Maybe someone would believe you if you post pre-and-after modification measurement. Until then...
Why you need measurements of B200 below 500 Hz, when there everything is OK? Problems above 500 Hz are clearly shown. I have complete measurement below 500 Hz, but I didn't post them here because there is no need for that, not because I didn't test it below 500 Hz. So, your analogy with car is naive.
Guys please.
There are speakers that measure good and sound bad.
There are speakers that measure bad and sound good.
There are very good sounding Fullrangers
and very good sounding Coax speakers.
Both have strength and weaknesses.
When DSP and phase corrections are applied the Coax has better high frequency presentation. That's my experience with over 40 years of speaker building.
YMMV
Klaus
There are speakers that measure good and sound bad.
There are speakers that measure bad and sound good.
There are very good sounding Fullrangers
and very good sounding Coax speakers.
Both have strength and weaknesses.
When DSP and phase corrections are applied the Coax has better high frequency presentation. That's my experience with over 40 years of speaker building.
YMMV
Klaus
No.
No.
No.
Yes.
Yes... sort of... Only one strength at fullrangers - step response, everything else is much worse.
Yes.
I do appreciate your calming tone.
No.
No.
Yes.
Yes... sort of... Only one strength at fullrangers - step response, everything else is much worse.
Yes.
I do appreciate your calming tone.
re:coaxial woofer + compression driver on the woofer's backplate - how about an LC-LC allpass on the woofer in attempt to achieve better time alignment ?
hi Sonce - for what little its worth I "thought" an LCLC allpass with my Eminence C12CX's lowpass made it snap into better subjective focus - but did not verify via any measurements,
I miss this line of Eminence - they were made with and without a protruding horn with 54-109oz ferrite magnets. This one had an 80oz magnet and edge-wound 2.5" voice coil and was nice in my Karlson12 - probably would work in the Karlsonator12 tho that one is tuned to 37Hz.
I miss this line of Eminence - they were made with and without a protruding horn with 54-109oz ferrite magnets. This one had an 80oz magnet and edge-wound 2.5" voice coil and was nice in my Karlson12 - probably would work in the Karlsonator12 tho that one is tuned to 37Hz.
Just noticed: This is my workbench, so it should be my modified BG !
Regarding the initial posting, as the guy who put the BG20 mods together, some comments:
- The most relevant mods, damping of the surround and elimination of the dustcap were initiated by a former designer of VISATON and this is where the measurements in #1 come from.
- Replacing the (sealed) dustcap by an (more open) textile cap, results in ventilation of the coil cavity (which isn´t there at all initially). This improves Rms drastically.
- Most importantly: The BG20 is not a fullrange speaker! Modified it is an excellent mid-range which, given a somewhat excessive enclosure, can also produce very nice bass-notes.
Please note: I am not biased - there are only in total fourteen modified BG20´s working happily in my household ...
Addendum:
In 2017 Visaton added the coating of the surround to their off the line standard BG20 as it was standard practice from the beginning with the B200 facing the same issue.
I still feel that a sensible manual coating in two or three steps gives a better result compared to the automated process though.
In 2017 Visaton added the coating of the surround to their off the line standard BG20 as it was standard practice from the beginning with the B200 facing the same issue.
I still feel that a sensible manual coating in two or three steps gives a better result compared to the automated process though.
i am a great fan of fullrange drivers.
I regret that rarely all measures are taken to get fullrange drivers up to their maximal quality of sound possible.
So with some DIY techniques you can realize a lot of it.
One of these is adding a faraday ring on the pole piece:
I regret that rarely all measures are taken to get fullrange drivers up to their maximal quality of sound possible.
So with some DIY techniques you can realize a lot of it.
One of these is adding a faraday ring on the pole piece:
Here a description how to add DIY a Faraday / copper ring to a loudspeaker in order to reduce distortion and minimize inductivity of the voice coil.
First some information on how to remove a dust cap of a loudspeaker driver (detailed description follow the link) :
https://www.diyaudio.com/community/threads/how-to-remove-a-dustcap.397165/
First some information on how to remove a dust cap of a loudspeaker driver (detailed description follow the link) :
https://www.diyaudio.com/community/threads/how-to-remove-a-dustcap.397165/