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expiredvid1900 posted Jul 3, 2026 1:53 AM

Monolith by Monoprice M7100X 7x 90W/ch Home Theater Power Amplifier

$325

$650

50% off
+ Free S&Hat Monoprice
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Deal Details
Monoprice has Monolith by Monoprice M7100X 7x90 Watts Per Channel Multi-Channel Home Theater Power Amplifier with RCA & XLR Inputs (43866) on sale for $649.99 - 50% with promo code SHOP50 in cart = $324.99. Shipping is free.

Thanks to Community Member vid1900 for sharing this deal.

Details:
  • 7-channel Class AB power amplifier
  • 90W per channel into 8 ohms, all channels driven
  • THD < 0.02% with SNR > -100 dB
  • Unbalanced RCA and XLR inputs
  • 3RU height

Editor's Notes

Written by SaltyOne | Staff
  • Rated 4.9 out of 5 stars from customer reviews.
  • At the time of this posting, our research indicates that this is $195 lower than the next best comparable online prices starting from $519.99.

Original Post

Written by vid1900
Community Notes
About the Poster
Deal Details
Community Notes
About the Poster
Monoprice has Monolith by Monoprice M7100X 7x90 Watts Per Channel Multi-Channel Home Theater Power Amplifier with RCA & XLR Inputs (43866) on sale for $649.99 - 50% with promo code SHOP50 in cart = $324.99. Shipping is free.

Thanks to Community Member vid1900 for sharing this deal.

Details:
  • 7-channel Class AB power amplifier
  • 90W per channel into 8 ohms, all channels driven
  • THD < 0.02% with SNR > -100 dB
  • Unbalanced RCA and XLR inputs
  • 3RU height

Editor's Notes

Written by SaltyOne | Staff
  • Rated 4.9 out of 5 stars from customer reviews.
  • At the time of this posting, our research indicates that this is $195 lower than the next best comparable online prices starting from $519.99.

Original Post

Written by vid1900

Community Voting

Deal Score
+76
Good Deal
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Price Intelligence

Model: Monolith by Monoprice M7100X 7x90 Watts Per Channel Multi-Channel Home Theater Power Amplifier with RCA & XLR Inputs

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187 Comments

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Jul 3, 2026 7:20 AM
139 Comments
Joined Mar 2016
HanL1318Jul 3, 2026 7:20 AM
139 Comments
Wow that's a ridiculously good price on a 7 channel power amp. I would get it, if my nearly 20 year old Anthem PVA7 weren't still going strong.
Jul 3, 2026 7:27 AM
1.3K Comments
Joined Feb 2010
ROOSKIEJul 3, 2026 7:27 AM
1.3K Comments
People who are looking.
You gain 3db of sound pressure in 1 speaker when you double the power to that speaker.

(Voltage is a better trait to use for audio-nuts but since watts is more commonly understood )

If your speaker is a very common 87db sensitive at 1watt from 1 meter away, then with 2watts it can play 90db
4watts = 93 db, 8watts = 96db, 16watts=99db, 32 watts = 102db, 64 watts =105db.
(You will also gain a couple db based on the size of your room due to reflections adding SPL.)

105+db is very, very loud but are you 1 meter away?

I am just more than 3.5 meters from my speakers. I lose about 11db due to distance.
So that 87db speaker hits 94db peaks with 64 watts, not the 105 @1meter.
94db peaks are fairly common if you play at higher levels & to ensure headroom and no clipping I would double the power to 128watts and double it again to about 250watts.
Of course this is one speaker and when I add a stereo pair in or more for home theater the calculation changes.

The point is power goes fast at higher SPL because you need double the power to gain 3db and at larger listening distance you lose plenty of SPL.
At lower to medium SPL you are hardly using any power & if you sit fairly close you are using even less.

For my main 2 channel set-up in a medium sized living room where I sit 3.5meters/12ftfrom the closest speaker I like 250-400 watts per channel for loud playback but I almost never actually use that much and most speakers can't actually handle that much power for long if they can at all.
1
1
Jul 3, 2026 7:34 AM
70 Comments
Joined Nov 2016
sks4hereJul 3, 2026 7:34 AM
70 Comments
Buyer beware! This has faint hum that won't go away. The power cord only has two prongs, so no ground support.
1
Jul 3, 2026 7:41 AM
1.3K Comments
Joined Feb 2010
ROOSKIEJul 3, 2026 7:41 AM
1.3K Comments
Quote from khalid7412002 :
I'm using kef R11 for LR, Kef R2C for center, kef R3 for surrounds.

Using an older marantz SR7007 avr waiting on a deal for next gen avr with full bandwidth hdmi 2.1 ports

Was thinking about buying a used marantz 5 channel amp for like $500-$600 but maybe this would work as well

I live an apartment so don't get too loud but wondering if an external amp might help me, which I'm guessing 99% I won't notice a difference at my mid-volume levels but wanted to ask the experts here
You very likely do not need this amp.
There are many types of 'apartments' including some that are very lux and very large and very sound isolating.
That said if you have a typical average apartment your set-up is already overkill.

The R11 are about 89db sensitive @2.83volts, they are lower impedance designs that will work best with high current amplification but this factors in more when driven fairly hard.
They have a very, very difficult to drive area from 30-40hrz. If you even start hitting those high SPL levels consider buying a different amp (and maybe a separate sub or two) but why Marantz? KEF uses science and controlled blind testing to design their products, they present white papers to the engineering community on their designs. Match with a suitably engineered amp if the need arises.
3
Jul 3, 2026 7:47 AM
1.6K Comments
Joined Nov 2005
KublakhanJul 3, 2026 7:47 AM
1.6K Comments
I have an Onkyo RZ50 powering a pair of Polk LSIM 703, 704c, 702 and 2 in-ceiling atmos/height speakers. I have a subwoofer. Would this external amp benefit my situation or should I look into getting a better rated 3 channel amp to power just my fronts?
Jul 3, 2026 7:57 AM
1.3K Comments
Joined Feb 2010
ROOSKIEJul 3, 2026 7:57 AM
1.3K Comments
Quote from Kublakhan :
I have an Onkyo RZ50 powering a pair of Polk LSIM 703, 704c, 702 and 2 in-ceiling atmos/height speakers. I have a subwoofer. Would this external amp benefit my situation or should I look into getting a better rated 3 channel amp to power just my fronts?
Whether you buy a larger 3 channel amp depends on the size of your room, your listening distance and how loudly you listen.

If you do playback very loudly then you may actually want larger speakers which will have an easier time with high output and generally require less power to do it vs monitor sized speakers - though the Polks you have are measured at [email protected] so good for their size in terms of efficiency.

Do not buy the Monoprice amp as it is more or less the same amount of power.
The difference is not meaningful.
Long term it is possible that the Monoprice has a easier time driving the speakers and thus runs a bit cooler and lasts longer or something like that, performance wise not much difference.
1
1
Original Poster
Pro
Jul 3, 2026 10:34 AM
3.1K Comments
Joined Sep 2016
vid1900
Original Poster
Pro
Jul 3, 2026 10:34 AM
3.1K Comments
Quote from Kublakhan :
I have an Onkyo RZ50 powering a pair of Polk LSIM 703, 704c, 702 and 2 in-ceiling atmos/height speakers. I have a subwoofer. Would this external amp benefit my situation or should I look into getting a better rated 3 channel amp to power just my fronts?
The Onkyo RZ50 is one of the 'limp mode' receivers, so you are the target audience for this amp.

https://www.audiosciencereview.co...avr.30842/

The 30wpc that you are currently getting from the receiver seems loud, but you are missing out on the dynamic peaks that can be 100w, even on moderate volume movie watching.

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Jul 3, 2026 1:23 PM
2.4K Comments
Joined Apr 2009
vicheJul 3, 2026 1:23 PM
2.4K Comments
I have a Denon 4300h and elac unifi speakers (1st gen), which are rated at just about 4 ohms. I use the speakers in a home theater setup and sit about 7 to 8 feet from the fronts. I don't generally blast audio, but for movies, I'll listen at a comfortably loud level. Would this amplifier improve sound quality for me? Is 90 wpc enough for those speakers at that distance? I believe the 4300 does not have dedicated preamp mode, but is also less likely to go into limp mode.

I plan to buy the Denon 3800h at some point, which has dedicated preamp mode and which I understand is more likely to go into limp mode.

So maybe it wouldn't really help much with the 4300 but be beneficial for the 3800?
Last edited by viche July 3, 2026 at 06:44 AM.
Pro
Jul 3, 2026 1:40 PM
15.1K Comments
Joined Aug 2010
turnne
Pro
Jul 3, 2026 1:40 PM
15.1K Comments
This is a very good price...and along with XLRs as well

I am also going to assume this is a true 90 watts all channels driven...as other Monolith amps are ...then this unit is more powerful that all but a very few AVR's you see here posted on Slick deals


This excludes the Onkyo RZ70( and its sister units) the Onkyo RZ70 AVR as it will actually outbench this amp and surpass its own published specs
https://www.bing.com/videos/river...&FORM=VIRE


For those that may have low impedance speakers and like to drive them to louder levels this could be a winner

I have used a Monolith 7X for a few years now to run the core of my main system and I have say..based on that unit..Monoprice has some high performing units
Jul 3, 2026 1:41 PM
59 Comments
Joined Apr 2019
SplendidSnow110Jul 3, 2026 1:41 PM
59 Comments
I have a 5 channel version 5100 of this same model added to my Denon 3700 7.1.2 setup. Amp is powering the front LCR and it can certainly make lot of difference. I would highly recommend for this price. Paid 399$ for my 5 channel amp.
Pro
Jul 3, 2026 1:43 PM
15.1K Comments
Joined Aug 2010
turnne
Pro
Jul 3, 2026 1:43 PM
15.1K Comments
Quote from vid1900 :
The Onkyo RZ50 is one of the 'limp mode' receivers, so you are the target audience for this amp.

https://www.audiosciencereview.co...avr.30842/

The 30wpc that you are currently getting from the receiver seems loud, but you are missing out on the dynamic peaks that can be 100w, even on moderate volume movie watching.
That and if you are running speakers that dip into low impedance ranges and you like to play them loudly, to boot

However, the speakers commonly posted on Slick deals are not in that group
Jul 3, 2026 1:49 PM
169 Comments
Joined Oct 2018
SDR1290Jul 3, 2026 1:49 PM
169 Comments
I did not realize the Onkyo rz30 had this limp mode flaw, when I purchased it last year. Should I get this amplifier?

I'm driving klipsch rp 504c, pair of 8000f, and mirage nanosats for height and surround, with a monolith m12v2 subwoofer.
Original Poster
Pro
Jul 3, 2026 2:24 PM
3.1K Comments
Joined Sep 2016
vid1900
Original Poster
Pro
Jul 3, 2026 2:24 PM
3.1K Comments
Quote from sks4here :
Buyer beware! This has faint hum that won't go away. The power cord only has two prongs, so no ground support.
You get a 3 year replacement warranty, I'd just exchange it for an undamaged unit.
Original Poster
Pro
Jul 3, 2026 2:34 PM
3.1K Comments
Joined Sep 2016
vid1900
Original Poster
Pro
Jul 3, 2026 2:34 PM
3.1K Comments
Quote from viche :
I have a Denon 4300h and elac unifi speakers (1st gen), which are rated at just about 4 ohms. I use the speakers in a home theater setup and sit about 7 to 8 feet from the fronts. I don't generally blast audio, but for movies, I'll listen at a comfortably loud level. Would this amplifier improve sound quality for me? Is 90 wpc enough for those speakers at that distance? I believe the 4300 does not have dedicated preamp mode, but is also less likely to go into limp mode.

I plan to buy the Denon 3800h at some point, which has dedicated preamp mode and which I understand is more likely to go into limp mode.

So maybe it wouldn't really help much with the 4300 but be beneficial for the 3800?
4300 has "amp assign" so you can use whatever channels you want with an external or the internal amps.

Even if it didn't, you would connect an external amp to the "pre-outs" and just not plug anything into the receiver's speaker terminals. The receiver runs cooler when it does not have to deliver power to the speakers.
1

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Original Poster
Pro
Jul 3, 2026 2:52 PM
3.1K Comments
Joined Sep 2016
vid1900
Original Poster
Pro
Jul 3, 2026 2:52 PM
3.1K Comments
Quote from SDR1290 :
I did not realize the Onkyo rz30 had this limp mode flaw, when I purchased it last year. Should I get this amplifier?

I'm driving klipsch rp 504c, pair of 8000f, and mirage nanosats for height and surround, with a monolith m12v2 subwoofer.
Yeah, Onkyo, Pioneer, Denon and Integra are just like KIA Motors....not exactly bragging about their limp modes.

The Klipsch are listed as 8 ohm speakers, but they actually dip down to 5.6 ohms. I'm not sure if that's low enough to trigger the limp mode; they are pretty easy speakers to drive.

If you have car audiophile friends, see if one of them will lend you their watt meter and measure if you are stuck in limp mode or not.

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