Gauss Meter Readings

[@E-raticWarrior]

800+ That's like the top end of ferrite capabilities.

[@MrM_Full-Send]

it’s for a 4” 8layer so… should get some good BL numbers too🤔.. however the topplate is only 20mm so that will cause some losses

[@subdynoman]

I also want to measure the motor force of alum to copper by mass and then by total winding turns. AAAHHH SO MANY VARIABLES. It's hard to be a sub dyno man!

[@subdynoman]

I've been trying to come up with a crude way of measuring motor force just for the purposes of sensing the power made by the coil. I'm thinking of directly attaching the coil to a apparatus that will measure the force in different coil locations.

[@MrM_Full-Send]

i believe coil strength is measured in amp turns however this is a pretty useless variable without motor details… due to the fact that a specific VC will perform differently in different motors. force will be directly related to power applied adjusted for efficiency (determined by motor details, mms, etc). if i was going to set up an apparatus to measure force specifically i would build a sub using a motor with a pole vent then mount the sub up firing with no dust cap, 3d print a cone flange to sit on the cone over the vc run a linkage from the printed flange, through the pole vent to a fixed measuring device. then i would apply DC at specific Power increments and record force for each increment. Then I would graph the results.. These results would allow you to calculate a power to force relationship and determine efficiency for the specific motor/coil combination that was used 😊😉

[@MrM_Full-Send]

i wouldn’t leave dc applied for long periods. just enough to read force then shut it off. Just an Idea 🤷‍♂️

[@PunisherOfDeath101]

Im trying to rebuild my dd9500j subwoofers and need help picking out coils. Pole measurements are 75.70 ID 86.70 OD Im trying to decide between a copper coil with and od of 81.46 Vs a aluminum with an od of 83.8. My goal is a sql 10" with the ti frame. Id really appreciate your help. Thanks

[@MrM_Full-Send]

aluminum versus copper in and of itself will have little impact on sq. however the weight of the voice coil will affect efficiency as well as responsiveness and resonant frequency (heavier coil will be lower fs). it sounds like the aluminum might be an 8 layer? with such a difference in OD, 8 layer should provide a better BL…. I’m making some pretty large assumptions without knowing the exact coils you are looking at🤷‍♂️ there are lots of variables to consider here. box will play a significant roll too

[@KnowName33]

Where did you get your meeter from and how much was it?

[@MrM_Full-Send]

amazon, like… $160cdn I think?

[@woldemortxyz7996]

Hi, I've got a custom nsv318 I'm going to just change the coil on, how do you recommend removing the surround and spider from the basket without damaging them? They are glued on with CA. Also, how do you recommend removing them from the old coil? They use CA and some epoxy on the cone.

[@MrM_Full-Send]

CA glue is extremely brittle and can be “shattered”… you need to basically crack it with a screwdriver. it’s a pain in the ass and hard to explain without showing you.. in the past I just placed a screwdriver on top of the glue in between the basket flange and surround and tapped it with a screwdriver until it “broke”. Chemicals work however there is always a risk that the parts being separated will be damaged so on more expensive equipment i avoid using solvents… if your replacing a fried coil you can grind the adhesive off or burn it by heating the coil from the inside(always in a well ventilated area or outside) there is a video on my channel about burning voice coils to release them

[@MrM_Full-Send]

kzbin.info/www/bejne/iKfbd5dpl7ZppJYsi=EOq-nVnkzJ15GAi0

[@woldemortxyz7996]

Nice, thanks. Should I then remove all of the old CA before gluing them back to the basket? I bought some E6000 for the surround this time just in case. Also, would you recommend a triple joint ring? It's a pretty beefy sub with a 90mm long coil and 12" spiders. Using 10kW so I might reach the 45mm xmax.

[@MrM_Full-Send]

@@woldemortxyz7996 well.. I like triple rings so I would say yes to that by default. your not going to be able to remove all of the CA from the surround without… compromising the surround. if you are able to successfully remove the surround with out damaging it, I would just clean the basket flange with a bit of acetone or that chlorine stuff (i will look it up and add a reply) and glue the surround to the cleaned basket, as is. the surround and spider flanges should be essentially spotless. obviously the existing glue is well bonded to the surround so you shouldn’t have any adhesion issues. in high stress situations that are not for my personal use I typically order complete replacement cone assemblies from DTX, Corey, Otis Designs or somewhere like that. I can tell you what I would do however, the decision to proceed lies solely with you. there are a lot of places where things can get challenging so exercise caution

[@MrM_Full-Send]

@@woldemortxyz7996 dichloromethane paint remover