Monolith by Monoprice 12in THX Ultra Certified 500-Watt Subwoofer Amplifier
Product # 24457
$799.99
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Questions and Answers
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Browse 45 questions
Browse 45 questions
and 86 answers
What color is it? It appears to be more gray than black.
David K
on Nov 15, 2018
BEST ANSWER: The color is black. It's not a reddish black, dark gray, or blueish black, it's black black.. The unit has a bit of wood grain (may be plastic, looks like wood) so in pictures that grain likely reflects some light. In person the actual wood grain isn't very obvious. For a good size black box it looks nice. The chamfered edges help with the appearance.
I purchased four of the units around the middle of October. They arrived very well packed, double boxed, in perfect condition, and have worked flawlessly. Four subs this size aren't really required, but I have the room so why not.
I purchased four of the units around the middle of October. They arrived very well packed, double boxed, in perfect condition, and have worked flawlessly. Four subs this size aren't really required, but I have the room so why not.
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- Kay S on Nov 15, 2018
- Purchased on Sep 25, 2018
BEST ANSWER: The color is black. It's not a reddish black, dark gray, or blueish black, it's black black.. The unit has a bit of wood grain (may be plastic, looks like wood) so in pictures that grain likely reflects some light. In person the actual wood grain isn't very obvious. For a good size black box it looks nice. The chamfered edges help with the appearance.
I purchased four of the units around the middle of October. They arrived very well packed, double boxed, in perfect condition, and have worked flawlessly. Four subs this size aren't really required, but I have the room so why not.
I purchased four of the units around the middle of October. They arrived very well packed, double boxed, in perfect condition, and have worked flawlessly. Four subs this size aren't really required, but I have the room so why not.
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- Kay S on Nov 15, 2018
- Purchased on Sep 25, 2018
Its black not grey at all. If they could offer a version with a rustic finish (Restoration Hardware look) that would be killer ... if anyone is listening there are high quality cheap "rustic look" laminates from Italy that some companies (Barker modern) use to make rustic kitchen cabinets - its just high quality synthetic but would be very "current" if a sub was offered in such a finish... higher wife acceptance factor.... but it sounds great and looks fine (big and black).
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- Robert D on Nov 15, 2018
- Purchased on Nov 5, 2018
Finish of the Monoprice 12" THX Ultra Certified 500 watt subwoofer is satin black with attractive wood grain texture. The speaker surface is non reflective and blends well with earth toned furniture and speaker finishes.
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- dexter m on Nov 15, 2018
- Purchased on Oct 17, 2018
It's black. Not quite matte, but not glossy in any way. It's meant to look like a black Ash color, and matches the speakers in have with actual black Ash veneers quite nicely.
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- Eric P on Nov 15, 2018
- Purchased on May 20, 2018
This is what I would term piano black. It is BLACK with the grain pattern showing through. It is not GLOSS black. Color rendering on video screens can vary widely.
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- Todd on Nov 15, 2018
- Purchased on Sep 20, 2018
It is black. There is a wood grain finish which you can see from only a close distance.
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- Martin P on Nov 16, 2018
- Purchased on May 21, 2018
The sub is black. The grain pattern in veneer makes appear grey in picture.
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- Jeremy D on Nov 16, 2018
- Purchased on Oct 25, 2018
It is definitely black. I was very pleased with the look of this sub.
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- Jared W on Nov 15, 2018
- Purchased on Nov 2, 2018
It’s black. It’s got a wood grain texture, but it’s pure black.
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- Loris M on Nov 15, 2018
- Purchased on Sep 19, 2018
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Is this too big for a bedroom? 15' long x 10' wide?
Gary N
on Feb 20, 2020
BEST ANSWER: As far as sound I’d say no. I think one will be great in that size space. I would suggest measuring and mocking up the physical space it’ll take up. These are large subs. I measured around my previous subs and thought they would be perfect. They seemed much larger when they arrived. I love them but they are a noticeable presence in the room because of their size. I’m sure you’ll love the sound.
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- John F on Feb 20, 2020
- Purchased on Aug 3, 2019
BEST ANSWER: As far as sound I’d say no. I think one will be great in that size space. I would suggest measuring and mocking up the physical space it’ll take up. These are large subs. I measured around my previous subs and thought they would be perfect. They seemed much larger when they arrived. I love them but they are a noticeable presence in the room because of their size. I’m sure you’ll love the sound.
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- John F on Feb 20, 2020
- Purchased on Aug 3, 2019
I have the 12" in a 12'x 12' dedicated gaming room with 65" OLED and associated H/T gear. For me, the question was, would the 15" be too big. I rightfully settled on the 12" and glad I did. It is a true beast, serving as a discrete end-table. Never had anything but joy on ultimately selecting this size. Room gain in smaller rooms like this is considerable.
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- William O on Feb 21, 2020
- Purchased on Feb 26, 2019
How tall is the room? You need to know the cubic feet. Honestly I would say go for it. Unless you are married. She won't be super happy. However, the 10" option would probably be more than enough.
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- Matt H on Feb 20, 2020
- Purchased on Nov 29, 2019
No, would be perfect for a room that size. The better question is, what kind of bedroom needs a subwoofer?
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- Nick K on Feb 20, 2020
- Purchased on Apr 13, 2019
Is a McLaren too fast for a public highway? Yes it is overkill but to each their own.
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- Reinier R on Feb 20, 2020
- Purchased on Apr 29, 2019
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Will two monolith 12” subwoofers out perform one monolith 15?
michael g
on Jan 8, 2021
BEST ANSWER: The 15" under benchmarks can get down to 12.5Hz range, whereas the 12 can only get as low as 16 hz.
That being said, two subs evenly distribute base throughout your room better than one sub.
I personally went with two 12" Monolith 500-Watts and they perform exceptionally good.
Just a word of caution: Hooking two 12" subs on the same 15 amp electric circuit is not sufficient. They wont both run. So you need two 15 amp circuits or a single larger circuit (e.g. 20 or 30 amp).
Chris
That being said, two subs evenly distribute base throughout your room better than one sub.
I personally went with two 12" Monolith 500-Watts and they perform exceptionally good.
Just a word of caution: Hooking two 12" subs on the same 15 amp electric circuit is not sufficient. They wont both run. So you need two 15 amp circuits or a single larger circuit (e.g. 20 or 30 amp).
Chris
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- CHRISTOPHER S on Jan 8, 2021
- Purchased on Sep 8, 2020
BEST ANSWER: The 15" under benchmarks can get down to 12.5Hz range, whereas the 12 can only get as low as 16 hz.
That being said, two subs evenly distribute base throughout your room better than one sub.
I personally went with two 12" Monolith 500-Watts and they perform exceptionally good.
Just a word of caution: Hooking two 12" subs on the same 15 amp electric circuit is not sufficient. They wont both run. So you need two 15 amp circuits or a single larger circuit (e.g. 20 or 30 amp).
Chris
That being said, two subs evenly distribute base throughout your room better than one sub.
I personally went with two 12" Monolith 500-Watts and they perform exceptionally good.
Just a word of caution: Hooking two 12" subs on the same 15 amp electric circuit is not sufficient. They wont both run. So you need two 15 amp circuits or a single larger circuit (e.g. 20 or 30 amp).
Chris
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- CHRISTOPHER S on Jan 8, 2021
- Purchased on Sep 8, 2020
Hi mike I prefer two of the 12s for my room because I believe it gives good balance of Base with one on the left front and one on the right front and I’ll be honest with you because my room being 14 x 24 one of these THX 12s would’ve been enough I can only imagine what the 15 with a 1000 watts is like, if you’re short on space the 12 mite be the way to go, the Cabinet for my 12s are pretty big so you’re going to have to figure in we’re to put it I hope this helps you out Mike
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- Dana W on Jan 8, 2021
- Purchased on Oct 17, 2020
Typical math What argue that two 12s well approximately equal one 15. You will get approx a 3db gain by doubling the cone size and 3db by doubling wattage. Those don't add linearly so you should see 4-5db gain.
The benefit of two 12s is smoothing out the peaks and nulls. The benefit of the 15 is more output at lower octaves.
Hopefully that answers your question.
The benefit of two 12s is smoothing out the peaks and nulls. The benefit of the 15 is more output at lower octaves.
Hopefully that answers your question.
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- Donald P on Jan 8, 2021
- Purchased on Nov 27, 2020
in terms of basic area involved I would say yes, you have a total of 24" of cone over a much wider area of sound field, granted the 15 has more power, but the 12's are quite impressive on thier own, even more so with 2 of them.
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- Kenneth A on Jan 8, 2021
- Purchased on Aug 31, 2020
Yes! Mainly because you'll have a 3 to 6 dB gain with two. I have two myself. In no way do I feel it lacking. These subs are devastating! I would say buy two and don't look back.
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- Bob L on Jan 9, 2021
- Purchased on Sep 25, 2020
Good question I only have one 12” and it’s definitely nice. If I were you I’d probably get a 15” now and possibly another down the line
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- Fedor K on Jan 8, 2021
- Purchased on Aug 29, 2020
Short answer yes, two will always be better then one.
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- Matthew S on Jan 9, 2021
- Purchased on May 20, 2020
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Why are the 10" and 12" monolith thx subwoofer rated at the same 500 watts RMS ? I would think the 12" would be rated at a much higher wattage than the 10". Can someone please give a good explanation for that? Thanks
A shopper
on Sep 30, 2018
BEST ANSWER: Because they use the same amplifier.
At the same power the larger woofer still has more displacement, which means lower response and more output.
At the same power the larger woofer still has more displacement, which means lower response and more output.
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- kevin o on Oct 1, 2018
- Purchased on May 20, 2018
BEST ANSWER: Because they use the same amplifier.
At the same power the larger woofer still has more displacement, which means lower response and more output.
At the same power the larger woofer still has more displacement, which means lower response and more output.
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- kevin o on Oct 1, 2018
- Purchased on May 20, 2018
I don't think you will notice the difference,,, if you have a small room get the 10 inch! The 12" is big and extremely heavy!!
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- New User U on Oct 19, 2018
- Purchased on Oct 15, 2018
Refer to the measurements given at the bottom of each product listings. The 12" model has much more output than the 10" model. The goal in buying a subwoofer is the getting the most low-distortion output. The details of the amplifier, etc., are interesting, but not really relative to the purchase decision.
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- Jeff S on Nov 15, 2018
500 watts is plenty to drive whatever woofer you want. The 10 will not have the output of the 12 even with same power rating.
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- New User U on Sep 30, 2018
- Purchased on Nov 7, 2017
Enclose size . More cabinet more pressure and air for driver
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- john s on Sep 30, 2018
- Purchased on Jun 8, 2018
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Would this sub be enough for a 17x17 living room (not sealed)? Or should I get the 15 inch model instead?
New User U
on Feb 6, 2019
BEST ANSWER: The 12" will do just fine for that size room.
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- New User U Staff on Feb 6, 2019
BEST ANSWER: The 12" will do just fine for that size room.
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- New User U Staff on Feb 6, 2019
It will be plenty I assure you! I just installed in my 15x19 room and it’s overwhelming when cranked up
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- Corey B on Feb 6, 2019
- Purchased on Jan 26, 2019
Thank you!
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- New User U on Feb 6, 2019
assuming you have 8 foot high ceilings, your room would be about 2300 cubic feet. this sub is thx certified up to 3000 cubic feet so i think it would be plenty
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- New User U on Jan 19, 2021
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When I turn off the subwoofer, the on light stays on for 30 seconds. Also, after the unit has been on and then the signal is turned off for a period, when the signal is turned back on the unit has to be powered off/on for it to pick up the signal again. Is this common?
morgan d
on Jul 1, 2020
BEST ANSWER: Morgan, are you manually turning the subwoofer on and off by means of the power toggle or the main power switch?
If you turn off the amp it will go through a powering off process which takes around 30 sec to 1 min.
Do you have the rear power toggle on auto/on/or off?
If you turn off the amp it will go through a powering off process which takes around 30 sec to 1 min.
Do you have the rear power toggle on auto/on/or off?
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- New User U on Jul 1, 2020
- Purchased on Dec 3, 2019
I'm only manually turning the power off with the power switch when the subwoofer does not come out of standby mode. Cycling the power brings it out of standby. Toggle set on auto.
What equipment is the subwoofer connected to?
How do you have it connected?
What cables are you using?
How do you have it connected?
What cables are you using?
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- New User U on Jul 1, 2020
It's connected to yamaha rx-a2080 receiver via this cable sold on Amazon KabelDirekt RCA Subwoofer Cable, Cord (20 feet Long, 1 RCA Male to 1 RCA Male Audio Video Cable, Digital & Analogue, Double Shielded, Pro Series) Supports (Subwoofers, AV Receivers, Hi-Fi)
Ok. Have you tried putting the subwoofer power toggle on “auto” and In your receiver settings put the dB higher for the subwoofer?
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- New User U on Jul 2, 2020
Also, I run my sub slightly higher due to room size. My other sub will kick on before my monolith sub turns on. The sub will measure a quick sound compared to consistent sound of a movie or music. I sometimes have to allow 5-10 seconds of consistently louder portions of a movie before the sun will turn itself on.
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- New User U on Jul 2, 2020
BEST ANSWER: Morgan, are you manually turning the subwoofer on and off by means of the power toggle or the main power switch?
If you turn off the amp it will go through a powering off process which takes around 30 sec to 1 min.
Do you have the rear power toggle on auto/on/or off?
If you turn off the amp it will go through a powering off process which takes around 30 sec to 1 min.
Do you have the rear power toggle on auto/on/or off?
- Reply(1)
- Inaccurate
- New User U on Jul 1, 2020
- Purchased on Dec 3, 2019
I'm only manually turning the power off with the power switch when the subwoofer does not come out of standby mode. Cycling the power brings it out of standby. Toggle set on auto.
What equipment is the subwoofer connected to?
How do you have it connected?
What cables are you using?
How do you have it connected?
What cables are you using?
- Reply (1)
- New User U on Jul 1, 2020
It's connected to yamaha rx-a2080 receiver via this cable sold on Amazon KabelDirekt RCA Subwoofer Cable, Cord (20 feet Long, 1 RCA Male to 1 RCA Male Audio Video Cable, Digital & Analogue, Double Shielded, Pro Series) Supports (Subwoofers, AV Receivers, Hi-Fi)
Ok. Have you tried putting the subwoofer power toggle on “auto” and In your receiver settings put the dB higher for the subwoofer?
- Reply
- New User U on Jul 2, 2020
Also, I run my sub slightly higher due to room size. My other sub will kick on before my monolith sub turns on. The sub will measure a quick sound compared to consistent sound of a movie or music. I sometimes have to allow 5-10 seconds of consistently louder portions of a movie before the sun will turn itself on.
- Reply (1)
- New User U on Jul 2, 2020
Yes, my is behaving the same way, its normal, just takes getting use to it. Mine takes almost a month for it to be fully break in to sound great and full. This is different from all the subs that I had before, once you are use to the clean sound, you will love it.
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- Leng C on Jul 1, 2020
- Purchased on Jan 21, 2020
The light usually stays on like that, although I barely turn it off . It has happened to mine a few times where I have to turn it off then back on, but not that often.
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- Kyle K on Jul 1, 2020
- Purchased on Dec 8, 2019
Stop turning the subwoofer off. It automatically will go into stand by after it detects no signal. You dont keep turning the subwoofer on and off.
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- Brian K on Jul 1, 2020
- Purchased on Dec 21, 2019
No this is not common. Seems to be a technical issue with the subwoofer.
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- Malik I on Jul 1, 2020
- Purchased on Jul 21, 2019
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Can you please provide specifications in terms of power requirements for a North American household? I'd like to run 2 of these in my home theater currently under construction and want to know if I can run them both on the same dedicated 15 A circuit... or if I need to run them both on a dedicated 20 A circuit. Thanks!
A shopper
on Oct 27, 2017
BEST ANSWER: I'm an E..E. for whatever that's worth. The units likely will run fine on a 15A circuit. However, a 20A circuit will only cost a little extra for the wire (you'll need #12 instead of #14 Romex) and nothing extra for the breaker or the outlet. A 20A 120V outlet will take either a 20A or 15A plug. There will be less voltage drop in the circuit with larger wire and you'll not wonder over the years if you should have spent another $25 and gotten a larger circuit. If the electrical service panel isn't very far away from the new room, and there are spaces in the panel for extra breakers, then it doesn't cost much extra to run extra circuits, or higher capacity circuits when you are building a room. It will cost a lot more to add circuits in the future.
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- Kay S on Nov 15, 2018
- Purchased on Sep 25, 2018
BEST ANSWER: I'm an E..E. for whatever that's worth. The units likely will run fine on a 15A circuit. However, a 20A circuit will only cost a little extra for the wire (you'll need #12 instead of #14 Romex) and nothing extra for the breaker or the outlet. A 20A 120V outlet will take either a 20A or 15A plug. There will be less voltage drop in the circuit with larger wire and you'll not wonder over the years if you should have spent another $25 and gotten a larger circuit. If the electrical service panel isn't very far away from the new room, and there are spaces in the panel for extra breakers, then it doesn't cost much extra to run extra circuits, or higher capacity circuits when you are building a room. It will cost a lot more to add circuits in the future.
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- Kay S on Nov 15, 2018
- Purchased on Sep 25, 2018
15A will likely work. During the construction phase changing to a 20A circuit will only add a little cost for the wire (go to #12 from #14). The circuit breaker and the outlet will cost the same. The 20A outlet will support both 15A or 20A plugs. It makes good sense to spend what should be $25 extra or so to go with the 20A circuit.
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- Jeff S on Nov 15, 2018
I has a 20 amp circuit put in for this sub and a 12" SVS sub.
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- New User U on Dec 11, 2017
- Purchased on Nov 7, 2017
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Hello. I just looked at the manual and it appears the 10” goes lower than the 12 according to the manual. Is this correct?
New User U
on Nov 8, 2017
BEST ANSWER: The 12" subwoofer goes lower and plays louder, as a 12" should. The Monolith 12" subwoofer has a 4 to 6 dB advantage over the 10" at 16Hz and 20Hz.
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- New User U Staff on Nov 8, 2017
Thank you for the answer.
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- New User U on Nov 8, 2017
BEST ANSWER: The 12" subwoofer goes lower and plays louder, as a 12" should. The Monolith 12" subwoofer has a 4 to 6 dB advantage over the 10" at 16Hz and 20Hz.
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- New User U Staff on Nov 8, 2017
Thank you for the answer.
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- New User U on Nov 8, 2017
Go to the Monoprice webpage. Go to the Monolith subwoofers. Access the 10" Monolith sub in one window, the 12" Monolith sub in another separate instance of your browser. Place the two windows side by side. Go to the bottom of each page. You will see the measurements of the two subs. You'll see that the 12" sub has more output than the 10" sub at all frequencies, ported and sealed.
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- Jeff S on Nov 15, 2018
Refer to the measurements given at the bottom of each of the product listings. The 12" model has much more output than the 10" model at all frequencies and with all port configurations.
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- Jeff S on Nov 15, 2018
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is this 220v?
A shopper
on Feb 25, 2020
BEST ANSWER: Thank you for your question.
No this product is not compatible with 220v power.
No this product is not compatible with 220v power.
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- Tyler C Staff on Feb 25, 2020
BEST ANSWER: Thank you for your question.
No this product is not compatible with 220v power.
No this product is not compatible with 220v power.
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- Tyler C Staff on Feb 25, 2020
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My led power indicator is flashing red and green and will not turn on. What is the cause of this??
William L
on Sep 11, 2020
BEST ANSWER: Something inside the sub's fuse setup flipped and didn't go back. Usually occurs if your power goes out and comes back on rapidly. Mine has done it a few times. I just unplugged it from the wall for a few minutes and then after I plugged it back in everything was back to normal. Hope this helps.
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- jamie m on Sep 11, 2020
- Purchased on Jan 20, 2020
BEST ANSWER: Something inside the sub's fuse setup flipped and didn't go back. Usually occurs if your power goes out and comes back on rapidly. Mine has done it a few times. I just unplugged it from the wall for a few minutes and then after I plugged it back in everything was back to normal. Hope this helps.
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- jamie m on Sep 11, 2020
- Purchased on Jan 20, 2020
The amp has to reset, try unplugging the power cord from the back until the light stops flashing and plug it back in and wait for the light to turn solid green
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- Matthew S on Sep 12, 2020
- Purchased on May 20, 2020
It only flashes red and green when turning it on off with subwoofer switch. Put it in auto and leave the subwoofer on.
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- Brian K on Sep 12, 2020
- Purchased on Dec 21, 2019
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I'm just wondering if there are threaded inserts on the bottom of the sub for spikes etc? I'd be interested in adding the svs sounpath isolation feet.
A shopper
on Mar 11, 2018
BEST ANSWER: Yes, there are threaded steel inserts.
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- New User U Staff on Mar 12, 2018
BEST ANSWER: Yes, there are threaded steel inserts.
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- New User U Staff on Mar 12, 2018
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Will the subwoofer run on 220v electricity?
A shopper
on Feb 3, 2019
Check the back power toggle . I believe it has that option . If you don’t see toggle it is 210
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- john s on Feb 3, 2019
- Purchased on Jun 8, 2018
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Whats the difference between this monolith 12 ported and the sealed as far as performance? Thanks
A shopper
on Nov 29, 2019
BEST ANSWER: The output data is listed on both of the products to make it easy to compare.
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- New User U Staff on Nov 29, 2019
BEST ANSWER: The output data is listed on both of the products to make it easy to compare.
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- New User U Staff on Nov 29, 2019
The ported lends itself more towards home theater. Digs deeper in 20-40hz range where it counts. Remember you use the port plugs too and run in “sealed” mode too. It’s a much larger cabinet too. But if the size of sub is not an issue for living space. The ported gives you the ultimate flexibility for music or theater.
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- New User U on Nov 29, 2019
- Purchased on Nov 18, 2019
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My living room doesnt have a ton of extra space but I want to run dual subs. Would stacking two 12 inch subs be an issue?
New User U
on Jul 31, 2020
BEST ANSWER: No it wont be a problem. if that is your only option for running two subs that will be just fine. In fact you will live it. It will give great bass in more area of your room.
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- Brian K on Aug 1, 2020
- Purchased on Dec 21, 2019
BEST ANSWER: No it wont be a problem. if that is your only option for running two subs that will be just fine. In fact you will live it. It will give great bass in more area of your room.
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- Brian K on Aug 1, 2020
- Purchased on Dec 21, 2019
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Can you add maximum SPL in the various modes (THX, etc.) to the spec sheets for all of these new subwoofers? Thanks!
Jason G
on Sep 2, 2017

Monolith by Monoprice 12in THX Ultra Certified 500-Watt Subwoofer Amplifier

Monolith by Monoprice 10in THX Select Certified Subwoofer Amplifier

Monolith by Monoprice 15in THX Ultra Certified 1000-Watt Subwoofer Amplifier
BEST ANSWER: We will be adding CEA-2010 @2M burst and RMS measurements by frequency in the near future.
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- New User U Staff on Sep 5, 2017
BEST ANSWER: We will be adding CEA-2010 @2M burst and RMS measurements by frequency in the near future.
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- New User U Staff on Sep 5, 2017
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Can these sub woofers be positioned on their side for a lower profile? I have a large projection screen and plan on placing two subs up front.
Shawn P
on Oct 29, 2017
BEST ANSWER: Yes, you can lay the subwoofer on its side with no loss in performance.
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- New User U Staff on Oct 30, 2017
BEST ANSWER: Yes, you can lay the subwoofer on its side with no loss in performance.
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- New User U Staff on Oct 30, 2017
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Can you tell me the size of the threaded inserts on the bottom of the sub?
A shopper
on Mar 23, 2018
BEST ANSWER: M6-1.00 (course thread) 20-25mm long machine screws depending on your application. For feet, Reliable Hardware Company RH-1606-8-A Guitar Amplifier Cabinet feet (1-pack of 8) work fine.
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- Dennis R on Oct 14, 2018
BEST ANSWER: M6-1.00 (course thread) 20-25mm long machine screws depending on your application. For feet, Reliable Hardware Company RH-1606-8-A Guitar Amplifier Cabinet feet (1-pack of 8) work fine.
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- Dennis R on Oct 14, 2018
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Are there any issues with placing the subs on their side? The THX 12 and THX 15 height will get too close interfere with my screen and make reflections. Particular concern of amplifier air flow and over heats?
A shopper
on May 14, 2018

Monolith by Monoprice 12in THX Ultra Certified 500-Watt Subwoofer Amplifier

Monolith by Monoprice 10in THX Select Certified Subwoofer Amplifier

Monolith by Monoprice 15in THX Ultra Certified 1000-Watt Subwoofer Amplifier
BEST ANSWER: No issues, you can place the subwoofer on its side.
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- New User U Staff on May 15, 2018
BEST ANSWER: No issues, you can place the subwoofer on its side.
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- New User U Staff on May 15, 2018
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Are the feet removable? if so, are they the screw on type or adhesive?
kevin o
on May 19, 2018
BEST ANSWER: The feet are removable, and they are screw on.
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- New User U Staff on May 21, 2018
BEST ANSWER: The feet are removable, and they are screw on.
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- New User U Staff on May 21, 2018
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Will these ever be available to buy again? Been waiting since late June and eta keeps getting pushed back?
A shopper
on Aug 6, 2018
BEST ANSWER: Yes, these should be arriving in mid to late September.
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- New User U Staff on Aug 6, 2018
BEST ANSWER: Yes, these should be arriving in mid to late September.
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- New User U Staff on Aug 6, 2018
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Does this have a 12V monaural mini plug Trigger jack for automatically turning on and off automatically when the receiver is turned off?
A shopper
on Sep 17, 2018
BEST ANSWER: Thank you for your question.
Currently we do not sell trigger cables.
Currently we do not sell trigger cables.
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- Tyler C Staff on May 22, 2019
BEST ANSWER: Thank you for your question.
Currently we do not sell trigger cables.
Currently we do not sell trigger cables.
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- Tyler C Staff on May 22, 2019
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More photos? Especially with grill on?
A shopper
on Oct 4, 2018
BEST ANSWER: You can see photos at Audioholics.com or avsforum.com
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- New User U Staff on Oct 4, 2018
BEST ANSWER: You can see photos at Audioholics.com or avsforum.com
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- New User U Staff on Oct 4, 2018
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230VAC, 50Hz workable?
A shopper
on Oct 7, 2018
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What is the total weight and dimensions of the box this comes in? I want to get an estimate from my freight forwarder to ship to Hawaii.
New User U
on Jan 16, 2019
BEST ANSWER: Weight: 103lbs Box Dimensions: 33x22x30.5
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- New User U Staff on Jan 16, 2019
BEST ANSWER: Weight: 103lbs Box Dimensions: 33x22x30.5
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- New User U Staff on Jan 16, 2019
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Where near San Francisco can I hear it?
Ivan B
on Mar 31, 2019

Monolith by Monoprice 12in THX Ultra Certified 500-Watt Subwoofer Amplifier

Monolith by Monoprice 10in THX Select Certified Subwoofer Amplifier

Monolith by Monoprice 10" THX Select Certified 500 Watt Powered Subwoofer (Open Box)

Monolith by Monoprice 12" THX Ultra Certified 500 Watt Powered Subwoofer (Open Box)
BEST ANSWER: Thank you for your question.
We would not offer a place to get a live demonstration of our subwoofers.
We would not offer a place to get a live demonstration of our subwoofers.
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- Tyler C Staff on Sep 3, 2019
BEST ANSWER: Thank you for your question.
We would not offer a place to get a live demonstration of our subwoofers.
We would not offer a place to get a live demonstration of our subwoofers.
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- Tyler C Staff on Sep 3, 2019
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Is the grille made from steel or a hardened material to prevent damaging the woofer?
A shopper
on May 21, 2019
BEST ANSWER: The grille is cloth, and I'm not sure who or what you would need to protect the woofer from.
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- New User U Staff on May 21, 2019
BEST ANSWER: The grille is cloth, and I'm not sure who or what you would need to protect the woofer from.
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- New User U Staff on May 21, 2019
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With both ports plugged, would this 12" THX Ultra sub sound similar to the M12-S?
A shopper
on Jul 8, 2019

Monolith by Monoprice 12in THX Ultra Certified 500-Watt Subwoofer Amplifier

Monolith by Monoprice M12-S 12" THX Certified Sealed 500-Watt Powered Subwoofer
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My amplifier has both left and right RCA outputs for a subwoofer. What kind of ended cable will I need to connect my 10" sealed Monolith subwoofer?
New User U
on Jul 8, 2019
I know THAT! My question was what ENDED cable to use...is single ended or double? RCA cables come both single ended and double ended ( is left and right) at either one end of the cable or both.
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- New User U on Jul 9, 2019
I know THAT! My question was what ENDED cable to use...is single ended or double? RCA cables come both single ended and double ended ( is left and right) at either one end of the cable or both.
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- New User U on Jul 9, 2019
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How come when fully vented this 12" subwoofer goes down to only 18Hz (Extended EQ) and 20Hz (THX EQ), exact same as the vented 10" subwoofer??
Razvan N
on Sep 4, 2019

Monolith by Monoprice 12in THX Ultra Certified 500-Watt Subwoofer Amplifier

Monolith by Monoprice 10in THX Select Certified Subwoofer Amplifier
BEST ANSWER: We publish CEA output numbers for all subwoofers. It might be better to look at those.
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- New User U Staff on Sep 16, 2019
Thanks Hobie but that does not clarify the issue. I remember when I drilled into this and went to take a look at the specs in the PDF that some of these were inconsistent; likely a typo, though I now don't remember which one was wrong - the website or the PDF. You may want to check those. However, if indeed the smaller subwoofer size has specs with lower bottom of Hz, my question is how would that be. I would think that as subwoofer goes up in size (for the same family of subwoofers at least) the lower Hz and be even lower...
BEST ANSWER: We publish CEA output numbers for all subwoofers. It might be better to look at those.
- Reply(1)
- Inaccurate
- New User U Staff on Sep 16, 2019
Thanks Hobie but that does not clarify the issue. I remember when I drilled into this and went to take a look at the specs in the PDF that some of these were inconsistent; likely a typo, though I now don't remember which one was wrong - the website or the PDF. You may want to check those. However, if indeed the smaller subwoofer size has specs with lower bottom of Hz, my question is how would that be. I would think that as subwoofer goes up in size (for the same family of subwoofers at least) the lower Hz and be even lower...
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Exactly how long is the power cable included with the 12" Ported? Is it grounded?
Matt H
on Nov 13, 2019
BEST ANSWER: It is grounded, I would say approximately 6'.
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- Dylan R on Nov 14, 2019
- Purchased on Feb 26, 2019
BEST ANSWER: It is grounded, I would say approximately 6'.
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- Dylan R on Nov 14, 2019
- Purchased on Feb 26, 2019
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Reviews
4.9 / 5.0
44 Reviews
5 Stars
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Rated 5 out of 5
Thank you Monoprice, for making such a well built product.
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Rated 5 out of 5
Love these subs! I got two and they are really something serious! Plus they look soo good! They are built like a tank. Very happy with them And monoprice customer service has been better than before! I would recommend these to anyone looking to add some serious bass to their HT.

Added Dec 24, 2020
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Rated 4 out of 5
Great value
Love the subwoofer still feel like it's lacking a bit . But this is my first subwoofer and I'm trying to learn how to use it properly.
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Rated 4 out of 5
For overall performance you can’t ask for a better sub
I’m using two monoliths 12 inch subs in my home theater room that is 14 x 24. I am very happy with the performance of the subs it gives me more than enough punch for this room probably overkill but I love my bass.They are set at +6 db witch suits me fine.The only Reason I gave it four stars because one of the boxes was damaged which scratched the back of the sub but does not change the performance of the sub.They need to package the sub better.
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Rated 5 out of 5
These are Beasts and Awesome for it. I have two of them and they Devastate. Overjoyed!!
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Rated 4 out of 5
Great performance!
I own two of these badboys (dual subs is a must) and the performance for the money is top notch!
One sub came with a bad driver but Monoprice took care of it and sent a replacement after few days of receiving bad sub.
One thing I would like for Monoprice is to do schedule pick up for warranty/replacement subs or an option to send replacement parts like SVS does. They’re heavy and pain to take them to the drop off locations. (The reason for 4 stars)
One sub came with a bad driver but Monoprice took care of it and sent a replacement after few days of receiving bad sub.
One thing I would like for Monoprice is to do schedule pick up for warranty/replacement subs or an option to send replacement parts like SVS does. They’re heavy and pain to take them to the drop off locations. (The reason for 4 stars)


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Rated 5 out of 5
great sub, outperforms much more expensive units.
The frequency response, and tight control of this sub easily outperforms subs twice the price. The amp is clean and responsive and the driver itself is equally tight and responsive. The auto on does seem "less than responsive" at really low levels but this is in my dedicated theater so it's never at low levels. The sub is rather large, and very powerful so low volume listening isn't really it's purpose anyways. I chose the ported version for the size of my theater and it performs perfectly. I have absolutely no regrets of this purchase and would definitely purchase again. I've had it for several months, and friends and family are all blown away by its performance from a brand some of them have never heard of.
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Rated 5 out of 5
Couldn't be happier
Had a M&K 125mkII which I always thought performed very well. To say I was blown away by the monolith is an understatement. My room is right at the 3,000 cu ft limit and this thing fills it with sound fully. Very happy.
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Rated 5 out of 5
Awesome. Freaking. Sub.
Incredible! Bringing this sub home meant bringing home the Dolby Atmos theater! I LOVE feeling my movies in my couch. This really stepped up the game in my home theater. Awesome. Freaking. Sub.
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Rated 5 out of 5
Good strong bass that reaches way down to be felt more than heard. A nice massage for sure.
I just got this so I cannot give it a fair review yet. But so far it seems to be exactly what I wanted. For the small studio room I have it is overkill.
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