Monolith by Monoprice M-15 V2 15in THX Certified Ultra 1000-Watt Subwoofer Amplifier
Product # 42851
UPC # 889028170441
$1,499.99
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Browse 13 questions
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and 22 answers
Is Fedex Freight usually good with these large Monoprice Monolith Boxes? My subwoofers delivery date has been postponed 2 times and its now about a week late so I am very concerned. Secondly if the box is damaged enough to cause concern should I then refuse the package? Thanks
James J
on Apr 9, 2022
BEST ANSWER: Although the specs say speaker weighs 133lbs, the shipping weight is 220lbs. Mine was delayed a few days also, but it finally got here. It requires a special truck for delivering boxes that are that big (over a yard high and wide and tall) and weigh that much, so scheduling is a challenge. They did keep me informed though. I needed mine in the basement where I had built a theater, but to get there they would need to cross the lawn. He said that the dolly they use would never make it. Their dolly moves on pavement only. So it went intop the garage and I had to figure out how to get it to the basement.
The box would need a very large dent in it to reach the speaker. They really protected it in there.
The box would need a very large dent in it to reach the speaker. They really protected it in there.
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- Gerald G on Apr 11, 2022
- Purchased on Mar 23, 2022
BEST ANSWER: Although the specs say speaker weighs 133lbs, the shipping weight is 220lbs. Mine was delayed a few days also, but it finally got here. It requires a special truck for delivering boxes that are that big (over a yard high and wide and tall) and weigh that much, so scheduling is a challenge. They did keep me informed though. I needed mine in the basement where I had built a theater, but to get there they would need to cross the lawn. He said that the dolly they use would never make it. Their dolly moves on pavement only. So it went intop the garage and I had to figure out how to get it to the basement.
The box would need a very large dent in it to reach the speaker. They really protected it in there.
The box would need a very large dent in it to reach the speaker. They really protected it in there.
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- Inaccurate
- Gerald G on Apr 11, 2022
- Purchased on Mar 23, 2022
They were fine with my delivery, the sub came on a pallet and was well packed in the box. The sub itself was covered in a fabric wrap and styrofoam all around. Make sure you have a friend and a hand truck to get it inside, it weighs just shy of 150lbs out of the box.
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- ERIC K on Apr 11, 2022
- Purchased on Mar 28, 2022
I too have yet to receive mine. So the question is , is it the shipping company or is it incorrect data that the item has been shipped? Best of luck to you.
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- william m on Apr 11, 2022
- Purchased on Apr 1, 2022
If they were good , you would have your shipment by now …….
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- James F on Apr 11, 2022
- Purchased on Apr 1, 2022
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What are the power requirements for a 1000 Watt RMS amplifier? Does it need a dedicated circuit?
New User U
on Oct 26, 2021
BEST ANSWER: It depends on what else you have on the circuit if anything. If it maxes around 2000w its a simple math problem you divide by the Voltage. In the US 120 meaning max it should use just shy of 17 amps. You should be fine it is the only thing on a 20 amp circuit. If you have other items it may/will not be enough.
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- David H on Mar 3, 2022
BEST ANSWER: It depends on what else you have on the circuit if anything. If it maxes around 2000w its a simple math problem you divide by the Voltage. In the US 120 meaning max it should use just shy of 17 amps. You should be fine it is the only thing on a 20 amp circuit. If you have other items it may/will not be enough.
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- David H on Mar 3, 2022
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The title says it is Ultra certified, but the full specs it is Select certified. Which is it?
Gerald S
on Dec 16, 2021
The 10” is Select and the 12” and 15” are Ultra.
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- Ashraf S on Dec 16, 2021
- Purchased on Nov 30, 2021
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Is the wood grain finish vinyl or wood veneer?
A shopper
on Mar 24, 2022
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Can this subwoofer be laid on its side. What would be the impact to the sound, if any?
Chris F
on Mar 27, 2022
BEST ANSWER: Yes it can be laid on its side with no impact to sound quality.
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- New User U Staff on Mar 28, 2022
BEST ANSWER: Yes it can be laid on its side with no impact to sound quality.
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- New User U Staff on Mar 28, 2022
Yes it can be laid on it's side with no issues, no impact on sound quality or performance.
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- Corey B on Mar 27, 2022
- Purchased on Mar 14, 2022
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My goal for this unit was to "FEEL the thunder" or "FEEL the train going by" with out cranking up the over all volume. With this in mind, which is best, opening 2 ports or 3 ports? I know there are many other variables, but this is the one I'd like to address now.
Gerald G
on Apr 14, 2022
BEST ANSWER: You can download any of the subwoofer manuals as the manual applies to all the subwoofers.
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- New User U Staff on Apr 19, 2022
BEST ANSWER: You can download any of the subwoofer manuals as the manual applies to all the subwoofers.
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- New User U Staff on Apr 19, 2022
Ive used it with 3 ports open and 2 ports opened. Your whole house will definitely "feel" the thunder regardless of the number of ports opened. On paper it says it goes lower with 2 ports open but it dosen't matter in my house. And its in a large theater room.
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- Barry W on Apr 14, 2022
- Purchased on Apr 2, 2022
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What is better between
V2M15 and M210 Dual
I like low frequency and thunder also punchy bass and tighter bass?
V2M15 and M210 Dual
I like low frequency and thunder also punchy bass and tighter bass?
New User U
on May 15, 2022
BEST ANSWER: If you like low frequency and thunderous bass, I’d go with the monolith M15 V2’s. The room I have them in is 18X23 and two M15 V2’s fills that room with so much deep bass that it’s unreal. It almost give you that movie theater feel.
I use to have dual klipsch 12” subs and it’s nothing compared to what these 15’s can do.
I’ve never had any experiences with 10” subs but I’ve always heard and read that smaller subs are tighter and puncher but if you want deep bass, definitely go with the M15 V2’s. If you can afford it, get two. Plus a lot depends on the size of your room too. If you have a small room, one will be enough.
I use to have dual klipsch 12” subs and it’s nothing compared to what these 15’s can do.
I’ve never had any experiences with 10” subs but I’ve always heard and read that smaller subs are tighter and puncher but if you want deep bass, definitely go with the M15 V2’s. If you can afford it, get two. Plus a lot depends on the size of your room too. If you have a small room, one will be enough.
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- Inaccurate
- Ratana H on May 15, 2022
- Purchased on Mar 6, 2022
BEST ANSWER: If you like low frequency and thunderous bass, I’d go with the monolith M15 V2’s. The room I have them in is 18X23 and two M15 V2’s fills that room with so much deep bass that it’s unreal. It almost give you that movie theater feel.
I use to have dual klipsch 12” subs and it’s nothing compared to what these 15’s can do.
I’ve never had any experiences with 10” subs but I’ve always heard and read that smaller subs are tighter and puncher but if you want deep bass, definitely go with the M15 V2’s. If you can afford it, get two. Plus a lot depends on the size of your room too. If you have a small room, one will be enough.
I use to have dual klipsch 12” subs and it’s nothing compared to what these 15’s can do.
I’ve never had any experiences with 10” subs but I’ve always heard and read that smaller subs are tighter and puncher but if you want deep bass, definitely go with the M15 V2’s. If you can afford it, get two. Plus a lot depends on the size of your room too. If you have a small room, one will be enough.
- Reply
- Inaccurate
- Ratana H on May 15, 2022
- Purchased on Mar 6, 2022
1. It will depend on the structure of the home and placement.
2. 15” will hit really low, more cone area. I wanted those ultra low frequencies that 10’s can hit.
3. Both will sound like monsters and you’ll be super happy.
I chose 15” and you can always plug ports for more punch and tune for better punchiness
Hope you enjoy. .
2. 15” will hit really low, more cone area. I wanted those ultra low frequencies that 10’s can hit.
3. Both will sound like monsters and you’ll be super happy.
I chose 15” and you can always plug ports for more punch and tune for better punchiness
Hope you enjoy. .
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- Steve T on May 15, 2022
- Purchased on Mar 13, 2022
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What's changed in V2???
nik g
on Oct 26, 2021
BEST ANSWER: Updated appearance and improved magnet structure for the woofer.
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- New User U Staff on Oct 27, 2021
BEST ANSWER: Updated appearance and improved magnet structure for the woofer.
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- New User U Staff on Oct 27, 2021
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main difference between the M15 and the M15 V2?
A shopper
on Oct 26, 2021
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Other than aesthetics, what is different between v1 and v2? Performance metrics appear identical
A shopper
on Oct 29, 2021
BEST ANSWER: It's mainly aesthetics, but there is a smidge more output in the new subs of roughly 0.7-1.2 db in some frequencies.
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- New User U Staff on Oct 29, 2021
BEST ANSWER: It's mainly aesthetics, but there is a smidge more output in the new subs of roughly 0.7-1.2 db in some frequencies.
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- New User U Staff on Oct 29, 2021
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How does this stack up against the 13 in over all performance for music?
A shopper
on Nov 4, 2021
BEST ANSWER: Both subwoofers have more than enough low distortion output for music so there is effectively really no difference unless you want to make yourself deaf. Look at CEA-2010 comparisons for max output. 13in has more output overall but for some reason the 15in does better at 12.5hz.
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- New User U on May 3, 2022
- Purchased on Mar 11, 2022
BEST ANSWER: Both subwoofers have more than enough low distortion output for music so there is effectively really no difference unless you want to make yourself deaf. Look at CEA-2010 comparisons for max output. 13in has more output overall but for some reason the 15in does better at 12.5hz.
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- New User U on May 3, 2022
- Purchased on Mar 11, 2022
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Would the v1 and v2 M15's be close enough in response to be matched in a two-sub system?
Ashraf S
on Nov 25, 2021
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What is the best cable to connect this subwoofer to a receiver?
New User U
on Jan 25, 2022
BEST ANSWER: I am using a well insulated subwooder cable into a shielded y splitter to the subwoofer. It only needs to pass a signal, so not much is needed for a 30ft run for example.
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- Inaccurate
- Alexander M on Jan 26, 2022
- Purchased on Jan 11, 2022
BEST ANSWER: I am using a well insulated subwooder cable into a shielded y splitter to the subwoofer. It only needs to pass a signal, so not much is needed for a 30ft run for example.
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- Inaccurate
- Alexander M on Jan 26, 2022
- Purchased on Jan 11, 2022
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Reviews
4.9 / 5.0
7 Reviews
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Rated 5 out of 5
Insanely Awsome! ??
It is insanely awesome! People really don?t get how hard this thing hits for the money. It?s super heavy and high quality build.
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Rated 5 out of 5
Monolith 15" THX
15" THX is musical enough it allowed me to set crossover higher and let the Klipsch RF7III's really breath and open up ! With movies WOW !

15" THX with RF7III
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Rated 5 out of 5
Adds a whole new dimension.
I wanted to be able to hear the thunder in a movie. I got wat I wanted. It does pass the rumble of thunder or a freight train passing or the ominous sounds of a scary movie. It adds a whole new dimension.
But, be prepared for some setup challenges if your not an audiophile. Crank it up a little and you'll be swamped with rumble that you never knew existed in a movie.
But, be prepared for some setup challenges if your not an audiophile. Crank it up a little and you'll be swamped with rumble that you never knew existed in a movie.
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Rated 5 out of 5
Amazing product just bought it at the wrong time.
Love the product but not too thrilled that it went on sale just after the 7 day buyers protection. I bought two M15 V2?s for $1499 each and by the tenth day the price dropped to $1199.
It?s too expensive to return and ship back and buy it back at a lower price so I ended up keeping it.
It?s too expensive to return and ship back and buy it back at a lower price so I ended up keeping it.

Added Mar 28, 2022
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Rated 5 out of 5
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Rated 5 out of 5
Headroom to the Moon and back.
Have a pair in my theater. I invested into overkill now as I plan to finish a larger space in the future and wanted subwoofers that could fill a larger space than I have now. These subs are incredible at performance. Currently in a 12ftx17ftx8ft room. One of these is overkill, but is much smoother over a greater area with 2. I am enjoying the fact that I cannot make these guys sweat even a little. They are just too much. Like driving a Viper through a 20mph neighborhood. But I have no fear of blowing or damaging them in use, they can take it. Even dialed down, they can be intense with a giant monster movie. Only thing I would specifically note, when the auto on feature is used, the amps make a slight pop when turning on. I figure this is normal, but wanted to point out as I read it referenced on different reviews. If you get this sub and dial it in well, I can't imagine someone wanting or needing more than its output.

Added Jan 16, 2022
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Rated 4 out of 5
Monolith 15
Hits real hard for music and sound great on movies definitely an up grade from the 12" Klipsch that I had! I was pretty skeptical on buying the sub but for the price and comparable to svs it's a good deal
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