Ported Speakers and Tube Amps??

Sean is absolutely correct on port loaded speakers! I ended up "stuffing" the ports with foam (beside other things i had to do to the volume of the enclosure) to make them aperiodic. Results are satisfactory, but i believe ported speakers, even though top design choice amongst speaker-bulders, should be avoided.

Sean, When you talk about bass what range are you referring to hz wise? When you talk about large drivers what sizes are you talking about? I have ported speakers with a 9" dynaudio driver, driven by 160wt mono tube amps and the bass sounds about as tight (not loud) as my Quad 63's. What I have noticed though is they don't seam to like amps w/no negative feed back. Does that make any sense to you?

I'm using ported Coincident speakers (92db) with an SET amp. Works great! flat 8 ohms, easy to drive, really tight bass.

Good answer Karls.

As a general rule, the bigger the woofer that one uses, the sloppier the bass will be when ported. For reasonably "tight" bass, smaller woofers work better if you really must port the cabinet.

Since bigger woofers typically use bigger motor structures, they generate more reflected EMF. This makes it harder for the amp to load into and control the driver. Combining a lack of control over the driver with a lack of damping or "air spring" in the cabinet due to having a "blow hole" in it typically results in noticeable "sloppiness". Add a driver with a high Qms ( big impedance peak at resonance ) and you've got a real problem with "bloat". This is true for SS or tube based amps but tubes may have a harder time due to the lack of current needed to "muscle" the cone around. As such, it is best to avoid ported speakers and go for the quality of bass rather than the quantity of bass. Sean
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PS... Pmkalby's point about using a higher efficiency design is quite valid, as a speaker that is more efficient won't have to make as long of an excursion. The less excursion, the less reflected EMF and the easier the amp can load into & control the driver. As such, it's kind of a "catch 22" situation and you have to choose what you like best and what sacrifices you are willing to live with. You should still avoid ported speakers though : )

It all depends on what you like. Most ported speakers are going to sound looser than sealed or TL, and most tube amps are going to sound looser than SS. Put the two together and you get more of the same, only compounded because ported speakers rely more on the amp to control the woofer, and this is an area where tubes are notoriously bad. Of course, this is only a generalization and there are exceptions. You won't know until you try it. Don't get your hopes up though if you like tight bass.

Shouldn't matter any more than the color of the paint in your listening room. A generalization based on the experiences of one or two individuals, most likely.

A properly ported woofer COULD be more efficient, and might actually be a BETTER match for tubes, since it COULD take more power to get satisfying bass from a sealed speaker, which COULD be lacking with a tube amp. The ported speaker COULD have been ported to "help" frequency response, though, which COULD sound bloated with a tube amp that lacks power and or control, or is described as having lots of "bloom" or a "tubey" sound.

Of course this COULD be the total opposite if you pick just the right amp and speaker combo. You need to be more specific about what amp and speakers you are considering and I'm sure someone will chime in.