10" GRS subwoofers showed up today...

[[email protected]]

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

I wonder what listening tests have been done to confirm whether the "ideal" 0.707 Qts for full-range speakers is also ideal for subwoofers, or whether a Qts between 1.0 and 1.5 would be more satisfying in its character. It would be good to read some impressions of this.

[ROTECH]

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.

RF stuff was paper coned. I lost my audio virginity during those days of RF. This $20 driver would probably be really nice tripled up with 500w in a trunk.

[Jethro]

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

RF stuff was paper coned. I lost my audio virginity during those days of RF. This $20 driver would probably be really nice tripled up with 500w in a trunk.

That's true, it was their cheaper "Series1" line that had the poly cones -- and no vented pole piece. I still have my original Punch 12's from ~1989 -- but they are just wall art now.

[johnnyrichards]

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

That's true, it was their cheaper "Series1" line that had the poly cones -- and no vented pole piece. I still have my original Punch 12's from ~1989 -- but they are just wall art now.

All of the Series 1 I had used a similar paper pulp cone to the Punch, the first several pairs had the gray cone treatment, and another pair had black cones. I believe the later RF subs utilized a lot of poly cones, like the Prime and the later Punch.

[johnnyrichards]

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

This $20 driver would probably be really nice tripled up with 500w in a trunk.

I think so, too.

[johnnyrichards]

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

Yessir, wee bit sharp in there.

The frame itself is a bit noisy, but at full excursion the motor itself seemed to hold together pretty well. No chuffing from the backplate vent, spider behaved itself quietly and audible distortion from the cone was very minimal. When I had it pumping in free air and held the thing by the basket it was pretty quiet over all. A very good candidate for some rope caulk basket treatment.

[Jethro]

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

I wonder what listening tests have been done to confirm whether the "ideal" 0.707 Qts for full-range speakers is also ideal for subwoofers, or whether a Qts between 1.0 and 1.5 would be more satisfying in its character. It would be good to read some impressions of this.

It really comes down to how well a given subwoofer/enclosure system can be integrated into the rest of the sound system / room to provide optimally flat frequency response. In the case of my own listening room and system, the lower Qtc alignments are simply easier to integrate into the rest of the system, and therefore tend to sound better. Here's an example:

Blue line is SW10-4 in 3 cu. ft. sealed (.79 Qtc), and the Red line is SW10-4 in 1 cu. ft. sealed (1.05 Qtc).


The main differences in this graph are the better low-end extension in 3 cf (25Hz vs. 38 Hz in 1 cf), and the fact that I wouldn't have a ~2.75 dB resonant peak at 78 Hz to deal with. If you want to advertise drivers as fitting into smaller boxes than is really optimum, that is your prerogative -- you will probably sell more woofers that way; but that doesn't mean it's really the best size for it.

[mattsk8]

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

Great find Johnny! Can't wait to hear these.

RF stuff was paper coned. I lost my audio virginity during those days of RF. This $20 driver would probably be really nice tripled up with 500w in a trunk.

This brings back some memories!! Can't remember the exact name, it was something like Carbenaw Industries, but they were right in Grand Rapids when I was growing up and they made the Punch woofers. I think it was late 80s and I was a younger teenager, but my dad had a bunch of them because my uncle worked there and would get the "blems". Replaced the 12" woofers in his Sony monkey coffins with some, a pair of 12" in his van. So I can relate, those were the days

[tmhutson]

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

I bet these have a similar sound to the kicker 12" woofers I bought for cheap recently. They are from very early 90's and want a big sealed cabinet.
I still want to do a PPSLIB on the rear deck of a car with a bunch of these or it's smaller 8" brother. :D

[Ray Tremblay]

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.

Exactly! Looks like an old JL 10W1.

[Paul Ebert]

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

I wonder how these, or the 12" model, would do in a dipole line array....

[Jethro]

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

I wonder how these, or the 12" model, would do in a dipole line array....

I would think the high Qts of the 12" model would make it favorable for dipole use. http://www.parts-express.com/grs-12s...4-ohm--292-484

Just modeling up some IB options, a quad of the 12's mounted IB (I modeled in 21 cu. ft. total) with 500W total would make a nice poor man's sub setup -- under $100 for four 12's. The Qtc would still be right around 1.0, but the low Fc of 32 Hz, combined with an F3 under 30 Hz, should be pretty manageable in-room.

FR Graph - (4) GRS SW12-4 in 21 cu. ft. (IB, no room gain)


Cone Displacement with 500W total

[Pete Basel]

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

Reminds me a lot of a 4 ohm version of the old Eclipse 10" - but it could just be looks:

https://www.madisoundspeakerstore.com/approx-10-woofers/eclipse-w1038r-10-poly-cone-woofer-8-ohm/

The Eclipse 10" was optimized by Mark at Meniscus and he says that they worked hard to
get a smooth upper end response and that they (the Eclipse woofers) are very similar
to the old woofers from Audio Concepts. The Eclipse 10" was previously made by
Eminence and Mark says that these are just as good - I have not tried them since I want
a 4 ohm version.

This GRS seems to have a weaker motor - too bad, I'd pay $10 more for more magnet.
I'd really like to see their frequency response. Price is certainly good.

[JasonP]

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

... I'd really like to see their frequency response. Price is certainly good.

+1

[johnnyrichards]

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

Well, judging strictly by the impedance profile, I would say there is little to no breakup. I would say it is safe to shoot for no higher than 1000Hz. If I get some time later in the week, I will do a baffleless near field on it.