Vdub sql

[Bassballer150 10+ year member]

3.7cf@32hz

 

[jockhater2 10+ year member]

3.7cf@32hz

Are you going to keep the red port with black carpet?

And a ported enclosure isn't exactly SQL. A passive radiator set up would have been SQL.

That is an SPL set up.

 

[Bassballer150 10+ year member]

So ported makes it an spl?

 

[Bassballer150 10+ year member]

Box will be black/white

 

[jockhater2 10+ year member]

@ciaonzo ;
Ported is definitely not SQL in any sense.

 

[mlstrass 5,000+ posts]

[quote name='jockhater2']@ciaonzo ;
Ported is definitely not SQL in any sense.[/QUOTE]

All your opinion which it seems he didn't ask for...

 

[jockhater2 10+ year member]

All your opinion which it seems he didn't ask for...

Its not opinion though. Ported box are designed to hit a small range of frequencies very loud. While you lose the ability to play other frequencies that are away from port tuning very well.

Its not an opinion. Its fact. Check out a frequency response curve on a ported enclosure and you will see. His front stage is definitely going to sound great.

And the bass will too. But he won't be able to play all the frequencies from 20-80 hertz the same. There will be a lot of humps and dips.

And that is fine. Its just not "SQL"

 

[ciaonzo 5,000+ posts]

Well, SQL is a misnomer like that other popular one, substage. I hate both of those 'words' and I refuse to acknowledge them, but I'm lovin' that little DD full range amplifier. I'd like to try one of those at some point.

It's important to think of vented enclosures and PR enclosures as practically synonymous, but certainly interchangeable. You can achieve identical frequency response plots with both in the pass band, the only exception is the 28dB rolloff with PR compared to 24dB with vented. Other than that, they do exactly the same thing. Each has it's own advantages. PR is a little touchier and a horrid transient response is guaranteed if done wrong. Vented is much more forgiving if tuning is off target.

To say that you can't have a sound quality setup with a vent is incorrect, you can. You just need to preserve certain things like frequency extension and low group delay within the important thresholds. Another point of interest is the response from 20-80hz. Even if I have an absolutely perfect frequency response profile from 5 to 500hz as measured in an anechoic space, the second I introduce it into the vehicle's interior, that is out the window. The vehicle's acoustics will dominate no matter what. This is why it is ABSOLUTELY essential to have equalization capabilities.

I'm at work so gotta go for now.

 

[jockhater2 10+ year member]

Well, SQL is a misnomer like that other popular one, substage. I hate both of those 'words' and I refuse to acknowledge them, but I'm lovin' that little DD full range amplifier. I'd like to try one of those at some point.
It's important to think of vented enclosures and PR enclosures as practically synonymous, but certainly interchangeable. You can achieve identical frequency response plots with both in the pass band, the only exception is the 28dB rolloff with PR compared to 24dB with vented. Other than that, they do exactly the same thing. Each has it's own advantages. PR is a little touchier and a horrid transient response is guaranteed if done wrong. Vented is much more forgiving if tuning is off target.

To say that you can't have a sound quality setup with a vent is incorrect, you can. You just need to preserve certain things like frequency extension and low group delay within the important thresholds. Another point of interest is the response from 20-80hz. Even if I have an absolutely perfect frequency response profile from 5 to 500hz as measured in an anechoic space, the second I introduce it into the vehicle's interior, that is out the window. The vehicle's acoustics will dominate no matter what. This is why it is ABSOLUTELY essential to have equalization capabilities.

I'm at work so gotta go for now.

Bam. I just got schooled. But there is nothing wrong with that //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif I am learning.

So you can achieve a a good transient response from a vented elcosure? How so?

Why do you hate the term "sub stage"?

How do you feel about the terms "SPL" and "SQ"?

 

[ciaonzo 5,000+ posts]

Bam. I just got schooled. But there is nothing wrong with that //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif I am learning.
So you can achieve a a good transient response from a vented elcosure? How so?

Why do you hate the term "sub stage"?

How do you feel about the terms "SPL" and "SQ"?

As I said, the key is group delay. Someday you will sit in my vehicle and have a reference for what a low group delay vented alignment sounds like. Hopefully this year, lol. Basically sounds like sealed with more balls. Here's some copypasta on group delay.

"Group delay is a measure of how sharply the phase of a signal

changes from one frequency to the next. If the group delay

remains low at all frequencies, the bass will be taut and well

controlled. But if the group delay at some frequencies is much

higher than 20 ms, the woofer is likely to exhibit poor transient

response, thickening sounds at those frequences while robbing the

woofer of clarity and impact."

Delay audibility mechanisms (this says nothing about the thresholds, just the mechanisms):

Delay skews perception of second harmonic distortion,

but amazingly, in such a way that the skew is level dependent. This

is an artifact of gross delay distortion that can easily be shown

from a steep filter. It may explain the harshness many people

talked about with old steep anti-aliasing filters.

Another point is that the non linearities in the ear itself can lead to

changes in the transfer from outer to inner ear that are phase, not

power, dependent. Some monaural phase effects can be explained

by the concept of the inner spectrum, the spectrum available to

the inner ear. This is different than the spectrum at the outer ear

due to non linearities in the middle ear and inner ear. Identical

external power spectra can lead to substantially different inner

spectra for different phase angles.

A third aspect is that reversals of phase for some

harmonics can create "beats" that change masking thresholds quite

dramatically, often up to 30 dB. There are some major implications

here for keeping tweeters and woofers in phase, keeping xover phase

on a symmetrical basis and NOT just judging success on a power

basis. Finally, I found a reference describing the threshold for

localization movement based upon group delay. I have applied it as a

group delay criteria for maintaining sharp images in multi way

speaker systems.

There's also a good paper that looked at the impact of group delay across

the spectrum, starting with 30 Hz fundamentals. The group delay

across the board impacted the ability to pick out mid-range detail.

 

[LosIsATool 5,000+ posts]

Bam. I just got schooled. But there is nothing wrong with that //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif I am learning.
So you can achieve a a good transient response from a vented elcosure? How so?

Why do you hate the term "sub stage"?

How do you feel about the terms "SPL" and "SQ"?

The top SQ car in the worls runs a 4th order. It only plays 20-40hz... Thats it.

 

[ciaonzo 5,000+ posts]

The top SQ car in the worls runs a 4th order. It only plays 20-40hz... Thats it.

I'd be interested to know how old that judge was, lol.
Infinite baffle, dipole, transmission line, sealed, EBS tunings... these remind me of reference level playback designs. Fourth order, not so much. Could happen, though. Would need some serious DSP involved.

What vehicle, BTW?

 

[LosIsATool 5,000+ posts]

I'd be interested to know how old that judge was, lol.
Infinite baffle, dipole, transmission line, sealed, EBS tunings... these remind me of reference level playback designs. Fourth order, not so much. Could happen, though. Would need some serious DSP involved.

What vehicle, BTW?

Hybrids Infinity

 

[ciaonzo 5,000+ posts]

Hybrids Infinity

Link? Name? MECA? Throw me a bone, here.

 

[LosIsATool 5,000+ posts]

Link? Name? MECA? Throw me a bone, here.

Scott Bulwalda- Hybrid audios owner