More Box Discussion

[Mister.Lull]

Simple question this time.

Will a foreward facing box (ports and driver facing the back seat from
the trunk) run into any problems air-space wise?

Mister.Lull

[MOSFET]

Every situation is different so I think it is nearly impossible to give you
a definitive answer.

But my experience has been that subs that face the rear of the car, instead
of forward towards the back seats, are ALMOST ALWAYS louder.

I believe this is because of cancellation effects. Think about a home
subwoofer. Does it work better sitting in the middle of a room or against a
wall or in a corner? Obviously, against a wall or corner. This is because
bass is omni-directional and the farther you place a sub from a wall or
barrier, the better the chance that reflected sound waves will cancel each
other out.

Example: I had a car once (a long time ago) where I had a custom enclosure
made with two 12" subs facing the back seats, in fact they were nearly
touching the back of the seats. They were in sealed enclosures in the right
amount of airspace for this type of enclosure (they were Soundstream SPL12's
in 1.5 cubic feet of air-space each). The bass sounded OK, but what was
REALLY weird was that when I opened the trunk, the bass (in the driver's
seat) multiplied by four!!!!! Back then, I didn't understand exactly what
was happening, but now I realize that some of the sound waves (which are
omni-directional) were bouncing off the back of the trunk, becoming 180
degrees out of phase, and canceling out some of the sound waves.

Ever since then, I have always experimented with this (just because it
interests me) and have found that it is nearly ALWAYS the case that there is
more bass if the subs face the rear of the trunk or, even better, face the
rear corner of the trunk.

The exception to this would be if you could COMPLETELY ISOLATE the trunk
from the subs so no bass waves could bounce back. This is a little tricky
to do but SPL vehicles do it all the time.

MOSFET
"Mister.Lull" > wrote in message
ups.com...
> Simple question this time.
>
> Will a foreward facing box (ports and driver facing the back seat from
> the trunk) run into any problems air-space wise?
>
> Mister.Lull
>

[Matt Ion]

MOSFET wrote:

> But my experience has been that subs that face the rear of the car, instead
> of forward towards the back seats, are ALMOST ALWAYS louder.
>
> I believe this is because of cancellation effects. Think about a home
> subwoofer. Does it work better sitting in the middle of a room or against a
> wall or in a corner? Obviously, against a wall or corner. This is because
> bass is omni-directional and the farther you place a sub from a wall or
> barrier, the better the chance that reflected sound waves will cancel each
> other out.

Well, Nick, I hate to nit-pick, but you're talking about a phenomenon known as
"boundary reinforcement". You'll actually get MORE chance of cancellation the
closer you move a sub to a wall or corner, because the reflected out-of-phase
waves are that much stronger... but so are the IN-phase waves.

There's a good article on it here:
http://www.stereophile.com/features/706deep/index1.html

[MOSFET]

> Well, Nick, I hate to nit-pick, but you're talking about a phenomenon
known as
> "boundary reinforcement". You'll actually get MORE chance of cancellation
the
> closer you move a sub to a wall or corner, because the reflected
out-of-phase
> waves are that much stronger... but so are the IN-phase waves.

Well, OK, fine, I'm no engineer. I'm sure you're probably right, Matt, and
thank you for not trying to dazzle us with a whole bunch of acronyms and
terms we don't understand.

And Matt, I DO think this DOES fall under the category of nitpicking because
although you do clarify some things, DOES IT FUNDAMENTALLY CHANGE MY ADVICE?

SHOULD HE FACE THE SUBS TOWARDS THE REAR SEATS?

These are the questions I want you to ask yourself when you respond to my
posts. For instance, I responded to your iRiver post ONLY because what you
said was not good advice (there are cheap pre-amps he can buy for his
iRiver). NOT because you didn't dot your "i" or cross your "t".

Was my post bad advice, Matt? If it is, let's hear it, let's have a debate
and if your argument is stronger I'll happily concede. Otherwise, please
leave my posts alone because this nitpicking (correcting irrelevant details)
is getting REALLY, REALLY OLD (or block me).

Nick

[Mister.Lull]

Thank you gentlemen.

Hmmm. Certainly, sub direction is something to think about.

No matter what, I was thinking about blocking off the trunk from the
rest of the car (just with 3/4" MDF, so I realize that bass will still
get through that). I'm getting tired of having an almost un-usable
trunk for fear of damaging some part of the stereo, ya know? But in
order to not have to worry about damaging anything, that means (to me)
a blank, carpeted wall facing the trunk.

Now that only (absolutely) cancels out one of six surfaces on a box.

So it all boils down to the very basic part of the original question
that I didn't articulate very well... regardless of which direction
the sub and ports face (not necessarily the same direction, mind you)
does Air Space outside the box play much of a factor? An example: Say
I decide to go with a downward firing sub and forward facing ports.
The sub would probably only have one inch of clearance (sub poised 1
inch above the floor of the trunk [already cut off from the rest of the
trunk, snugged up next to the back seats]), is that enough space or
will that somehow mess with the sound or volume of the bass?

~Mister.Lull
MOSFET wrote:
> Every situation is different so I think it is nearly impossible to give you
> a definitive answer.
>
> But my experience has been that subs that face the rear of the car, instead
> of forward towards the back seats, are ALMOST ALWAYS louder.
>
> I believe this is because of cancellation effects. Think about a home
> subwoofer. Does it work better sitting in the middle of a room or against a
> wall or in a corner? Obviously, against a wall or corner. This is because
> bass is omni-directional and the farther you place a sub from a wall or
> barrier, the better the chance that reflected sound waves will cancel each
> other out.
>
> Example: I had a car once (a long time ago) where I had a custom enclosure
> made with two 12" subs facing the back seats, in fact they were nearly
> touching the back of the seats. They were in sealed enclosures in the right
> amount of airspace for this type of enclosure (they were Soundstream SPL12's
> in 1.5 cubic feet of air-space each). The bass sounded OK, but what was
> REALLY weird was that when I opened the trunk, the bass (in the driver's
> seat) multiplied by four!!!!! Back then, I didn't understand exactly what
> was happening, but now I realize that some of the sound waves (which are
> omni-directional) were bouncing off the back of the trunk, becoming 180
> degrees out of phase, and canceling out some of the sound waves.
>
> Ever since then, I have always experimented with this (just because it
> interests me) and have found that it is nearly ALWAYS the case that there is
> more bass if the subs face the rear of the trunk or, even better, face the
> rear corner of the trunk.
>
> The exception to this would be if you could COMPLETELY ISOLATE the trunk
> from the subs so no bass waves could bounce back. This is a little tricky
> to do but SPL vehicles do it all the time.
>
> MOSFET
> "Mister.Lull" > wrote in message
> ups.com...
> > Simple question this time.
> >
> > Will a foreward facing box (ports and driver facing the back seat from
> > the trunk) run into any problems air-space wise?
> >
> > Mister.Lull
> >

[MOSFET]

Matt, you are obviously knowledgable when it comes to car audio and I have
learned a lot from you. I don't want to fight with you so PLEASE hear what
I am saying, as a friend.

I do not mind being corrected when I make a fundamental mistake which leads
to bad advice. In fact, I would want ANYONE to correct me if I ever gave
bad advice to someone (and, of course, I HAVE in the past!!). We are here
to help people, first and foremost.

But what you do is different. PLEASE try to hear what I am saying. You
correct terms used incorrectly, concepts not "properly" explained. While to
you, this may SEEM like an important service. And I can certainly see
situations where someone might completely bungle an explanantion of
something and clarification might be needed. But with you it is a constant
barage of small corrections that do not fundamentally change the advice
given. You're like some grade school techer-from-hell whose RIGHT THERE to
rub your nose in the smallest missuse of a term or concept.

Perhaps in your proffesion, this is encouraged. Perhaps it is MANDATORY in
your profession (if you are designing airplane wings, I certainly don't want
ANY mistakes). But this group is for recreation. Car audio is about fun,
Matt. But this constant badgering does not make it fun for me or for other
people who you also badger.

Again, please try to see the difference between getting something
fundamentally wrong like offering bad advice and just using a term
incorrectly. WE ARE NOT DOING ROCKET SCIENCE HERE.

I know you don't give a rat's ass if I block you or not, but I am
considering it and I REALLY don't want to because you are SO KNOWLEDGEABLE
and I can learn from you. I am just hoping you will see my point. This is
about fun. We are not building the hydrogen bomb here.

Thanks,

Nick

[Matt Ion]

MOSFET wrote:
>>Well, Nick, I hate to nit-pick, but you're talking about a phenomenon
>
> known as
>
>>"boundary reinforcement". You'll actually get MORE chance of cancellation
>
> the
>
>>closer you move a sub to a wall or corner, because the reflected
>
> out-of-phase
>
>>waves are that much stronger... but so are the IN-phase waves.
>
>
> Well, OK, fine, I'm no engineer. I'm sure you're probably right, Matt, and
> thank you for not trying to dazzle us with a whole bunch of acronyms and
> terms we don't understand.
>
> And Matt, I DO think this DOES fall under the category of nitpicking because
> although you do clarify some things, DOES IT FUNDAMENTALLY CHANGE MY ADVICE?

What advice? You gave a bunch of anecdotes.

> SHOULD HE FACE THE SUBS TOWARDS THE REAR SEATS?

....and your anecdotes don't answer that question. It's worked in YOUR cars,
with YOUR subs... his system may not be affected the same way.

> These are the questions I want you to ask yourself when you respond to my
> posts.

Yes, mommy. Whatever you say, mommy. You are the boss of me. I am here to
cater only your needs and desires.

> Was my post bad advice, Matt?

Not at all. I only pointed out an inaccuracy in your home-subwoofer anaolgy.

> and if your argument is stronger I'll happily concede. Otherwise, please
> leave my posts alone because this nitpicking (correcting irrelevant details)
> is getting REALLY, REALLY OLD (or block me).

You really need to get a grip. IT'S NOT ABOUT YOU. It's about helping the OP.
If your information is inaccurate, that doesn't help.

[Matt Ion]

Mister.Lull wrote:

> So it all boils down to the very basic part of the original question
> that I didn't articulate very well... regardless of which direction
> the sub and ports face (not necessarily the same direction, mind you)
> does Air Space outside the box play much of a factor? An example: Say
> I decide to go with a downward firing sub and forward facing ports.
> The sub would probably only have one inch of clearance (sub poised 1
> inch above the floor of the trunk [already cut off from the rest of the
> trunk, snugged up next to the back seats]), is that enough space or
> will that somehow mess with the sound or volume of the bass?

The thing about bass in a car is, there's a lot of voodoo involved... you can
calculate some of the factors, but some things just aren't quantifiable.
Certainly the airspace in the trunk, and indeed the rest of the car, are a part
of the whole subwooder *system*. It all affects the bass response, usually in
ways that you can only determine yourself, once the box is in the car. What
works in one car may work in yours, or it may not. Google the term "transfer
function" (WITH the quotes) for more details.

Even the SHAPE of your trunk/hatch/etc. can play a role - those guys back in
high school (well, when I was in high school anyway) who got nice pounding bass
from the 6x9s in the rear deck of their Trans Ams were (usually unknowingly)
taking advantage of the curve of the rear window, which effectively horn-loaded
the speakers and created a reinforced sound wave; it's a principle used a lot in
live-sound reinforcement to get a lot of sound out of a small package.

Basically, you need to experiment with it once the box is in, to find out what
works best FOR YOU.

[Matt Ion]

Here's some advice back: LIGHTEN UP.

This is rec.audio.car, not rec.audio.car.nick's-ego

Someone disagreeing with you, or correcting you, or in some way contradicting
you, is NOT A PERSONAL ATTACK. DON'T TAKE IT AS SUCH. Everyone is NOT out to
get you!

This may come as a shock to you, but YOU TOO can be wrong now and then. Accept
it, learn from it, and move on. Don't argue it to death.

You didn't create this group, you don't own this group, you don't run this
group. You have no right to tell others how to conduct themselves. If I want
to give someone terse, smart-ass replies, I can. If I want to provide long,
rambling, detail-laden explanations, that's my right too. Just because YOU
don't, can't, or don't want to understand it, doesn't mean someone else doesn't
find the information useful. My methods are not for you to criticize. Neither
are anyone else's.

[Rick Brandt]

Matt Ion wrote:
> Here's some advice back: LIGHTEN UP.
>
> This is rec.audio.car, not rec.audio.car.nick's-ego
>
> Someone disagreeing with you, or correcting you, or in some way
> contradicting you, is NOT A PERSONAL ATTACK. DON'T TAKE IT AS SUCH. Everyone
> is NOT out to get you!
>
> This may come as a shock to you, but YOU TOO can be wrong now and
> then. Accept it, learn from it, and move on. Don't argue it to
> death.
> You didn't create this group, you don't own this group, you don't run
> this group. You have no right to tell others how to conduct
> themselves. If I want to give someone terse, smart-ass replies, I
> can. If I want to provide long, rambling, detail-laden explanations,
> that's my right too. Just because YOU don't, can't, or don't want to
> understand it, doesn't mean someone else doesn't find the information
> useful. My methods are not for you to criticize. Neither are anyone
> else's.

One should always remember that newsnet groups are *discussion forums*. You
make a post and a discussion follows. If a question that is asked is eventually
answered that is all fine and good, but it is not the end-all purpose of the
group's existence. Only in moderated groups is the discussion subject to any
one person's whims.

There is no such thing as a hi-jacked thread. When a post isn't of interest to
you, ignore it. When the thread becomes of no interest to you, move on.
Expecting anything else will only aggravate you.

[Matt Ion]

Rick Brandt wrote:
> Matt Ion wrote:
>
>>Here's some advice back: LIGHTEN UP.
>>
>>This is rec.audio.car, not rec.audio.car.nick's-ego
>>
>>Someone disagreeing with you, or correcting you, or in some way
>>contradicting you, is NOT A PERSONAL ATTACK. DON'T TAKE IT AS SUCH. Everyone
>>is NOT out to get you!
>>
>>This may come as a shock to you, but YOU TOO can be wrong now and
>>then. Accept it, learn from it, and move on. Don't argue it to
>>death.
>>You didn't create this group, you don't own this group, you don't run
>>this group. You have no right to tell others how to conduct
>>themselves. If I want to give someone terse, smart-ass replies, I
>>can. If I want to provide long, rambling, detail-laden explanations,
>>that's my right too. Just because YOU don't, can't, or don't want to
>>understand it, doesn't mean someone else doesn't find the information
>>useful. My methods are not for you to criticize. Neither are anyone
>>else's.
>
>
> One should always remember that newsnet groups are *discussion forums*. You
> make a post and a discussion follows. If a question that is asked is eventually
> answered that is all fine and good, but it is not the end-all purpose of the
> group's existence. Only in moderated groups is the discussion subject to any
> one person's whims.
>
> There is no such thing as a hi-jacked thread. When a post isn't of interest to
> you, ignore it. When the thread becomes of no interest to you, move on.
> Expecting anything else will only aggravate you.

Well said.

[[email protected]]

What a ****stick you are. Little girly bitch. slap!!!! Such a ****ing
victim.


MOSFET wrote:
> Matt, you are obviously knowledgable when it comes to car audio and I have
> learned a lot from you. I don't want to fight with you so PLEASE hear what
> I am saying, as a friend.
>
> I do not mind being corrected when I make a fundamental mistake which leads
> to bad advice. In fact, I would want ANYONE to correct me if I ever gave
> bad advice to someone (and, of course, I HAVE in the past!!). We are here
> to help people, first and foremost.
>
> But what you do is different. PLEASE try to hear what I am saying. You
> correct terms used incorrectly, concepts not "properly" explained. While to
> you, this may SEEM like an important service. And I can certainly see
> situations where someone might completely bungle an explanantion of
> something and clarification might be needed. But with you it is a constant
> barage of small corrections that do not fundamentally change the advice
> given. You're like some grade school techer-from-hell whose RIGHT THERE to
> rub your nose in the smallest missuse of a term or concept.
>
> Perhaps in your proffesion, this is encouraged. Perhaps it is MANDATORY in
> your profession (if you are designing airplane wings, I certainly don't want
> ANY mistakes). But this group is for recreation. Car audio is about fun,
> Matt. But this constant badgering does not make it fun for me or for other
> people who you also badger.
>
> Again, please try to see the difference between getting something
> fundamentally wrong like offering bad advice and just using a term
> incorrectly. WE ARE NOT DOING ROCKET SCIENCE HERE.
>
> I know you don't give a rat's ass if I block you or not, but I am
> considering it and I REALLY don't want to because you are SO KNOWLEDGEABLE
> and I can learn from you. I am just hoping you will see my point. This is
> about fun. We are not building the hydrogen bomb here.
>
> Thanks,
>
> Nick

[MOSFET]

Who is this? Captain?

MOSFET

> wrote in message
oups.com...
> What a ****stick you are. Little girly bitch. slap!!!! Such a ****ing
> victim.
>
>
> MOSFET wrote:
> > Matt, you are obviously knowledgable when it comes to car audio and I
have
> > learned a lot from you. I don't want to fight with you so PLEASE hear
what
> > I am saying, as a friend.
> >
> > I do not mind being corrected when I make a fundamental mistake which
leads
> > to bad advice. In fact, I would want ANYONE to correct me if I ever
gave
> > bad advice to someone (and, of course, I HAVE in the past!!). We are
here
> > to help people, first and foremost.
> >
> > But what you do is different. PLEASE try to hear what I am saying. You
> > correct terms used incorrectly, concepts not "properly" explained.
While to
> > you, this may SEEM like an important service. And I can certainly see
> > situations where someone might completely bungle an explanantion of
> > something and clarification might be needed. But with you it is a
constant
> > barage of small corrections that do not fundamentally change the advice
> > given. You're like some grade school techer-from-hell whose RIGHT THERE
to
> > rub your nose in the smallest missuse of a term or concept.
> >
> > Perhaps in your proffesion, this is encouraged. Perhaps it is MANDATORY
in
> > your profession (if you are designing airplane wings, I certainly don't
want
> > ANY mistakes). But this group is for recreation. Car audio is about
fun,
> > Matt. But this constant badgering does not make it fun for me or for
other
> > people who you also badger.
> >
> > Again, please try to see the difference between getting something
> > fundamentally wrong like offering bad advice and just using a term
> > incorrectly. WE ARE NOT DOING ROCKET SCIENCE HERE.
> >
> > I know you don't give a rat's ass if I block you or not, but I am
> > considering it and I REALLY don't want to because you are SO
KNOWLEDGEABLE
> > and I can learn from you. I am just hoping you will see my point. This
is
> > about fun. We are not building the hydrogen bomb here.
> >
> > Thanks,
> >
> > Nick
>

[MOSFET]

You know, Matt, I just made a simple request. Please, please, please, don't
nitpick my posts. That's ALL I asked (and I'm saying please). But that is
way too much for YOUR ego.

Why did I even bother with the friendly approach? You're too arrogant to
ever consider anyone but THE GREAT MATT!!!

On to my blocked list you go. Pitty.

Nick


"Matt Ion" > wrote in message
news:vWIKg.513575$IK3.242491@pd7tw1no...
> Rick Brandt wrote:
> > Matt Ion wrote:
> >
> >>Here's some advice back: LIGHTEN UP.
> >>
> >>This is rec.audio.car, not rec.audio.car.nick's-ego
> >>
> >>Someone disagreeing with you, or correcting you, or in some way
> >>contradicting you, is NOT A PERSONAL ATTACK. DON'T TAKE IT AS SUCH.
Everyone
> >>is NOT out to get you!
> >>
> >>This may come as a shock to you, but YOU TOO can be wrong now and
> >>then. Accept it, learn from it, and move on. Don't argue it to
> >>death.
> >>You didn't create this group, you don't own this group, you don't run
> >>this group. You have no right to tell others how to conduct
> >>themselves. If I want to give someone terse, smart-ass replies, I
> >>can. If I want to provide long, rambling, detail-laden explanations,
> >>that's my right too. Just because YOU don't, can't, or don't want to
> >>understand it, doesn't mean someone else doesn't find the information
> >>useful. My methods are not for you to criticize. Neither are anyone
> >>else's.
> >
> >
> > One should always remember that newsnet groups are *discussion forums*.
You
> > make a post and a discussion follows. If a question that is asked is
eventually
> > answered that is all fine and good, but it is not the end-all purpose of
the
> > group's existence. Only in moderated groups is the discussion subject
to any
> > one person's whims.
> >
> > There is no such thing as a hi-jacked thread. When a post isn't of
interest to
> > you, ignore it. When the thread becomes of no interest to you, move on.
> > Expecting anything else will only aggravate you.
>
> Well said.

[MOSFET]

"Rick Brandt" > wrote in message
. ..
> Matt Ion wrote:
> > Here's some advice back: LIGHTEN UP.
> >
> > This is rec.audio.car, not rec.audio.car.nick's-ego
> >
> > Someone disagreeing with you, or correcting you, or in some way
> > contradicting you, is NOT A PERSONAL ATTACK. DON'T TAKE IT AS SUCH.
Everyone
> > is NOT out to get you!
> >
> > This may come as a shock to you, but YOU TOO can be wrong now and
> > then. Accept it, learn from it, and move on. Don't argue it to
> > death.
> > You didn't create this group, you don't own this group, you don't run
> > this group. You have no right to tell others how to conduct
> > themselves. If I want to give someone terse, smart-ass replies, I
> > can. If I want to provide long, rambling, detail-laden explanations,
> > that's my right too. Just because YOU don't, can't, or don't want to
> > understand it, doesn't mean someone else doesn't find the information
> > useful. My methods are not for you to criticize. Neither are anyone
> > else's.
>
> One should always remember that newsnet groups are *discussion forums*.
You
> make a post and a discussion follows. If a question that is asked is
eventually
> answered that is all fine and good, but it is not the end-all purpose of
the
> group's existence. Only in moderated groups is the discussion subject to
any
> one person's whims.
>
> There is no such thing as a hi-jacked thread. When a post isn't of
interest to
> you, ignore it. When the thread becomes of no interest to you, move on.
> Expecting anything else will only aggravate you.
>
Not true.

We ALL get aggravated at Bob's posts because we like RAC and take this forum
seriously and we don't like seeing ridiculous posts on it. FURTHERMORE,
when a newbie asks a question and it is answered by Bob, REAL HARM could be
done to a system if his advice were taken. So I would say there ARE
EXPECTATIONS. Like, for instance, advice that does not cause your system
to blow up.

I mean, I would hope we all want this to be an enjoyable newsgroup and
there's nothing wrong with expecting things like courtesy, friendliness, and
helpfulness.

Matt's constant badgering of my posts DOES effect my enjoyment of this
group. Does this make me a crybaby? Maybe, but it's MY enjoyment that
matters to me. So I asked him, politely, to either block me (which seems
logical since he seems to find so many things wrong with what I say) or stop
badgering my posts. Both reasonable requests.

Apparently not for Matt.

MOSFET

[Matt Ion]

MOSFET wrote:
> You know, Matt, I just made a simple request. Please, please, please, don't
> nitpick my posts. That's ALL I asked (and I'm saying please). But that is
> way too much for YOUR ego.
>
> Why did I even bother with the friendly approach? You're too arrogant to
> ever consider anyone but THE GREAT MATT!!!
>
> On to my blocked list you go. Pitty.

Well good then, you won't see this.

You're posting in a public forum, and you expect your words not to be
criticized? You think your words are sacred?

No, that is the ultimate in arrogance.

[Matt Ion]

MOSFET wrote:

> Matt's constant badgering of my posts DOES effect my enjoyment of this
> group. Does this make me a crybaby? Maybe, but it's MY enjoyment that
> matters to me. So I asked him, politely, to either block me (which seems
> logical since he seems to find so many things wrong with what I say) or stop
> badgering my posts. Both reasonable requests.
>
> Apparently not for Matt.

I badger all equally. You seem to think I go looking for your posts
specifically to pick them apart. You give yourself far too much credit.

Like I said, r.a.c does not exist for the pleasure of, or revolve around the
life of, Nick Tanner.

Get over yourself.

[Matt Ion]

If it is, I'm starting to agree with him.

MOSFET wrote:
> Who is this? Captain?
>
> MOSFET
>
> > wrote in message
> oups.com...
>
>>What a ****stick you are. Little girly bitch. slap!!!! Such a ****ing
>>victim.
>>
>>
>>MOSFET wrote:
>>
>>>Matt, you are obviously knowledgable when it comes to car audio and I
>
> have
>
>>>learned a lot from you. I don't want to fight with you so PLEASE hear
>
> what
>
>>>I am saying, as a friend.
>>>
>>>I do not mind being corrected when I make a fundamental mistake which
>
> leads
>
>>>to bad advice. In fact, I would want ANYONE to correct me if I ever
>
> gave
>
>>>bad advice to someone (and, of course, I HAVE in the past!!). We are
>
> here
>
>>>to help people, first and foremost.
>>>
>>>But what you do is different. PLEASE try to hear what I am saying. You
>>>correct terms used incorrectly, concepts not "properly" explained.
>
> While to
>
>>>you, this may SEEM like an important service. And I can certainly see
>>>situations where someone might completely bungle an explanantion of
>>>something and clarification might be needed. But with you it is a
>
> constant
>
>>>barage of small corrections that do not fundamentally change the advice
>>>given. You're like some grade school techer-from-hell whose RIGHT THERE
>
> to
>
>>>rub your nose in the smallest missuse of a term or concept.
>>>
>>>Perhaps in your proffesion, this is encouraged. Perhaps it is MANDATORY
>
> in
>
>>>your profession (if you are designing airplane wings, I certainly don't
>
> want
>
>>>ANY mistakes). But this group is for recreation. Car audio is about
>
> fun,
>
>>>Matt. But this constant badgering does not make it fun for me or for
>
> other
>
>>>people who you also badger.
>>>
>>>Again, please try to see the difference between getting something
>>>fundamentally wrong like offering bad advice and just using a term
>>>incorrectly. WE ARE NOT DOING ROCKET SCIENCE HERE.
>>>
>>>I know you don't give a rat's ass if I block you or not, but I am
>>>considering it and I REALLY don't want to because you are SO
>
> KNOWLEDGEABLE
>
>>>and I can learn from you. I am just hoping you will see my point. This
>
> is
>
>>>about fun. We are not building the hydrogen bomb here.
>>>
>>>Thanks,
>>>
>>>Nick
>>
>
>

[Rick Brandt]

"MOSFET" > wrote in message
...
>
> "Rick Brandt" > wrote in message
> . ..
>> There is no such thing as a hi-jacked thread. When a post isn't of
>>interest to you, ignore it. When the thread becomes of no interest to you,
>> move on. Expecting anything else will only aggravate you.
>>
> Not true.
>
> We ALL get aggravated at Bob's posts because we like RAC and take this forum
> seriously and we don't like seeing ridiculous posts on it.

You are perfectly correct in calling a ridiculous post a ridiculous post within
a post of your own (that is called "discussion"). You are not correct when you
suggest that people should not post in threads that you are participating in
simply because it annoys you.

> FURTHERMORE,
> when a newbie asks a question and it is answered by Bob, REAL HARM could be
> done to a system if his advice were taken. So I would say there ARE
> EXPECTATIONS. Like, for instance, advice that does not cause your system
> to blow up.

Then it would be reasonable to point out such errors in a post of your own. It
would even be reasonable to state in that post that all advice given by "so and
so" should be doubted because he has shown a history of not knowing what he's
talking about. Again, that is all part of having a discussion.

> I mean, I would hope we all want this to be an enjoyable newsgroup and
> there's nothing wrong with expecting things like courtesy, friendliness, and
> helpfulness.

Certainly, but pointing out factual errors in a post can be done in a courteous,
friendly manner. That doing do still bothers the person who made those errors
is not the problem of the person pointing them out.

> Matt's constant badgering of my posts DOES effect my enjoyment of this
> group. Does this make me a crybaby? Maybe, but it's MY enjoyment that
> matters to me. So I asked him, politely, to either block me (which seems
> logical since he seems to find so many things wrong with what I say) or stop
> badgering my posts. Both reasonable requests.

I disagree. Your enjoyment of a discussion is your concern, no one else's. As
long as posts are not outwardly rude and/or making personal attacks then they
are reasonable. The mere act of "annoying" someone is not a concern and in many
groups is practically impossible to avoid.

Newsnet is not a place for thin skins. Every group eventually attracts a
handful of people who are VERY knowledgeable about the topic the group focuses
on. They will tend to participate heavily and point out factual errors in other
posts. Many of these people are not very "nice" or tactful but as long as they
stick to the topic and don't get personal then you just need to learn to deal
with it.

[SQNexus]

About 15 years ago, I had a $6000 system installed in an 87' Grand National. A cabinet maker built the enclosure in to the rear of the trunk up against the back seat, and spanned the entire height of the trunk. Each chamber (for 2 BA Pro 12's) was 2+ ft.^3, and ported. The front of the box was completely flush up against an mdf board with 12" cut-outs. A piece of 3" thick nomex foam was compressed between the mdf and the enclosure (also with cut-outs for the woofers). The ports fired up through the rear deck, which was also sealed off from the trunk through the factory speaker locations. The results were amazing to say the least. SPL outside the car was minimal, while output and SQ within the cabin was phenominal. This type of intallation may not be suitable for every application, however, I could not be more satisified with the results in my vehicle.

[MOSFET]

Many of these people are not very "nice" or tactful but as long as they
> stick to the topic and don't get personal then you just need to learn to
deal
> with it.
>
VERY WISE!

Thank you Rick. You are ABSOLUTELY 100% RIGHT!!!! I am probably spending
too much time on RAC and letting stupid **** bother me. This happened with
Captain Howdy and now I'm letting Matt get to me. It's just my personality
(hey, nobody's perfect).

I am not going to block Matt because A) he's very knowlegable and I learn
from his posts and B) we will end up both answering the same questions if I
can't see his posts.

Matt IS a nit-picker and that DOES become annoying (but HE DOES know his
****), but you are right, it's not enough to expect him or anyone else to
change for me. I can just live with that. He won't change, but I made my
point.

Thanks Rick for your wise advice,

Nick

[MOSFET]

> If it is, I'm starting to agree with him.
>

ha ha

Well, I think his new handle is a hoot! ;)

Nick

[Mister.Lull]

I've actually thought about doing that (almost exact) type of enclosure
before!! The problem is that there is no way of knowing the volume of
the cabin (passenger area) of the vehicle, and therefore you would be
taking a gigantic chance in creating what would essentially be a giant
bandpass box. You are the second person to say that they did it and
loved the way it turned out...

Hmmmm...... So much possibility.

Here's my REAL problem: I don't want to **** around with a box once
I've installed it. This means that I'll probably end up doing
something very typical (installation wise) and/or something I've done
in the past that turned out well.

So now what I'm leaning towards is an upward firing box with upward
firing ports. I've done a few boxes where the sub fired upwards and
the ports fired back into the trunk, and those have all turned out
great! What I'm hoping is that by having the ports fire upwards as
well, it will either get better or only be minimally worse. I'm only
pushing a single 10, so the better I can make the box the better that
10 will sound.

~Mister.Lull
SQNexus wrote:
> About 15 years ago, I had a $6000 system installed in an 87' Grand
> National. A cabinet maker built the enclosure in to the rear of the
> trunk up against the back seat, and spanned the entire height of the
> trunk. Each chamber (for 2 BA Pro 12's) was 2+ ft.^3, and ported. The
> front of the box was completely flush up against an mdf board with 12"
> cut-outs. A piece of 3" thick nomex foam was compressed between the mdf
> and the enclosure (also with cut-outs for the woofers). The ports fired
> up through the rear deck, which was also sealed off from the trunk
> through the factory speaker locations. The results were amazing to say
> the least. SPL outside the car was minimal, while output and SQ within
> the cabin was phenominal. This type of intallation may not be suitable
> for every application, however, I could not be more satisified with the
> results in my vehicle.
>
>
>
>
> --
> SQNexus

[[email protected]]

Matt Ion wrote:

> Even the SHAPE of your trunk/hatch/etc. can play a role - those guys back in
> high school (well, when I was in high school anyway) who got nice pounding bass
> from the 6x9s in the rear deck of their Trans Ams were (usually unknowingly)
> taking advantage of the curve of the rear window, which effectively horn-loaded
> the speakers and created a reinforced sound wave; it's a principle used a lot in
> live-sound reinforcement to get a lot of sound out of a small package.

hee-hee. i second that! ever been in a volkswagen beetle with a
couple 6x9's in the back aimed straight up? that round backwindow and
rounded roof make one heck of a means for waves to follow.

vee-dubs... mmm, mmm, mmm

:~)>

[Matt Ion]

wrote:
> Matt Ion wrote:
>
>
>>Even the SHAPE of your trunk/hatch/etc. can play a role - those guys back in
>>high school (well, when I was in high school anyway) who got nice pounding bass
>>from the 6x9s in the rear deck of their Trans Ams were (usually unknowingly)
>>taking advantage of the curve of the rear window, which effectively horn-loaded
>>the speakers and created a reinforced sound wave; it's a principle used a lot in
>>live-sound reinforcement to get a lot of sound out of a small package.
>
>
> hee-hee. i second that! ever been in a volkswagen beetle with a
> couple 6x9's in the back aimed straight up? that round backwindow and
> rounded roof make one heck of a means for waves to follow.
>
> vee-dubs... mmm, mmm, mmm

Oh yeah, and just to clarify: it's NOT necessarily "good" sound when you do this
- just as some frequencies are reinforced, others are cancelled - it's by no
means ACCURATE sound, but it's a useful design when pure SPL is more critical
than accuracy (like in a concert system). It makes for some impressive thump in
the car, but it ain't gonna win you points on the RTA :)

[Stephen McLuckie]

Matt Ion wrote:
> Well, Nick, I hate to nit-pick, but you're talking about a phenomenon
> known as "boundary reinforcement". You'll actually get MORE chance of
> cancellation the closer you move a sub to a wall or corner, because
> the reflected out-of-phase waves are that much stronger... but so are
> the IN-phase waves.
>
> There's a good article on it here:
> http://www.stereophile.com/features/706deep/index1.html

Have you read this article? For example:

"At low frequencies, the phase difference between these sources becomes
negligible because of the long wavelength, so their outputs combine
constructively. One boundary thereby adds 6dB to the sound-pressure
level, two boundaries add 12dB, and three boundaries add 18dB, assuming
that they reflect perfectly and that the loudspeaker's radiation is
omnidirectional (which at low frequencies is usually the case)." And....

"With a subwoofer we can learn the lesson taught by Roy Allison many
years ago: that if we put the bass driver (and port, if the subwoofer is
reflex-loaded) sufficiently close to as many boundaries as possible, the
boundary lift can be exploited to achieve a smooth overall bass
response." And...

"In the case of fig.2a, the sound source is positioned 3.3' (1m) away
from all three boundaries, as a result of which there are a series of
deep notches in the response beginning at 100Hz. If we move the source
much closer to the corner, so that it is just 9.4" (24cm) from one wall,
7.5" (19cm) from the other, and 4.7" (12cm) up from the floor—distances
that are not unrealistic with a downward-firing subwoofer—we get the
much improved result of fig.2b."

In fact, this article disproves your statement quite nicely. Please look
at fig. 6, the in-room response measurement, and tell me where the
cancellations are.

Stephen

[GregS]

In article >, Stephen McLuckie > wrote:
>Matt Ion wrote:
>> Well, Nick, I hate to nit-pick, but you're talking about a phenomenon
>> known as "boundary reinforcement". You'll actually get MORE chance of
>> cancellation the closer you move a sub to a wall or corner, because
>> the reflected out-of-phase waves are that much stronger... but so are
>> the IN-phase waves.
>>
>> There's a good article on it here:
>> http://www.stereophile.com/features/706deep/index1.html
>
>Have you read this article? For example:
>
>"At low frequencies, the phase difference between these sources becomes
>negligible because of the long wavelength, so their outputs combine
>constructively. One boundary thereby adds 6dB to the sound-pressure
>level, two boundaries add 12dB, and three boundaries add 18dB, assuming
>that they reflect perfectly and that the loudspeaker's radiation is
>omnidirectional (which at low frequencies is usually the case)." And....

Sounds like somebody added incorrectly. If you add one boundry, it would be 6 dB.
3 Boundries would be 12 dB.

greg


>"With a subwoofer we can learn the lesson taught by Roy Allison many
>years ago: that if we put the bass driver (and port, if the subwoofer is
>reflex-loaded) sufficiently close to as many boundaries as possible, the
>boundary lift can be exploited to achieve a smooth overall bass
>response." And...
>
>"In the case of fig.2a, the sound source is positioned 3.3' (1m) away
>from all three boundaries, as a result of which there are a series of
>deep notches in the response beginning at 100Hz. If we move the source
>much closer to the corner, so that it is just 9.4" (24cm) from one wall,
>7.5" (19cm) from the other, and 4.7" (12cm) up from the floor—distances
>that are not unrealistic with a downward-firing subwoofer—we get the
>much improved result of fig.2b."
>
>In fact, this article disproves your statement quite nicely. Please look
>at fig. 6, the in-room response measurement, and tell me where the
>cancellations are.
>
>Stephen

[GregS]

In article >, (GregS) wrote:
>In article >, Stephen
> McLuckie > wrote:
>>Matt Ion wrote:
>>> Well, Nick, I hate to nit-pick, but you're talking about a phenomenon
>>> known as "boundary reinforcement". You'll actually get MORE chance of
>>> cancellation the closer you move a sub to a wall or corner, because
>>> the reflected out-of-phase waves are that much stronger... but so are
>>> the IN-phase waves.
>>>
>>> There's a good article on it here:
>>> http://www.stereophile.com/features/706deep/index1.html
>>
>>Have you read this article? For example:
>>
>>"At low frequencies, the phase difference between these sources becomes
>>negligible because of the long wavelength, so their outputs combine
>>constructively. One boundary thereby adds 6dB to the sound-pressure
>>level, two boundaries add 12dB, and three boundaries add 18dB, assuming
>>that they reflect perfectly and that the loudspeaker's radiation is
>>omnidirectional (which at low frequencies is usually the case)." And....
>
>Sounds like somebody added incorrectly. If you add one boundry, it would be 6
> dB.
>3 Boundries would be 12 dB.

It would be really hard or mpossible to cerate more than on boundry, since only
half the output is really being reflected. Getting more than 10 dB in any scenereo
is very difficult, unless its resonance.

greg