10" GRS subwoofers showed up today...

[johnnyrichards]

...pics for now, need to get them warmed up and broken in before doing some sweeps. Built like a tank, $20 gets a lot of driver.

The website pics make it hard to tell, but the dustcap is inverted. The motor large, bumped and vented backplate, 2" voice coil. Frame is typical cheaper stamped steel, but it has an extra roll around the inside edge of the "knockouts". Little bit of squeeze of glue around the gasket. Otherwise, looks very good.





I happen to have a pair of cabinets out in the garage that I have been looking to repurpose for some time now. These will be perfect.

[Jethro]

Re: 10" GRS subwoofers showed up today...

They look like the kind of stuff Rockford Fosgate sold with a Punch logo for $150 each 20+ years ago.

What size cabinets are you planning to put them in? IIRC, they model OK in as small as 1 cf each sealed and stuffed, but really modeled well in 2 cf plus.

[johnnyrichards]

Re: 10" GRS subwoofers showed up today...

They look like the kind of stuff Rockford Fosgate sold with a Punch logo for $150 each 20+ years ago.

What size cabinets are you planning to put them in? IIRC, they model OK in as small as 1 cf each sealed and stuffed, but really modeled well in 2 cf plus.

Well... if I measure them to be very close to advertised T/s, I am going to do this with them:







This is modeled using the Dayton 250W plate with the 6db of boost at 30Hz enabled, and 80Hz lowpass added. 3" x 16" port. F3/6/10 of 29.4/26.6/23.8

No exceeding of Xmax, port velocity under control. Me likey.

[craigk]

Re: 10" GRS subwoofers showed up today...

Well... if I measure them to be very close to advertised T/s, I am going to do this with them:

[ATTACH=CONFIG]52916[/ATTACH]

[ATTACH=CONFIG]52917[/ATTACH]

[ATTACH=CONFIG]52918[/ATTACH]

This is modeled using the Dayton 250W plate with the 6db of boost at 30Hz enabled, and 80Hz lowpass added. 3" x 16" port. F3/6/10 of 29.4/26.6/23.8

No exceeding of Xmax, port velocity under control. Me likey.

these look like they could be a nice find.

[Jethro]

Re: 10" GRS subwoofers showed up today...

Hopefully the design works out well -- definitely wouldn't be my first choice based on T/S parameters: http://www.parts-express.com/grs-10s...4-ohm--292-482

[johnnyrichards]

Re: 10" GRS subwoofers showed up today...

Broke in for 15 minutes at 30Hz at close to Xmax.

Very impressed with the consistency between advertised and measured. The differences between the two are well within tolerances, and attributable to different test methods.



56.8L = 2ft^3

[Jeff B.]

Re: 10" GRS subwoofers showed up today...

Hopefully the design works out well -- definitely wouldn't be my first choice based on T/S parameters: http://www.parts-express.com/grs-10s...4-ohm--292-482

Off topic, but shouldn't that equation be written as:
[(Vas/Vbox)+1]^.5=a or sqrt[(Vas/Vbox)+1]=a

[Jethro]

Re: 10" GRS subwoofers showed up today...

Off topic, but shouldn't that equation be written as:
[(Vas/Vbox)+1]^.5=a or sqrt[(Vas/Vbox)+1]=a

I'm pretty sure you are technically correct. I should probably fix that...

[Jay1]

Re: 10" GRS subwoofers showed up today...

Broke in for 15 minutes at 30Hz at close to Xmax.

Very impressed with the consistency between advertised and measured. The differences between the two are well within tolerances, and attributable to different test methods.

[ATTACH=CONFIG]52921[/ATTACH]

56.8L = 2ft^3

Nice! That's a lot better then advertising Qts in the .4 range when they are really .6

[Jethro]

Re: 10" GRS subwoofers showed up today...

Very impressive tolerances, indeed. Not much worse than changing your design after drivers arrive because they measure so far out of spec...

[tomzarbo]

Re: 10" GRS subwoofers showed up today...

That looks like a pretty good deal for a low-reaching sub. $20 is a super-nice price if it does what it looks like it will do. I'm tempted to purchase a few for making mid-size subs as gifts for friends/family.

How was it when you were breaking it in Johnny,... was it mechanically very noisy? I see what you're saying about the openings in the basket being rolled in -- which I would think would add some additional stiffness. And probably make it sharp too! Your pics were a little more revealing of surface details, PE's pics of speaks are often kind of dark.

Thanks for posting about this.
TomZ

[JasonP]

Re: 10" GRS subwoofers showed up today...

Glad these are looking as good as they promised in the first thread, thanks for testing and sharing JR!

[[email protected]]

Re: 10" GRS subwoofers showed up today...

Kind of a good looking cone. Like that big vent too.

[jhollander]

Re: 10" GRS subwoofers showed up today...

Hopeful they can make 1000 Hz x-o....

[Jethro]

Re: 10" GRS subwoofers showed up today...

Seems like it could be a good low power / larger box sub option. Modeling in a 2 cu. ft. sealed PE knock-down cab with 50% fill and 100W amp yields 42 Hz / 35 Hz / 28 Hz (F3 / F6 / F10) with a Qtc of ~.86 (approx. 1.8 cu. ft. net after subtracting woofer basket and amp). Should actually handle close to 175W before reaching Xmax in this box.

FR Graph. Red line is anechoic, Blue line is w/ room gain.


Cone displacement.