More often than not, yes.
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If space is a premium...then I would opt for a front ported design...however...front ports tend to suffer from "chuffing" problems at higher volumes...that is the port tends to add audible noise and distortion...again...this is most noticable at higher volumes...with rear ports this is less of an issue since the port is facing away from the listener...I tend to like depth...so I have my rear ported speakers 3-4 ft from the rear wall...if this is not feasible...go with a front port design...Energy c-3 is a great affordable monitor for under $500...good luck..
Port noise or "chuffing" has more to do with port shape and size than where it is mounted. While it is true that it would probably be more apparent on a front mounted design, it would still be taking place if the port was rear mounted. You just wouldn't notice it as much.
If it were up to me, i would design / look for a speaker with the vent opening out of the bottom ( if you MUST use ported designs ). Part of the problem with ANY open vent in a cabinet is that, not only do the low frequencies which the vent is tuned for come out of the hole, but other frequencies above that frequency can also "sneak out". This allows out of phase upper bass and midrange to tamper with the in-phase output of the drivers within those frequency ranges. This obviously results in less than optimum linearity ( frequency response ) due to the cancellation that occurs. By directing the higher frequencies that leak out of the port downward, they are likely to be partially absorbed by carpeting or dispersed in a manner that is less likely to interfere with the primary wave. Obviously, this would make their effects slightly less noticeable.
While some might say that mounted the port on the rear does the same thing in terms of directionality, the sound firing out of the back is more likely to be reflected and dispursed by the wall behind it, creating an even "weirder" presentation with even more placement variables to deal with.
The fact that the port on a downloaded design would be at a right angle to the backwave of the drivers should also reduce the quantity of higher frequencies from finding their way out through the hole. Due to their increased directionality, higher frequencies are less likely to "bend" inside the cabinet, especially if the cabinet has some form of acoustic damping material inside of it to absorb internal sound waves.
Now compare this design to a rear mounted vent. The driver is directly loading and pushing soundwaves into the port from the back-wave of the driver. The benefits of a non line of site vent to driver configuration should be obvious. While the front mounted port is not as much of a "direct shot" in terms of the back-wave being forced out of it, the "single bounce" reflections inside the cabinet can help push higher frequencies right out the front of the box. The sound coming out of the back of the driver could hit the rear wall and then be reflected right out the front mounted port. That is, IF the port was improperly placed and there was a lack of acoustic damping material inside the box to begin with.
Another benefit to a down-loaded port is that one could actually alter the tuning of the vent by changing the distance and material below the cabinet. This would allow slight alterations to the frequency response curve that could come in handy for fine tuning the output in individual rooms. Obviously, if one were not careful, they could do this by mistake and end up with something worse than what the manufacturer designed.
Obviously, the "wind" inside the cabinet blowing across the open mouth of a port is not ideal, but you get that with all ported designs. On top of that, down-loaded ports can play games with how you can mount the speaker if it requires some type of stand, but like everything else, EVERY design has trade-offs.
As a side note, I would also look for a speaker whose port was flared ( like a "rolled" horn loading ) at the output end and possibly had a slight taper to it. Other things to look for would be that the port should have a pattern ( aka "golf ball dimples" ) molded inside of it. These all help to reduce port turbulence and port stalling, which results in more linear operation regardless of volume levels. In case you didn't know this, vents DO change tuning and output levels as the volume is altered. As such, the more that you can do to increase vent linearity, the more enjoyable and accurate a speaker would be over a wider spl range. Sean
I would agree...most cheaper "ports" are simply a hole to increase bass response and to some extent sensitivity/efficiency...that being said...the best "ported" designs take into account phase cancellation,distortion,etc to obtain accurate bass reproduction(ie no boom-box bass)...unfortunately this comes with a high labor/design cost...usually at the 1k level...the new Quad Ls I own have two distinct "chambers" each with their own port...and Im sure damping,etc comes into play...the bottom line: placed away from walls...they produce clean,deep,tight bass...and I am not of fan ports to begin with...but when executed properly...they can sound amazing...and even at high volume there is no audible "chuffing"....once again...it comes down to performance vs. on paper design tendencies...I have heard many highly touted sealed enclosure designs that couldnt compete (ie no bass)....
The problem with most all economical ported designs is that the upper bass (around 100hz or so) is slightly elevated to give the speaker more extension down lower. Most ported designs, even expensive ones, roll off pretty fast below about 60hz. Some ported speakers are actually allowed to go with a bigger boost at mid to upper bass frequency's so that you think they have more perceived bass than they really do. You get these speakers close to a wall and boom, the room boundary increases this even more.
I like sealed speakers for this reason. They are more inefficient and evidently more expensive to build since you see ports in the cheapest of speakers (build wise).
If I had to go with a port, get one with the port in the back or bottom.
Thanks to all-- I appreciate the info. I clicked on the "near backwall placement" thread and it was helpful too. As long as we're on the topic, the range of monitors I'm looking in is the SF Concerto and smaller Energy Veritas, that sort of thing (around $1.5K). Given a small apartment-- listening area is about 10' x 10' and whole room is 13' wide x 27' long x 9.2' high-- i listen across the width of the room--what are your suggestions?
Please keep in mind that I don't want to get too far ahead of my front-end equipment-- I'm running a Rotel rsp-960ax preamp into a Parasound HCA-806 (6 X 80 wpc if I recall correctly). I anticipate upgrading the amp set-up to use the Parasound for center and surrounds only, and power the mains with a nice ss 2-channel amp like a little Bryston. Down the road, I definitely anticipate biamping the mains using the 2 channel solid state for the lows and a tube amp for the highs--nothing too esoteric though.
In short, I need speakers that will work nicely with my current mid-fi set-up but that will be good enough to take me through a couple substantive upgrades over the next couple of years.
Once again, thanks a lot.