Why are most speakers rear ported instead of front ported ?

Everything does something at the cost of something else and it's a continuum from infinite-baffle to sealed to aperiodic to vented to "TL" to "horn". I think everyone should hear everything at least once :) My own preferences would agree with the previous post about closed-box bass presentation. Labels/semantics and language get in the way in discussing "TL" speakers as the original meaning to (say) EE's is quite strict vs. common hobbyist usage. "TL's" can be magical IMO, but they are almost never small. If you are interested in further info, there are worse places to start than Martin King's pages: http://www.quarter-wave.com/
 
So, if one puts their mind to it, purely as an idea, what is the best in terms of porting as an idea in terms of sound?
(let's leave out powering it)
What's the best port idea for a speaker theoretically?
@Decadent_Spectre @Vineethkumar01 @grindstone
@kpad: I didn't really understand the question.
But for now, I am guessing that you are asking about the best port design we can have in a bass reflex box.
Theoretical ideal is if the port does its job, i.e. reproduce the narrow range of frequencies it is supposed to without causing any midrange leakage and chuffing/port noises when driven hard. Also it would be nice to have a bass reflex alignment which causes less group delay/comparable to that of sealed.
But, in the practical world, as in every other engineering aspect, a port is a trade off. One can only do things to alleviate the damages it cause while trying to get every bit of performance possible. If you want to know the best port construction methods available for diyers, this is worth a read: https://www.somasonus.net/box-construction-methods
Along with speaker box construction methods, many port designs are explored here and conclusions are arrived at based on measurements.
This was what Technics did in the past (a simple method that seemed to produce good results): https://www.audiosciencereview.com/...-suppression-inspiration-from-technics.13202/
Kef also has alternate port design techniques.
Off course, in speaker design, the impact of any component part should be viewed from the larger system's point of view. But, in isolation, just from the port design point of view, the above links are what I know currently.
 
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Also, theoretically, a port also needs to be damped, mass loaded or braced to suppress port resonances; that is something most ignore. These resonances show up in measurements although, like with most anal methods, how much of this is audible is a different matter. :p
 
KEF in their Q Series have passive bass radiators. Are these any better or worse than the ports ?
 
KEF in their Q Series have passive bass radiators. Are these any better or worse than the ports ?
This explains it best:

 
So, if one puts their mind to it, purely as an idea, what is the best in terms of porting as an idea in terms of sound?
(let's leave out powering it)
What's the best port idea for a speaker theoretically?
@Decadent_Spectre @Vineethkumar01 @grindstone

Lots of people argue that ported systems as a class are a poor choice (and I was once among them).

For non-commercial/diy'ers (and particularly for home use), I think the way to look at it is to try to make sure you don't shoot yourself in the foot if you employ a "port" of some sort. Specific examples are always much easier to talk/post about. Absent that, it takes large amounts of time to think and write and, well, there are already almost 100 years of writings about those things by people much more qualified than me.

The members here are abreast of current thinking/advances of the larger manufacturers who truly are pursuing advancement. There are already some good links on the forum. If you have deeper interest in the topic, I would say to just keep reading and reading. Truly not trying to be evasive (or vacuous), but "best" always comes down to "best for what?", etc. Even enclosures without openings in them have resonances. To Keith's point, how deeply-concerned might we be about a given specific thing? Depends on the goals/application.

What I would say is to focus on what you're really trying to do--shape a resonant bandwidth to achieve some set of goals. Stick to that first. In the process, just pay attention to what might kill you :) Unless they're infinite/imaginary, there will be resonances--figure out where they are and look at how hard they get excited. Look at what you can do to absorb or damp them if they are detrimental to your goals. Figure-out what's practical for you to be able to predict and to observe them. Again to Keith's point, ask yourself how much that matters and what efforts are justified in addressing them. Look at the location(s) of the openings in your design vs. the first few harmonics of standing waves. Look at their size in terms of radiation resistance--and their spacing(s) in terms of coupling. Consider the self-resonance of the port vs. the driver's passband. Consider their placement relative to boundaries and drivers and wavelengths.

At the barest level, people put openings in enclosures chiefly to extend LF and some other subset of goals. This lets rear radiation out--and this has accompanying costs. Not trying to be cagey, it's just that people have very different goals for their loudspeaker applications. A person can get into at least one argument on any single thing in audio. If you aren't sure if something might matter, post for sanity-check-input and prepare for 11 strong opinions from any 10 people. I say take advantage of the slinkier-flow port tubes if they work for you and do the other basics as above.

I think people "earn" a set of goals the hard-way. Keep listening. And measuring. And reading. And building. This stuff is fun, after-all, and there are no boundaries to the learning. Pick a design, dive-in, beat everything all up in your analysis, look at what's happening and try to understand why and compare your predictions. Consider how much work all that was and how much you'd do again or how deeply. Then do it again and again :) You will have Earned some of your goals & priorities. I'm not smart-enough to know any other way. If it's not fun or interesting, don't do it--that'd be my approach. It might be fun or interesting later--take data you don't even care about while you're already set-up and SAVE EVERYTHING and label things with DATES and BACK-IT-UP. Take pics of your measurement rigs--this will jog your memory when it needs jogging.

Almost forgot. Don't forget to read in other disciplines (the muffler-people, wall-soundproofing people, musical instrument people, etc.) The whole world works with resonant systems and it seems there's always a gem somewhere.
 
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