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Perhaps also try some soft glue on the back of the cone, at the outer rim, a strip about 1cm wide all the way around - helps tame the behaviour of surface waves at the cone-surround boundary. The glue needs to remain soft/flexible for this to work. I smeared some silicone on my 15" driver (Audio Nirvana).
I've found that there's only so much you can do to flatten the frequency response though so you either live with it or go for some line-level EQ (in my case I have found the Audio Nirvana OK to live with as-is).
I've found that there's only so much you can do to flatten the frequency response though so you either live with it or go for some line-level EQ (in my case I have found the Audio Nirvana OK to live with as-is).
I bought a pair of 8" full range drivers from a speaker builder in Melbourne. He has glued a a ring of felt about 10cm wide around the rear of the cone near the surround, exactly as you describe. I guess that the felt is less messy than a smear of silicon. But definitely aiming for the same effect that you are.
He also has a ring of felt on the front of the cone underneath the whizzer. He had previously used wool loosely wound around whizzer (is this the 99cent Lowther tweak) but says that he finds the felt more effective.
See my previous thread if interested in some pictures.
My OB Project
He also has a ring of felt on the front of the cone underneath the whizzer. He had previously used wool loosely wound around whizzer (is this the 99cent Lowther tweak) but says that he finds the felt more effective.
See my previous thread if interested in some pictures.
My OB Project
Thank you both 
I'll try and post.
Actually it sounds good and I don't bother too much with what measures tell.
The soft glue changed the sound presentation, now it's more "relax", in fact it didn't loose sparkle but it tamed a little bit what is so often irritating with full range drivers: cymbals, a feeling of false clarity.
Don't get me wrong, this is a very nice driver for the price, right out of the box.
I'll try and post.
Actually it sounds good and I don't bother too much with what measures tell.
The soft glue changed the sound presentation, now it's more "relax", in fact it didn't loose sparkle but it tamed a little bit what is so often irritating with full range drivers: cymbals, a feeling of false clarity.
Don't get me wrong, this is a very nice driver for the price, right out of the box.
Thanks, you mean 1mH in series then 5 to 8 ohms in parallel with the driver?
If that's correct, am I supposed to use the 4 ohm tap of the amplifier, instead of 8 ohm?
See picture, now there is one layer of soft glue on the rear of the whizzer and the woofer (about the same area as the whizzer).
I can't say if I hear any difference, but have to listen for a longer time.
Then do some tests with felt between the woofer and whizzer.
I wonder what will happen if I decide to glue the whole woofer? from calculation, it should add between 6 and 12g. Maybe not a good idea if it tends to reduce sensitivity at lower frequencies..
If that's correct, am I supposed to use the 4 ohm tap of the amplifier, instead of 8 ohm?
See picture, now there is one layer of soft glue on the rear of the whizzer and the woofer (about the same area as the whizzer).
I can't say if I hear any difference, but have to listen for a longer time.
Then do some tests with felt between the woofer and whizzer.
I wonder what will happen if I decide to glue the whole woofer? from calculation, it should add between 6 and 12g. Maybe not a good idea if it tends to reduce sensitivity at lower frequencies..
Attachments
This is the BSC circuit.
In your case, it may kill the highs after 10k though, but will sound more balanced.
In your case, it may kill the highs after 10k though, but will sound more balanced.
An externally hosted image should be here but it was not working when we last tested it.
It seems a RLC notch did the trick.
mh-audio.nl - Home
Very pleasing now but maybe too much attenuation, it depends on what kind of music is played. Good with classical or jazz in general but bass seems to be a little bit too prominent now.
I may try reducing the resistor from 8.6 ohms to 3.3 ohms if that's correct way of reducing attenuation.
mh-audio.nl - Home
Very pleasing now but maybe too much attenuation, it depends on what kind of music is played. Good with classical or jazz in general but bass seems to be a little bit too prominent now.
I may try reducing the resistor from 8.6 ohms to 3.3 ohms if that's correct way of reducing attenuation.
Attachments
-5db and 2000hz gives me the values 6.8ohm resistor, 14.22uF cap and 0.43 mH coil.
But I entered 8.8ohm impedance, since that's just about what it looks like around 2khz on the spec sheet of the 15-300TC.
... I like playing about with DSP because it's a bit cheaper than buying lots of components. It's been quite a few times I've bought caps and coils etc, only to find I did the math wrong, or had to adjust something, then it's off to order more stuff I will never be able to use for other projects...
Still think a well made passive solution is great, it's just not "simple".
But I entered 8.8ohm impedance, since that's just about what it looks like around 2khz on the spec sheet of the 15-300TC.
... I like playing about with DSP because it's a bit cheaper than buying lots of components. It's been quite a few times I've bought caps and coils etc, only to find I did the math wrong, or had to adjust something, then it's off to order more stuff I will never be able to use for other projects...
Still think a well made passive solution is great, it's just not "simple".
I put mine in a W bin.
hello
i intend to make and ob for theses drivers anyway as it is simpler , but i have a question about the w bin : for the hight frequencies are 'directional' is it good to place the driver 'backside' ?
the low frequencies will follow the horn but the hf?,
how does the speaker sound compared with ob if you have listened to both
thank you
dondiba
hello
i intend to make and ob for theses drivers anyway as it is simpler , but i have a question about the w bin : for the hight frequencies are 'directional' is it good to place the driver 'backside' ?
the low frequencies will follow the horn but the hf?,
how does the speaker sound compared with ob if you have listened to both
thank you
dondiba
I'd guess that you'd sacrifice a bit of top end in a W bin.
Dynamics would be fun, but probably a bit uneven response.
The 15" Fane works very well OB, if you are going to use it by itself, better use some EQ on it, either some dsp solution or the PC route with eqAPO or VM banana or whatever.
No problem punishing it a bit to get more low end.
Dynamics would be fun, but probably a bit uneven response.
The 15" Fane works very well OB, if you are going to use it by itself, better use some EQ on it, either some dsp solution or the PC route with eqAPO or VM banana or whatever.
No problem punishing it a bit to get more low end.
board dimension
hi
before ordering the wood :
120 cm * 60 is really huge, in my room
what if i cut a smaller one?
as i understand (almost nothing!) in an ob the board 's purppose is to avoid the cancellation of the lf waves
cancellation due to the shortcut between the front and the rear wave
in this respect the board in only as good as it shorter edge (width 60 cm)
so why not cuting a square 60 * 60 cm board ?
would that jeopardize the sound quality?
another question : is it better for the sound quality if the board is flush to the floor?
i intend to place the board onto small wooden feet 2'' - 3'' (5 - 7 cm) high : this will be kind of an aperture at the bottom of the speaker...
dondiba
hi
before ordering the wood :
120 cm * 60 is really huge, in my room
what if i cut a smaller one?
as i understand (almost nothing!) in an ob the board 's purppose is to avoid the cancellation of the lf waves
cancellation due to the shortcut between the front and the rear wave
in this respect the board in only as good as it shorter edge (width 60 cm)
so why not cuting a square 60 * 60 cm board ?
would that jeopardize the sound quality?
another question : is it better for the sound quality if the board is flush to the floor?
i intend to place the board onto small wooden feet 2'' - 3'' (5 - 7 cm) high : this will be kind of an aperture at the bottom of the speaker...
dondiba
I'm sure others with more knowledge will chime in here. The rule of thumb is the bigger the baffle the better. You can put "wings" on either side of the front baffle to make the effective baffle size larger while making it visually smaller. If you do that make one wing longer than the other.
Who needs experts? Aren't we all n00bs?
With the desired measurements, the baffle will roll off severely from a bit high up.
This is the reason I suggested using some form of eq to compensate, the wings should be relatively short, or it might cause a lot of reflections and sound weird.
If you get some more woofers for bass duty and implement an xo, you can work around the issue of rolled off bass with brute force.
I think the FC 152 sounded quite nice in OB, it was loud enough for me down to 30hz or so, even on a 55cm baffle with 10-15cm wings. Lots of eq helped, want less eq? get more woofers.
With the desired measurements, the baffle will roll off severely from a bit high up.
This is the reason I suggested using some form of eq to compensate, the wings should be relatively short, or it might cause a lot of reflections and sound weird.
If you get some more woofers for bass duty and implement an xo, you can work around the issue of rolled off bass with brute force.
I think the FC 152 sounded quite nice in OB, it was loud enough for me down to 30hz or so, even on a 55cm baffle with 10-15cm wings. Lots of eq helped, want less eq? get more woofers.
After having read all your comments I would have thought of making an ob with the fane 15-300TC and the fane 15 400-LF
on a 60x120 cm panel, possibly without any passive filtering. The OBs would be installed in a 10x10 meter salon.
and powered by a solid stage pre and final (McIntosh 100 / Proton 100 / Tecnics 110 w rms / ch)
Alternatively I could also use the 15-300TC and a Velodine Servo F-1000 sub (20-85 + - 3db, 80 Watt).
I already realized, several years ago, the Pensil 10.2 and I like them a lot, that's why I am tempted by full range more performing.
I thank everyone for the interesting discussions
Translated with Google.
on a 60x120 cm panel, possibly without any passive filtering. The OBs would be installed in a 10x10 meter salon.
and powered by a solid stage pre and final (McIntosh 100 / Proton 100 / Tecnics 110 w rms / ch)
Alternatively I could also use the 15-300TC and a Velodine Servo F-1000 sub (20-85 + - 3db, 80 Watt).
I already realized, several years ago, the Pensil 10.2 and I like them a lot, that's why I am tempted by full range more performing.
I thank everyone for the interesting discussions
Translated with Google.