Monolith by Monoprice M-IWSUB8 8in In-Wall Subwoofer
Product # 42831
UPC # 889028170243
$209.99
$399.99
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Do you have any recommendations on what amp to use to power it? I presume a unity amp won't cut it. What is the Peak and RMS wattage? Also are the pink measurements on the graphic in the description intended to be the cutout measurements?
Brian C
on Apr 8, 2022
BEST ANSWER: These have a pretty high sensitivity so most amps will do.
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- Inaccurate
- New User U Staff on Apr 19, 2022
BEST ANSWER: These have a pretty high sensitivity so most amps will do.
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- Inaccurate
- New User U Staff on Apr 19, 2022
Vote for the best answer above!
Vote for the best answer above!
I am used to a subwoofer that has a single RCA cable that connects to the AVR, not a L/R speaker wire connection. Given that my AVR also has a single RCA input for the subwoofer, how would I best utilize the M-IWSUB8 for my system?
A shopper
on May 18, 2023
BEST ANSWER: Hello and thank you for your question. You will need an amplifier. The RCA out of the AVR may not be provide the necessary power for the subwoofer. It would be the subwoofer out from the AVR into the amplifier's RCA in and the the speaker wire terminals out to the subwoofer's terminals.
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- Carlos R Staff on Jul 12, 2023
BEST ANSWER: Hello and thank you for your question. You will need an amplifier. The RCA out of the AVR may not be provide the necessary power for the subwoofer. It would be the subwoofer out from the AVR into the amplifier's RCA in and the the speaker wire terminals out to the subwoofer's terminals.
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- Carlos R Staff on Jul 12, 2023
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What is the depth “?
George V
on Apr 27, 2022
Reviews
4.0 / 5.0
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Rated 4 out of 5
Easy to install, sounds great, don't like the grill
Easy to install. Good punch. Heavy, quality piece. Installed my my living room in new 2.1 setup and it sounds crisp and lively.
Only thing that keeps me from giving a 5 star is that the grill fits weird. Others have mentioned the same thing. The grill sticks on with magnets and is basically the same dimensions as the sub housing itself with no overhang, so you end up seeing the black lip from the sub housing. Would look cleaner if the grill was slightly wider than the housing so that it could cover it completely and sit flush with the wall.
Only thing that keeps me from giving a 5 star is that the grill fits weird. Others have mentioned the same thing. The grill sticks on with magnets and is basically the same dimensions as the sub housing itself with no overhang, so you end up seeing the black lip from the sub housing. Would look cleaner if the grill was slightly wider than the housing so that it could cover it completely and sit flush with the wall.
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Rated 3 out of 5
Grill design doesn't sit flush with the wall
I've purchased and installed several Monoprice in-wall speakers/subwoofers over the years. All of them had grill covers that were flush with the wall so you the underlying speaker wasn't visible.
I purchased this subwoofer and noticed that there was a gap that would show the black speaker underneath and contacted customer support. They were really helpful and processed an exchange. The replacement came and had the same issue. I contacted Customer Support and was told it was likely an issue with a "batch" and there was little they could do other than refund my money (which I did).
Then around the holidays there was a nice sale so I bought two more. Unfortunately, they both are the exact same. I went ahead and installed one of them (see photos). Still deciding what to do, but wanted to share my experience for other potential buyers.
Otherwise, the speaker sound/build quality seems great.
I purchased this subwoofer and noticed that there was a gap that would show the black speaker underneath and contacted customer support. They were really helpful and processed an exchange. The replacement came and had the same issue. I contacted Customer Support and was told it was likely an issue with a "batch" and there was little they could do other than refund my money (which I did).
Then around the holidays there was a nice sale so I bought two more. Unfortunately, they both are the exact same. I went ahead and installed one of them (see photos). Still deciding what to do, but wanted to share my experience for other potential buyers.
Otherwise, the speaker sound/build quality seems great.



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Rated 5 out of 5
Worth the risk!!!
Purchased this to replace the 10? alpha installed in an outdoor patio 5.1 system paired with 6.5? alpha series. The alpha was good but not overly accurate, distorted at higher volumes, and the grille liked to rattle.
This little 8? is amazingly clear and tight at all ranges. I have had it installed for less than 2 hours and it sounds awesome. I?m sure after break in and adjustments it will only sound better.
If you are torn between this and the alpha and can afford this one get it. Build quality is unbelievable the grill is far superior and the sound quality is awesome. Ive had multiple monoprice home theater setups and have always been impressed this one by far is the cleanest sound yet.
I will likely be replacing my 2 12? klipsch in the house with the dual 8? Version very soon. Maybe 2 ??
For those wondering 150rms at 4ohms dimensions are now listed for cut out dimensions.
This little 8? is amazingly clear and tight at all ranges. I have had it installed for less than 2 hours and it sounds awesome. I?m sure after break in and adjustments it will only sound better.
If you are torn between this and the alpha and can afford this one get it. Build quality is unbelievable the grill is far superior and the sound quality is awesome. Ive had multiple monoprice home theater setups and have always been impressed this one by far is the cleanest sound yet.
I will likely be replacing my 2 12? klipsch in the house with the dual 8? Version very soon. Maybe 2 ??
For those wondering 150rms at 4ohms dimensions are now listed for cut out dimensions.

Added May 13, 2022
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