NEW GRS 10SW-4HE 10" High Excursion Subwoofer 4 Ohm

[rpb]

This is an inexpensive driver! I modeled it in 1 cu-ft, since I have an existing box that size, and then in a larger box shown below. It can play much louder with more power, but the port length gets excessive. At 100w, I think a 2" port might be OK. (30 m/s at 20hz ) If the amp has a high pass filter, that would be reduced. If tuned even lower, the vent air velocity drops to 20 m/s at 20hz, and 30 m/s at 15hz.

I'm tempted to get one, although, I don't really need it. (On sale for less than $50 )

[Harvylogan]

Interesting driver. If used below 100hz it would be much more efficient than the 84db @ 2.83v on the spec sheet would indicate.

[johnnyrichards]

Model the 8"...

The 12" is my daily driver subwoofer. It is a great performer and IMNSHO represents the best value in bass drivers currently available. I run a pair in the basement powered by the old Dayton 240W plate amps. 2.5 cubic feet, tuned fairly low. Lot of clean output. The 10" looks good as well, and the 8" models superbly. The 15" is priced way too high and models relatively poorly for HT use. Probably insane in a car, though.

[Chris Roemer]

Yup. It models about +3dB louder than spec.
In a 1.0cf box w/an 11" long 3" PrecisionPort it does mid 30s, and can take 200wRMS (@ < Xmax) below 30Hz. About 110dB.

[wogg]

Jeebus that 8" sub is great. That's now the top contender for a Bazooka EL8 killer replacement someday for my SUV. Can easily get into the 20's in a cubic foot or so, blasting past my current 40Hz sharp roll off in the car that I don't like.

[Brian Steele]

The published specs seem to be off a bit for that driver. When I imported its ZMA file into my semi-inductance workbook, it suggests that the Qes is actually 0.52, not 0.34. That much of a difference will change things considerably.

Here are the parameters that the workbook derived from the driver's ZMA file:
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Also, neither the 8" or 12" version quote Qes values as low as the 10" version, which further suggests that the published values might be incorrect.

[billfitzmaurice]

Something is off. When I entered everything but Qes and Qts into WinISD it calculated a Qes of 41.7 and Qts of .363. It's still a very good driver for the $$, but I'd break in and measure it before settling on a box design.

[wogg]

I did notice BB6 complained about a couple parameters when i plugged them in. I agree measurements would be good. Still looks promising, could be quite a bit worse than the published spec and still competitive.

[Chris Roemer]

Not sayin' that GRS' specs are accurate, but Qts = Qes * Qms / (Qes+Qms)
Brian and Bill's numbers don't jive, but the 10SW-4HE' s do.

Also, an (old) AUDAX HM210G0 had a Qes = 0.36, Qms = 2.70, and Qts = 0.32 (which are nearly identical).
So there's nothing wrong w/those Q numbers (mathematically).

[billfitzmaurice]

There's nothing wrong with the Q numbers if they're the only thing you look at. But when taken in context with the rest of the published specs they don't hold up to the light of day. In WinISD, for instance, if you enter the Q numbers from the spec sheet first the calculated electro-mechanical parameters don't agree with the spec sheet. If you enter the electro-mechanical numbers first the calculated Q numbers don't agree with the spec sheet.

[Brian Steele]

Not sayin' that GRS' specs are accurate, but Qts = Qes * Qms / (Qes+Qms)
Brian and Bill's numbers don't jive, but the 10SW-4HE' s do.

Um, I didn't quote Qts in my post. I provided only Qes and Qms. They're calculated using a curve fit in the workbook that I used, so if the ZMA file for the driver is accurate, then the calculated values for Qes and Qms I provided should be accurate as well, more accurate than DATS IMO because DATS does not take the semi-inductance parameters into consideration.

Given the values for Qes and Qms provided by the workbook, Qts works out to (0.519 * 3.73) / (0.519 + 3.73) = 0.46. That's quite a bit higher than the published value of 0.31.

So, either the published values for the driver are incorrect, or the published ZMA file for the driver is incorrect. My money's on the former because both the 8" and 12" versions of the driver have higher published values for Qts.



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[rpb]

So, show us what your sim shows for a 47 l box with a 60hz low-pass, and a 19hz high-pass. It doesn't matter to me, cause I'm going to buy the 12" version.

[Brian Steele]

So, show us what your sim shows for a 47 l box with a 60hz low-pass, and a 19hz high-pass. It doesn't matter to me, cause I'm going to buy the 12" version.

Unfortunately I can't do that, as if the published spec for Qts is off, there's a good possibility that the published spec for Vas is off as well, and at the minimum Vas, Qts and Fs are needed to any box modeling.

[rpb]

So if there's a good chance the specs are off, there's also a good chance that the driver may perform even better than what's shown in my sim!

OK so, I randomly changed Vas, Qes, and fs in my sim, and left the box size, and tuning the same. Just look at that f3! I conclude that this is still very nice, and the room acoustics will have a much larger effect than your suggested imperfections in the specs. I can make up some more specs if I didn't make my point here. Also, I suppose some builders might use a little EQ as well.


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[aarond]

Last year I bought a set of Polk SRT's. Price was good as one of the sub amps was inop and one of the 4 10" subs had been replaced after being blown. The mains had some beat up grills ans some slight damage to the cabs but work great and are sitting in my living room (with the grills off), In the meantime the second sub amp quit working.

I've gone back and forth trying to decide on what it would take to return these to their full glory. The sub amps at the very least need the PS caps replaced (10,000µF x 4 x 2) and who knows what else. But the amps are only rated for 300 watts each, good by mid-90's standards but not so much by today's standards. I have other working amps I could use instead and a single 1,000 wat amp seems like the most practical solution.

I've debated dropping a single 15" Dayton RSS HF sub into each 3 cubic foot sub cabinet. That would probably yield the most impressive result but it's also the most expensive option. I've been meaning to shop for 10" diver options as well but the cabinet is a single reflex bandpass design so getting a driver with specs close to the factory sub is key to getting predicable results. I'd been contemplating a post asking for help on this. Considering the price of these GRS drivers and how close the (yet to be fully determined) specs seem to be then I might have a pretty affordable option.

Polk Sub:
Qt: .584
Fs: 29.6
Vas: 1.284cf
It's basically a 2 ohm driver. 2/side in series for a 4 ohm leod on each dedicated amp.

GRS sub:
Qt: .31 (published), .46 (figured from published ZMA files)
Fs: 29Hz (published)
Vas: 1.36cf (published)
Power is rated at 200 watts. I'm not sure if this is more of a thermal or mechanical limit. A bandpass enclosure should help limit excursion. If I use a 1,000 watt amp then 250w/sub doesn't seem too crazy.

Maybe the folks at PE could test these drivers (8,10 and 12 and 15) so we know exactly what to expect.​

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[billfitzmaurice]

Power ratings are thermal. Most modeling software programs will show mechanical limits. Since it will be different in every enclosure there's no point in testing it, especially as you can calculate it for whatever enclosure you use.

[[email protected]]

We reviewed the specs on these 3 new GRS drivers and did find quite a few discrepancies in the T/S parameters... specifically on the 10" (292-818) and the 15" (292-822).
Here are the verified specifications:

8SW-4HE SPECS (292-816):

Impedance: 4 Ohm
Re: 3.8 Ohms
Le: 2.7mH
Fs: 24.9Hz
Qms: 4.42
Qes: 0.51
Qts: 0.45
Mms: 93.7g
Cms: 0.44 mm/N
Sd: 227 cm3
Vd: 243.9 cm3
BL: 10.51
Vas: 31.6L
Xmax: 10.5mm
VC Diameter: 50.8 mm
SPL: 85 dB @ 2.83V
Power Handling (AES426B): 150
Usable Frequency Range (HZ): 30 – 700


​10SW-4HE SPECS (292-818):

Impedance: 4 Ohm
Re: 3.8 Ohms
Le: 3 mH
Fs: 25.2 Hz
Qms: 4.00
Qes: 0.57
Qts: 0.50
Mms: 110.7g
Cms: 0.36 mm/N
Sd: 346.4 cm3
Vd: 379 cm3
BL: 10.8 Tm
Vas: 60.7 L
Xmax: 11 mm
VC Diameter: 50.8 mm
SPL: 87.5 dB @ 2.83V
Power Handling (AES426B): 200
Usable Frequency Range (HZ): 26 – 500


15SSW-4HE SPECS (292-816):

Impedance: 4 Ohm
Re: 4.2 Ohms
Le: 3.7 mH
Fs: 20.7Hz
Qms: 4.27
Qes: 0.55
Qts: 0.49
Mms: 283.8 g
Cms: 0.21 mm/N
Sd: 819.4 cm3
Vd: 998.6 cm3
BL: 16.6 Tm
Vas: 196.6 L
Xmax: 12.3 mm
VC Diameter: 63.5 mm
SPL: 90 dB @ 2.83V
Power Handling (AES426B): 300
Usable Frequency Range (HZ): 20 - 300
​

All of the physical dimensions, impedance curve, and measured frequency response are correct.
​The product page on the website will be corrected as soon as possible and new spec sheets will be up in a few days.

Thank you for bringing this to our attention.