I can't see value in knowing the cone velocity in a sealed box, so it didn't occur to me that it would be plotted. Basta does it too so maybe someone has a use for it or knows what the reason for calculating it is.
Wording it like that could be misleading because if the F3 was made low enough the F10 would then become irrelevant for audible extension.
Everything matters it just depends how much, and often the relative values change depending on other parameters.
Seems to be an increasing trend recently to have back and forth between members overshadow the useful content 🙁
Well at least we now know that the 2 way passive ported is the game changer the industry needed for 2022 and beyond. Back to the drawing board for me.
well Adude’s approach is very interesting.
but yes I will stop for the greater good.
Someone wiser than me once said that he bit his tongue rather than getting too involved.
Another person who lived a 100 years ago said that arguing was futile.
You can’t win an argument, because if you lose, you lose it; and if you win it, you lose it.
but yes I will stop for the greater good.
Someone wiser than me once said that he bit his tongue rather than getting too involved.
Another person who lived a 100 years ago said that arguing was futile.
You can’t win an argument, because if you lose, you lose it; and if you win it, you lose it.
At the risk of encouraging this thread farther afield, am I understanding correctly, that DSP can be used to control directivity? How does that work? Is it just via phase adjustment? How much impact can it have? Specifcally, can it help match a 6.5" driver to a 25 mm tweeter? I'm currently planning to use a midrange between my PTT6.5 and my T25B, pretty much solely to help with the directivity mismatch between the two. I am not interested in trying a waveguide on the T25B due to fear of damaging the Be dome either during assembly or in use.
DSP isn’t used to control directivity. That’s done by the baffle shape, waveguides, absorbent treatments etc.
An alternative to a waveguide is baffle treatment such as what’s used on this speaker.
An alternative to a waveguide is baffle treatment such as what’s used on this speaker.
Thanks for clarifying and mentioning this approach. I'm planning to use this window (while I wait for availability of the Purify small midrange, measurements for the Bliesmas, etc.) to investigate meta-material absorption of in-cabinet backwaves. Maybe I should add baffle treatments to the research.
No problem. Also if you’re making a passive speaker consider stepping back the mid and tweeter for time alignment. Makes a massive difference. And without DSP you must do it in a similar way to Vandersteen. This speaker uses both baffle treatment, and physical time alignment. This approach helps with lobing, directivity, and time alignment.
Personally I don’t use horn style waveguides. Although the results might look good on paper, they add a cuppy sound to the speaker. Kinda like if you cup your hands around your ears when listening to a stereo. Might sound cool for a few minutes, then you realize it doesn't sound natural.
Personally I don’t use horn style waveguides. Although the results might look good on paper, they add a cuppy sound to the speaker. Kinda like if you cup your hands around your ears when listening to a stereo. Might sound cool for a few minutes, then you realize it doesn't sound natural.
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I got that too... until I EQ'ed them properly. Then the "cuppy" sound disappeared 👍
I guess more of these designs need more EQ then. I prefer waveguides made of softer more absorbent materials.
well... it's just how I made it work with the Seas DXT. No one says that you will hear exactly the same, but I really like this tweeter with my newly bought SB MW13TX and slanted baffle(Avalon style). Very clean and smooth sound, with pin-point image right in the middle of the speakers.
A small waveguide like the DXT has is fine. I’m talking about the real big deep kinds.
Some waveguide info here:
http://www.troelsgravesen.dk/ScanSpeak-waveguides.htm
Note the comment:
“The 6640 was tried out with the same waveguide by Scott/US here. I've tried the felt ring and get identical measurements.”
Same measurements, but not same sound. So I suggest experimenting.
http://www.troelsgravesen.dk/ScanSpeak-waveguides.htm
Note the comment:
“The 6640 was tried out with the same waveguide by Scott/US here. I've tried the felt ring and get identical measurements.”
Same measurements, but not same sound. So I suggest experimenting.
Any crossover will have an effect on the directivity in the crossover region and the shallower the slopes the wider range it can have an influence. It is limited to making the best out of what already exists in your example. If arrays of drivers are used then positioning and DSP together can have significant control over directivity.
No DSP can "match" directivity electrically that was mismatched acoustically.
Be careful what felt is used as much of what is available that looks similar to the Wilson is actually very reflective and would just introduce reflections rather than absorbing the off axis. Also possible that the star shape with reflective felt makes a diffractive spread on purpose or by accident.
I am using a proprietary material that is unbelievable at absorbing sound. It’s like a black hole.
For those who might be interested, Troels Gravesen has another Purifi speaker.
Purifi 6661 floorstander
Purifi 6661 floorstander
I don’t understand why he would use the short throw woofers when he’s using them as pure woofers and driving them actively.
Edit: I now see he compromised the design by making it both a passive tube friendly speaker, and optional active option. Personally I would have made the bass section active with the long throws, and just made the top section passive for tube lovers. Or for anyone that wants to use something better than the -85dB THD+N Hypex fusion plates to feed the mid and tweeter. Obviously they deserve better than that.
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You mustn't conflate DSP with the process. Phased arrays were first described over 200 years ago, and have been used in optics, antennas and to a lesser degree speakers for a very long time.
Hi, i am a big fan of aerogel, my first speakers that i have built around 15 years ago were using only Audax aerogel midwoofers and midranges, these were very good at the time. But i didn´t know that you can buy it ready made as an absorption material, can you share the source please? Thanks!