A real *midrange cardioid response (the ripple on the low-end is a measurement artifact of the way it was supported):
https://www.diyaudio.com/forums/multi-way/142691-adventures-cardioid.html#post1808323
-and hopefully that helps-out with dc655321's search skills.
*from a driver that isn't a midrange. (..and disregard the polar above 1.5 kHz.)
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That's not to say that I haven't recommended it in certain instances before, even recently as a design "notion" for a particular situation.
Here:
https://www.diyaudio.com/forums/mul...d-advice-please-offer-02-a-2.html#post5871935
Note in this instance the complication is more than just a back-wall reflection.
Other than the problem with *resistance and subjective results, a line-array has merit here because it's vastly more sensitive below 1 kHz (..plus, such a design would represent a very narrow baffle if done right - something also desired by the thread-poster).
*Note: you don't have to do a resistance design, you could do an "active-delayed" design to (more or less) circumvent the problem with a resistance design in the midrange.
Active-delayed designs are where you have a secondary driver on the rear of the loudspeaker that's out-of-phase and where the front driver is delayed so that it's near in time with the rear driver; no leaky side ports needed. You can even go Hyper-Cardiod with this. Baffle effects are still a problem though - so upper freq.s always have some sort of limit to how closely (or not) they approach a real cardioid response.
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There are several measurements published for the 8c - soundstage, stereophile, their own. I have to guess you're referring to the NRC results, and their distortion measurement in particular.
Of course, there would be no guessing required if you could communicate more clearly. Not sure if you think you're being clever, or mysterious, or you simply can't help being obtuse. Maybe all of the above?
Doesn't controlling the dispersion of the midrange and tweeter help smooth out the crossover? Doesn't it reduce interference between the drivers in the crossover region?
I experimented with using felt between the woofer and tweeter in a two way and it made a small audible difference with one configuration. Crossover was at 2 kHz (very audible).
I've seen the Klipsch speakers with the waveguide tweeters. It seems like there might be something to this, especially with crossover points at very audible frequencies.
I experimented with using felt between the woofer and tweeter in a two way and it made a small audible difference with one configuration. Crossover was at 2 kHz (very audible).
I've seen the Klipsch speakers with the waveguide tweeters. It seems like there might be something to this, especially with crossover points at very audible frequencies.
-ironic, I thought you were being obtuse.
ex. ..is there any other non-linear distortion *measurement available for the 8C?
ex. what was I referring to all along here?
"..substantial pressure loss creating: lower sensitivity (all-else-equal), higher resulting non-linear distortion"
I even connected the fairly obvious "dots" for you:
"..see what pressure drop (from the cardioid) and a resulting "boost" with eq. will do to non-linear distortion."
I'm really not sure what sort of clarity you are looking for - I thought I was perfectly clear.
What I'm not in the habit of doing is spending time researching and providing links for something that you could do yourself (..ESPECIALLY IF YOU ALREADY KNOW THEM). If the proof is lacking within my posts - there is a reason for that: it takes my time when it should be taking yours if you are really that interested.
*and that non-linear result with the 8C was horrific below 300 Hz, particularly when you consider that any more gain is going to substantially increase that distortion. ..and while 90db is loud (even at only 1 meter relative to a typical 2+ meter listening distance), it's not that loud - and particularly with dynamic "peaks".
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As a referee I want to say that Scottg wins the distortion battle!
This is what Martijn says at ASR:
Now on to distortion. The 8c is a relatively compact full-range loudspeaker that offers low distortion at normal and somewhat elevated listening levels. At high levels distortion can become audible on some program material. This is the price we choose to pay for a cardioid radiation pattern in a speaker this size. However, 96 dB at one meter at a single frequency from a single speaker is very loud. In practice, in rooms with some reflections a pair of 8c’s can be played quite loudly and they do actually sound clean at quite high levels. But if you’re into very loud music, they certainly have their limits.
96dB at 1m isn't actually very loud. 105dB would be and still something that is not terrible as peak spl.
This is what Martijn says at ASR:
Now on to distortion. The 8c is a relatively compact full-range loudspeaker that offers low distortion at normal and somewhat elevated listening levels. At high levels distortion can become audible on some program material. This is the price we choose to pay for a cardioid radiation pattern in a speaker this size. However, 96 dB at one meter at a single frequency from a single speaker is very loud. In practice, in rooms with some reflections a pair of 8c’s can be played quite loudly and they do actually sound clean at quite high levels. But if you’re into very loud music, they certainly have their limits.
96dB at 1m isn't actually very loud. 105dB would be and still something that is not terrible as peak spl.
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The most troubling thing about the 8C is the that the distortion is as high as it is in the lower midrange and upper bass BEFORE signal "peaks".
Mechanically the driver is already getting enough excursion to move past the point of a mostly linear force curve, and just a little bit more could push (cause increased excursion) the driver(s) to substantially leave the magnetic gap (even with extended VC's "over-hung" design - it's really bad once the VC nears the end of the gap). Once this happens distortion goes WAY up.
So at 150 Hz for this design at 90 db 1 meter (and rarely do you listen that close, meaning the result will be bit worse at a further distance), it's about 8%? distortion (THD - which hopefully is mostly composed of 2nd instead of 3rd).
Mechanically the driver is already getting enough excursion to move past the point of a mostly linear force curve, and just a little bit more could push (cause increased excursion) the driver(s) to substantially leave the magnetic gap (even with extended VC's "over-hung" design - it's really bad once the VC nears the end of the gap). Once this happens distortion goes WAY up.
So at 150 Hz for this design at 90 db 1 meter (and rarely do you listen that close, meaning the result will be bit worse at a further distance), it's about 8%? distortion (THD - which hopefully is mostly composed of 2nd instead of 3rd).
-btw, the "dip" at 60 Hz looks like a dsp/eq issue (not a mode in the anechoic chamber - which would show-up with similar-sized speakers measured in the same location). You can look through their listing of other measurements and it's just not there.
As to *vague comments on driver resistance, here is some *anecdotal evidence I had with another forum member:
(my comments start here, but its several posts below):
https://www.diyaudio.com/forums/full-range/75940-fostex-fe-108ez-project-2-a-2.html#post873226
-the restive vent for the cardiod effect is similar. (..and I don't have a problem with "flow" vents lower in freq., in fact they are often beneficial.)
*again, intentionally vague because it isn't regarded as fact.
As to *vague comments on driver resistance, here is some *anecdotal evidence I had with another forum member:
(my comments start here, but its several posts below):
https://www.diyaudio.com/forums/full-range/75940-fostex-fe-108ez-project-2-a-2.html#post873226
-the restive vent for the cardiod effect is similar. (..and I don't have a problem with "flow" vents lower in freq., in fact they are often beneficial.)
*again, intentionally vague because it isn't regarded as fact.
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-only a cardioid response on the low-end of the midrange.
It's basically an open-back design 1st, an aperiodic design 2nd, and a cardioid pattern 3rd.
Different priority and different result.
It might however be useful in the context of resonance from the "front" wall (..the wall behind the loudspeaker), depending on the distance from the front wall.
It's basically an open-back design 1st, an aperiodic design 2nd, and a cardioid pattern 3rd.
Different priority and different result.
It might however be useful in the context of resonance from the "front" wall (..the wall behind the loudspeaker), depending on the distance from the front wall.
Yes, I guess too that combination of dipole and monopole would give widest cardioid range, if distance between sources is minimal.
Any cardioid "unit" has certain response curve and cardioid pattern is lost at some high frequency. It is quite a lot like a dipole, there must happen nulling of front- and backside wavefronts, this time on the backside.
We have several special threads here already, they have been linked already.
Any cardioid "unit" has certain response curve and cardioid pattern is lost at some high frequency. It is quite a lot like a dipole, there must happen nulling of front- and backside wavefronts, this time on the backside.
We have several special threads here already, they have been linked already.
From Sound Reproduction, Floyd Toole Chapter 4.9 Non-Linear Distortion
The D&D spinorama is excellent, but so are the listening results from what I understand. If the customer is someone like me I will like the D&D because I don't turn my music up loud.
However, if the Kii Three is similar in price but doesn't suffer the distortion at higher listening levels due to active cardioid design then, as a consumer, I'd choose that speaker even though I'd never benefit because I'd never listen to it that loud.
As a DIYer who doesn't need to sell speakers to the public I have more flexibility because I could place a speaker in a wall. On the other hand, I read something about "proximity" that makes me wonder -- if I understood the concept -- if you should move a speaker closer to a listener. In which case I'd have to pull the speaker out of the wall. Another problem with in-wall might be loss of spaciousness.
I do wonder why D&D didn't use active like Kii rather than passive. Was it a cost or quality tradeoff?
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