sp10 fs.

[killa]

So I finally have a wt3 and have been testing it. I tested my sp10 sunfire true sub clone and fs. was at a little over 50. I knew it didn't sound like it was tuned right. I checked wt3 on some other drivers and they tested close to published specs. So here are my free air measurements. Re 3.4ohm, Fs 42.39, Qts .604, Qms 5.388, Le 3.36. I am curious if these no. are close to others measurements?

[Jeff B.]

So I finally have a wt3 and have been testing it. I tested my sp10 sunfire true sub clone and fs. was at a little over 50. I knew it didn't sound like it was tuned right. I checked wt3 on some other drivers and they tested close to published specs. So here are my free air measurements. Re 3.4ohm, Fs 42.39, Qts .604, Qms 5.388, Le 3.36. I am curious if these no. are close to others measurements?

Those are almost exactly the parameters I measured on my Sunfire woofer. Vas is very small, which is what allows it to work so well in a very small enclosure. (By the way, I don't think the SP10 is a clone ).

[killa]

Those are almost exactly the parameters I measured on my Sunfire woofer. Vas is very small, which is what allows it to work so well in a very small enclosure. (By the way, I don't think the SP10 is a clone ).

I bought a passive off ebay and built my own so it is a clone Shouldn't the fs be lower with the passive though? It is a truesub replacement pr. and the box should be very close internally. I tried reverse mounting the sp10 to get more internal volume but fs didn't change much. Thanks for all the help btw. Its nice to know the wt3 came close to your measurements.

[Chris Roemer]

I bought a passive off ebay and built my own so it is a clone Shouldn't the fs be lower with the passive though? It is a truesub replacement pr. and the box should be very close internally. I tried reverse mounting the sp10 to get more internal volume but fs didn't change much. Thanks for all the help btw. Its nice to know the wt3 came close to your measurements.

I just happened to win a used SP10 (from miniscus) as a door prize at the recent Chicago DIY (my wife won me an emm-6 ;-) ). Not sure how many (if any) hours were put on it, but it WAS mounted. I measured it "cold" right out of a cold trunk when I got home. A few days later I tried to break in the suspension (not sure if it needed it or not). Kinda funny, but that suspension is soooooooo hard, I flipped the driver face down on a teflon cutting board and really pushed down hard to try to compress it (the weight of the 30 lb magnet alone barely budges it) ! I'm building a slot ported box for it, which I'll probably document during the Holidays.

I'm also listing some specs from Wolf (he said someone else verified them - it MIGHT have been Jeff?), and the "specs" that I've seen.

Yours:
Re 3.4ohm, Fs 42.39, Qts .604, Qms 5.388, Le 3.36
Mine - cold:
Re 3.7ohm, Fs 42...., Qts .61, ................. Le 3.16, Vas 0.26 cf
broken in:
Re 3.5ohm, Fs 40...., Qts .56, ................. Le 3.19, Vas 0.27 cf
from Wolf:
Re 3.3ohm, Fs 40...., Qts .552, ............... Le 2.3, . Vas 0.25
"spec"
Re 3.4ohm, Fs 34...., Qts .57, ................. Le 1.35, Vas 0.60

Notes:
Re - very consistent with spec, just don't measure it cold
Fs - VERY consistently about 41- kinda high compared to "spec"
Qts - pretty consistent with spec
Le - consistent between yours and mine, FAR OFF spec, Wolf's in between ?
Vas - very consistent, but VERY FAR OFF spec

It's POSSIBLE that after prolonged use, Fs could come down and Vas could rise, but would they ever approach "spec"? Don't know. I can certainly report back in a few years.

What's your PR tuned to (what's its moving mass), and how big is your box?
I'm shooting for a net Vb of 0.88 cf with an Fb near 24 Hz. Wolf was looking at using a PR, and I THINK his Vb is 1.3? cf with an Fb near 20?

Chris

[Jeff B.]

I bought a passive off ebay and built my own so it is a clone Shouldn't the fs be lower with the passive though? It is a truesub replacement pr. and the box should be very close internally. I tried reverse mounting the sp10 to get more internal volume but fs didn't change much. Thanks for all the help btw. Its nice to know the wt3 came close to your measurements.

I don't understand the question. How would the passive radiator lower the driver Fs? Are you referring to the box tuning instead? In my Sunfire the passive radiator tuned the system to about 22Hz.

A driver and system like this can be hard to measure because their suspensions are so stiff. It is possible that the WT3 is not generating enough current to activate the passive radiator and see its effect on the system impedance. I measured the passive tuning using a close-mic'ing method instead.

[Wolf]

Wolf was looking at using a PR, and I THINK his Vb is 1.3? cf with an Fb near 20?

Chris

I'm using the BASH 500W from PE, and the boost-setting is incorporated into the design. I've heard something recently that states the stock boost setting may have changed on the BASH500, so I don't know how repeatable this will be.
There you go!
Wolf

[killa]

I don't understand the question. How would the passive radiator lower the driver Fs? Are you referring to the box tuning instead? In my Sunfire the passive radiator tuned the system to about 22Hz.

A driver and system like this can be hard to measure because their suspensions are so stiff. It is possible that the WT3 is not generating enough current to activate the passive radiator and see its effect on the system impedance. I measured the passive tuning using a close-mic'ing method instead.

Yes I meant box tuning. I was thinking that wts might not work well with the stiff suspension. i'll try close micing it.

[killa]

What's your PR tuned to (what's its moving mass), and how big is your box?
I'm shooting for a net Vb of 0.88 cf with an Fb near 24 Hz. Wolf was looking at using a PR, and I THINK his Vb is 1.3? cf with an Fb near 20?

Chris

Not sure how much mass is on it. It is a sunfire replacement PR so I figured if I make the box the same as the sunfire the tuning should be the same. That is why I measured it.