Intriguing thread, but I think there's a lot of misunderstanding unfortunately.
I've been seeing how sealed enclosures is refered to as a SQ enclosure and know that it is very misleading. ...If you think about it, sealed has many limitations that would not justify it as SQ.
A sealed box is a permanent suspension counter on a woofer, which basically strongly restricts cone movement. With the highly restricted cone movement, the woofer losses the ability to fully reproduce all the low frequencies well...
....The woofer in a vented box is less restriced by air pressure and the cone can more accuratly, to vibrate the -boom- sound, that your supposed to hear as Warren G produced. I believe in opinions of ones self to be valid, thats why I dis-agree with SQ refering to sealed universaly. If anything, vented is the true SQ enclosure.
Unfortunately, it sounds like you have some misconceptions about ported and sealed boxes, and the physics behind each.
Understandable misconceptions, mind you, as there is what seems to be a "hole in the box"...
But you must understand that that "hole in the box" [if the subwoofer is operated in a frequency range that was intended to be used with that subwoofer/enclosure combination] is actually
increasing the forces inside the box that the subwoofer must contend with.
The sealed box is actually the easier, lower-pressure environment for your subwoofer.
There are also some fundamental reasons that the ported box cannot be sonically superior to a sealed box.
A sealed box is a simple, single-sound-source. Sound eminates from the subwoofer itself. The entire rear wave (which is inherently 180 degrees out of phase) is simply contained and dissipated. The sound coming off the speaker is pure, and at risk of oversimplification (without considering factors like how the enclosure design itself can color the shape of the response), the sound is both frequency respose-correct, and phase-correct... within reason (more so than other enclosure types).
A ported box involves the use of a port in the enclosure, to (in effect) delay the rear wave as it exits the enclosure... in fact, so it doesn't behave just like "a hole in the box". By the time the wave exits the enclosure, it is more in-phase than it is out-of-phase, so rather than cancelling out the sound energy coming directly off the front of the subwoofer, it combines constructively with it, boosting the amplitude of the sound rather than cancelling it.
However, bear in mind that the sound is never fully in-phase.. in fact, the closest it comes is rougly 90 degrees out of phase. So to begin with, there's a blurring of the two waves, cone-sound vs. port-sound, which have a 90 degree phase difference between them.
This much is inherent.
Then, consider that the two waves are most in-phase only "at" the "tuning frequency"... as you travel away from that tuning frequency in either direction, the phase difference increases, making the situation worse from a phase perspective.
Consider also that at the tuning frequency, the majority of the sound is eminating from the port.
Because of the previous statement about phase, as you travel away from the tuning frequency in either direction, this shifts, as progressively less output comes from the port, and more output comes from the cone.
Also, because of the phase relationship, at the tuning frequency, the cone is battling the in-out air motion of the port... they are the most "in phase" that they can be... so as the cone is trying to move inwards towards the enclosure, there is also momentum from the air rushing in the port, which is also working to pressurize the interior of the enclosure. The subwoofer must battle more than the ambient air pressure that it would face in a sealed enclosure (one reason they generally need to be larger than sealed counterparts).
The end result being, if you send the subwoofer a signal, that signal may be:
1) Essentially purely delayed a full 1/4 wave (playing a signal at the resonant frequency, at which the cone isn't contributing much).
2) Essentially blurred, at the point where the cone and port are both contributing to the sound in equal parts, as the cone will eminate a tone at the correct phase point, while the inherent delay and phase difference of the port makes it output that signal more than a quarter wave later...
3) Essentially cancelling out... particularly at frequencies well below tuning, when the port and cone are out of phase, the port truly does behave as a "hole in the box", the subwoofer becomes
completely unloaded, it does not see any air resistance (quite a change, compared to playing at the tuning frequency), and the output level is appropriately greatly reduced, particularly with respect to the tremendous (dangerous even) levels of excursion the cone is reaching in that environment.
First off I can respect the fact that some people don't like boom, wave, extended bass (what-ever else its called). Another fact is, its supposed to sound like that. I'm going of hip-hop for this. Example; Warren G's track, "This DJ". It's is a boom-bass heavy track. If you play that in a sealed box, you hear the faint struggling boom and heavy kick drum. Play it, in a vented box and the boom comes out in full force.
So SQ should not be used to describe enclosure types, only woofer brands themselves. [/color]
Another misunderstanding.
First off, you are making claims about enclosures without respect to their size, or their tuning.
You are also making claims about enclosures without respect to the design properties of a subwoofer...
Stronger subwoofers will tend to perform well in ported enclosures.. largely because they can contend with the forces of the port inside the enclosures... while weaker subwoofers would struggle fighting them, distorting.
However, stronger subwoofers raise the resonant frequency, and generally (by nature of motor design trade offs) have lower excursion capability. So, they generally won't play as low for both these reasons, and in fact can have a peaky response if the enclosure is not carefully constructed... particularly "in-car" response.
Sealed subwoofers tend to have less-forceful motors, with low resonant frequencies, and by design can yield long excursions, making them actually better candidates for high output in sealed environments.
Sealed enclosures actually roll off more slowly, and sooner...
When coupled with the acoustical gain of your car's interior (read up on "cabin gain" and "transfer function"), what you end up with is a truly flat, smooth, "in car response". //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif
That's important to audiophiles who care about sound quality.
If you design a ported enclosure that has a flat anechoic response (as you see on the screen, in a design program like WinISD), your car's cabin gain will boost the low end to the degree of 12dB/octave beginning at some frequency fairly high up (corresponding to your vehicle's personal resonance).
You'll end up with a bottom-heavy, boom car.
That's not SQ. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif
If you use a subwoofer meant for ported boxes, and you hear it in a ported box, then try it in a sealed box, it of course will sound superior in a ported box. It won't have any depth, or possibly even impact, in the sealed enclosure.
That's a design property of the driver itself... and it doesn't have anything to do with whether it's a SQ woofer or not... //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif
And, if you use a subwoofer that is ideal in a sealed enclosure in a ported enclosure, it will fall flat on it's face, it won't sound good, it won't be able to contend with the extra forces inside the enclosure. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif
Consider also:
Hoffman's Iron Law states that the following three items are mutually exclusive in a subwoofer/enclosure alignment:
1) low frequency extension
2) high efficiency
3) small enclosure size
In a sealed box, you manipulate these factors simply by changing the enclosure size.
And with it, you also change the damping properties of the enclosure, which affect the sound
and impact.
In a sealed box, as you make it larger, you increase low frequency extension, damping, and efficiency (as you sacrifice off "small enclosure size".
And conversely, as you make it smaller, you decrease low frequency extension, damping, and efficiency (as you increase "small enclosure size").
A subwoofer in a small sealed enclosure is a completely different animal than a subwoofer in a large sealed enclosure.
Your generalization doesn't make clear what you are comparing to.
In a ported box, you can manipulate each of these factors individually, as you can change not only enclosure size, but tuning...
In a ported box, as you tune it higher, you gain efficiency around the tuning frequency, but you lose low frequency extension as you do.
As you tune it lower, you lose efficiency, but gain low frequency extension...
You can gain efficiency back by making the enclosure larger, but you are sacrificing off "small enclosure size" to do it.
etc.
A small ported box tuned around 30hz, compared to a large ported box tuned very low, compared to a large ported box tuned very high are very completely different beasts.
Your generallization doesn't make clear what you are comparing to.
Unfortunately, you are misunderstanding the factors involved in what you are hearing. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif
