weighted
higher than regular classes.

What a wonderful demonstration of the difference between intelligence and
wisdom. Wanting 110 dB + in a constitutes "Youthful Folly" leading to either
deafness or damage to the ligaments in the middle ear or both. That ligament
damage leaves with rattling anvil and stirrup bones already at modest SPL.

Proud Dad

Perhaps, but it is time to convey wisdom to the dear child, responsiblity by
a legalese definition still rests with you.


Kind regards

Peter Larsen

[amdx]

"Peter Larsen" wrote in message
...
amdx wrote:

"dizzy" wrote in message
news
amdx wrote:

Not to brag, but you called her stupid, she's carrying a 4.538
grade point
average.

I thought 4.0 was the highest possible.

Is an "A" worth 10 points these days? 8)

I knew that was coming, I wondered that for a while myself. She is
taking 4- Advanced Placment (AP) classes
and 1- dual (HS/college) enrollment class. These classes are weighted
higher than regular classes.

What a wonderful demonstration of the difference between intelligence and
wisdom. Wanting 110 dB + in a constitutes "Youthful Folly" leading to
either deafness or damage to the ligaments in the middle ear or both. That
ligament damage leaves with rattling anvil and stirrup bones already at
modest SPL.

Proud Dad

Perhaps, but it is time to convey wisdom to the dear child, responsiblity
by a legalese definition still rests with you.


Kind regards

Peter Larsen

I have pointed out to her that you can know something,
but if you don't use the knowledge to your benefit then
it doesn't do you any good. Such as the overweight problem, how many people
don't know that's unhealthy
but don't change.
Mike

[GregS[_3_]]

In article , "Peter Larsen" wrote:
AZ Nomad wrote:

If its less than 70 Hz you can't tell. With a good sub you can't
tell direction.

no ****, sherlock.

Read what I wrote. I wasn't talkinig about stereo imaging and
suggested mixing to mono. I was talking about the idea of using just
one channel.

In your situation, if the bass player was on the left, and the right
channel was selected to drive the sub, the bass would be distorted
and attenuated as hell.

First of all: what he said was to put both subs in the same box and then
wire each sub to each amplifier channel. With a standard panpot ... ie. a 4
dB compromise boost of what is panned to one side only ... the loss of level
would be 2 dB. So attenuated as hell does not apply. Distorted as hell also
not, it is good enough in this context to consider the unused sub to
constitute cabinet wall if it is connected to an active amplifier channel,
not a perfecly rigid wall, but better than just flapping around.

Next: Not to worry, masterman has the plug in that fixes the sound if
mixerman panned a low bass instrument to one side only. It costs some USD 50
and - as I recall this - is called "Mono".


Kind regards

Peter Larsen

I was also thinking about the case where listening in stereo the bass
is center, but if it did move to one side only, would be up to 6dB down,
and would not sound so neat.

greg

[GregS[_3_]]

In article , "Arny Krueger" wrote:
"GregS" wrote in message

In article
, "Arny
Krueger" wrote:
"dizzy" wrote in message
news amdx wrote:

My 16 yr old daughter bought an Insignia IS-PCSS101-Two
12" 8 Ohm speakers and amp, 200 Watts into 4 ohms. This
is a subwoofer system. Dad's job- Get the most thump
from what she's got. I will build a cabinet for the
trunk.

I tried putting subs in the trunk, once. I was not
pleased with the coloration that resulted from shooting
the sound through the back seats.

That's often a pretty effective low-pass filter.

One friend of mine cut out the back of the well the rear
arm rest folded into. You just popped it down for
critical listening. ;-)

If the sub is only low bass, there should be no
coloration except for possible resonance
effects.

Agreed - if you cross the sub over low enough.

I built one system with a bandpass, with the
port entering the passenger
compartment with the box in the trunk. That gets rid of
any possible effect.

You keep talking about bandpass speakers this way, which forces me to
mention that some bandpass alignments are very dependent on a good
electrical low pass filter, because the FR of the port's output is very
rough in the upper bass and/or lower midrange.

You probably picked an alignment with well-controlled port radiation - mazel
tov!

Its very inportant to properly damp the chamber which drives the port,
and even try to best position the driver so its not facing the port. This
helps control upper resonances and feedthrough that should not be there.

greg

[Trevor Wilson[_2_]]

"amdx" wrote in message
...

"Trevor Wilson" wrote in message
...

"amdx" wrote in message
...
My 16 yr old daughter bought an Insignia IS-PCSS101-Two 12" 8 Ohm
speakers and amp, 200 Watts into 4 ohms. This is a subwoofer system.
Dad's job- Get the most thump from what she's got. I will build a
cabinet for the trunk. Some options- #1-combine L+R (sub freqs) and
bridge amp into parallel speakers. (500W into 4 ohms) one cabinet (no
partition) two speakers. Option #2-Build cabinet with partition , drive
each 8 ohm speaker with L or R side amp, I think that's 100 watts times
two speakers. So now I think I'm comparing 500 watts to 200 watts.
Feedback? I've measured Qms,Qes,Qts,Cms,and calculated a Vas of 2.32cuft
for each speaker. Do I just double the cabinet size if I put two
speakers in with no partition? (mono)

**Oh great! Just what this planet needs - ANOTHER deaf, stupid 16 year
old,



Not to brag, but you called her stupid, she's carrying a 4.538 grade
point average.

**I have no idea what a 4.538 grade point average is. I _do_ know about
idiots who play car stereos at obscene levels however. They annoy the people
around them, damage their own hearing and they place the lives of others
(emergency vehicles et al) at risk. In my state, police are now entitled to
confiscate vehicles where car stereos are played too loud. Which is as it
should be.

Spend the money and time on a decent education, an appreciation of how
valuable her hearing is and respect for those around her.


Trevor Wilson

[dizzy]

GregS wrote:

"Arny Krueger" wrote:
"dizzy" wrote in message
amdx wrote:

My 16 yr old daughter bought an Insignia IS-PCSS101-Two
12" 8 Ohm speakers and amp, 200 Watts into 4 ohms. This
is a subwoofer system. Dad's job- Get the most thump
from what she's got. I will build a cabinet for the
trunk.

I tried putting subs in the trunk, once. I was not
pleased with the coloration that resulted from shooting
the sound through the back seats.

That's often a pretty effective low-pass filter.

One friend of mine cut out the back of the well the rear arm rest folded
into. You just popped it down for critical listening. ;-)

If the sub is only low bass, there should be no coloration except for possible resonance
effects.

Define "low bass". As I recall, I was using 90Hz, with an 18dB/octive
crossover.

I built one system with a bandpass, with the port entering the passenger
compartment with the box in the trunk. That gets rid of any possible effect. You
can also use that on ported boxes, if the bass is limited in range.

The port exiting through a hole in the rear "dash" or whatever it's
called?

[dizzy]

jakdedert wrote:

Arny Krueger wrote:
"dizzy" wrote in message
news
amdx wrote:

My 16 yr old daughter bought an Insignia IS-PCSS101-Two
12" 8 Ohm speakers and amp, 200 Watts into 4 ohms. This
is a subwoofer system. Dad's job- Get the most thump
from what she's got. I will build a cabinet for the
trunk.

I tried putting subs in the trunk, once. I was not
pleased with the coloration that resulted from shooting
the sound through the back seats.

That's often a pretty effective low-pass filter.

One friend of mine cut out the back of the well the rear arm rest folded
into. You just popped it down for critical listening. ;-)

If one has speakers in the rear deck area (between the seats and back
window) with the rear of the cones exposed, there's a possibility of
serious modulation of those cones by the pressure waves from the subs.

Hadn't thought of that... Maybe that was the problem, but I don't
think so... The bass sounded like sound that's been run-through a
cushion. 8)

[jakdedert]

dizzy wrote:
jakdedert wrote:

Arny Krueger wrote:
"dizzy" wrote in message
news amdx wrote:

My 16 yr old daughter bought an Insignia IS-PCSS101-Two
12" 8 Ohm speakers and amp, 200 Watts into 4 ohms. This
is a subwoofer system. Dad's job- Get the most thump
from what she's got. I will build a cabinet for the
trunk.
I tried putting subs in the trunk, once. I was not
pleased with the coloration that resulted from shooting
the sound through the back seats.
That's often a pretty effective low-pass filter.

One friend of mine cut out the back of the well the rear arm rest folded
into. You just popped it down for critical listening. ;-)

If one has speakers in the rear deck area (between the seats and back
window) with the rear of the cones exposed, there's a possibility of
serious modulation of those cones by the pressure waves from the subs.

Hadn't thought of that... Maybe that was the problem, but I don't
think so... The bass sounded like sound that's been run-through a
cushion. 8)

Well, it was....

Different problem.

jak

[Ron]

On Jan 30, 2:00 pm, "amdx" wrote:

I haven't found any newsgroups devoted to autosound, any names?
Thanks, Mike

rec.audio.car

Just be prepared for several "experts" to give their advice and then
end up arguing with each other over who's design is the best.