uwotm8
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Oh, I have read that btw. And again I believe this thing has potential.The measured data is at HiFicompass
Oh, I have read that btw. And again I believe this thing has potential.The measured data is at HiFicompass
Correct. An idiosyncrasy of the score is it prefers narrow directivity. You can see for the JBL that the SM_PIR score is lower while this one is higher.Mainly because the estimated in-room response is smoother and more tilted than that of the 708P.
@mitchco reviewed the SPK4 and was duly impressed by its performance incl bass. Where did Purifi go wrong with the updated/improved SPK5 version?
The benefit of planar tweeter is the more narrow vertical beam and some designs provide the lowest possible inter modulation distortion and high max spl. Some of the mundorf amts are very good.I don't know why people are bothering with planars going that low. Domes do much better job, especially waveguide loaded.
I don't disagree with the first part of this sentence but the second part seems... like a weird potshot to take.That's a lotta bucks for those speakers. USD $2700.00 could buy some pretty nice factory made speakers but I guess that defeats the DIY MODDER mentality.
Correct. An idiosyncrasy of the score is it prefers narrow directivity. You can see for the JBL that the SM_PIR score is lower while this one is higher.
However, it’s not just the wideness of the dispersion; looking at the PIR for the JBL, it is not linear. You can draw a downward sloping line from 100Hz-1500Hz, but above that you would need to draw an upward sloping line:
Great example of the scoring not making any sense whatsoever. @amirm , is this not the straw that breaks the camel’s back? We need a better score that relates to subjective, empirical, listening experience.
Yah, I mean that incredible Xmax is easily outdone if you can use a larger system. I guess the whole point of the Purifi to allow one to stay small.Spatial characteristics are not bad. Surprised the bass didn't wow more but who knows, maybe there's only so much you can do with a small woofer.
This kit looks surprisingly good for meThe JBL 708P has a very robust DSP engine built in.
It has a myriad of presets and customizable features. Quite robust. One could likely adjust the speaker in such a way as to greatly increase the Harman score, or more meaningfully to match ones tastes/needs/room.
I am actually not sure what setting the 708P test was conducted under.
In any case it seems that the Harman score is what it is - an indicator. A probability, a likelihood - not a fact.
Now most everyone knows this and knows that data is older now and somewhat limited in scope compared with ideals, it can be improved. That requires a mess load of people to participate in a new, bigger, better more comprehensive study. Even then there will still be times where the score simply doesn't match.
This Purifi woofer really is polarizing receiving compliments and severe criticism & IMHO it should. It is really a very niche product that is practically equal/inferior to much less expensive and much less flashy design in many ways, it does however have some very nice attributes that if are properly contemplated, could position this woofer in a nice design that makes sense for certain purposes. The ultimate cost of the RAW drivers is problematic as IMHO they just are not competitive, if they gain a market share and can drop the price I can certainly see the tech having value.
Yah, I mean that incredible Xmax is easily outdone if you can use a larger system. I guess the whole point of the Purifi to allow one to stay small.
Just sort of apples to big apples size wise but really similar in terms of "DIY" vibes and what you can get for a price,
Look at what the cash buys.
This uses a passive radiator, a truly world class 9.5" woofer with a fantastic world class waveguide loaded beryllium tweeter.
Yah you have to put it together but what is shown below is a retail kit price for a pair with passive crossover parts- the RAW driver cost is in the same ball park as a RAW Purifi with Passive Radiator and that iffy tweeter.
You can do the Helios kit or in my case you can buy the raw drivers and DIY an active design.
Anyway I am not salesman for anyone, just a interesting example. This DIY speaker uses 1 cubic foot of volume so not huge. No way I buy a Purifi system for the same price as what I'd get in this example kit.
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The artifacts at 350Hz are caused by the port and it doesn't beam more. It beams less you can see it in the DI.Can a port resonance cause a speaker to ‘beam’? With an output 6-8 dB below the woofer? Or is there something else going on directly from the Purifi woofer that causes this?
No it is about 3,5kHz you can see it at the woofer slope and at the change in the DI.The speaker’s listed attributes says the crossover is 3.2 kHz, but the measurements look more like 2.1 kHz. Isn’t that a bit weird?
You cannot equate near-field measurements of the chassis with far-field measurements. For example, the influence of the baffle is missing in the near-field measurements. In Amir's near-field measurements, all drivers radiate sound, so there is additional interference.The speaker’s listed attributes says the crossover is 3.2 kHz, but the measurements look more like 2.1 kHz. Isn’t that a bit weird?
You can do the Helios kit or in my case you can buy the raw drivers and DIY an active design.
This kit looks surprisingly good for me
The artifacts at 350Hz are caused by the port and it doesn't beam more. It beams less you can see it in the DI.
Since the port resonance is out of phase with the woofer, it is causing cancellations in different places around the speaker. It is not beaming per-se.Can a port resonance cause a speaker to ‘beam’?
If you imagine one sphere around the speaker the figure you shown represents only a line on the sphere. So yes you get some dips and peaks due to the phase difference between woofer and port. At this line there is a dip. But over the whole sphere the speaker radiates more energy into the room, as you can see in the DI.Check again.
View attachment 110921
As the frequency drops below 1 kHz the beam width broadens out to 200 degrees then suddenly it beams again to under 100 degrees at 400 Hz.
Not a pot shot at all. I meant it. The MODDERS and DIY crowd like to build themselves and they enjoy that and buy tools and all sorts of stuff for the tasks. I've been a DIY MODDER in the past and it's fun.I don't disagree with the first part of this sentence but the second part seems... like a weird potshot to take.