Do they have differing audio qualities? Are there applications where one is preferred over the other?
Do they have differing audio qualities? Are there applications where one is preferred over the other?
Depends, yes, though this gets fairly involved technically, so the relatively simple answer is that if using a TL, MLTL or similar alignment where the cab loads the vent enough to shorten it WRT a standard calculated length, then a a simple baffle thickness reflex vent is fine. For all other alignments a ducted port vent system is preferred since it controls the driver better at resonance, i.e. a higher Q/faster decaying port resonance for 'tighter' bass and why the Onken is so popular.
All that said, many Altec, PA driver alignments typically require a large vent area just to be baffle thickness and since an equivalent ducted port must have a larger vent area which causes its own organ pipe 'coloration', it's normally best overall to use the reflex vent in a HIFI/HT app.
GM
Loud is Beautiful if it's Clean! As always though, the usual disclaimers apply to this post's contents.
As far as technical differences I haven't a clue. The only comparison I've ever made was between the Altec 846A Valencias I have and a pair of 846B Valencias. The A model has the vent alongside the horn and the B model has a ducted port. I prefer the A model but then I'm old, nearly deaf and have lived with the A's for over 40 years so YMMV.
Life is too short to be taken Cirrus.
I'm curious as to in what way you perceive it different/better? WRT 'deaf', how 'deaf'? I mean I'm trying to get a 'feel' for how us older folks into HE HIFI/HT perceive subtleties. The few folks I know around my age either are satisfied with whatever comes out of their stereo TVs, car radios, phones and/or wear hearing aids, so no help there.
My comparison of the two was only at the time the 846B first arrived at the distributor, so obviously had much younger ears and it was enough of an improvement in controlling the woofer at high power that it convinced me ducted port was the way to go when practical. The first 500 Hz 'clones' I built were owned by a Ga.Tech student and I remember them filling an outdoor frat party with a far more balanced, smoother, bass line than their EQ'd A7s.
GM
Loud is Beautiful if it's Clean! As always though, the usual disclaimers apply to this post's contents.
Here's my take on age and hearing: The difference I hear in sound, even when focusing on barely perceptual differences, is in detail. At one time I sold stereo gear and hence, taught myself how to listen for differences in presentation between speakers, amps, etc.. I am also a life-long musician.
I don't think my hearing was necesarily any better than average but I do know I was able to differentiate small, subtle differences in sound. Now, I am still able to hear the differences but really need to concentrate to hear those differences. Also, the high-end of frequencies, as most folks, is greatly diminished. Perhaps what I can barely hear now, compared to what was easy when younger, is the harmonics.
I'm not an audiologist so lack the vocabulary to convey exactly what I'm hearing/not hearing but for lack of better words, I'd call it shaded or somewhat muffled, or absent of detail.
Originally Posted by GM
Yeah, this is my problem also and why I'm so curious what differences Mike's hearing that makes him prefer the 846A's simple reflex with its somewhat more 'muddy' bass line over the somewhat more tightly controlled 846B's. Now if both were tuned much lower, then the differences get lost in the room's high noise 'floor' and our increasing hearing acuity loss with decreasing frequency. Indeed, here the reflex can be superior due to its minimal port depth, i.e. no pipe harmonics.
GM
Loud is Beautiful if it's Clean! As always though, the usual disclaimers apply to this post's contents.
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