Rear Ported versus Non Rear Ported floor standing

Whether or not a speaker works well near the wall depends on the details of the design. While as a general rule of thumb we could say that the average rear-ported speaker would not work well in such situations, there are exceptions that work exceptionally well.

For instance, Audio Note uses rear-porting on speakers specifically designed to go in or near a corner. They use a lower-than-normal tuning frequency. I can think of four reasons why their approach is a good idea.

First, by tuning the port lower than normal the bass boost from corner loading results in deeper bass extension instead of boomy bass.

Second, it is not terribly difficult to shape the low-end response of a reflex enclosure so that it's approximately the inverse of the low-frequency gain from boundary reinforcement. The shape of the low-end response of a sealed box speaker has a much more limited range of adjustment, and the only way to get a reasonably close approximation of the inverse of boundary reinforcement is to use equalization.

Third, lower tuning frequencies call for longer port lengths, and longer ports are more likely to emit some midrange coloration (at a reduced level of course due to damping material inside the box). By directing this undesirable midrange energy away from the listening area, it is less likely to be audible (and in most cases is inaudible).

Fourth, by staggering the distances from the low frequency sources (woofers and ports) to room boundaries in all three planes, the bass is likely to be a bit smoother at the listening position.

I like Audio Note's approach enough that I use a variation thereof in some of my own designs.

In my opinion rear ported speakers specifically designed for (or adaptable to) placement close to the wall can work very well there.

Just for the record, I'm not really an advocate of vented boxes as inherently superior to sealed boxes in the bass region. I do like the greater design flexibility of the vented box, but overall it's a trade-off of one set of compromises versus another. All else being equal, vented box woofers have more powerful magnets than comparable sealed box woofers, and this usually translates into better midrange performance.

Duke

Of the three you listened to - what did you like best? What other speakers have you owned that you like? How important are aesthetics? Do you have an amp already or what will you use to drive them? There are a great many good speakers out there - each with strengths and weaknesses.

Does anybody have suggestions for front ported or non ported floor standing speakers for a L shaped room 11x14 & 10x10. thx for the suggestions

>>If a speaker goes too low for a room to contain the bass the speaker can produce you are in for standing room city, which is worse than a little extra bass bloat by putting a rear ported speaker in a cabinet!<<

This is a huge assumption and mostly hifi wives tale. Standing waves in the bass regions are mostly a function of diaphramic losses and in reality no playback room is big enough to properly handle the bottom octave.

In a very truncated nutshell, you can have great bass behavior, even down to 16Hz in a small room. Standing waves will likely be more of an issue in small rooms with bass in the 50Hz to 80 Hz range.

I recommend you bone up on this a little. There are a couple references that will help you understand better:

One is "Fundamentals of Acoustics", Third of Fourth Edition
Wiley press

The other is Harry F. Olson's book. It contains less math, fewer proofs and is totally solid; easier to understand if you do not have a strong math and physics background.

You should look for manufacturers that design for this issue. Some front ported and non-ported speakers will still sound awful if shoved into a corner or rear wall.

The fact that a speaker is rear ported is immaterial. Most of the energy is coming out the front of the speaker. A port acts as a camber to lower the resonant frequency and increase the efficiency of the design.

In my 20 years of professional experience it depends on the room as well as the speaker how the sound will interact.

Also with many rear ported speakers you can try an old trick of stuffing things in the port to change the loading. Many companies include pre made bass plugs for this very purpose.

We used to use tubes from paper towels in a pinch which sometimes tightened the bass and dissappated bass bloat.

Really matching a speakers bass output with room size is much more relevant. If a speaker goes too low for a room to contain the bass the speaker can produce you are in for standing room city, which is worse than a little extra bass bloat by putting a rear ported speaker in a cabinet!

I'm using Spendor S8es which have a rear port and are only about 8" from the rear wall without any problems. (I had the smaller Spendor S5e prior to that and they had no issues either.) Spendor makes a point that their slotted linear flow port is designed to be less sensitive to placement near to a rear wall than some other designs. My experience supports that statement.

Of course, the best thing to do with ANY speaker is to try it in your listening room and see what you think of it before you buy.

A sealed design may be the best way to go (if you can find one you like), and if you must place the speakers that close to the wall. If you go with a ported design...I'd go front port.

Dave

You should stay away from ported speakers. Unless you like an overly heavy bass. A speaker with a leaner precise bass response ( non-ported ) will give you far better transient response and the roll-off of 6 db per octave (versus 12) makes this ideal to place against a wall where you get reinforcement in the bass (as a bonus you actually get more ultra LF energy than a ported speaker at frequencies below the port resonance - so the bass sounds smoother and integrated rather than a mupy one note bass)