[s*****[email protected]]

Hi guys, this is a car audio question, but I've been here for party/
club music questions before and you guys seem to know what you're
doing.

I have a subwoofer amp (1000watts @ 2 ohms) that has a variable LPF
built in. The LPF only goes up to 200Hz.

With certain songs, parts of the beat are pretty quiet, but low parts
of the beat (below 200Hz) rattle my teeth loose. It sounds horrible.

I'm considering selling this amp at a considerable loss to get a
similar amp that has a variable LPF that goes up to 320Hz (1300watts @
2 ohms, if it even matters). Do you guys think that this will fix the
problem? Is it just certain low frequencies that cause extra rumble?

I'm not sure what 200-300Hz sounds like... is it more or less
impossible to get a thump in that freq range, in which case I should
blame my music for being defective and having beats in freq ranges
that are unable to cause thump?

Another thing I plan on doing is replacing my factory 8" door woofers
with something more serious and have a 200-350Hz band pass filter on
them, so they can complement my 15-200Hz thumper in the back. My
worry is that they will not create the follicle-massaging bass to
match the rear amp/sub.

Thanks in advance to any help you guys may have to offer.

I would not consider 200-300 as bass freq's

that is more "mids" or Low mids in my eyes

something like a 4-6 inch speaker should fill that out

I will not comment on why so many car stereos sound like ****
as I appreciate sound way too much to get in a ****ing match with the car
stereo "experts"

take care

[coreybenson]

On Sep 20, 2:57 pm, wrote:
Hi guys, this is a car audio question, but I've been here for party/
club music questions before and you guys seem to know what you're
doing.

I have a subwoofer amp (1000watts @ 2 ohms) that has a variable LPF
built in. The LPF only goes up to 200Hz.

With certain songs, parts of the beat are pretty quiet, but low parts
of the beat (below 200Hz) rattle my teeth loose. It sounds horrible.

I'm considering selling this amp at a considerable loss to get a
similar amp that has a variable LPF that goes up to 320Hz (1300watts @
2 ohms, if it even matters). Do you guys think that this will fix the
problem? Is it just certain low frequencies that cause extra rumble?

I'm not sure what 200-300Hz sounds like... is it more or less
impossible to get a thump in that freq range, in which case I should
blame my music for being defective and having beats in freq ranges
that are unable to cause thump?

Another thing I plan on doing is replacing my factory 8" door woofers
with something more serious and have a 200-350Hz band pass filter on
them, so they can complement my 15-200Hz thumper in the back. My
worry is that they will not create the follicle-massaging bass to
match the rear amp/sub.

Thanks in advance to any help you guys may have to offer.

The issue you're having is that you have WAY too much power available
in the bottom end, and not enough in your low-mid on up section. Turn
the crossover section down to around 80-100 hz (100 hz MAX!!!!!) and
you may find it sounds better (but probably still not correct).

The problem many car audio enthusiasts have is they focus on adding
Bass! Bass! Bass! but never make sure the rest of the system is set up
properly.

You can't just load in a boomer and expect it to sound good, Steve.
You have to balance the system now. Find out where the rest of your
system falls off, and bring the sub in below that.

Good luck!

Corey

[Geoff]

wrote:
Hi guys, this is a car audio question, but I've been here for party/
club music questions before and you guys seem to know what you're
doing.

I have a subwoofer amp (1000watts @ 2 ohms) that has a variable LPF
built in. The LPF only goes up to 200Hz.

Only ?


With certain songs, parts of the beat are pretty quiet, but low parts
of the beat (below 200Hz) rattle my teeth loose. It sounds horrible.

Why do you have a sub then ? Or choos eto listen to those songs ? Do yo
have the level set reasonably ?

I'm considering selling this amp at a considerable loss to get a
similar amp that has a variable LPF that goes up to 320Hz (1300watts @
2 ohms, if it even matters). Do you guys think that this will fix the
problem? Is it just certain low frequencies that cause extra rumble?

No, subwoofer frequncis should never go ovr 120Hz or so. Because above that
frequencies become direction and the bass driver cone is more likely to
generate distortion.

I'm not sure what 200-300Hz sounds like... is it more or less
impossible to get a thump in that freq range,

Yes.

geoff

[tmaki[_2_]]

wrote:
Hi guys, this is a car audio question,

I'm not sure what 200-300Hz sounds like...

A lot like the octave centered around middle C (give or take
a little)

is it more or less
impossible to get a thump in that freq range,

Can't say I've ever heard heard middle C (give or take a
little) thump. Maybe it's different in a car. SEMA and CES
guys would know, though.

[Scott Dorsey]

wrote:

I have a subwoofer amp (1000watts @ 2 ohms) that has a variable LPF
built in. The LPF only goes up to 200Hz.

Okay, this is part of what you need to know. The OTHER part is what the
slope of the filter is. If it's a 12 dB/octave filter (a second order
filter, which is a pretty common design) set to 200 Hz, then the signal
is down only 12 dB at 400 Hz. So you have a whole lot of stuff higher
than the crossover point in there.

With certain songs, parts of the beat are pretty quiet, but low parts
of the beat (below 200Hz) rattle my teeth loose. It sounds horrible.

200 Hz is hardly even bass... it's sort of the point at which midrange
turns to bass.

I'm considering selling this amp at a considerable loss to get a
similar amp that has a variable LPF that goes up to 320Hz (1300watts @
2 ohms, if it even matters). Do you guys think that this will fix the
problem? Is it just certain low frequencies that cause extra rumble?

Get a cd with warble tones on third-octave centers, and play it back
with the analogue Radio Shack sound level meter at the driver's position.
Get a rough idea of what the system response is.

If you have no high-pass network on the main speakers, you're going to
have all the low end going to both the mains and the sub, and the mix
between them will be strange. How strange? I dunno, but you can measure
it and see.

I'm not sure what 200-300Hz sounds like... is it more or less
impossible to get a thump in that freq range, in which case I should
blame my music for being defective and having beats in freq ranges
that are unable to cause thump?

I wouldn't call 200 Hz a thump. It's only an octave below middle A on
the piano.

Another thing I plan on doing is replacing my factory 8" door woofers
with something more serious and have a 200-350Hz band pass filter on
them, so they can complement my 15-200Hz thumper in the back. My
worry is that they will not create the follicle-massaging bass to
match the rear amp/sub.

It doesn't matter, you're pumping low end into a sealed box, it's going
to go everywhere.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[s*****[email protected]]

Ahhh. Thank you everyone for clearing that up. I listened to a 300Hz
test tone. 300Hz is alot higher than I had imagined.

The issue I was experiencing was that certain bass beats were very
loud while certain others were relatively quiet. Now that I know what
200-300hz sounds like, I don't think any of those beats were ever
close to 200Hz.

I'm still not sure what's causing the beats to sound uneven. I'm
using an average class-D amp (Alpine PDX-1.1000), that I expect to
have at least reasonably linear output in its narrow output range
(0-200Hz)...

Now that I know that I know how useless a 300Hz LPF would be, I'm less
inclined to switch to a different amp. But from this, do you guys
have any suspicion that I need a different or better amp?

I know I haven't given alot of details, but I'll be happy to fill in
any blanks. Otherwise, I am also comfortable operating on "hunches"
you may have, because your hunches will probably have more technical
reasoning behind it than my noobish reasoned thinking. So all ideas
are welcome, thanks.

[Scott Dorsey]

wrote:

The issue I was experiencing was that certain bass beats were very
loud while certain others were relatively quiet. Now that I know what
200-300hz sounds like, I don't think any of those beats were ever
close to 200Hz.

Yes, this is what happens when you have a very narrow bandpass system,
either because you have a speaker cabinet designed as a thump box or
because you have standing wave problems inside the car.

I'm still not sure what's causing the beats to sound uneven. I'm
using an average class-D amp (Alpine PDX-1.1000), that I expect to
have at least reasonably linear output in its narrow output range
(0-200Hz)...

It's not the amp, it's the speakers and the car. Sweep a tone back and
forth and find where the center frequency of the hump is, and the approximate
width of the hump.

Now that I know that I know how useless a 300Hz LPF would be, I'm less
inclined to switch to a different amp. But from this, do you guys
have any suspicion that I need a different or better amp?

No, you need a different speaker system or a different speaker setup.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Deputy Dumbya Dawg[_9_]]

Steve:

From what you have told us I am pretty sure the problem with
your sound is there is a nut loose behind the knobs.


peace
dawg.


wrote in message
oups.com...
Ahhh. Thank you everyone for clearing that up. I listened
to a 300Hz
test tone. 300Hz is alot higher than I had imagined.

The issue I was experiencing was that certain bass beats
were very
loud while certain others were relatively quiet. Now that I
know what
200-300hz sounds like, I don't think any of those beats were
ever
close to 200Hz.

I'm still not sure what's causing the beats to sound uneven.
I'm
using an average class-D amp (Alpine PDX-1.1000), that I
expect to
have at least reasonably linear output in its narrow output
range
(0-200Hz)...

Now that I know that I know how useless a 300Hz LPF would
be, I'm less
inclined to switch to a different amp. But from this, do
you guys
have any suspicion that I need a different or better amp?

I know I haven't given alot of details, but I'll be happy to
fill in
any blanks. Otherwise, I am also comfortable operating on
"hunches"
you may have, because your hunches will probably have more
technical
reasoning behind it than my noobish reasoned thinking. So
all ideas
are welcome, thanks.

steve
you have a resonant freq , what that means is the space your speaker is
mounted in and the speaker you have choosen combine at a certian freq and it
reinforces itsself
you need to change the speaker or the cavity in which it exists
George

[Geoff]

wrote:
steve
you have a resonant freq , what that means is the space your speaker
is mounted in and the speaker you have choosen combine at a certian
freq and it reinforces itsself
you need to change the speaker or the cavity in which it exists
George

Or tighten up the loose thing.

geoff