Greets!
Who knows? There's various reasons why there's discrepancies over the course of a driver's production run with the original often based on theory/specific app rather than available (cheap) parts, especially in ones that run into many decades!; so we can design based on an average or do as many of us 'old timers' have done and just make the biggest version that can be tolerated and tune to 'taste' in room.
Take care you can close the window.
Any damping like foam directly behind the driver will help. Does not need to be much. But often there is no damping at all and that sounds bad.
You can use white polyester baf wadding or foam. If the window is no problem you can put more damping.
But you are secure concerning space with just one layer of 3 to 5 cm foam behind the driver.
The small resitance in line with the driver can be done if you use no crossover at all like LCR correction in the mids.
It's derived from Esa Merilainens simple resistor method of lowering distortion and even small resistances do some magic. (website current drive info).
I know that this tweak makes work and rarely people dare to try it out.
But this does not mean it has no benefits. In the thread "How to make a loudspeaker sandwich cone" I tell about loudspeaker history, the theory behind it and I give three times arta waterfall measurements which show for fullrange drivers - usually resonant in the mids - results which justify the effort.
https://www.diyaudio.com/community/...loudspeaker-sandwich-cone.402917/post-7444206
The tweak mainly influences stability and damping of the loudspeaker cone.
Indeed! I have a pair of some no-name ~5"? FR drivers from a DIYer 'somewhere' in Europe (need to 'dig out' the box for name, etc.) + another pair with tinfoil as the main tweak and while the sum total of differences 'sound' modest due to a higher Qt combined with ~no motor/frame reflections/resonances tweaks they still manage a 'night n' day' difference WRT perceived detail, clarity, transient response that makes it a worthwhile endeavor to those with the patience (not me).
Thanks for this, good suggestion. I did some playing around in Win ISD and I agree 70L looks good, or possibly 75.
I was initially chasing the QB3 alignment because my last speaker was a SBB4 and had disappointing bass performance, however it was a completely different beast to this one. 75L and 35Hz looks to be a good intermediate configuration and the box size is definitely more manageable!
I am thinking of using bitumen tape and expanding polyurethane foam to proof the door. Do you think this would be sufficient?
The drivers got delivered today.
Bitumen is good.
Any damping is better than no damping. Yours will help the sound a lot.
Make a comparison with the balance knob on your car radio: same speaker with and without damping.
Then you get a feeling what it makes.
Diy doing your own car speakers gives you the chance of making listening tests.
People only buying ready made products can never learn what a single tweak can make a difference
Any damping is better than no damping. Yours will help the sound a lot.
Make a comparison with the balance knob on your car radio: same speaker with and without damping.
Then you get a feeling what it makes.
Diy doing your own car speakers gives you the chance of making listening tests.
People only buying ready made products can never learn what a single tweak can make a difference
So I got the drivers and I wanted to try them out before installing in the car. I installed them in an enclosure of some vintage 2-way Sony 8 inch speakers with passive radiators and they seem to have a lot of potential, so now I want to buy another pair (one for the car and one for the speakers).
I need some help deciding what's the best approach to utilise the enclosures as I love their look. The enclosure is about 26L, 15.5x30x56cm
a) Replace the passive radiators and if so with which? I have no idea about radiators and how much difference they will make but my options for 8'' seem to be limited to
SB Acoustics SB20PFCR-00
Dayton Audio Designer DSA215-PR
Dayton Audio DS215-PR
b) change the front panel of the speaker completely and go sealed
c) change the front panel of the speaker completely and go ported
d) leave the old radiators and use it as it is using low shelf filter
I get the feeling that the current radiators make the mid bass sound muddy. As they are currently they drop really quickly below 75-80 hz. I want to make them reach as low as possible before using DSP.
I need some help deciding what's the best approach to utilise the enclosures as I love their look. The enclosure is about 26L, 15.5x30x56cm
a) Replace the passive radiators and if so with which? I have no idea about radiators and how much difference they will make but my options for 8'' seem to be limited to
SB Acoustics SB20PFCR-00
Dayton Audio Designer DSA215-PR
Dayton Audio DS215-PR
b) change the front panel of the speaker completely and go sealed
c) change the front panel of the speaker completely and go ported
d) leave the old radiators and use it as it is using low shelf filter
I get the feeling that the current radiators make the mid bass sound muddy. As they are currently they drop really quickly below 75-80 hz. I want to make them reach as low as possible before using DSP.
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Get the sb20pfcr and go 1.5 way aperiodic, xo between 150 - 300 hz on the woof only.
That way you keep the sensitivity high, taking care of the baffle step and running the full range as a real full range.
Place a divider to split the volume in two, larger portion for the woof, smaller for the fr.
Use Basta to simulate all this.
That way you keep the sensitivity high, taking care of the baffle step and running the full range as a real full range.
Place a divider to split the volume in two, larger portion for the woof, smaller for the fr.
Use Basta to simulate all this.
Hi there. Trying to decode everything as I am not that knowledgable on these. Going aperiodic would mean to use a flow resistance vent where the tweeter was? And how is 1.5 possible with just one driver and a passive radiator? I also don't understand how a crossover would be applied for just one driver. I am sorry but I feel a bit stupid tbh trying to understand.
Larger volume may work better for the FR. It needs a bigger box than the woofer. Q is about .85 with 23l full range and 17l woofer with a coil in place.
26L total sounds pretty small for the pair, but if you make it leaky enough it’ll probably work
Styjp, he is saying to replace the passive radiator with a woofer run in a 1.5 way configuration. Coil and maybe zobel on the woofer and no components on the full range. Resistive vent usually go on the back.
It’s techniqually too small a box for that driver with a passive radiator. You need about twice that size. But if you must, you could use the matching SB 8” passive radiator.
If it was me, I’d block off the opening for the passive and use it sealed. Near wall or with a sub it’d sound quite strong in the bass
It’s techniqually too small a box for that driver with a passive radiator. You need about twice that size. But if you must, you could use the matching SB 8” passive radiator.
If it was me, I’d block off the opening for the passive and use it sealed. Near wall or with a sub it’d sound quite strong in the bass
It’s probably too small ported but no harm in trying. But a lightly stuffed port makes a pretty good aperiodic. Heavily stuffed for sealed.
Btw, I modeled the scanspeak discovery horn tweeter (the old vifa one) and it looks great crossed to the SB full range driver. Not sure if that fits your tweeter cutout but I think they are still on sale atm.
Btw, I modeled the scanspeak discovery horn tweeter (the old vifa one) and it looks great crossed to the SB full range driver. Not sure if that fits your tweeter cutout but I think they are still on sale atm.
Finally got around to putting them into an old enclosure. I've got a mountain of this open cell eggcrate foam so that went in there. Very roughly set up over a 15", so far sounds quite detailed. Haven't bothered sealing the old driver holes yet as they're lying on some carpet tile and rolled off at 400hz.
Thought I'd give these drivers a go in an open baffle arrangement to see if I like the open baffle experience (never tried it before). Other than very little bass (as expected) they sound pretty good! I might try some kind of baffle step compensation or inductor in series to see if I can increase the bass output slightly. The baffle size is 50x70cm with the driver centres 20cm from the top edge. Any thoughts on a good starting point?
Will definitely be trying a "proper" open baffle design next with some 15" woofers.
Will definitely be trying a "proper" open baffle design next with some 15" woofers.