Monolith by Monoprice 15in THX Certified Ultra 1000-Watt Subwoofer Amplifier
Product # 24458
UPC # 889028055960
$1,499.99
*Affirm is not available for business or international orders
Qty:
Out of Stock
ETA: TBD
Note:
Due to limited supply, all products are sold on a first-come first-serve basis. Auto Notification does not guarantee either availability or price. All prices are subject to change without notice.
*Your information will only be used to notify you when this item becomes available.
Qty: 1
$1,499.99
Qty: 2-9
$1,454.99
Qty: 10-19
$1,432.49
Qty: 20-49
$1,409.99
Qty: 50+
$1,387.49
To see and take advantage of our member pricing sign up for a business account or contact our sales team.
To see and take advantage of our member pricing sign up for a business account or contact our sales team.
Customers Also Shopped For
Questions and Answers
Do not include HTML, links, references to other stores, pricing or contact info.
My question is about:

If your question is about more than one item, click + to add them.

Browse 75 questions
Browse 75 questions
and 132 answers
Do any users have issues with the volume or loudness of the Subwoofer being too low at 0db gain setting on back of subwoofer? Does everyone set the gain to +15 db?
Ernie Kuo Wei L
on May 26, 2021
BEST ANSWER: Haven't received my 15s yet but I have the 12s and assume they are similar in function. The gain on these subs is a little different than other subs I've owned and generally need to be run a little higher, but should not need to be maxed out. A lot has to do with the room dimensions and volume, and you may also be sitting in a bass null and feel that there is a lack of volume. Also, because these subs have such low distortion, you may feel that they are not playing as loudly as there is less harmonic frequencies being emitted than with a lot of other subs (which for accuracy is a very good thing, but may be a different sound than you are used to).
- Reply
- Inaccurate
- Michael M on May 27, 2021
- Purchased on May 13, 2021
BEST ANSWER: Haven't received my 15s yet but I have the 12s and assume they are similar in function. The gain on these subs is a little different than other subs I've owned and generally need to be run a little higher, but should not need to be maxed out. A lot has to do with the room dimensions and volume, and you may also be sitting in a bass null and feel that there is a lack of volume. Also, because these subs have such low distortion, you may feel that they are not playing as loudly as there is less harmonic frequencies being emitted than with a lot of other subs (which for accuracy is a very good thing, but may be a different sound than you are used to).
- Reply
- Inaccurate
- Michael M on May 27, 2021
- Purchased on May 13, 2021
It really depends on your sub/LFE source. A lot of receivers Sub/LFE out runs around .9V output, but higher end receivers may run up to 2V output. Depending on your source, you may need to run your sub a little "HOT" which would mean bumping the gain up to suite your preference.
I hope this helps to answer your question.
I hope this helps to answer your question.
- Reply(1)
- Inaccurate
- Richard P on May 27, 2021
- Purchased on Mar 22, 2021
Also your sub placement is critical. You may also be experiencing a NULL in your room. Try placing your sub in different position in your room. You can also do a Sub crawl (google it) to locate the best location for your Subwoofer. Although this is a pretty large sub to place in your listening position, it can still be done.
I think I have mine set to +7ish. My preamp has sublevel adjustment too. So it's currently at -3. This gives me plenty of range to go up or down when I see fit.
- Reply
- Inaccurate
- Notch on May 27, 2021
- Purchased on Apr 5, 2021
I would pass on this subwoofer. I Purchased 2 of them for my father. Had issues with both from the first day
- Reply
- Inaccurate
- New User U on May 27, 2021
- Purchased on Jun 10, 2020
Yes, if you want to hear it you must turn it all the up with low volume listening..
- Reply
- Inaccurate
- Robert S on May 27, 2021
- Purchased on Mar 30, 2021
Even at 0db the subs are extraordinary loud.
- Reply
- Inaccurate
- Tube Maze I on May 27, 2021
- Purchased on Apr 15, 2021
Vote for the best answer above!
Is this subwoofer vented or sealed??
A shopper
on Nov 14, 2021
BEST ANSWER: You can used it as a vented or it comes with 3 foam plugs so you can seal it with them. I got 2 off them and love it. Get them.
- Reply
- Inaccurate
- New User U on Nov 14, 2021
- Purchased on Jul 18, 2021
BEST ANSWER: You can used it as a vented or it comes with 3 foam plugs so you can seal it with them. I got 2 off them and love it. Get them.
- Reply
- Inaccurate
- New User U on Nov 14, 2021
- Purchased on Jul 18, 2021
It can be either. It comes with foam plugs to run sealed or you can run it without the foam plugs for vented.
- Reply
- Inaccurate
- New User U on Nov 14, 2021
- Purchased on Nov 25, 2020
It shows 3 circular vent holes below the driver. You can seal them with the provided port plugs if desired.
- Reply
- Inaccurate
- Casey B on Nov 14, 2021
- Purchased on Feb 26, 2021
This is a 3 port sub. It comes with foam plugs to seal ports. But is still a ported sub.
- Reply
- Inaccurate
- Ken N on Nov 14, 2021
- Purchased on Mar 3, 2021
Vented but comes with seals for the open ports so you can customize your sound.
- Reply
- Inaccurate
- John B on Nov 14, 2021
- Purchased on Dec 31, 2020
Vote for the best answer above!
How would this subwoofer perform in a 19'x15' room with an 8 foot ceiling?
A shopper
on Jun 2, 2022
BEST ANSWER: I have this in a 17x17 room with 11’ high ceilings. My room is not closed it opens to my dining room so it’s a lot of square footage to pressurize. It does sound good but I added two more subs(DN15 Definitive Technology) to get the sound I was looking for. Sound is an odd thing though…after adding two more subs I replaced my towers from the Klipsch FA625 to the Polk R700 and now I have way more than enough bass. I dialed back the power on the subs after changing towers. So there are a lot of variables but most likely with a room as big as yours you’re looking at 2 or more subs. That all sound I love how this thing sounds especially for the price. I’d say start with this and decide from there.
- Reply
- Inaccurate
- William Z on Jun 2, 2022
- Purchased on Aug 11, 2021
BEST ANSWER: I have this in a 17x17 room with 11’ high ceilings. My room is not closed it opens to my dining room so it’s a lot of square footage to pressurize. It does sound good but I added two more subs(DN15 Definitive Technology) to get the sound I was looking for. Sound is an odd thing though…after adding two more subs I replaced my towers from the Klipsch FA625 to the Polk R700 and now I have way more than enough bass. I dialed back the power on the subs after changing towers. So there are a lot of variables but most likely with a room as big as yours you’re looking at 2 or more subs. That all sound I love how this thing sounds especially for the price. I’d say start with this and decide from there.
- Reply
- Inaccurate
- William Z on Jun 2, 2022
- Purchased on Aug 11, 2021
My room is roughly the same size. I have two subs but one will be plenty enough.
These things easily pressurize the room and play down to 14hz without breaking a sweat.
These things easily pressurize the room and play down to 14hz without breaking a sweat.
- Reply
- Inaccurate
- Jeffrey R on Jun 3, 2022
- Purchased on Oct 21, 2021
I have mine in a 25’ x 15’ room with an 8 foot ceiling and am very impressed. Substantially outperformed the pb-2000 it replaced.
- Reply
- Inaccurate
- John F on Jun 3, 2022
- Purchased on Jul 5, 2021
I would say perfectly. Its a monster. I have it in a 10 by 12 room with 12 ft ceiling high
- Reply
- Inaccurate
- stephen o on Jun 2, 2022
- Purchased on Jun 18, 2021
Should sound great. I run 2 of thise in a 30x20 open room and my lallycolums shake
- Reply
- Inaccurate
- Mark B on Jun 2, 2022
- Purchased on Oct 25, 2021
Very well! It goes very low and loud. I would not be without it!
- Reply
- Inaccurate
- Terrence P on Jun 6, 2022
- Purchased on Aug 14, 2021
Vote for the best answer above!
can spikes be install on this unit?
A shopper
on Jul 13, 2020
BEST ANSWER: Please note: this unit is very heavy , i assume you want spikes so it doesn't move? currently my subwoofer sets on polish tile marble floor . The weight keeps it stable there is no movement what so ever ... the subwoofer comes with 6 rubber low-profile gliders which are attached and secured.
- Reply
- Inaccurate
- Chris S on Jul 14, 2020
- Purchased on May 17, 2020
BEST ANSWER: Please note: this unit is very heavy , i assume you want spikes so it doesn't move? currently my subwoofer sets on polish tile marble floor . The weight keeps it stable there is no movement what so ever ... the subwoofer comes with 6 rubber low-profile gliders which are attached and secured.
- Reply
- Inaccurate
- Chris S on Jul 14, 2020
- Purchased on May 17, 2020
I'm not sure but I would recommend installing SVS soundpath subwoofer isolation system. These subs hit hard and go low, shaking your walls. These feet will help minimize it.
- Reply
- Inaccurate
- omero m on Jul 13, 2020
- Purchased on Feb 13, 2020
Yes, it in fact comes with 6. I however had some tile in my room, so I bought rubber sound isolators. It's an incredible subwoofer.
- Reply
- Inaccurate
- Benjamin H on Jul 14, 2020
- Purchased on May 25, 2020
Yes. There are 6 feet that just screw in/out. I installed the SVS Subwoofer Isolation System on the bottom with no issues.
- Reply
- Inaccurate
- Shaun P on Jul 13, 2020
- Purchased on May 11, 2020
Yes, however I would highly recommend using heavy duty isolation feet like the ones from SVS instead of spikes.
- Reply
- Inaccurate
- New User U on Jul 13, 2020
- Purchased on May 11, 2020
The preinstalled feet are removable.
- Reply
- Inaccurate
- Phillip S on Jul 14, 2020
- Purchased on Jun 25, 2020
Vote for the best answer above!
Can someone tell me if the 15 ported or the 13 would be better mainly for 2.1 music listening? Thanks
A shopper
on Apr 12, 2022
BEST ANSWER: Depends on your size. If you need to move a lot of air like say your in a big area go with 15in. The bigger subs move for air and hit much harder, even though the 13in has a 2000 watt amp. You still need the head room of a 15. One pro enthusiast told me the anything under a 15in sub does not belong in a theater room. So I sold my svs pro 2000 and got the monolith 15’s and was very impressed. Remember no less than 2 subs.
- Reply
- Inaccurate
- Brandon H on Apr 12, 2022
- Purchased on Jul 13, 2021
BEST ANSWER: Depends on your size. If you need to move a lot of air like say your in a big area go with 15in. The bigger subs move for air and hit much harder, even though the 13in has a 2000 watt amp. You still need the head room of a 15. One pro enthusiast told me the anything under a 15in sub does not belong in a theater room. So I sold my svs pro 2000 and got the monolith 15’s and was very impressed. Remember no less than 2 subs.
- Reply
- Inaccurate
- Brandon H on Apr 12, 2022
- Purchased on Jul 13, 2021
I’ve been listening to the 15 for about a year now. I love it. Depending on the music sometimes those low frequency hits become a little irritating. Movies this is never an issue since the sub is barely used. The 13 would be perfect for music. Just my opinion.
- Reply
- Inaccurate
- Michael S on Apr 12, 2022
- Purchased on Jul 22, 2021
For music listening the 13” would be real good. The 15” would be more ideal for a 7..1 or more setup. That is just my thoughts. I have two 2.1 music setups and I am running 10” and it sounds great and full.
- Reply
- Inaccurate
- ARTURO L on Apr 12, 2022
- Purchased on May 13, 2021
I have the 15. It is a battle for a full 5.1 elac system to keep up with it's gargantuan output. If you're only doing 2.1 go smaller
- Reply
- Inaccurate
- Brett W on Apr 13, 2022
- Purchased on May 24, 2021
I have two of the fifteens and they aren't slouches by any stretch.
- Reply
- Inaccurate
- Jeffrey R on Apr 18, 2022
- Purchased on Oct 21, 2021
Vote for the best answer above!
I have this sub. It is forward firing so I don't see why not. It would, however, make accessing the controls somewhat awkward. Hope this helps.
- Reply
- Inaccurate
- james s on May 29, 2018
- Purchased on Dec 15, 2017
I wouldn't want to even if it can because you will likely scratch the nice sides plus I don't think it's meant to be laid down on side
- Reply
- Inaccurate
- New User U on Jun 1, 2018
- Purchased on Apr 23, 2018
Vote for the best answer above!
Can I get exact shipping box dimensions? Want to know if I can fit 2 in my truck for local pickup.
A shopper
on Sep 14, 2018
BEST ANSWER: Shipping dims are 37x24x34 inches 133lbs.
- Reply
- Inaccurate
- Dave L Staff on Sep 17, 2018
BEST ANSWER: Shipping dims are 37x24x34 inches 133lbs.
- Reply
- Inaccurate
- Dave L Staff on Sep 17, 2018
While I don't have for you exact box measurement (seems Monoprice could provide that for you) I believe you could fit two of the 15" Subwoofer shipping cartons in a normal size truck bed (say a Ford F150 size bed). Congrats on the awesome bass coming your way. Two of these babies will be an incredible audio add!!
- Reply
- Inaccurate
- Michael F on Sep 17, 2018
- Purchased on Jun 24, 2018
It will fit into a full-size truck.
- Reply
- Inaccurate
- keith s on Sep 17, 2018
- Purchased on Apr 23, 2018
Vote for the best answer above!
if the feet on that subwoofer are removable?
A shopper
on Oct 31, 2019
BEST ANSWER: Yes, they seem to be threaded in with the rubber cone on each the only contact between the cabinet which is about 125 lb and the floor,
- Reply
- Inaccurate
- TAD on Nov 2, 2019
- Purchased on Mar 19, 2019
BEST ANSWER: Yes, they seem to be threaded in with the rubber cone on each the only contact between the cabinet which is about 125 lb and the floor,
- Reply
- Inaccurate
- TAD on Nov 2, 2019
- Purchased on Mar 19, 2019
Yes. They can be replaced with larger feet (6)
- Reply
- Inaccurate
- New User U on Oct 31, 2019
- Purchased on Aug 7, 2019
Yes I replaced mine with SVS isolators
- Reply(1)
- Inaccurate
- Kevin M on Oct 31, 2019
- Purchased on Aug 23, 2019
Vote for the best answer above!
Can the Monolith 15 inch subwoofer be set up wirelessly with an adapter?
New User U
on Dec 4, 2020
BEST ANSWER: It has no built in wireless but works well with wireless adapters I have two of these subs and both use an svs wireless adapter.
- Reply(2)
- Inaccurate
- Gregoy H on Dec 4, 2020
- Purchased on May 23, 2020
Is this connected by USB on sub, or what connection is used on the Subwoofer, some subs cant be made wireless,, by the way how do you like your sub, I have a svs pb3000, and was looking at buying a second Subwoofer, but was worried because everyone says you need to buy the same sub, for your second sub, to sound as one sub
Thanks for your help
Thanks for your help
- Reply (1)
- New User U on Dec 5, 2020
The SVS wireless adapter has RCA connections to the AV receiver and to the sub. It works well and doesn’t require anything special that the sub doesn’t happen. I sold 2 svs sb13 ultra subs and the monoprice plays much loader and deeper. Apples and oranges going from sealed to ported. The clean output of the monoprice thx15 is much higher than the svs at subsonic frequencies. There is no detectable drawback to having one port plugged on the Thx15 but the deep bass really benefits. The pair of thx15s blend very smoothly with my Martin Logan mains. These subs brought my system to life and seem to be the best clean flat output to dollar sub you can get. With two subs I don’t think I will ever need more or better bass.
Thanks for the info, my movie sound thanks you, I have a cd collection, how do these sound with music
- Reply
- New User U on Dec 5, 2020
Have you ever used the app,, I have a app on my pb3000, if I wanted to do this to the 15 thx, do I have to buy a equalizer to set the subs frequency, or are the buttons on the back pretty close to what a equalizer can do
No more questions i promise,, thanks so much for your time
Cheers
No more questions i promise,, thanks so much for your time
Cheers
- Reply
- New User U on Dec 5, 2020
What connection on the back of your 15 Thx sub do you use,, so I can make sure my receiver has the same connection,, for the adapter.
Thanks so much you made my Christmas, CHEERS TO YOU
Thanks so much you made my Christmas, CHEERS TO YOU
- Reply
- New User U on Dec 5, 2020
BEST ANSWER: It has no built in wireless but works well with wireless adapters I have two of these subs and both use an svs wireless adapter.
- Reply(2)
- Inaccurate
- Gregoy H on Dec 4, 2020
- Purchased on May 23, 2020
Is this connected by USB on sub, or what connection is used on the Subwoofer, some subs cant be made wireless,, by the way how do you like your sub, I have a svs pb3000, and was looking at buying a second Subwoofer, but was worried because everyone says you need to buy the same sub, for your second sub, to sound as one sub
Thanks for your help
Thanks for your help
- Reply (1)
- New User U on Dec 5, 2020
The SVS wireless adapter has RCA connections to the AV receiver and to the sub. It works well and doesn’t require anything special that the sub doesn’t happen. I sold 2 svs sb13 ultra subs and the monoprice plays much loader and deeper. Apples and oranges going from sealed to ported. The clean output of the monoprice thx15 is much higher than the svs at subsonic frequencies. There is no detectable drawback to having one port plugged on the Thx15 but the deep bass really benefits. The pair of thx15s blend very smoothly with my Martin Logan mains. These subs brought my system to life and seem to be the best clean flat output to dollar sub you can get. With two subs I don’t think I will ever need more or better bass.
Thanks for the info, my movie sound thanks you, I have a cd collection, how do these sound with music
- Reply
- New User U on Dec 5, 2020
Have you ever used the app,, I have a app on my pb3000, if I wanted to do this to the 15 thx, do I have to buy a equalizer to set the subs frequency, or are the buttons on the back pretty close to what a equalizer can do
No more questions i promise,, thanks so much for your time
Cheers
No more questions i promise,, thanks so much for your time
Cheers
- Reply
- New User U on Dec 5, 2020
What connection on the back of your 15 Thx sub do you use,, so I can make sure my receiver has the same connection,, for the adapter.
Thanks so much you made my Christmas, CHEERS TO YOU
Thanks so much you made my Christmas, CHEERS TO YOU
- Reply
- New User U on Dec 5, 2020
Probably, I don’t see why not. It has a regular rca plug for audio input.
- Reply
- Inaccurate
- Elliott W on Dec 5, 2020
- Purchased on May 20, 2020
Yes, if you have a wireless receiver system, then yes.
- Reply(1)
- Inaccurate
- Alfredo G on Dec 4, 2020
- Purchased on Jul 6, 2020
Will a Svs wireless adapter work, do you have the connection ability on the back of the sub
- Reply
- New User U on Dec 5, 2020
You may need to buy wireless transmission kit
- Reply(1)
- Inaccurate
- Gopi B on Dec 5, 2020
- Purchased on Oct 13, 2020
Thats what i was asking,, does this sub have a USB connection on the back of subwoofer
- Reply
- New User U on Dec 5, 2020
Vote for the best answer above!
Is this subwoofer active or passive? do I need woofer amplifier or it has its own?
A shopper
on Jan 8, 2018
BEST ANSWER: It's active with a 1000 watt amplifier.
- Reply
- Inaccurate
- New User U Staff on Jan 9, 2018
BEST ANSWER: It's active with a 1000 watt amplifier.
- Reply
- Inaccurate
- New User U Staff on Jan 9, 2018
Active - it has its own amp, plugs into the wall. I like it as it can be on a separate circuit. But ... trying to pass the low signal over speaker wire is giving me hum, so I'm direct wiring it now under the carpet. :)
- Reply
- Inaccurate
- Robert L on Jan 10, 2018
- Purchased on Dec 27, 2017
Active, it has an 1000 Watt amplifier in it if you read the specs.
- Reply
- Inaccurate
- Bill T on May 27, 2021
- Purchased on May 13, 2021
Vote for the best answer above!
I've got the 3-ported predecessor to this. Why would I want this one?
Mike E
on Mar 16, 2019

Monolith by Monoprice 15in THX Certified Ultra 1000-Watt Subwoofer Amplifier

Monolith by Monoprice M15-S 15in THX Ultra Certified Sealed 1000-Watt Powered Subwoofer
BEST ANSWER: Sealed subs offer lower Q at the expense of bass extension. For the same output level at a given frequency, they have to be bigger. Arguably, they are more "musical" in the sense that they have a lower Q: they are "tighter". The bass is less "muddy" and less "boomy", desirable qualities for music. Q is a measure of the "resonance" of the sub. A sub that resonates will be "boomy" and "muddy". So, lower Q is good: 0.707 (half of the square root of two) is "critically damped", about as high as you want to go, though more Q will give you more output at lower frequencies. See the dilema? Higher Q means louder but not as clean. A Q of 0.6 is considered good for a "musical" or "accurate" sub, and my preference.
- Reply
- Inaccurate
- Rene H on Jun 19, 2019
BEST ANSWER: Sealed subs offer lower Q at the expense of bass extension. For the same output level at a given frequency, they have to be bigger. Arguably, they are more "musical" in the sense that they have a lower Q: they are "tighter". The bass is less "muddy" and less "boomy", desirable qualities for music. Q is a measure of the "resonance" of the sub. A sub that resonates will be "boomy" and "muddy". So, lower Q is good: 0.707 (half of the square root of two) is "critically damped", about as high as you want to go, though more Q will give you more output at lower frequencies. See the dilema? Higher Q means louder but not as clean. A Q of 0.6 is considered good for a "musical" or "accurate" sub, and my preference.
- Reply
- Inaccurate
- Rene H on Jun 19, 2019
If you have the ported model, like I do, then there is no reason at all. A sealed sub may be better for when you are mainly playing music rather than movies as you don't need the more "tactile" feel of the ports' airflow. Some believe sealed subs are more accurate than ported, though you lose the reproduction of some of the lowest frequencies. Unless you're playing pipe organ music a lot, you may never miss them.
- Reply
- Inaccurate
- Dan H on Mar 16, 2019
Not sure you would. The big debate between ported and non-ported is to do with the type of music/movies and the ratios you listen to them.
I have the 15" THX with two-ports plugged - it rocks our 'great room' - but I have over 11k cubic feet to fill and open to kitchen on one side
I have the 15" THX with two-ports plugged - it rocks our 'great room' - but I have over 11k cubic feet to fill and open to kitchen on one side
- Reply
- Inaccurate
- Patrick M on Mar 16, 2019
No, I don’t think specs wise there is any difference. Comparing the two it seems more cosmetic than sound quality difference. I prefer 3 ported than the new one.
- Reply
- Inaccurate
- Ironnerve on Mar 16, 2019
Vote for the best answer above!
Hi I am thinking of putting some isolator under the woofer to help with the laminate flooring I got. Would this work Does the woofer have place to screw this in ?
SVS SoundPath Subwoofer Isolation System, Pack of 6
Or do you guys have something similar ? or better ?
SVS SoundPath Subwoofer Isolation System, Pack of 6
Or do you guys have something similar ? or better ?
New User U
on Jul 6, 2019
BEST ANSWER: The SVS isolation system will work with our subwoofers.
- Reply
- Inaccurate
- New User U Staff on Jul 8, 2019
BEST ANSWER: The SVS isolation system will work with our subwoofers.
- Reply
- Inaccurate
- New User U Staff on Jul 8, 2019
If you are doing this to reduce rattle, the svs isolation kit should work good. You may have to drill a few small holes, but as far as I know the svs kit is pretty universal. I have this sub on carpet and do not have any issues, so I have not bothered with isolation feet. I do have a friend who used the svs kit for his sub on hardwod and swears it made a big difference.
- Reply
- Inaccurate
- Nathan W on Jul 6, 2019
- Purchased on Feb 26, 2019
Yes the feet are screwed in, so they could be easily replaced. They are also rather short, so a little extra height would make getting a hold on the box to adjust easier as well (walking, aiming etc). I was checking into those SVS feet as well and think I saw on a forum they fit but haven't used them yet myself.
- Reply
- Inaccurate
- M O on Jul 6, 2019
- Purchased on Feb 26, 2019
I used the SVS Isolation system, worked great.
- Reply(1)
- Inaccurate
- Muhammed S on Jul 7, 2019
- Purchased on Feb 26, 2019
Hi Muhammad, thank you were you able to get all six in ? Also did you have to drill any holes ?
- Reply (1)
- New User U on Jul 7, 2019
No, they simply replaced the existing feet. Screwed out the existing feet and replaced them with the SVS ones.
- Reply
- Muhammed S on Jul 8, 2019
Vote for the best answer above!
Other than some cosmetic differences, recessed driver and such, what are the actual differences to product #24458, the other 15" sub?....specs seem exact?.... on that note, would it be better to get two of these and space them around the theatre, or 1 - M215? the logic being that the sum power of two single 15's is about the same as one M215.... does the splitting of location to two locations with single subs, out perform the dual driver in one location?
Curtis S
on Oct 19, 2022

Monolith by Monoprice 15in THX Certified Ultra 1000-Watt Subwoofer Amplifier

Monolith by Monoprice M-15 V2 15in THX Certified Ultra 1000-Watt Subwoofer Amplifier
BEST ANSWER: The driver was upgraded in V2 and the cabinet appearance was changed. The V2 15" performs slightly better than the V1. I would get 2 15" subs and place them around the room for smoother bass response in the room.
- Reply
- Inaccurate
- New User U Staff on Oct 19, 2022
BEST ANSWER: The driver was upgraded in V2 and the cabinet appearance was changed. The V2 15" performs slightly better than the V1. I would get 2 15" subs and place them around the room for smoother bass response in the room.
- Reply
- Inaccurate
- New User U Staff on Oct 19, 2022
Splitting the subs to 2 locations doesn't normally mean more output but almost always leads to more even bass throughout the room if set up correctly with time alignment and proper placement expecially with more than one seating location. I can't speak for the m215s output though. Hope this helps
- Reply
- Inaccurate
- Sean B on Nov 30, 2022
In most case, I would say 2 is better than one larger one. Sometimes two subs are more hassle to set.
- Reply
- Inaccurate
- Ralph C on Nov 30, 2022
NO. SAME OUTPUT IF PLACED IN 1/8 SPACE (CORNER) MIKE IN SEDONA
- Reply
- Inaccurate
- michael g on Nov 30, 2022
Vote for the best answer above!
Is this subwoofer active or passive? do I need woofer amplifier or it has its own?
New User U
on Jan 8, 2018
BEST ANSWER: It's active with a 1000 watt amplifier.
- Reply
- Inaccurate
- New User U Staff on Jan 9, 2018
BEST ANSWER: It's active with a 1000 watt amplifier.
- Reply
- Inaccurate
- New User U Staff on Jan 9, 2018
The sub has an internal 1000 watt RMS plate amp.
- Reply
- Inaccurate
- Jason H on Jan 9, 2018
- Purchased on Dec 15, 2017
Active - 1000w RMS, just under 2000w peak (dynamic) - no external amp needed.
- Reply
- Inaccurate
- New User U on May 29, 2020
- Purchased on May 11, 2020
Vote for the best answer above!
How far apart are the feet on the bottom?
A shopper
on Apr 24, 2019
BEST ANSWER: The 15" THX Ultra pictured is contained within an enclosure that is approximately 18" wide and 27.5" deep .... The front grill snaps on the front of this cabinet. So picture this rectangle enclosure: 18"W by 27.5"D (w/o grill as pictured above).
There are six motion dampening circular "feet" on the bottom of the cabinet. Picture them as: four feet placed within the enclosure's footprint, one on each corner, with the remaining two feet placed on the 27.5" long sides between each of the front and back feet.
Measuring that distance, to directly address your question, there are approximately 11 inches between ALL feet, spreading the sub's weight and balance across all six. These feet not only expertly spread the overall weight of this very solid sub, they also ensure that your sub does not move from where you place it.. And it doesn't.
There are six motion dampening circular "feet" on the bottom of the cabinet. Picture them as: four feet placed within the enclosure's footprint, one on each corner, with the remaining two feet placed on the 27.5" long sides between each of the front and back feet.
Measuring that distance, to directly address your question, there are approximately 11 inches between ALL feet, spreading the sub's weight and balance across all six. These feet not only expertly spread the overall weight of this very solid sub, they also ensure that your sub does not move from where you place it.. And it doesn't.
- Reply
- Inaccurate
- Michael F on Apr 24, 2019
- Purchased on Jun 24, 2018
BEST ANSWER: The 15" THX Ultra pictured is contained within an enclosure that is approximately 18" wide and 27.5" deep .... The front grill snaps on the front of this cabinet. So picture this rectangle enclosure: 18"W by 27.5"D (w/o grill as pictured above).
There are six motion dampening circular "feet" on the bottom of the cabinet. Picture them as: four feet placed within the enclosure's footprint, one on each corner, with the remaining two feet placed on the 27.5" long sides between each of the front and back feet.
Measuring that distance, to directly address your question, there are approximately 11 inches between ALL feet, spreading the sub's weight and balance across all six. These feet not only expertly spread the overall weight of this very solid sub, they also ensure that your sub does not move from where you place it.. And it doesn't.
There are six motion dampening circular "feet" on the bottom of the cabinet. Picture them as: four feet placed within the enclosure's footprint, one on each corner, with the remaining two feet placed on the 27.5" long sides between each of the front and back feet.
Measuring that distance, to directly address your question, there are approximately 11 inches between ALL feet, spreading the sub's weight and balance across all six. These feet not only expertly spread the overall weight of this very solid sub, they also ensure that your sub does not move from where you place it.. And it doesn't.
- Reply
- Inaccurate
- Michael F on Apr 24, 2019
- Purchased on Jun 24, 2018
About 3/4 of an inch from the front and sides and on the back the same distance. So that makes the feet almost to each corner. I would call it ideally positioned on the bottom of the cabinet for maximum stability. The sub is built to hold it's position while producing the lower octaves with outstanding accuracy free of aprotching tubby. It is what is experienced in properly tuned rooms with a live performance. I have four other decent subs but none come close to this. Terrific value but it is not easy to move.
- Reply
- Inaccurate
- TAD on Apr 24, 2019
- Purchased on Mar 19, 2019
It is 13 and half inches on the front between center of the feet. It is 25 and 5/8 inches on the sides between center of the feet.
- Reply
- Inaccurate
- Ironnerve on Apr 24, 2019
- Purchased on Nov 23, 2018
Vote for the best answer above!
Why two RCA inputs? (My soundbar has only 1 RCA out to subwoofer...)
Razvan N
on Aug 31, 2019
BEST ANSWER: I can't answer the "why" part of your question, but I can say, that while only one of the RCA inputs needs to be plugged in for the Monolith to function, I found that by using a 1-Female to 2-Male RCA Y-Adapter (which split the single RCA sub woofer pre-out from my receiver to plug into both RCA inputs on the Monolith) allowed me to lower the gain level on the Monolith and maintain output.
- Reply
- Inaccurate
- Nick G on Sep 1, 2019
- Purchased on Feb 26, 2019
BEST ANSWER: I can't answer the "why" part of your question, but I can say, that while only one of the RCA inputs needs to be plugged in for the Monolith to function, I found that by using a 1-Female to 2-Male RCA Y-Adapter (which split the single RCA sub woofer pre-out from my receiver to plug into both RCA inputs on the Monolith) allowed me to lower the gain level on the Monolith and maintain output.
- Reply
- Inaccurate
- Nick G on Sep 1, 2019
- Purchased on Feb 26, 2019
One RCA is fine. It can take one or two. You probably have a single sub out line, which will work fine. I only run a single from my Integra reciever. However, I am not sure you will get good quality out of a soundbar. You really need a reciever to handle a SUB of this size.
- Reply(1)
- Inaccurate
- Nathan W on Aug 31, 2019
- Purchased on Feb 26, 2019
Thanks Nathan. I don't have the space for discrete speaker/amp system so opted for the best soundbar I can get - the newly released Sennheiser AMBEO. I did not receive it yet but reviewers were pretty impressed and I am trying to round up its sound with a dedicated sub. My room is close to 4000 cuft and main seat is only about 6 ft from the short wall (w/65" TV) and only have room for speakers under the TV. Now I am trying to decide between 1 x 15" or 2 x 12"...
You can get a rca spitter but will only add a few watts... 1 rca is fine.
- Reply
- Inaccurate
- Jaren B on Aug 31, 2019
- Purchased on Sep 23, 2018
Vote for the best answer above!
Can I use with 220v power input?
A shopper
on May 13, 2021
BEST ANSWER: Hi, the usa models are 120 volts ac . The fuse rating is 250 volt. You would have to check with monoprice to see if they offer overseas models made for higher voltage. Hope that helps.
- Reply
- Inaccurate
- Ken N on May 14, 2021
- Purchased on Mar 3, 2021
BEST ANSWER: Hi, the usa models are 120 volts ac . The fuse rating is 250 volt. You would have to check with monoprice to see if they offer overseas models made for higher voltage. Hope that helps.
- Reply
- Inaccurate
- Ken N on May 14, 2021
- Purchased on Mar 3, 2021
The speaker only requires 110v. Here in the US but if your overseas you just need a power adapter.
- Reply
- Inaccurate
- John B on May 13, 2021
- Purchased on Dec 31, 2020
I'd like to use this In Germany. So should I Use voltagr transformer?
- Reply
- Inaccurate
- New User U on May 13, 2021
Vote for the best answer above!
What is the peak wattage of the amplifier?
A shopper
on Nov 18, 2021
BEST ANSWER: I believe it is 2000w peak.
- Reply
- Inaccurate
- ARTURO L on Nov 18, 2021
- Purchased on May 13, 2021
BEST ANSWER: I believe it is 2000w peak.
- Reply
- Inaccurate
- ARTURO L on Nov 18, 2021
- Purchased on May 13, 2021
Vote for the best answer above!
Are threaded inserts available, if so, what size thread?
A shopper
on Apr 20, 2022
BEST ANSWER: We do not sell additional threaded inserts.
- Reply
- Inaccurate
- New User U Staff on Apr 20, 2022
BEST ANSWER: We do not sell additional threaded inserts.
- Reply
- Inaccurate
- New User U Staff on Apr 20, 2022
I assume you are talking about inserts for the feet. I used the SVS Soundpath Subwoofer Isolation System. It included several screw sizes so I don't remember which one I used but it included the correct size.
- Reply
- Inaccurate
- Doug R on Apr 25, 2022
- Purchased on Nov 28, 2021
Vote for the best answer above!
Does this 15 inch subwoofer only play up to 90db before it distorts? Harmonic Distortion<1% 20-100Hz (90dB @ 1m) Does not seem to be very loud. Would think we need it to play at 105db with less than 1% distortion for a ultra THX theater.
jct
on Sep 24, 2017
BEST ANSWER: We have posted the CEA measurements on our site. The 15" inch has substantial output at 20Hz--over 112db.
- Reply
- Inaccurate
- New User U Staff on Nov 28, 2017
BEST ANSWER: We have posted the CEA measurements on our site. The 15" inch has substantial output at 20Hz--over 112db.
- Reply
- Inaccurate
- New User U Staff on Nov 28, 2017
90db@1M refers to sensitivity. It means that supplying 1 watt to the speaker will produce 90db SPL at one meter’s distance, usually reproducing pink noise. From this sensitivity statement, you can determine the speaker’s SPL at various distances when supplied with various wattages.
- Reply
- Inaccurate
- Bryan P on Dec 2, 2017
Vote for the best answer above!
Is the finish a real wood veneer or a vinyl finish? Thank you.
Ralph E L
on Nov 19, 2017
BEST ANSWER: Vinyl - matches other "black ash" speakers perfectly. very durable, it needs to be weighing so much.
- Reply
- Inaccurate
- New User U on May 29, 2020
- Purchased on May 11, 2020
BEST ANSWER: Vinyl - matches other "black ash" speakers perfectly. very durable, it needs to be weighing so much.
- Reply
- Inaccurate
- New User U on May 29, 2020
- Purchased on May 11, 2020
Vinyl finish and it's nice but not a real wood veneer, hence the low price.
- Reply
- Inaccurate
- New User U on Dec 22, 2017
Vote for the best answer above!
How is this shipped? Regular ground?
A shopper
on Jan 1, 2018
Ground - this came surprisingly fast from Kentucky to Florida, 3 days I think.
- Reply
- Inaccurate
- New User U on May 29, 2020
- Purchased on May 11, 2020
Vote for the best answer above!
My home theater size is 25x11x7.5 and planning to get 2 monolith 15 sub. Is that an overkill? Will a 2 monolith 12 sub fit my room better?
A shopper
on Apr 27, 2019
BEST ANSWER: Thank you for your question.
For a room that size you could use a 12" without any problems.
For a room that size you could use a 12" without any problems.
- Reply
- Inaccurate
- Tyler C Staff on Sep 11, 2019
BEST ANSWER: Thank you for your question.
For a room that size you could use a 12" without any problems.
For a room that size you could use a 12" without any problems.
- Reply
- Inaccurate
- Tyler C Staff on Sep 11, 2019
My home theater is 3000 cu/ft and a single fills it just fine - I wouldn't hesitate getting another, but its also not "needed". for clarity, I love bass and would consider another but am satisfied with the single.
- Reply
- Inaccurate
- New User U on May 29, 2020
- Purchased on May 11, 2020
Vote for the best answer above!
For the Monolith 15 ultra thx, I am buying isolation feet by SVS, and I need to know how many feet are on the bottom of this Subwoofer 4 or does it does this have 4 or have 6 feet on the bottom of Subwoofer??
Thanks
Thanks
New User U
on Dec 9, 2020
BEST ANSWER: I wish I could answer your question. I put an order in for one of these and have had to open up a case ticket with FedEx due to FedEx stating it was delivered but not at my address that it was supposed to be shipped to. Going on a week now and still no expensive sub!
- Reply
- Inaccurate
- D G on Dec 9, 2020
- Purchased on Nov 28, 2020
BEST ANSWER: I wish I could answer your question. I put an order in for one of these and have had to open up a case ticket with FedEx due to FedEx stating it was delivered but not at my address that it was supposed to be shipped to. Going on a week now and still no expensive sub!
- Reply
- Inaccurate
- D G on Dec 9, 2020
- Purchased on Nov 28, 2020
Vote for the best answer above!
Is there a break in period for the Monolith?
Matthew T
on Jul 29, 2021
BEST ANSWER: There was no break in period for either of mine. Went through the settings and determined how they would do best in my room. Played with them for a couple of hours with meters, and listening to different movies like 'Lucy' and 'Hacksaw Ridge'. Am very pleased with the purchase!!!
- Reply
- Inaccurate
- Brad E on Jul 29, 2021
- Purchased on Jan 18, 2021
BEST ANSWER: There was no break in period for either of mine. Went through the settings and determined how they would do best in my room. Played with them for a couple of hours with meters, and listening to different movies like 'Lucy' and 'Hacksaw Ridge'. Am very pleased with the purchase!!!
- Reply
- Inaccurate
- Brad E on Jul 29, 2021
- Purchased on Jan 18, 2021
Maybe few hours to release the tightness of driver, I started enjoying from day 1, it is my home shaker, best bass so far I have experienced.
- Reply
- Inaccurate
- Gopi B on Jul 29, 2021
- Purchased on Oct 13, 2020
Vote for the best answer above!
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 15in THX Certified Ultra 1000-Watt Subwoofer Amplifier

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

Monolith by Monoprice 10in THX Certified Select Subwoofer Amplifier
BEST ANSWER: We will be adding CEA-2010 @2M burst and RMS measurements by frequency in the near future.
- Reply
- Inaccurate
- 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.
- Reply
- Inaccurate
- New User U Staff on Sep 5, 2017
Vote for the best answer above!
Vote for the best answer above!
Is this just a private label “last year’s model” SVS sub?
A shopper
on Nov 30, 2017
BEST ANSWER: This subwoofer is not affiliated with SVS in any way. SVS subwoofers are not THX certified, and they have never produced a 15" subwoofer. The Monolith subwoofers have been designed and engineered from the ground up for us.
- Reply
- Inaccurate
- New User U Staff on Nov 30, 2017
BEST ANSWER: This subwoofer is not affiliated with SVS in any way. SVS subwoofers are not THX certified, and they have never produced a 15" subwoofer. The Monolith subwoofers have been designed and engineered from the ground up for us.
- Reply
- Inaccurate
- New User U Staff on Nov 30, 2017
Vote for the best answer above!
How long does it usually take to ship via trucking, and you you provide a tracking number?
Derek C
on Jan 23, 2018
BEST ANSWER: We do provide a tracking number once the subwoofer ships. Depending on where you are located, it would most likely take 3-7 days for transit.
- Reply
- Inaccurate
- New User U Staff on Jan 23, 2018
BEST ANSWER: We do provide a tracking number once the subwoofer ships. Depending on where you are located, it would most likely take 3-7 days for transit.
- Reply
- Inaccurate
- New User U Staff on Jan 23, 2018
Vote for the best answer above!
Are the in-house CEA-2010 numbers listed in THX mode or Extended mode?
A shopper
on Mar 4, 2018

Monolith by Monoprice 15in THX Certified Ultra 1000-Watt Subwoofer Amplifier

Monolith by Monoprice 10in THX Certified Select Subwoofer Amplifier

Monolith by Monoprice 12in THX Certified Ultra 500-Watt Subwoofer Amplifier
Vote for the best answer above!
Reviews
4.9 / 5.0
91 Reviews
5 Stars
4 Stars
3 Stars
2 Stars
1 Star
85
3
2
1
0
Rated 5 out of 5
Monolith 15"
Had it for about a year now and is working well. It is performing well, happy with purchase.
- Was this review helpful? Yes (0) No (1)
- Flag as Inappropriate
- Was this review helpful? Yes (0) No (1)
- Flag as Inappropriate
Rated 5 out of 5
An Excellent Value
I purchased a set of these and have enjoyed them with my KLF 20s for 9 months now. For the money these subs are impossible to beat unless you can find a used set from a high end brand name. I have recomended these to a few friends and Facebook group peers for those looking to beat out the mid to low end SVS models and spend less half as much.
- Was this review helpful? Yes (0) No (1)
- Flag as Inappropriate
- Was this review helpful? Yes (0) No (1)
- Flag as Inappropriate
Rated 5 out of 5
Insane Output
Had this for over a year now - still blown away by it (sometimes literally!). More than enough output for my theater area at the end of a basement great room. Highly recommended!
- Was this review helpful? Yes (0) No (1)
- Flag as Inappropriate
- Was this review helpful? Yes (0) No (1)
- Flag as Inappropriate
Rated 5 out of 5
Make sure your foundation is strong
This does exactly what you expect: rattle your house down and vibrate your ribs. It is precise and powerful and it brings the boom. I seal one of the ports and it is amazing for music, and it was made for movies and I find myself craving explosions. It handles subtlety and mid-bass great as well, but this sub always feels like it is just waiting to roar.
This thing is a tank, huge and insanely heavy, but it fills everything with bass. What more can you ask for in a sub than one that you can feel in your chest?
This thing is a tank, huge and insanely heavy, but it fills everything with bass. What more can you ask for in a sub than one that you can feel in your chest?
- Was this review helpful? Yes (3) No (1)
- Flag as Inappropriate
- Was this review helpful? Yes (3) No (1)
- Flag as Inappropriate
Rated 5 out of 5
Best Bass for the Buck
I got 2 of these as part of a home theatre/2ch system for music. They play low, loud and clean. Nothing that I've been able to find in this price range comes close to the performance of these.
That being said they are big and they are loud so WAF is not something to be ignored.
That being said they are big and they are loud so WAF is not something to be ignored.
- Was this review helpful? Yes (0) No (2)
- Flag as Inappropriate
- Was this review helpful? Yes (0) No (2)
- Flag as Inappropriate
Rated 5 out of 5
Amazing product for the price! Has absolutely no problem shaking the house.
- Was this review helpful? Yes (0) No (2)
- Flag as Inappropriate
- Was this review helpful? Yes (0) No (2)
- Flag as Inappropriate
Rated 5 out of 5
Good
I really liked it immediately after I heard it for the first time.
- Was this review helpful? Yes (0) No (2)
- Flag as Inappropriate
- Was this review helpful? Yes (0) No (2)
- Flag as Inappropriate
Rated 5 out of 5
Totally AWESOME subs. Everyone needs these.
I love how they come we'll protected in a bag. I love the performance so much I got a second one for the extreme bass head in me. Truthfully, one is all ya need.




- Was this review helpful? Yes (2) No (1)
- Flag as Inappropriate
- Was this review helpful? Yes (2) No (1)
- Flag as Inappropriate
Rated 5 out of 5
bought 2, no regrets.
I bought two of these when they were on sale, and the price point was around $1100. I am impressed with the subsonic that these produce more than anything else. I notice my couch moving and almost feels like it is kicking me when some movie effects happen. I almost pulled the trigger on 2 or the THX 16 but the 5k+ price tag after tax, made me do some comparison shopping. Ultimately looked like output was close enough that the $3000 saving made this a logical choice for me. Overall I am happy, the only minor complaint is the slight pop they make when they power on with the auto turn on. Time will tell if this was a good investment.
- Was this review helpful? Yes (2) No (1)
- Flag as Inappropriate
- Was this review helpful? Yes (2) No (1)
- Flag as Inappropriate
Rated 5 out of 5
Ok., I don?t have words to describe it. Best I can buy for the price!!! My wife just told me that she can feel the bass in the parking of my house? she just arrived from shopping!!! ????
My neibrorss most be so happy
Seroiously it is big, but if your are looking for bass, here it is!!!
My neibrorss most be so happy
Seroiously it is big, but if your are looking for bass, here it is!!!

Added Dec 31, 2021
- Was this review helpful? Yes (1) No (1)
- Flag as Inappropriate
- Was this review helpful? Yes (1) No (1)
- Flag as Inappropriate