This is a review and detailed measurements of the Zaph Audio ZA5.2 2-way ported stand-mount speaker. It was kindly built and sent to me by member @Winkleswizard. This is what he has post on the cost: "A kit for pair of ZA5.2 MTs is about $292 (with binding posts) and pair of cabinets would be about $50 (from PE). So, assuming free shipping to me, the total cost is about $342."
The build for the unit I received was quite substantial:
Clever use of textured paint to give something extra to an otherwise bland sides. That said, it cannot compete in looks with either vinyl wraps or painted enclosure from commercial suppliers.
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 reference to tweeter axis with the grill removed. Frequency resolution is 2.7 Hz. Previous tests used 0.7 Hz resolution which hugely inflated the storage requirements and was well beyond what research calls for. I scanned at 0.7 Hz as well and difference was negligible so I will be going with this resolution from here on.
All measurements are relative to tweeter center.
Spinorama Audio Measurements
Acoustic measurements can be grouped in a way that can be perceptually analyzed to determine how good a speaker can be used. This so called spinorama shows us just about everything we need to know about the speaker with respect to tonality and some flaws:
I must say, I was impressed with how flat the response is on-axis (red arrow). The dips in mid frequency though don't track the same way in early window (dashed blue) so causes the directivity index (dashed blue at the bottom) to vary. This is usually due to mismatch of the directivity of the woofer and tweeter.
Note the very low sensitivity. You better have lots of wattage to drive these little speakers.
Predicted in-room response is somewhat ragged and depending on how you draw the line through it, may have too little slope (i.e. sound bright):
Impedance is higher than many mass market speakers:
Distortion seems to show the struggle of the little midwoofer driver trying to produce bass:
Here is the waterfall:
And contours:
Speaker Listening Tests
In use the ZA5 in my main system sounded quite bright. This was not due to tilted up highs but lack of any bass to speak of. There isn't lower bass. There isn't midbass. As predicted from measurements, efficiency is quite poor causing me to turn up my amplifier to very high amplification levels (1000 watts on tap) to drive them. Before you got any bass the highs were killing you and the midwoofer would start to bottom out. On the latter though, it took a ton of power before it mildly stepped into that region.
With one speaker and in a very large space, these speakers don't do it for me subjectively.
Conclusions
On-axis performance is surprisingly good as is craftsmanship of @Winkleswizard. Ultimately though, there is just no bass response and with it, music is not music. For a few hundred dollars you want to have bass. I know you can add a sub but that limits the audience a ton.
So personally I don't think we have shown the DIY route has merit with this sample, sad to say.
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As always, questions, comments, recommendations, etc. are welcome.
With the stock market crashing, I am not feeling like I have any assets left. Could use some money to change my mood. So please donate using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
The build for the unit I received was quite substantial:
Clever use of textured paint to give something extra to an otherwise bland sides. That said, it cannot compete in looks with either vinyl wraps or painted enclosure from commercial suppliers.
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 reference to tweeter axis with the grill removed. Frequency resolution is 2.7 Hz. Previous tests used 0.7 Hz resolution which hugely inflated the storage requirements and was well beyond what research calls for. I scanned at 0.7 Hz as well and difference was negligible so I will be going with this resolution from here on.
All measurements are relative to tweeter center.
Spinorama Audio Measurements
Acoustic measurements can be grouped in a way that can be perceptually analyzed to determine how good a speaker can be used. This so called spinorama shows us just about everything we need to know about the speaker with respect to tonality and some flaws:
I must say, I was impressed with how flat the response is on-axis (red arrow). The dips in mid frequency though don't track the same way in early window (dashed blue) so causes the directivity index (dashed blue at the bottom) to vary. This is usually due to mismatch of the directivity of the woofer and tweeter.
Note the very low sensitivity. You better have lots of wattage to drive these little speakers.
Predicted in-room response is somewhat ragged and depending on how you draw the line through it, may have too little slope (i.e. sound bright):
Impedance is higher than many mass market speakers:
Distortion seems to show the struggle of the little midwoofer driver trying to produce bass:
Here is the waterfall:
And contours:
Speaker Listening Tests
In use the ZA5 in my main system sounded quite bright. This was not due to tilted up highs but lack of any bass to speak of. There isn't lower bass. There isn't midbass. As predicted from measurements, efficiency is quite poor causing me to turn up my amplifier to very high amplification levels (1000 watts on tap) to drive them. Before you got any bass the highs were killing you and the midwoofer would start to bottom out. On the latter though, it took a ton of power before it mildly stepped into that region.
With one speaker and in a very large space, these speakers don't do it for me subjectively.
Conclusions
On-axis performance is surprisingly good as is craftsmanship of @Winkleswizard. Ultimately though, there is just no bass response and with it, music is not music. For a few hundred dollars you want to have bass. I know you can add a sub but that limits the audience a ton.
So personally I don't think we have shown the DIY route has merit with this sample, sad to say.
------------
As always, questions, comments, recommendations, etc. are welcome.
With the stock market crashing, I am not feeling like I have any assets left. Could use some money to change my mood. So please donate using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
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