Hi
I'm just wondering how many people using this driver notice severe sibilance with it, and what they've done, if anything, to mitigate it.
I have done a search but only one other person seems to have referred to it, which surprises me given how noticeable I'm finding it in my application which is in a Dallas II horn with a Fostex FT96H super-tweeter.
Thanks in advance for any input
Chris
I'm just wondering how many people using this driver notice severe sibilance with it, and what they've done, if anything, to mitigate it.
I have done a search but only one other person seems to have referred to it, which surprises me given how noticeable I'm finding it in my application which is in a Dallas II horn with a Fostex FT96H super-tweeter.
Thanks in advance for any input
Chris
I have a pair of a Basszilla Platinum open baffle speakers which I built several years ago. They utilize the Fostex drivers you mentioned. I would suggest you reach out to Dick Olsher of black dahlia audio. He designed these speakers and was very helpful with any questions I had. Perhaps he would be willing to help?
Dear kr1s,
I used to use Fostex 206∑ before.
I tried various methods, and MAESTRO(treatment lacquer) was the most effective.
The tweeter used FT90H (+0.33μF).
STEIN Music "Maestro"
Maestro Laquer/CD-Plus/CCS - SteinMusic
I used to use Fostex 206∑ before.
I tried various methods, and MAESTRO(treatment lacquer) was the most effective.
The tweeter used FT90H (+0.33μF).
STEIN Music "Maestro"
Maestro Laquer/CD-Plus/CCS - SteinMusic
Attachments
I also built the Basszilla Platinum open baffle speakers. Dick Olsher states that the driver really should not be used above 4 kHz, due to a break-up mode at 3.7kHz and ragged treble. He cuts in the Aurum Cantus ribbon tweeter at 4kHz. So you may want to consider a tweeter rather than a supertweeter, perhaps the Fostex T90A. You might also want to consider a horn loaded ribbon tweeter.
David
Thank you for the replies - very interesting.
I was coming to a similar conclusion regarding rolling the FE208eΣ off early and bringing in a tweeter so it's nice to have confirmation from someone who knows what they are doing that this may have some mileage - I will persue this avenue further. It may well be worth me investing in a set of Mr Olsher's plans, even if just for the cross-over details.
I hadn't considered a lacquer - I will probably try that after exhausting other possibilities as I'm a bit reluctant to do something irreversible (I assume?) to my drivers.
I was coming to a similar conclusion regarding rolling the FE208eΣ off early and bringing in a tweeter so it's nice to have confirmation from someone who knows what they are doing that this may have some mileage - I will persue this avenue further. It may well be worth me investing in a set of Mr Olsher's plans, even if just for the cross-over details.
I hadn't considered a lacquer - I will probably try that after exhausting other possibilities as I'm a bit reluctant to do something irreversible (I assume?) to my drivers.
Hi Chris,
Like many fullrange drivers with relatively strong motors, the Fostex even on the Fostex website with smoothed curves display the expected response: a quite large upper midrange/lower treble "mountain" with probably a lot of break-ups, and a somewhat diminished uper treble/supertreble region. This will result in a simply unbalanced sound.
Doping the cones in whatever overpriced magic goo will most probably not resolve the issue.
You can correct the balance, but breakups will remain. You can try by ear, but that´s a lot of guesswork. A decent microphone and a free measurement software will show you the direction you are going and will provide a solid ground for any further evaluations by ear.
The correction filter can be made passive, which is generally a series LCR filter with a parallel notch in it´s most simple form. It can be made with high-quality dsp as well.
Now you say you have a supertweeter as well, but how is the crossover done? Is there anything to control the Fostex´ rising response?
Whatever there is, and without wanting to diminish the importance of listening, doing some FR measurements will give you some insight what´s going on.
All the best
Mattes
Like many fullrange drivers with relatively strong motors, the Fostex even on the Fostex website with smoothed curves display the expected response: a quite large upper midrange/lower treble "mountain" with probably a lot of break-ups, and a somewhat diminished uper treble/supertreble region. This will result in a simply unbalanced sound.
Doping the cones in whatever overpriced magic goo will most probably not resolve the issue.
You can correct the balance, but breakups will remain. You can try by ear, but that´s a lot of guesswork. A decent microphone and a free measurement software will show you the direction you are going and will provide a solid ground for any further evaluations by ear.
The correction filter can be made passive, which is generally a series LCR filter with a parallel notch in it´s most simple form. It can be made with high-quality dsp as well.
Now you say you have a supertweeter as well, but how is the crossover done? Is there anything to control the Fostex´ rising response?
Whatever there is, and without wanting to diminish the importance of listening, doing some FR measurements will give you some insight what´s going on.
All the best
Mattes
I have not done FE208e∑, but have done a few FE168e∑ and FE108e∑.
I eould not recommend lacquer. It stiffens the cone, and can lead to exacerbating the classic Fostex shout.
I use thinned modPodge which dries flexible, still ties the surface paper fibres together, and damps, not makes worse, the shout.
dave