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Home / Product Category / SPEAKERS / Subwoofers / Outdoor Subwoofers / OSD In-Ground 8" 500W Outdoor Underground Burial Rated Subwoofer GLS8 Green

OSD In-Ground 8" 500W Outdoor Underground Burial Rated Subwoofer GLS8 Green

Product code: GLS8

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OSD Price: $169.99
Compare at: $449.00 You Save: $279.01 (62%)
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Features & Specifications

Get ready to rumble Bring your landscape to life with our powerful GLS8 In-Ground Subwoofer. To immerse yourself in music’s lowest tones while enjoying your outdoor retreat, OSD Audio offers the GLS8 In-Ground Subwoofer. Since the bulk of the subwoofer is buried underground, only the port needs to appear to the outside world. But just because you can’t see it doesn’t mean you won’t know it’s there. The subterranean design brings bold, deep bass and full-range audio to backyards of any size.

For optimum outdoor performance combine the GLS8 with our LS2 landscape satellite speakers. Create an unobtrusive stealthy outdoor sound system. Additional system configurations can be created for up to 8 pairs of speakers using multichannel amplifiers and or series parallel wiring.

• Buried subwoofer cabinet disappears into the landscape.
• Exposed vent can be primed and painted to blend into its surroundings.
• At less than 20 inches long, you can enjoy big sound with a small footprint.
• Easily expand your system with our compatible LS2 landscape satellite speakers.

Installation Tips:
• For the best quality sound place the subwoofer within 20 feet of the general listing area.
• Ensure the hooded output vent is away from the direct spray of sprinklers.
• Before burying the sub, put gravel at the bottom of the hole for drainage and leveling.



  View Owner's Manual          


11 Questions & 11 Answers
Kimball Willard
from St. George, UT asked:
September 20, 2019
Is there a 70V kit or adapter for this speaker?
1 Answer
Hi Kimball:

We do have an outdoor transformer, but its highest output wattage is 20W. I am not sure that will be enough for you.

The following is a link for a 50W transformer ( We also have a 100W version coming as well, but both are Indoor models. You would have to enclose them in a heavy-duty Waterproof enclosure.   We do have a couple of 70Volt subwoofer under our Black Series that have built-in transformers. The 8" has three power taps, 38W, 75W or 150W. The following is a link for Black Series 70V XSUB8 In-ground passive Subwoofer: and a 12 inch 70V: It has the following tap settings: 75W, 150W, 300W. How much wattage do you have available for your sub?

Let me know what you think:


Submitted by: Tim Leahy on September 22, 2019

Munroe Kelsay
from Houston, Texas asked:
May 18, 2019
This subwoofer has blue and brown speaker wires. Which is positive?
1 Answer
Hi Munroe:

Good question, I have been told the Green wire in Positive, Brown would be Negative. You can not hurt anything connecting it backward. It would be out of phase so cone would be going out when it should be going in. Connect to the Green (+) and Brown (-) and see how it sounds.


Submitted by: Tim Leahy on May 21, 2019

from asked:
March 16, 2019
Is the OSD SMP500 D too much amplifier for the GSL8? Appears the output of the amp far exceeds the max 500w the sub can handle. I was interested in the 250 mono however appears that model is no more?
1 Answer
Hi James: It is better to have a little more power, and the SMP500 rated at 400 Watts at 8 ohms. Which is perfect if you are connecting a single sub. But you can expand adding a second in-ground sub so the amp would see a 4-ohm load and increase the output to cover both subs. Still the perfect choice TL/5456
Submitted by: Tim Leahy on March 19, 2019

from Avon, IN asked:
March 14, 2019
Just received my GSL8 along with a few other goodies in the mail today. Looks AWESOME!!!!! Great service and very fast delivery thank you!! My plan was to use GR6 quad direct burial cable to connect the subwoofer to my amp but I see the GSL8 has a positive & negative wire. What's my best option? The subwoofer will be connected to a bridged amplifier. About 15-20' of total cable length buried and the cable will pass through the exterior wall / insulation & drywall.
1 Answer
Hi James: I believe you will have an issue terminating the cable to your bridged output from your amp to the input cable from the GSL8. You would be much better off using our CL3 12 gauge Direct Burial speaker wire. What amplifier are you using since most dedicated Sub amps are mono output already? Something like our SMP500 as an example. TL/5450
Submitted by: Tim Leahy on March 19, 2019

from 78023 asked:
March 11, 2019
What is the OHM of this speaker?
1 Answer
Hi Rob: The OSD 8" In-Ground Passive Subwoofer is 8 ohms. We recommend our SMP500 Digital DSP sub amplifier that is stable to 4 ohms so you can power two of these 8" In-Ground subs in parallel. You can see if a single sub will work for your application knowing you can add a second In-Ground sub if you feel you need more bass. TL/ 5448
Submitted by: Tim Leahy on March 14, 2019

from Florida asked:
September 10, 2018
My yard is 41’ d x 50’ wide, I have 6 pairs of LS3 speakers, I was thinking of adding 2 of the GLS8 subwoofers in each of the rear corners of my yard. Would this be enough to notice throughout the yard as far as the bass goes ?
1 Answer
Hi Rob: It sounds good, but what else are you not telling me. What is powering all of this, are you using volume controls, speaker selector and dedicated power amplifier? I would love to learn more maybe see a drawing of your outdoor area including dimensions. Maybe even include a few images of your yard? TL/5201
Submitted by: Tim Leahy on September 12, 2018

chad p
from KS asked:
June 2, 2018
Most receivers have an RCA jack for "Sub Out", how do I make this work assuming it's not an RCA from the Sub side?
1 Answer
HI Chad: The GLS8 is a passive subwoofer that is rated to handle 500 Watts. It has a 2 conductor speaker wire that you connect to a dedicated subwoofer amplifier. The Subwoofer amplifier is connected to the Pre-amp output of the Receiver. This is a low-level connection before the signal is amplified by the dedicated Sub Amp before it is connected to a low (or speaker) level 2 conductor input on the GLS8. Most outdoor subs especially in-ground are passive subs that need a dedicated sub amp to drive them. I hope that helps... TL/5025
Submitted by: Tim Leahy on June 4, 2018

from Atlanta, GA asked:
April 23, 2018
I am debating between this and the RSUB300 for our pool in the backyard. Does one provide more kick or better performance than the other or is it simply a matter of buried vs above ground? This would be paired with a pair of AP850's on a Denon 3805.
1 Answer
Hi Jason: The RS Sub has been around a while longer. It comes down to personal; preference on your layout. The RSUD300 goes a little lower with its 10" passive radiator 20Hz vs 28Hz. Plus the sensitivity matches the AP850, 90 dB (vs 84 dB) which means it is more efficient and does not take as much power to get it pounding. Both, we would recommend adding the SMP250 dedicated sub amp to drive them. TL/4927
Submitted by: Tim Leahy on April 27, 2018

from OK asked:
April 16, 2018
Would it be better to buy two of the small green subwoofers or 1 of these. Witch sound better
1 Answer
Hi Alana: That is a loaded question, what else are you planning to purchase for speakers? That would help depending on how much area you are covering. In the outdoors usually more is better... TL/4914
Submitted by: Tim Leahy on April 17, 2018

from Whittier, Ca asked:
March 29, 2018
i purchased 3 pairs of the ls2 speakers and a nero xd. every thing is working great but i need a little more kick. will the osd in-ground 8" 500w sub work with my set up? how would i hook it up(LT. Channel or RT channel or to the sub out)?...
1 Answer
Hi Paco: First thing the NERO is 4 ohm stable so should only have a maximum of two pair of 8 ohm speakers. If you are powering 3 pair of the LS-2 in parallel there maybe a problem where you can damage your NERO. What you might consider is adding a fourth pair of LS-2 (for more coverage) and wire the 8 speakers in series parallel configuration 4 speakers for the right and four speakers for the left. I can send you a wiring diagram so you have an 8 ohm load. there are a couple of options for your sub. If you add the GLS8 you will need an additonal dedicated power amplifier like our SMP250 to connect to the Sub out of the NERO and then connect directly to the GLS8. Another option is adding a OM SUB200 and connect to the speaker outputs to the NERO. And then connect the 8 speakers to the output of the OMSUB 200. and between the 8 ohm rating of the 2 sets of 4 speakers wired in series parallel (now 8 ohm) and the 8
Submitted by: Tim Leahy on April 15, 2018

Kent johnson
from OK asked:
March 24, 2018
What subwoofer sounds the best for the money. Looking for deep bass.
1 Answer
Hi Kent: 2 heads are better than one, the same with sub woofers. Check out our SAM300 Black Series Subwoofer amplifier to drive 2 subs with the single amp. It is rated at 4 ohms so will drive the 2 subs. The SAM300 is featured on the OSD Premium web site. You will need to call for price. TL/4861
Submitted by: Tim Leahy on April 5, 2018

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