Monoprice Monolith 7-Channel Amplifier Review

Verdinut

Verdinut

Audioholic Ninja
About comparing amplifiers, many years ago before they were bought up, McIntosh were conducting audio clinics in audio shops in Canada but I don't know if they were doing the same in the US.
My best friend who was then managing one of the audio stores in Montreal then reported what McIntosh reps were doing:

"Any audiophile was invited to bring his amp for testing. They started by measuring one of their own power amps, and then put the amp which was brought on the bench for the test. They were using a Variac for the tests, and when testing other manufacturers' products, they reduced the voltage on the Variac to something like 95 volts to make sure the other amplifier would not perform as well."
 
Last edited:
P

PENG

Audioholic Slumlord
About comparing amplifiers, many years ago before they were bought up, McIntosh were conducting audio clinics in audio shops in Canada but I don't know if they were doing the same in the US.
My best friend who was then managing one of the audio stores in Montreal then reported what McIntosh reps were doing:

"Any audiophile was invited to bring his amp for testing. They started by measuring one of their own power amps, and then put the amp which was brought on the bench for the test. They were using a Variac for the tests, and when testing other manufacturers. products, they reduced the voltage on the Variac to something like 95 volts to make sure the other amplifier would not perform as well."
Even if there isn't any such tricks being performed, imo a simple rule to follow is, never based one's decision on a dealer rep who want you to buy the amp he recommends and denmo, even if you hear, or think you hear a better difference. It's not about honesty, but bias, mainly.
 
Verdinut

Verdinut

Audioholic Ninja
Even if there isn't any such tricks being performed, imo a simple rule to follow is, never based one's decision on a dealer rep who want you to buy the amp he recommends and denmo, even if you hear, or think you hear a better difference. It's not about honesty, but bias, mainly.
I was relating to a manufacturer's rep not a dealer's rep and that's even worse from a company that was supposed to have a good reputation.
 
lovinthehd

lovinthehd

Seriously, I have no life.
Not exactly a new thing to sucker in the sales force themselves.
 
3

314carpenter

Enthusiast
Well, I must have been dissatisfied enough with the way 2CH music sounded with the Monolith 7X. I put my Classe CA-150 back into service for the main fronts, leaving 5 channels on the 7X to do the rest. Movies are not as loud/dynamic, but the 7x probably has a higher gain than the Classe. But, I am MUCH happier listening to music again. The 7X was just fatiguing to me. Perhaps the Classe is biased more into class A topology. Warmer.
Just saw this and thought I should jump back in at this point. I will update again later as things here change.

I have been alternating a Classe CAV-150 and Monolith 7X for my open concept listening space for the past year or so. I have decided the Monolith 7x will stay in that room. That setup in that space just has a more pleasing midrange tone, but works functionally the same. The lack of a 12V trigger was also an issue there.

Now the Classe CAV-150 is going through its paces in the dedicated home theater room. I also have a Monolith 7 non-x and will be alternating them back and forth in that space to decide which one I will be keeping long term. Up first I have the Classe running the LCR JBL 250Ti/240Ti 3 channels bridged @300W and the Monolith 7 running surround JBL 250Ti/Jbl L20T3 atmos. Wow my theater rack is doing a great job now warming up that closed up room. Running at about 7 amps idle.
 
Pogre

Pogre

Audioholic Warlord
I don't know how I missed that he did his listening tests with a SVS Ultra setup! I know exactly how well it powers the Ultra towers!
 
B

buckchester

Audiophyte
I'm hoping someone here can help me answer a question about this amp. I just bought a pair of Revel F208 speakers and am considering purchasing the 3-channel version of this amplifier to power them. I currently have a Marantz SR5005 receiver, which has pre-outs that I can use for this amp. Marantz has confirmed the pre-outs in this unit only output 1.2 volts RMS, however, Monoprice indicates 1.6 volts is necessary to fully power this amp. I contacted Monoprice and asked them what exactly this will mean for the performance of this amp and the only answer they would give me was to say it will "run quieter". They suggested I "check with a professional installer" if I need more details...

Is there a way I can calculate how many watts I will actually be able to get out of this amp if I pair it with this receiver? Thanks.
 
ryanosaur

ryanosaur

Audioholic Ninja
It seems many tests have shown the AVRs to be able to output more than spec’d. I was concerned briefly about that too, but my concern was unfounded. If you are able to find any bench tests for that, or similar aged AVRs from Marantz, you may find your answer.
 
Mitchibo

Mitchibo

Audioholic
I'm hoping someone here can help me answer a question about this amp. I just bought a pair of Revel F208 speakers and am considering purchasing the 3-channel version of this amplifier to power them. I currently have a Marantz SR5005 receiver, which has pre-outs that I can use for this amp. Marantz has confirmed the pre-outs in this unit only output 1.2 volts RMS, however, Monoprice indicates 1.6 volts is necessary to fully power this amp. I contacted Monoprice and asked them what exactly this will mean for the performance of this amp and the only answer they would give me was to say it will "run quieter". They suggested I "check with a professional installer" if I need more details...

Is there a way I can calculate how many watts I will actually be able to get out of this amp if I pair it with this receiver? Thanks.
Excellent question. Someone will be able to answer this in a more astute fashion than a neophyte like me, however I’m runner the monoprice 7 ch with revel 208’s. AVR is the Denon 5200X. I’m not sure about the output for mine but yours would seem negligible @ .5 watt differential. W/o an A/B test with perfect matching outputs I wonder if the performance suffers that is audible? If you get an answer please post as I’m curious too. Good luck.
 
Verdinut

Verdinut

Audioholic Ninja
I'm hoping someone here can help me answer a question about this amp. I just bought a pair of Revel F208 speakers and am considering purchasing the 3-channel version of this amplifier to power them. I currently have a Marantz SR5005 receiver, which has pre-outs that I can use for this amp. Marantz has confirmed the pre-outs in this unit only output 1.2 volts RMS, however, Monoprice indicates 1.6 volts is necessary to fully power this amp. I contacted Monoprice and asked them what exactly this will mean for the performance of this amp and the only answer they would give me was to say it will "run quieter". They suggested I "check with a professional installer" if I need more details...

Is there a way I can calculate how many watts I will actually be able to get out of this amp if I pair it with this receiver? Thanks.
Monoprice's answer is not totally accurate. If what Marantz told you about the 1.2 volts output before clipping, then it's quite possible that it will distort when driving the Monolith amp requiring 1.6 volts to get to its rated power, when you have music peaks or various noise peaks in movies.

First of all, what makes you think that you need exterior amplification. Does the SR5005 struggle to drive the Revels to your listening requirements, does it distort ? What distance is your listening position from the speakers, how loud do you listen and what kind of music you listen to are factors affecting your power requirements.

Here is a link for you to calculate how much power you need to get to your average SPL requirements and some power headroom:

 
Pogre

Pogre

Audioholic Warlord
Excellent question. Someone will be able to answer this in a more astute fashion than a neophyte like me, however I’m runner the monoprice 7 ch with revel 208’s. AVR is the Denon 5200X. I’m not sure about the output for mine but yours would seem negligible @ .5 watt differential. W/o an A/B test with perfect matching outputs I wonder if the performance suffers that is audible? If you get an answer please post as I’m curious too. Good luck.
I have a Monolith/Marantz setup too with a SR6011 and haven't had any trouble reaching high volumes and everything sounds great. If it's loud enough for you and not distorting or clipping, which you would hear, then you're good to go.
 
KEW

KEW

Audioholic Overlord
I'm hoping someone here can help me answer a question about this amp. I just bought a pair of Revel F208 speakers and am considering purchasing the 3-channel version of this amplifier to power them. I currently have a Marantz SR5005 receiver, which has pre-outs that I can use for this amp. Marantz has confirmed the pre-outs in this unit only output 1.2 volts RMS, however, Monoprice indicates 1.6 volts is necessary to fully power this amp. I contacted Monoprice and asked them what exactly this will mean for the performance of this amp and the only answer they would give me was to say it will "run quieter". They suggested I "check with a professional installer" if I need more details...

Is there a way I can calculate how many watts I will actually be able to get out of this amp if I pair it with this receiver? Thanks.
@PENG , do you happen to know anything about the SR5005?
 
B

buckchester

Audiophyte
Thank you, everyone, for your replies so far. Some comments and answers to your questions:

I searched for bench tests on Marantz receiver pre-outs and found a few from Audioholics that test this, however, I'm a little confused by what I've read.

For example, in this review (https://www.audioholics.com/av-receiver-reviews/marantz-sr8012-receiver/marantz-sr8012-bench-tests) Gene mentions that the Marantz SR8012 is capable of 4.5Vrms, but in his testing, he couldn't get more than 1.2Vrms. It sounds like the test signal was too strong to get more than 1.2, but with real-world material you can get 4.5. However, I'm not sure how he determined this.

In this review (https://www.audioholics.com/av-receiver-reviews/marantz-sr6004-1/sr6004-measurements) Gene says, "With 0dBFS in, the SR6004 was able to output a whopping 7Vpp unclipped (<.1%THD +N) or 2.49Vrms." So does this mean the SR6004 was capable of outputting 2.49Vrms from it's pre-outs?

If I'm understanding this correctly, then if the pre-outs in my Marantz receiver perform similarly to these models, then I should have no problem outputting 1.6Vrms to fully power the Monoprice amp with this receiver?

Regarding why I think I need an amp for these speakers, I'm not certain that I do. However, that seems to be what everyone says. For example, in the various reviews I've read on these speakers (e.g. Stereophile, Audio Science Review just to name a few), they point out that even though these speakers are spec'd at 8 ohms nominal, they fall down to 4 ohms for much of the frequency range, so they say an amp is necessary because of this. My Marantz receiver is also not spec'd to be able to drive 4 ohm speakers (only 6 to 8 ohms). Most people on the Revel owners thread on AVS forum seem to suggest an amp is the way to go as well.

I've only had these speakers for a week. So far, they sound fantastic with my Marantz receiver. I'd say they are the best sounding speakers I have ever heard. My last two sets of speakers were GoldenEar Triton Twos and Paradigm Studio 20s. I did a detailed A-B comparison between Revels and GoldenEars, and the Revels definitely sound better. I'm surprised how much better I think they sound. I thought the differences would be smaller since I thought the Triton Twos were quite good (however, next to the Revels, not so much).

My listening room is approx. 3,000 cubic feet. My speakers are about 10 feet away from me. I also have two PSA V1500 subs, which I cross over at 80hz, so I would think those take a lot of the load off of my receiver.

I like to listen loud. I like all sorts of music, but mostly listen to heavy stuff (like Tool). Using a UMIK at my listening seat, I usually listen to my music in the high 80s to mid 90s. With the Revels, I usually have my receiver volume set around -20 to -15 and this delivers high 80s to mid 90s db at the listening seat. If I turn it up louder than -15, it starts to sound harsh. Whether that's due to distortion being introduced, or just having the volume too high for my ears, I don't know. However, I'd like to make sure I have enough headroom for dynamic peaks without worrying that I might be sending a clipped signal to these speakers.

Any feedback would be appreciated!
 
P

PENG

Audioholic Slumlord
For example, in this review (https://www.audioholics.com/av-receiver-reviews/marantz-sr8012-receiver/marantz-sr8012-bench-tests) Gene mentions that the Marantz SR8012 is capable of 4.5Vrms, but in his testing, he couldn't get more than 1.2Vrms. It sounds like the test signal was too strong to get more than 1.2, but with real-world material you can get 4.5. However, I'm not sure how he determined this.
You got it right, he couldn't use higher than 1.2 V because the amp would trip, but that's was when he did a "continuous" sine wave frequency sweep, and the SR8012 does not have a preamp mode so the power amps were still connected. Real world material will not have contents anywhere close to being continuous sine waves so you should have no problem.

In this review (https://www.audioholics.com/av-receiver-reviews/marantz-sr6004-1/sr6004-measurements) Gene says, "With 0dBFS in, the SR6004 was able to output a whopping 7Vpp unclipped (<.1%THD +N) or 2.49Vrms." So does this mean the SR6004 was capable of outputting 2.49Vrms from it's pre-outs?
Your SR5005 should be able to output about the same at 0.1% THD and higher at higher THD.

If I'm understanding this correctly, then if the pre-outs in my Marantz receiver perform similarly to these models, then I should have no problem outputting 1.6Vrms to fully power the Monoprice amp with this receiver?
That is correct, your AVR can definitely output more than 1.6 Vrms and that would drive the Monolith 200 WX3 to about 200 W into 8 ohm or 400 W into 4 Ohm such as your F208 that is rated only 350 W maximum. So the SR5005/Monolith 200 WX3 combination would seem like a good match.

Regarding why I think I need an amp for these speakers, I'm not certain that I do. However, that seems to be what everyone says. For example, in the various reviews I've read on these speakers (e.g. Stereophile, Audio Science Review just to name a few), they point out that even though these speakers are spec'd at 8 ohms nominal, they fall down to 4 ohms for much of the frequency range, so they say an amp is necessary because of this. My Marantz receiver is also not spec'd to be able to drive 4 ohm speakers (only 6 to 8 ohms). Most people on the Revel owners thread on AVS forum seem to suggest an amp is the way to go as well.
Don't listen to hearsay, please go with specs, measurements, ie. facts and figures instead. Your Marantz can definitely drive the 4 ohm rated Revel speakers if your seating distance and target SPL allow them to do so. If your seating distance is far enough and your target SPL is high enough, then the 200 W Monolith can't do it either. To gain 3 dB spl you need double the power so the difference between the AVR and the amp is only about 3 dB. Having said that, the 200 W amp will allow you to take full advantage of the maximum capability (in terms of spl) of your speakers, so I think it is a good choice.

Any feedback would be appreciated!
It is possible that you listen at loud enough spl such that the SR5005 preout's distortion may be high enough to be audible. If so, It may be time to upgrade your AVR to an AVR-X3700H that has preamp mode, or the AVR-X3600H that has no all channel preamp mode but it does allow you to disconnect the front left and right channel. Obviously that's only if you can get one at a good discount when the X3700H is out.

Did you use an online spl calculator to find out your actual power need? And what did Audyssey set the trim levels to? Such info would help understand why the sound would get harsh with volume only at -15/-20.
 
B

buckchester

Audiophyte
I have tried online spl calculators, but it's hard to get a sense of what I need from them because depending on which one I use, I seem to get different results.

For example, this one (https://myhometheater.homestead.com/splcalculator.html) says I should get102db-105db at my listening position depending on whether or not I indicate my speakers are close to a wall or not (one speaker is close to a wall, the other is not).

This one (https://geoffthegreygeek.com/calculator-amp-speaker-spl/) says I'll get 96db at my listening position, and for a target spl of 100db it says I need 262 watts.

Audyssey se the trims to +1.5db and +2.5 db.
 
P

PENG

Audioholic Slumlord
I have tried online spl calculators, but it's hard to get a sense of what I need from them because depending on which one I use, I seem to get different results.

For example, this one (https://myhometheater.homestead.com/splcalculator.html) says I should get102db-105db at my listening position depending on whether or not I indicate my speakers are close to a wall or not (one speaker is close to a wall, the other is not).

This one (https://geoffthegreygeek.com/calculator-amp-speaker-spl/) says I'll get 96db at my listening position, and for a target spl of 100db it says I need 262 watts.

Audyssey se the trims to +1.5db and +2.5 db.
The first one is good. How far is the speaker from the wall, I mean the one that is not close to one?

Anyway, if the trim is set to +2.5, with volume set to -15, I can understand why it may sound harsh, depending on the media contents. For BR movies if you keep it below -20 you should be fine.
 
Pogre

Pogre

Audioholic Warlord
I have tried online spl calculators, but it's hard to get a sense of what I need from them because depending on which one I use, I seem to get different results.

For example, this one (https://myhometheater.homestead.com/splcalculator.html) says I should get102db-105db at my listening position depending on whether or not I indicate my speakers are close to a wall or not (one speaker is close to a wall, the other is not).

This one (https://geoffthegreygeek.com/calculator-amp-speaker-spl/) says I'll get 96db at my listening position, and for a target spl of 100db it says I need 262 watts.

Audyssey se the trims to +1.5db and +2.5 db.
For the homestead calculator I always figure away from walls. You know how loud 96 db is? That's really freaking loud. If you think you need more spl a better approach would be more sensitive speakers.
 
B

buckchester

Audiophyte
The first one is good. How far is the speaker from the wall, I mean the one that is not close to one?

Anyway, if the trim is set to +2.5, with volume set to -15, I can understand why it may sound harsh, depending on the media contents. For BR movies if you keep it below -20 you should be fine.
The speaker that is close to the wall is about 2 feet from the side wall, and about 3 feet from the back wall. The speaker that is far from the wall is about 6 feet from the side wall, and about 4 feet from the back wall.

Can you elaborate on your second point? If the trim is at +2.5, why do you think it would sound harsh at -15? And why would you recommend below -20?

Based on everything I've said, do you have a sense as to whether or not you think I would benefit from the Monolith amp?
 

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