Welcome to the IHoP

[Penguin4x4 1,761]

http://www.cnngo.com/bangkok/life/hitler-chic-trend-138530?hpt=hp_bn8

I know its Thailand and all but WTF?

[Aaron Clinton 2,372]

http://www.cnngo.com...8530?hpt=hp_bn8

I know its Thailand and all but WTF?

[ssh 924]

Closed box,

It also becomes necessary to introduce large amounts of absorbent material to damp dimensional resonances or standing waves, and to reinforce or brace the panels to reduce vibration. Fortunately, filling the enclosure with glass fibre or similar light absorbent material has the effect of partially changing the air operation from adiabatic to isothermal, which reduces the velocity of sound and may increase the effective volume of the box by as much as 40%.

-Audio Engineer's Reference Book

If I'm reading that correctly, the absorbent material would help attentuate the panel resonances and standing waves, and it allows the inside temperature to remain nearly constant.

So the reduction of standing waves causes an increase in the propagation of energy, which results in a dQ without the concomitant dT?

while the box without poly fill would experience changes in T without changes in Q, caused by dP

Also, the sound is slowed because the medium is more compressible than air alone and also more dense?

I'm not sure what any of your terms such as dQ and dT are referring to.

For this scenario:

The polyfill changes the interior "air operation" in the box. Allows for the temp. to stay consistent, instead of rising. Lower temp = lower speed of sound (velocity).

I don't know how the temp. change effects how the enclosure acts, sorry.

Polyfill also diffuses standing waves (resonance), which could reduce sound coloration, but I don't believe that's the reason why it makes the enclosure's volume more effective.

I could be wrong here, but I think it's just another issue.

I know in HT, multiple subwoofers can be used in a way to create interference that cancels out standing waves, thus improving the FR.

dQ= change in heat

dT= change in temp

Im just trying to understand this from the things ive learned in my physical biochem class but idk enough about waves to really grasp whats goin on

Is it the temp change that has the most effect to cause the slowed wave or the change in medium through which the wave propagates?

I see the ds as deltas, meaning change, but didn't know Q stood for heat, and so on.

Not sure which. I do know sound travels faster in liquids and solids then air.

We'll have to do some more reading.

[ssh 924]

Weird Shit.

[trod2902 26]

Closed box,

It also becomes necessary to introduce large amounts of absorbent material to damp dimensional resonances or standing waves, and to reinforce or brace the panels to reduce vibration. Fortunately, filling the enclosure with glass fibre or similar light absorbent material has the effect of partially changing the air operation from adiabatic to isothermal, which reduces the velocity of sound and may increase the effective volume of the box by as much as 40%.

-Audio Engineer's Reference Book

If I'm reading that correctly, the absorbent material would help attentuate the panel resonances and standing waves, and it allows the inside temperature to remain nearly constant.

So the reduction of standing waves causes an increase in the propagation of energy, which results in a dQ without the concomitant dT?

while the box without poly fill would experience changes in T without changes in Q, caused by dP

Also, the sound is slowed because the medium is more compressible than air alone and also more dense?

I'm not sure what any of your terms such as dQ and dT are referring to.

For this scenario:

The polyfill changes the interior "air operation" in the box. Allows for the temp. to stay consistent, instead of rising. Lower temp = lower speed of sound (velocity).

I don't know how the temp. change effects how the enclosure acts, sorry.

Polyfill also diffuses standing waves (resonance), which could reduce sound coloration, but I don't believe that's the reason why it makes the enclosure's volume more effective.

I could be wrong here, but I think it's just another issue.

I know in HT, multiple subwoofers can be used in a way to create interference that cancels out standing waves, thus improving the FR.

dQ= change in heat

dT= change in temp

Im just trying to understand this from the things ive learned in my physical biochem class but idk enough about waves to really grasp whats goin on

Is it the temp change that has the most effect to cause the slowed wave or the change in medium through which the wave propagates?

I see the ds as deltas, meaning change, but didn't know Q stood for heat, and so on.

Not sure which. I do know sound travels faster in liquids and solids then air.

We'll have to do some more reading.

Haha yep, i have some studying to do now though so it will have to wait

I have a test tm and really dont give a shit rn, not good...

[edouble101 314]

Weird Shit.

How are you liking your new front stage setup Stefan?

[ssh 924]

I am!

I had some noise issues, but left it on the back burner while I did everything else. I thought the ms8 was causing it, but it turned out the gain was set a little high on the amp. Weird because if I turned the volume on the ms8 and hu to 0, the noise was still there. Only way it went away was if I muted the signal with the ms8.

Finally I unplugged the inputs on the amp, and noise was still present. It must have been boosting the crap out of the floor noise level? I figured turning the volume up higher on the ms8 or headunit would do the same, nope.

Anyway, I got that fixed today. I've had the 3-way in for a few weeks, then pulled the pillars out for more work. Last two weeks has just been doors and kicks.

Either setup sounds good, but the tweets on the pillar definitely helps with the stage height. Depending on where I cross the mids, I can raise and lower the stage height by quite a bit.

I've been using a shallow slope between the mid and tweeter, seems to blend everything together, more natural. I thought it might cause some issues like comb filtering?, but I don't seem to notice.

Next month I'm probably going to try some 4" tb bamboos in replacement of the L4s, and see if I notice any difference.

[Julian 641]

I have some gnarly alt whine.. but it's not alt whine.. even when the car is off i get this terrible sound.. tried grounding my RCA's and it ended up turning out 8901020938120983102983 times worse.

Hmm maybe to much power?

[ssh 924]

Is this with the sundown amp? I've heard people having noise issues with some of their amps, may have been the older ones though.

Does the sound get louder when you turn up the volume?

You could try plugging an ipod directly into the amp, if it goes away then it's probably something with the headunit. If it stays, it might be the amp or grounding.

[Julian 641]

Is this with the sundown amp? I've heard people having noise issues with some of their amps, may have been the older ones though.

Does the sound get louder when you turn up the volume?

You could try plugging an ipod directly into the amp, if it goes away then it's probably something with the headunit. If it stays, it might be the amp or grounding.

Yeah it is the 125.2.. I'm running her at 2 ohms for 200w per channel

Imm go try that... I have everything set so at around hu lvl 30 it's the loudest

[lithium 358]

I am!

I had some noise issues, but left it on the back burner while I did everything else. I thought the ms8 was causing it, but it turned out the gain was set a little high on the amp. Weird because if I turned the volume on the ms8 and hu to 0, the noise was still there. Only way it went away was if I muted the signal with the ms8.

Finally I unplugged the inputs on the amp, and noise was still present. It must have been boosting the crap out of the floor noise level? I figured turning the volume up higher on the ms8 or headunit would do the same, nope.

Anyway, I got that fixed today. I've had the 3-way in for a few weeks, then pulled the pillars out for more work. Last two weeks has just been doors and kicks.

Either setup sounds good, but the tweets on the pillar definitely helps with the stage height. Depending on where I cross the mids, I can raise and lower the stage height by quite a bit.

I've been using a shallow slope between the mid and tweeter, seems to blend everything together, more natural. I thought it might cause some issues like comb filtering?, but I don't seem to notice.

Next month I'm probably going to try some 4" tb bamboos in replacement of the L4s, and see if I notice any difference.

i've noticed this as well with shallow slopes between mid and tweet. actually running my w4's without a LPF with the tweets picking up around 5k sounds good.

my transition between mid and mb is limited to a single slope, however.

[ssh 924]

I have a steep slope between the sub and ex-anarchies, at 80hz, and still I get them extending too far at times. When I raised the subwoofer level (not bass level) on the ms8, it still increased the amplitude going to the ex-anarchies. So I did a little eq, raised the gain on the sub amp, and lowered the subwoofer level on the ms8. Seems to work better now.

Then I have a 18db slope between the ex-anarchies and L4.

Once I get the tweets back in I'll have to try some more combos.

[edouble101 314]

I am!

I had some noise issues, but left it on the back burner while I did everything else. I thought the ms8 was causing it, but it turned out the gain was set a little high on the amp. Weird because if I turned the volume on the ms8 and hu to 0, the noise was still there. Only way it went away was if I muted the signal with the ms8.

Finally I unplugged the inputs on the amp, and noise was still present. It must have been boosting the crap out of the floor noise level? I figured turning the volume up higher on the ms8 or headunit would do the same, nope.

Anyway, I got that fixed today. I've had the 3-way in for a few weeks, then pulled the pillars out for more work. Last two weeks has just been doors and kicks.

Either setup sounds good, but the tweets on the pillar definitely helps with the stage height. Depending on where I cross the mids, I can raise and lower the stage height by quite a bit.

I've been using a shallow slope between the mid and tweeter, seems to blend everything together, more natural. I thought it might cause some issues like comb filtering?, but I don't seem to notice.

Next month I'm probably going to try some 4" tb bamboos in replacement of the L4s, and see if I notice any difference.

No lliking the L4's? Have you considerend FR89EX's?

[ssh 924]

I like them, but I want to compare them against some $30 drivers, and see if their mighty price tag is really worth it.

[lithium 358]

I like them, but I want to compare them against some $30 drivers, and see if their mighty price tag is really worth it.

too bad the w4 titanium are out of stock, bamboos probably aren't too bad though. i doubt the L4s will be better then either...

[lithium 358]

I am!

I had some noise issues, but left it on the back burner while I did everything else. I thought the ms8 was causing it, but it turned out the gain was set a little high on the amp. Weird because if I turned the volume on the ms8 and hu to 0, the noise was still there. Only way it went away was if I muted the signal with the ms8.

Finally I unplugged the inputs on the amp, and noise was still present. It must have been boosting the crap out of the floor noise level? I figured turning the volume up higher on the ms8 or headunit would do the same, nope.

Anyway, I got that fixed today. I've had the 3-way in for a few weeks, then pulled the pillars out for more work. Last two weeks has just been doors and kicks.

Either setup sounds good, but the tweets on the pillar definitely helps with the stage height. Depending on where I cross the mids, I can raise and lower the stage height by quite a bit.

I've been using a shallow slope between the mid and tweeter, seems to blend everything together, more natural. I thought it might cause some issues like comb filtering?, but I don't seem to notice.

Next month I'm probably going to try some 4" tb bamboos in replacement of the L4s, and see if I notice any difference.

No lliking the L4's? Have you considerend FR89EX's?

the fr89ex's are pretty good. favorite 3" i heard so far.

i have a set of hivi 3's that i will be using as computer speakers as soon as i build the boxes. cant wait to test them out.

Edited March 2, 2012 by lithium

[nem 2,019]

Wheat thins!

[Tirefryr 1,742]

Will kill me.

[ssh 924]

ewk.

[nem 2,019]

Er-rick

[Penguin4x4 1,761]

Rooting around the fridge I found leftover taco meat, homemade chili, Velveeta cheese dip, and some chopped BBQ brisket. So I did the only natural thing and made leftover nacho surprise.

Edited March 2, 2012 by Penguin4x4

[Penguin4x4 1,761]

And I cleared off an entire shelf in the fridge!

[ssh 924]

Sounds good.

[///M5 2,833]

A bunch of french pricks at my gate

Sean I have some questions about stuffing a sealed enclosure, over at SMD someone inquired about stuffing, I went on to explain this.

its maybe the easiest way to "increase" the volume. it actually alters the rate that the air inside the box changes temperature. lets use a sealed box as an example-

when your cone is at rest, the pressure inside the box is considered ambient. when the cone goes in, the pressure inside the box goes up. when you pressurize air, the temperature goes up. when the cone goes out, the pressure inside goes down, and temperature goes down. we're not talking about a couple of degrees, its generally a very small temperature change.

but once you add polyfill or fiberglass insulation, or something of that sort, it absorbs and radiates the heat at a different rate than just air. its a slower rate very similar to having more air, just like having a bigger box. it only works because there is so much surface area in proportion to mass, and finer materials tend to work better.

But the problem is it reaches diminishing returns quickly and will only work up to a certain point. Last time I looked into stuffing it was about 1 lb/ft^3

Some douchecanoe said this

Wow.....

Ok yeah, the poly fill would have an extremely small effect on tempterture differential but is NOT what's causing the desired effect.

What's causing the desired effect is a decrease in standing waves. The back waves from the cone are dispersed and slowed down, causing the driver to act as if it's in a slightly bigger box while maintaining the compression needed for cone control at high excursion.

and I responded

Not to call you out, but to get standing waves especially at such low frequencies wouldn't the volume of the car have to be huge? You really don't see standing waves in a car... more in home audio..

From what I've read stuffing is based solely on the principle of acoustical energy being turned into thermal energy, albeit very small change.

and he then replied

yes, you can still get standing waves inside a sealed box at low frequencies. imagine a bathtub full of water and the waves on the water are hitting the edges, coming back, hitting the opposite edge, and coming back, etc. Should give you a good visual of what's going on inside a sealed box.

Problem is obvious. Why the fuck would you spend any time in that shithole?

[///M5 2,833]

It still mentions the use of fiber for damping the standing waves, but I believe that's mainly just for reducing enclosure resonance & sound coloration.

Slow down. Realize that book isn't about subwoofers. Standing waves happen at ALL frequencies. The most audible ones are of course where your ear is most sensitive...and no, not sub freq's