This is a review, listening tests and detailed measurements of the Monoprice Monolith M1570C closed back planar magnetic headphone. It is on kind loan from a member and costs US $600 although I am told it goes on sale for just $200!
This is a large and heavy headphone. The owner sent it with the faux leather pads which made it gigantic width wise. With velour pads, it is much more manageable and it initially fit well on my head. After a few minutes though, the headband started to dig into my head so not sure I could wear it for more than half hour to an hour.
Note: The measurements you are about to see are made using a standardized Gras 45C. Headphone measurements by definition are approximate and variable so don't be surprised if other measurements even if performed with the same fixtures as mine, differ in end results. Protocols vary such as headband pressure and averaging (which I don't do). As you will see, I confirm the approximate accuracy of the measurements using Equalization and listening tests. Ultimately headphone measurements are less exact than speakers mostly in bass and above a few kilohertz so keep that in mind as you read these tests. If you think you have an exact idea of a headphone performance, you are likely wrong!
Fitment on the fixture was relative easy but there was an issue as you see below.
Monoprice Monolith M1570C Measurements
I started the measurements with the faux leather pads. That unfortunately has a deep hole right at the frequency that I calibrate to 94 dBSPL. It looked very odd that way so I broke my normal rule and brought the overall level to get compliance elsewhere:
The graph is very rough which typically indicates resonances (more on this later). I decided to switch to Velour pads which is shown in dashed brown. FYI, swapping pads was a royal pain as you have to insert a flexible lip into a very narrow slit all around the cup. Good thing I don't curse as there would have been plenty of that otherwise!
Anyway, the velour pad seemed more workable to me so let's go with that from here on:
At least now we are just short of bass and midrange as opposed to the uneven response of leatherette. Here is our relative curve for the much needed equalization:
Fortunately distortion is extremely low, sans some resonances:
The resonances were milder with the leather pad which may indicate it is the case resonance.
Group delay has a number of pronounced discontinuities which is likely partially generated by above resonances:
Impedance is relative low and flat as is typically the case with planar magnetic headphones:
Sensitivity is below average so you need some amplification:
Monoprice M1570C Listening Tests and EQ
Immediate impression was: "where is the bass?" So out came the EQ:
As you see, I just tried to compensate for lack of bass and midrange. Due to high amount of bass boost, you have to allow a lot of headroom. Above was good enough for my test tracks which includes some with very deep subbass. You lose fair bit of headroom because of this so best to have a powerful headphone amplifier. My RME ADI-2 Pro drove it with ease though.
With EQ, we now have very good bass with nice fidelity. Spatial qualities were also very good and pleasing in the way instruments were separated around my ears. I thought at times the highs were a bit unpleasant but it could be me being biased by the measurements. I tried a couple of sharp filters where the resonances are but that changed tonality too much to conclude that distortion was being reduced.
Conclusions
The Monoprice M1570C seems like a "phoned in" design to me. There is clearly no performance target as far as tonality. Likely specs were given at high level of manufacturer in far east and out come a heavy headphone with very odd frequency response. The saving grace is very low distortion courtesy of large drivers allowing EQ to correct many of its ills. If it does indeed go on sale for $200, and you can tolerate its weight, it may not be a bad option.
I can't recommend the Monoprice Monolith M1570C as is. With strong EQ, it does wake up and produce good fidelity. So with that, I can recommend it especially at at the $200 price point. Just don't try to change the pads if you are not in perfectly calm mood.....
-----------
As always, questions, comments, recommendations, etc. are welcome.
Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
This is a large and heavy headphone. The owner sent it with the faux leather pads which made it gigantic width wise. With velour pads, it is much more manageable and it initially fit well on my head. After a few minutes though, the headband started to dig into my head so not sure I could wear it for more than half hour to an hour.
Note: The measurements you are about to see are made using a standardized Gras 45C. Headphone measurements by definition are approximate and variable so don't be surprised if other measurements even if performed with the same fixtures as mine, differ in end results. Protocols vary such as headband pressure and averaging (which I don't do). As you will see, I confirm the approximate accuracy of the measurements using Equalization and listening tests. Ultimately headphone measurements are less exact than speakers mostly in bass and above a few kilohertz so keep that in mind as you read these tests. If you think you have an exact idea of a headphone performance, you are likely wrong!
Fitment on the fixture was relative easy but there was an issue as you see below.
Monoprice Monolith M1570C Measurements
I started the measurements with the faux leather pads. That unfortunately has a deep hole right at the frequency that I calibrate to 94 dBSPL. It looked very odd that way so I broke my normal rule and brought the overall level to get compliance elsewhere:
The graph is very rough which typically indicates resonances (more on this later). I decided to switch to Velour pads which is shown in dashed brown. FYI, swapping pads was a royal pain as you have to insert a flexible lip into a very narrow slit all around the cup. Good thing I don't curse as there would have been plenty of that otherwise!
Anyway, the velour pad seemed more workable to me so let's go with that from here on:
At least now we are just short of bass and midrange as opposed to the uneven response of leatherette. Here is our relative curve for the much needed equalization:
Fortunately distortion is extremely low, sans some resonances:
The resonances were milder with the leather pad which may indicate it is the case resonance.
Group delay has a number of pronounced discontinuities which is likely partially generated by above resonances:
Impedance is relative low and flat as is typically the case with planar magnetic headphones:
Sensitivity is below average so you need some amplification:
Monoprice M1570C Listening Tests and EQ
Immediate impression was: "where is the bass?" So out came the EQ:
As you see, I just tried to compensate for lack of bass and midrange. Due to high amount of bass boost, you have to allow a lot of headroom. Above was good enough for my test tracks which includes some with very deep subbass. You lose fair bit of headroom because of this so best to have a powerful headphone amplifier. My RME ADI-2 Pro drove it with ease though.
With EQ, we now have very good bass with nice fidelity. Spatial qualities were also very good and pleasing in the way instruments were separated around my ears. I thought at times the highs were a bit unpleasant but it could be me being biased by the measurements. I tried a couple of sharp filters where the resonances are but that changed tonality too much to conclude that distortion was being reduced.
Conclusions
The Monoprice M1570C seems like a "phoned in" design to me. There is clearly no performance target as far as tonality. Likely specs were given at high level of manufacturer in far east and out come a heavy headphone with very odd frequency response. The saving grace is very low distortion courtesy of large drivers allowing EQ to correct many of its ills. If it does indeed go on sale for $200, and you can tolerate its weight, it may not be a bad option.
I can't recommend the Monoprice Monolith M1570C as is. With strong EQ, it does wake up and produce good fidelity. So with that, I can recommend it especially at at the $200 price point. Just don't try to change the pads if you are not in perfectly calm mood.....
-----------
As always, questions, comments, recommendations, etc. are welcome.
Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
