Well, for tall boxes, it does make a difference. On floorstanding speakers the distance from the floor, wall, corner can induce room resonances in different strengths. With ideal speaker placement that's not a big issue but often (especally big speakers) aren't standing where they should be ideally.
It also makes a difference in the enclosure. For large speakers, because of the longer way the signal has to travel, the phase shift can influence the response. Visaton (German, sry, couldn't find a similar one in english) measured different port placements. They came to the conclusion the placements with the best results were close to the driver or farthest away from it and near the bottom board because the standing waves got there the lowest sound particle velocity (had to look that up, still lacking a lot of vocabulary
).
And these are small speakers — 0.8 litres net volume.
dave
Well, you do understand that was about the influence in the bass - neither about the mid-garbage nor the port folding? The former got top priority and the latter is a no-go anyway. Why are you still defending it as 'better'? You know the physics, you know how it affects the sound, audible as measurable. If you don't like the port upwards or downwards, then use a passive radiator. Or is it that someone else might be right and you are having a problem with that?
Oh, is that so? Then you're proud of being the reason something's stupid has been done 1000s times. Because then you could just have used a smaller port, made the enclosure smaller and saved a lot of wood of being cut down and the ppl who built it could have saved a lot of money. Why on earth would ANYONE want friction in the port in the first place and if that would make any sense, why go for friction in the port by extending it and then FOLDING it?
I'm really eager to hear an explanation for that.
The miniOnken alignment has proven to work very well. It relies on high ratio, high friction vents to push the box towards aperiodic so it isn’t strictly a bass reflex. It breaks many of the “common knowledge” rules of bass reflex boxes. It requires a very specific shape of the modeled curve. It yields boxes that are relatively small, that produce elegant, articulate, nuanced bass. They only go as low as they go. Boxes are more tolerant of dynamic changes in T/S parameters. Like any alignment they only work with certain drivers.
I tend to have an aversion to the typical circular tube vented speakers.
dave
I tend to have an aversion to the typical circular tube vented speakers.
dave
That sounds impressive. I'm a big fan of onken enclosures. But that's not what it is. The onken principle bases on a few characteristics, the symmetircal air load of the driver with symmetrically placed ports, a very large port surface of roughly the same as the Sd (but at least 1/2 of the membrane surface) and unobstructed, short ports, ideally shorter than 3/4 of the enclosure depth. So, what does your design makes it an onken then? (rhetoric question)
Don't get me wrong, I'm sure your speaker sounds very good, no question, otherwise there would not have been that many people building it and reporting being happy with it. But let's be honest: It's not ideal, it's not an onken (doesn't matter for the sound but still a wrong claim) and it's possible to improve it, a great basis for tuning. That's a good thing, isn't it? Why being sour if someone does invest a few thoughts into some improvements?
Yes, me too. For development it's great though because you can easily change the port length.
Hi ICG,
I've built a few speakers with Dave's miniOnken designs. For me, their strong points were very good bass articulation and clear mid-range. I am not saying that the ultimate design has been reached, but I would say that with Dave's boxes the mid-bass articulation is better than most of the ported designs I've heard. The paid plan-set designs have wide chamfers at the edges of the front baffle and image very well.
Can it be further improved by eliminating the small fold at the beginning of the port? In theory maybe yes, but we don't know. But what he's got is a design that works in line with his design goals, and he is happy with it (as are many of his builders).
I've built a few speakers with Dave's miniOnken designs. For me, their strong points were very good bass articulation and clear mid-range. I am not saying that the ultimate design has been reached, but I would say that with Dave's boxes the mid-bass articulation is better than most of the ported designs I've heard. The paid plan-set designs have wide chamfers at the edges of the front baffle and image very well.
Can it be further improved by eliminating the small fold at the beginning of the port? In theory maybe yes, but we don't know. But what he's got is a design that works in line with his design goals, and he is happy with it (as are many of his builders).
Well, there is a very easy way to learn about that, why not just build it and compare the measurements? The wood is dirt cheap, you don't have anything to lose and then we know for sure. So why not?
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