(wow I have a lot of posts here)
I've been working on MFB based circuitry, and got myself a test dummy speaker. The speaker in question is a Dayton E150HE-44. The cone is made of carbon fiber. Fortunately for me, the dust cap is not one continuous piece with the cone. It's glued in. With that in mind, would it be possible to maybe heat gun the glue to loosen the dust cap without destroying it? That way I could reuse it!... I hope...
I've been working on MFB based circuitry, and got myself a test dummy speaker. The speaker in question is a Dayton E150HE-44. The cone is made of carbon fiber. Fortunately for me, the dust cap is not one continuous piece with the cone. It's glued in. With that in mind, would it be possible to maybe heat gun the glue to loosen the dust cap without destroying it? That way I could reuse it!... I hope...
The usual way to remove a dust cap without destroying it is to use an X-Acto knife and a lot of skill.
If you can get the dust cap epoxy glue joint hot enough to burn, char or become brittle, (without burning the surround, spider and coil joint) you will still need to cut the glue joint.
What are you planning to put under the dust cap, and how will you connect it?
If you can get the dust cap epoxy glue joint hot enough to burn, char or become brittle, (without burning the surround, spider and coil joint) you will still need to cut the glue joint.
What are you planning to put under the dust cap, and how will you connect it?
I was looking into the piratelogic accelerometers for MFB. The voice coil is large enough to put in one of their more accurate sensors https://piratelogic.nl/?p=en.accelerometers the star bass
I was tinkering with the idea of making one on my own, but go figure parts are expensive, so I'm still fiddling with it. But yes MFB sensor thats the idea
I was tinkering with the idea of making one on my own, but go figure parts are expensive, so I'm still fiddling with it. But yes MFB sensor thats the idea
I have found that in all the cases i have seen, destruction of the cap is necessary. You can buy new dustcaps.
http://www.planet10-hifi.com/pp-install.html
I use a scalpel, and clean up with some sandpaper.
dave
http://www.planet10-hifi.com/pp-install.html
I use a scalpel, and clean up with some sandpaper.
dave
the relation between (active) driver and input signal is not here anymore, as for the helmholtz resonance frequency the active radiator barely moves while passive radiator(s) will produce the output.
also it is inherent to a resonator to have much more group delay (that's how the "free" additional output is produced). This output signal cannot be compated to the input anymore. If you monitor the cone movement of passive radiators to correct the active driver you would produce an oscillator.
Motion feedback only makes sense and is feasible with sealed enclosures, as far as i know.
Oh wow. That would be an issue. So one thing I am doing with this build is DSP and servo control for all speakers. With that said, what would be a greater improvement to the design overall: MFB or passive radiators?
Do PRs make it unsealed? Or is this just what it's referred to categorically?
Yes, just a more massive/resistant version of the air trapped in the vent, i.e. you can design a PR by simming a vent of the same piston area (Sd) and calculating its air mass plug's weight.
MFB if done right can increase the accuracy of output (including lowering extension, lowering harmonic distorsion). You still must (or should) stay within the excursion and power limits if your driver.
Passive radiators will increase the lower frequency output, just like bass reflex at the expense of higher group delay (less accurate transient reproduction).
With MFB you try to include the voice coil movement into a feedback loop of your amplifier, which can reduce unlinearities of the driver.
The most common loudspeaker glue is black and made by C P Moyen. It is easily remove by applying lacquer thinner or MEK. Apply it with a small brush directly to the dust cap edge at the glue line. Use lots of ventilation. There are some white glues used and they dissolve in water with a small amount of chlorine bleach. Some folks do use a two part adhesive that cures and cannot be partially dissolved and easily removed. Fortunately this is the least common adhesive and is typically used on the spider and rim where the stress is the highest.
Dude, you're a saint! Thanks! Will probably use this once I finish working on the sensor 🙂
If the chassis has a pole vent, put some non magnetic rod into the hole. That way you can apply (limited!) pressure to the dustcap from the inside, while heating it up from the outside or carefully applying some thinner.
If there is no hole in the magnet or a some type of mesh in the way, a vacuum cleaner with a round end piece can be used to pull out the dust cab without damadge.
The vacuum is also handy to remove dents from speaker cones. You can use some rubber or silicone hose to adapt to the specific case.
The pirate logic sensor is dead cheap and well developed. Get the electronics, too. No way to DIYS it cheaper if you want to have a working speaker during the next decade. This is serious engineering, physics and development where competent people have spent years of work on. Not some "any idiot can do it" stuff.
You will have enough trouble just implantig it, don't think you can copy it for 25$... even the plain sensor has gotten expensive in small numbers.
PirateLogic is not stupid publishing any detail freely, they know you can not build the system cheaper than they sell it.
If there is no hole in the magnet or a some type of mesh in the way, a vacuum cleaner with a round end piece can be used to pull out the dust cab without damadge.
The vacuum is also handy to remove dents from speaker cones. You can use some rubber or silicone hose to adapt to the specific case.
The pirate logic sensor is dead cheap and well developed. Get the electronics, too. No way to DIYS it cheaper if you want to have a working speaker during the next decade. This is serious engineering, physics and development where competent people have spent years of work on. Not some "any idiot can do it" stuff.
You will have enough trouble just implantig it, don't think you can copy it for 25$... even the plain sensor has gotten expensive in small numbers.
PirateLogic is not stupid publishing any detail freely, they know you can not build the system cheaper than they sell it.
I'm beginning to discover that. Trying to make my own the way I want to is apparently VERY expensive. 2 xyz sensors (using x and y to cancel out vibrating around the sensor and z to sense) and a laser diode is already hitting tilt. That and the piratelogic sensors at the moment are about 80usd a pop, and that's without shipping.