This is a review and detailed measurements of the Fostex PM.03 active monitor/speaker. It is on kind loan from a member who bought it new from drop.com and had it shipped to me. I think the model is discontinued and I can't find an accurate price for it. The owner paid US $90 on drop.
The PM.03 is by far the smallest speaker I have tested. I think it is about 6 inches tall:
This is the main unit which then powers the other speaker:
A laptop sized external supply powers the unit.
Yes there is a tiny port through which incredibly high pressure air escapes.
Product is made in China.
Measurements that you are about to see were performed using the Klippel Near-field Scanner (NFS). This is a robotic measurement system that analyzes the speaker all around and is able (using advanced mathematics and dual scan) to subtract room reflections (so where I measure it doesn't matter). It also measures the speaker at close distance ("near-field") which sharply reduces the impact of room noise. Both of these factors enable testing in ordinary rooms yet results that can be more accurate than anechoic chamber. In a nutshell, the measurements show the actual sound coming out of the speaker independent of the room.
All measurements are referenced to the tweeter axis with frequency resolution of 2.7 Hz.
We have a pretty smooth response until the crossover point of 2.6 kHz. Then response gets chewed up with a couple of dips, one at crossover and the other around 6 to 9 kHz.
Oh, please don't go by SPL scale. It is not correct and requires manual compensation (for active speakers) which I did not perform.
Frequency response of early and strongest reflections in a hypothetical room averages out reasonably well:
That helps the predicted in-room response simulation:
I have standardized at 96 dBL SPL at 1 meter for distortion measurements. Given how small the PM.03 is, I decided to stop 6 dB lower but even that was not enough:
That is one unhappy "mid-woofer."
Horizontal directivity shows an uneven dispersion:
Vertically it is a mess but fortunately, the good side is above the speaker:
The waterfall graph seems to have an error in it so I am not going to post it.
Note that this is an active speaker so makes no sense to measure "impedance."
Speaker Listening Test
I placed the single speaker on my desktop and ran through my reference tracks. I was pleased that even at extreme, there is no sudden distortion. The amplifier simply runs out of power and that is that. I have had super expensive studio monitors that break up something nasty. Obviously there is little bass here but compared to some junk plastic "computer speaker" you may buy, there is seemingly clean upper bass there.
To see if the dip can be compensated for, I dialed in a 2 dB boost at 2.2 kHz and it made a very positive effect, bringing out the ambiance and separation between notes. Once there, I also put in some salt and pepper in the forum of slight bass boost and that was a very welcome change:
With these two quick tweaks, the sound was quite transformed and very acceptable for everyday computer use (e.g. listening to youtube, etc.).
Conclusions
Seems like the target here was to build a small speaker that was not "junk." If so, Fostex seems to have succeeded. With a bit of EQ you get good sound that doesn't distort (subjectively), is not overly bright and does the job better than anything sold from the computer accessory vendors.
Based on low price from drop, and decent subjective experience, I am going to give a cautious recommendation for Fostex PM.03. I say cautious because we haven't tested much in its class. Over time it may turn out to be better or worse than the competition.
-----------
As always, questions, comments, recommendations, etc. are welcome.
Wasted two hours waiting to get into a discount grocery store, and waiting to check out! Need to hire a personal shopper so I can spend my time reviewing. So please donate what you can using : https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
The PM.03 is by far the smallest speaker I have tested. I think it is about 6 inches tall:
This is the main unit which then powers the other speaker:
A laptop sized external supply powers the unit.
Yes there is a tiny port through which incredibly high pressure air escapes.
Product is made in China.
Measurements that you are about to see were performed using the Klippel Near-field Scanner (NFS). This is a robotic measurement system that analyzes the speaker all around and is able (using advanced mathematics and dual scan) to subtract room reflections (so where I measure it doesn't matter). It also measures the speaker at close distance ("near-field") which sharply reduces the impact of room noise. Both of these factors enable testing in ordinary rooms yet results that can be more accurate than anechoic chamber. In a nutshell, the measurements show the actual sound coming out of the speaker independent of the room.
All measurements are referenced to the tweeter axis with frequency resolution of 2.7 Hz.
We have a pretty smooth response until the crossover point of 2.6 kHz. Then response gets chewed up with a couple of dips, one at crossover and the other around 6 to 9 kHz.
Oh, please don't go by SPL scale. It is not correct and requires manual compensation (for active speakers) which I did not perform.
Frequency response of early and strongest reflections in a hypothetical room averages out reasonably well:
That helps the predicted in-room response simulation:
I have standardized at 96 dBL SPL at 1 meter for distortion measurements. Given how small the PM.03 is, I decided to stop 6 dB lower but even that was not enough:
That is one unhappy "mid-woofer."
Horizontal directivity shows an uneven dispersion:
Vertically it is a mess but fortunately, the good side is above the speaker:
The waterfall graph seems to have an error in it so I am not going to post it.
Note that this is an active speaker so makes no sense to measure "impedance."
Speaker Listening Test
I placed the single speaker on my desktop and ran through my reference tracks. I was pleased that even at extreme, there is no sudden distortion. The amplifier simply runs out of power and that is that. I have had super expensive studio monitors that break up something nasty. Obviously there is little bass here but compared to some junk plastic "computer speaker" you may buy, there is seemingly clean upper bass there.
To see if the dip can be compensated for, I dialed in a 2 dB boost at 2.2 kHz and it made a very positive effect, bringing out the ambiance and separation between notes. Once there, I also put in some salt and pepper in the forum of slight bass boost and that was a very welcome change:
With these two quick tweaks, the sound was quite transformed and very acceptable for everyday computer use (e.g. listening to youtube, etc.).
Conclusions
Seems like the target here was to build a small speaker that was not "junk." If so, Fostex seems to have succeeded. With a bit of EQ you get good sound that doesn't distort (subjectively), is not overly bright and does the job better than anything sold from the computer accessory vendors.
Based on low price from drop, and decent subjective experience, I am going to give a cautious recommendation for Fostex PM.03. I say cautious because we haven't tested much in its class. Over time it may turn out to be better or worse than the competition.
-----------
As always, questions, comments, recommendations, etc. are welcome.
Wasted two hours waiting to get into a discount grocery store, and waiting to check out! Need to hire a personal shopper so I can spend my time reviewing. So please donate what you can using : https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/