Yeah, gearshift knobs, various organic shaped bottle caps, etc., have worked well IME, though needed the female's inputs to choose since I tended to only notice any obvious off axis differences. Personally preferred putting 5 star shaped stick-ons to the dustcap and knead the whizzer to work out its excessive starch to 'taste'.Lowther drivers with large phase plugs.
I look at the freq response charts. the one with ping pong looks more jagged than driver without ping pong in areas above the 10 K hz frequency .I tried measuring the on-axis response of the SB Acoustics SB20FRPC30-8 driver with a ping pong ball attached to the phase plug.
There is a slight change above 5kHz.
In terms of perceived sound, the presence of the ping pong ball results in smoother high frequencies.
It's intriguing how the addition of just one ping pong ball can alter the perceived sound.
View attachment 1185046
How does it correlate with audition ?
I look at the freq response charts. the one with ping pong looks more jagged than driver without ping pong in areas above the 10 K hz frequency .
How does it correlate with audition ?
The change above 10 kHz is worse on the graph, but audibly it's a high quality sound with little stimulation.
It's purely my speculation, but it's possible that the off-axis characteristics have improved.
So what's the verdict on ping pong idea?
There are as many "answers" as there are people using SB20FRPC30-8.
I would like to hear the answer from same64.
Not to be rude but it's just such a simple mod, double tape pinpong ball to tip of phase plug & that's it.So what's the verdict on ping pong idea?
As stated its about personal taste, if you don't like it just remove & be done.
Hmm. It was serious question guys. I'm interested in people opinions and do know what this hobby is all about. My drivers still in boxes waiting for enclosures.
Well like Nandappe says too many answers. Like food better to taste it yourself than to ask. Nothing better than experimenting ya
I tried these in a 2-way with Peerless DX25BG60-04 (crossed ~1.8k). But also added a switch to cut the wideband over to another set of terminals with baffle step and a notch to pad down the upper midrange a bit. Allows me to try both 2-way and FR. The 2-way can handle more technical stuff, but the 8" by itself makes more simple music quite spooky (in a good way). In fact I enjoy how it can take a track that is a bit too harsh (IE a "hot" mic that picks up alot of sibilance) and make it more listenable without losing perceived detail.
In-room response of the 8" by itself with the BSC and notch (~3k-6k). The notch only drops a few DB to leave enough on the table off-axis to play with toe-in. Easy enough to alter anyway by swapping out a resistor on the notch.
Enclosure is ~32liter. A design I came up with to use a single 2ftx4ft sheet per enclosure. Rear ported with a set of 2" precision port flares butted up to make about 4" estimated length. Nothing special about the bass, not amazing, but not bad. I find it adequate to provide an anchor to the music for the midrange to shine.
In-room response of the 8" by itself with the BSC and notch (~3k-6k). The notch only drops a few DB to leave enough on the table off-axis to play with toe-in. Easy enough to alter anyway by swapping out a resistor on the notch.
Enclosure is ~32liter. A design I came up with to use a single 2ftx4ft sheet per enclosure. Rear ported with a set of 2" precision port flares butted up to make about 4" estimated length. Nothing special about the bass, not amazing, but not bad. I find it adequate to provide an anchor to the music for the midrange to shine.
For fun re. strange phase plugs, check this out, at the end of the article, from Tony Gee:
post #516
How about Grounding the driver frame?
see the end of Tony Gee Solovox 206 pdf
https://www.diyaudio.com/community/attachments/solo-206_copy-pdf.1185555/
FTW! Crazy.
If the magnet cone is to reduce reflections, I think it should be an ogive shape like a rocket nosecone not an actual cone.
But, it’s best to listen and measure.
That’s not really grounding the frame, that’s connecting the negative wire to the frame. I might be splitting hairs here. (But isn’t that what we do?) I’m not sure that will do anything except open up your system to electronic/electrical noise. Running the vacuum might send a lot of energy into your amp.post #516
How about Grounding the driver frame?
see the end of Tony Gee Solovox 206 pdf
https://www.diyaudio.com/community/attachments/solo-206_copy-pdf.1185555/
I think it may be acting like a resistor or capacitor and cutting some bass and adding more treble. I’d like to see some measurements. Easy enough to put a switch on it.
How to ground the frame for the SB when it's plastic. Lol. Maybe should try connecting from pole pc to see if it makes any diff.
Personalmente ho aggiunto un nastro tw economico con un condensatore di 1+0.22 e si è subito trovato bene con l'intera gamma.
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