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Are passive radiator monitors true superior to ported, or are there any cons?
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Cost aside…
There are passive monitors like the Focal Shape 50 that are in the same price category as other ported monitors.
Same with the Amphion One15
If you need more specific information its better to start with a more specific question. A speaker is a complex system. You cant say in general a speaker with a passive is better than with a port at same price. Or vice versa. If you like to compare speakers, you have to compare speakers and not if they have a passive or BR.
Passive radiators are always technicaly worse than good slot-ported or port designs.
The distortion is higher with passive radiators. The only advantage is that you can shrink the cabinet and get the same -3 dB point in the bass , compared to a ported design.
This is a serious salespoint in a store, more important than really good sound.
The price for shrinking the cabinet and using a passive radiator are always: higher distortion and somewhat unarticulated bass, compared to good closed boxes and ported ones.
In 2022 you see a lot of designs with passive radiators from lots of companies.
I always stay away from those.
The distortion is higher with passive radiators. The only advantage is that you can shrink the cabinet and get the same -3 dB point in the bass , compared to a ported design.
This is a serious salespoint in a store, more important than really good sound.
The price for shrinking the cabinet and using a passive radiator are always: higher distortion and somewhat unarticulated bass, compared to good closed boxes and ported ones.
In 2022 you see a lot of designs with passive radiators from lots of companies.
I always stay away from those.
I wonder about passive/ported vs infinite baffle/closed and effect on group delay at LF.
Do the latter have an advantage due to lesser group delay?
Does GD matter… are there known thresholds of group delay where yes, it does start to matter?
Do the latter have an advantage due to lesser group delay?
Does GD matter… are there known thresholds of group delay where yes, it does start to matter?
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Everything has it advantages and disadvantages, passive radiators can be a good solution when the needed port length is too large. Also they have no air flow noises (for which a BR port needs to have extra measures to avoid) and can better damp parasitic noise in the mids which is often radiated from port designs.
Port compression is often not included in these kinds of conversations. I wonder why…
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In a minimal phase system like a woofer the group delay is a function of the highpass frequency response, meaning if you tune it to the same response it will have the same GR independently from if its closed, ported etc. There is a good article about it here.
There have been done quite some studies about the group delay audibility thresholds, exemplary
Group delay and phase delay - Wikipedia
Ok thanks, this surprises me as I had though GD increased with stored enclosure energy, such as mass of air in ports or passive radiators. I will do the reading !
Shouldn’t the room also be included in this? It will reek havoc with the frequency response and consequently group delay.
Basically you’ll need to make sure that the in-room frequency response is flat enough for the bandwidth you’ll need, and you should be good.
Not an issue with a good designed port. In many cases the ports are to small though.
Passive radiators are unlinear just like ordinary drivers depending on how loud the music plays.
As I wrote before - a passive radiator construction are mainly a salespoint because the boxes can be smaller for the same amount of bass , but the quality will suffer.
If you want to make a passive radiator construction less bad, you must have a steep HP filter just below the tuning point otherwise there is no damping of the cone at all. This is done in some of RELs subwoofers . The same can be done in all ported designs with a dsp , like Genelec does in its SAM monitors.
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There are some truly great passive radiator speakers out now.
Another factor not considered: shrinking the cabinet leads to a stronger cabinet with less need for bracing. Also helpful if you do a lot of international shipping.
If you can show me one ported speaker that Erin measured that doesn’t exhibit port compression i would be convinced.
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The cabinet volume difference isn’t really that much. Usually it’s about the same as a reflex alignment. Reflex just adds the port volume. What you do need though, is more surface area. You needs at least a passive radiator with twice the SD of the active driver, preferably 3x. All these PR’s need to go somewhere..
Ports have their own issues. For a smaller speaker, a large enough port is mostly fine. For low tuning, a port can quickly be very long and large. Taking up considerable volume and are prone to resonances. In those cases a few massive PR’s can really work very well.
Ports have their own issues. For a smaller speaker, a large enough port is mostly fine. For low tuning, a port can quickly be very long and large. Taking up considerable volume and are prone to resonances. In those cases a few massive PR’s can really work very well.
2x SD is not an issue since you would want one woofer and one waveguided tweeter of similar size at the front. So the back is more less available for 2x SD.
It’s just the cost imo, that’s the only negative.
You have a very good point in this . Most PRs are wrongly constructed, focusing only on the salespoints with smaller boxes, with a single and to small PR . And as I wrote earlier, a PR construction need a steep HP filter right below tuningpoint.
As for subwoofers - I would buy a Linkwitz transformed closed box with a low Q driver any day of the week .
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This makes a lot of sense for subwoofers because 99% of the time if you have decently sized ones you’re below excursion limits. So there is no reason to compromise 99% of the experience for an improved performance at the 1%.
But with a small 2-way speaker where you’re excursion limited over a wide band (think 5.25 woofer) i think PRs and ports are quite necessary if you’re not crossing over to a subwoofer. Which further complicates the design of small speakers.
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We don't see that a lot though, especially not on cheaper designs. Who wants to hide apparent woofers?
It is in many cases. Moreover, if you take a tower enclosure, and shove 1 driver and 2 PR's in it, it will look impressive, and also, you can actually use a cheaper driver with a relatively weak motor and larger VAS, since you'll use the whole tower volume for the single woofer, vs a tower that has to share the volume with two drivers and some ports. Obviously the same goes for a single driver + port, but the PR version will probably sell much better because it looks more impressive.
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