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Having been so pleasantly surprised by the somewhat more expensive M-Audio BX5 D3, I decided to purchase one of the brand's even cheaper offerings. These are the M-Audio BX4 D3s and they retail as a pair for just EUR 120.
One monitor is powered, while the other is passive and left/right placement is selectable. The front of the powered unit offers a white power LED, combination volume control and power switch, 3.5mm TRS headphone output and auxiliary 3.5mm audio input.
The design is quite similar to that of M-Audio's more expensive offerings, although the tweeter waveguide has been truncated and the baffle plastics are noticeably cheaper.
On the rear of the active speaker, we have both balanced 6.3mm TRS and unbalanced RCA inputs, along with a position selection switch for the active unit and a 3.5mm TS output to the passive speaker. There are also what appear to be LF and HF gain controls but as these speakers contain only two amplifiers and do not include proper crossovers (discussed later in greater detail), they are effectively simple tone controls.
![[removal.ai]_tmp-62225fbea6d1c_JS2L6A.png](https://www.audiosciencereview.com/forum/index.php?attachments/removal-ai-_tmp-62225fbea6d1c_js2l6a-png.190380/ "[removal.ai]_tmp-62225fbea6d1c_JS2L6A.png")
The amplifiers are 25W class AB modules and do not produce any significant heat, as was the case with the BX5 D3s.
With the practicalities out of the way, let's jump into the measurements. As always, we begin with the on-axis and off-axis measurements. These utilize a composite of ground plane, nearfield and gated methods, which should be reasonably comparable to data acquired using a Klippel NFS or anechoic chamber. For these measurements, the tone controls were in the "0dB" position.
Well, that's a rollercoaster of a response. The port appears to be doing little more than introducing a large hump around 80Hz and there are several resonances dotted throughout the data.
Directivity is relatively uniform until about 5-6KHz, where the midbass gradually begins to roll off (it has no crossover whatsoever) and the tweeter with its singular protection capacitor takes over. Between 8-10KHz, we can also see the unfortunate effects of diffraction within that truncated waveguide.
To my surprise, the predicted in-room response is actually somewhat reasonable and aligns well with my ungated in-room measurements for this speaker.
The general slope is reasonably correct, save for the shmoo around 2KHz.
Next, we have nearfield measurements of all driver components
"Crossover" slopes are rather different, as the only component in play here is a protection capacitor for the tweeter. The midbass is well behaved given the circumstances but a proper crossover could have improved directivity matching significantly. Port resonances are reasonably well controlled but it does chuff quite audibly.
Next are polar chars for directivity. Horizontal directivity is wide (~60°) but not particularly uniform beyond 3KHz.
Vertical directivity is predictably narrow and you will definitely want to remain within about 20 degrees of the acoustic center. If you must listen off-axis, then prefer below to above.
Finally, we have harmonic distortion. This data was acquired as part of the ground plane measurement and should be reasonably accurate.
Subjective impressions were not exactly poor, although I could definitely hear that something wasn't quite right. This turned out to be the wide bump between 2KHz and 7KHz, which emphasized vocals and caused them to become slightly sibilant.
Following a few (17!) PEQ filters, the response became far more pleasant but the trouble around 10KHz remained.
The improvement was quite dramatic and I happily listened to more than a few tracks with few complaints. I could still hear the oddities at 10KHz but they weren't particularly bothersome and at this price point, I'm inclined to be more forgiving. The directivity issue is not much of a problem in my very acoustically dead office but it does mean that the BX4 D3s will be very room dependent.
These little monitors are capable of delivering very reasonable volume levels and while they don't exactly reach far down into the sub-bass band, the bass response is adequate for the kickdrums in Kiara's Sparks and LUM!X' Scare Me to retain their fun. The vocals in Kovacs' Final Song were also reproduced very nicely, perhaps missing a little bit of sparkle around that troublesome spot.
A questionable on-axis response out of the box does not typically prevent me from recommending speakers but in conjunction with the directivity problems, these speakers are going to present an unknown variable in many situations. Ultimately, I can not recommend the M-Audio BX4 D3s. If you are located within the US, then the slightly more expensive Neumi BS5Ps offer substantially greater performance and value for money.
Thank you for reading and I hope this post has been of help to you!
One monitor is powered, while the other is passive and left/right placement is selectable. The front of the powered unit offers a white power LED, combination volume control and power switch, 3.5mm TRS headphone output and auxiliary 3.5mm audio input.
The design is quite similar to that of M-Audio's more expensive offerings, although the tweeter waveguide has been truncated and the baffle plastics are noticeably cheaper.
On the rear of the active speaker, we have both balanced 6.3mm TRS and unbalanced RCA inputs, along with a position selection switch for the active unit and a 3.5mm TS output to the passive speaker. There are also what appear to be LF and HF gain controls but as these speakers contain only two amplifiers and do not include proper crossovers (discussed later in greater detail), they are effectively simple tone controls.
The amplifiers are 25W class AB modules and do not produce any significant heat, as was the case with the BX5 D3s.
With the practicalities out of the way, let's jump into the measurements. As always, we begin with the on-axis and off-axis measurements. These utilize a composite of ground plane, nearfield and gated methods, which should be reasonably comparable to data acquired using a Klippel NFS or anechoic chamber. For these measurements, the tone controls were in the "0dB" position.
Well, that's a rollercoaster of a response. The port appears to be doing little more than introducing a large hump around 80Hz and there are several resonances dotted throughout the data.
Directivity is relatively uniform until about 5-6KHz, where the midbass gradually begins to roll off (it has no crossover whatsoever) and the tweeter with its singular protection capacitor takes over. Between 8-10KHz, we can also see the unfortunate effects of diffraction within that truncated waveguide.
To my surprise, the predicted in-room response is actually somewhat reasonable and aligns well with my ungated in-room measurements for this speaker.
The general slope is reasonably correct, save for the shmoo around 2KHz.
Next, we have nearfield measurements of all driver components
"Crossover" slopes are rather different, as the only component in play here is a protection capacitor for the tweeter. The midbass is well behaved given the circumstances but a proper crossover could have improved directivity matching significantly. Port resonances are reasonably well controlled but it does chuff quite audibly.
Next are polar chars for directivity. Horizontal directivity is wide (~60°) but not particularly uniform beyond 3KHz.
Vertical directivity is predictably narrow and you will definitely want to remain within about 20 degrees of the acoustic center. If you must listen off-axis, then prefer below to above.
Finally, we have harmonic distortion. This data was acquired as part of the ground plane measurement and should be reasonably accurate.
Subjective impressions were not exactly poor, although I could definitely hear that something wasn't quite right. This turned out to be the wide bump between 2KHz and 7KHz, which emphasized vocals and caused them to become slightly sibilant.
Following a few (17!) PEQ filters, the response became far more pleasant but the trouble around 10KHz remained.
The improvement was quite dramatic and I happily listened to more than a few tracks with few complaints. I could still hear the oddities at 10KHz but they weren't particularly bothersome and at this price point, I'm inclined to be more forgiving. The directivity issue is not much of a problem in my very acoustically dead office but it does mean that the BX4 D3s will be very room dependent.
These little monitors are capable of delivering very reasonable volume levels and while they don't exactly reach far down into the sub-bass band, the bass response is adequate for the kickdrums in Kiara's Sparks and LUM!X' Scare Me to retain their fun. The vocals in Kovacs' Final Song were also reproduced very nicely, perhaps missing a little bit of sparkle around that troublesome spot.
A questionable on-axis response out of the box does not typically prevent me from recommending speakers but in conjunction with the directivity problems, these speakers are going to present an unknown variable in many situations. Ultimately, I can not recommend the M-Audio BX4 D3s. If you are located within the US, then the slightly more expensive Neumi BS5Ps offer substantially greater performance and value for money.
Thank you for reading and I hope this post has been of help to you!
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