This is a review, listening tests and measurements of the AV123-CS center speaker. It was kindly sent to me by a member:
Speaker is long discontinued (reviews date back 2007). But it seems the designer (?) Danny Ritchie is selling a kit based on the same (GR Research X-CS Encore) for $239 (driver+xover only). Old prices I can find are just $139 for plain finish and $199 for the gorgeous sample I have:
As noted, the speaker weighs 33 pounds which is quite heavy. This is likely due to the very deep cabinet and heavy construction.
The grill is unusual: it is a very thick gage metal piece screwed to the cabinet using very long stand offs. Since it was fastened such, I assumed it was part of the design and performed my testing with it in place.
AV123 X-CS Speaker Measurements
As usual we start with our "spinorama" (CEA-2034) standardized frequency response measurements:
Man, that is a rough response although overall average is not bad. Major thing that stands out is the resonance around 420 Hz and sloping down before it. There is no measurements of the AV123 speaker but GR research provides one for their kit:
Typical of GR research measurements, they look good at first blush until you realize low frequency is cut off at 200 Hz. Due to heavy gating (to remove room reflections), low frequency is massively smoothed so doesn't show the large anomaly we see in upper bass/midrange. It does show the peaks and valleys at higher frequencies but again, 1/3 octave smoothing helps hide them more (my measurements are 1/24 octave). These aside, GR measurements validates what we see more or less.
We can confirm the issues we see with our near-field driver responses:
The woofer clearly has a resonance around 420 Hz and then another post 2 kHz. The tweeter shows the same ups and downs which could be due to the grill but then again, we saw them in GR research which I assume is without grill. Either way, the flaws are very obvious with the design.
Early/important room reflections are smoothed a bit but otherwise, are messy:
Resulting in predicted in-room response that has a lot of ups and downs:
Building an EQ by eye is going to be difficult for this speaker but I took a shot at it (see Listening Test section).
The two mid-woofers cancel each other ("beam") once the wavelength of the sound gets close to their distance as you shift left and right:
Which as we know is not a good thing for a center speaker. Best to stay close to the center of the tweeter or flip it up vertically if your display/screen allows it:
Here is our vertical which is naturally much cleaner since the drivers are aligned in that axis:
Impedance and phase show the clear resonances we have seen in the response:
GR research measurements again don't show these due to large vertical scale (and likely lack of overall resolution):
Minimum impedance of 6 ohm makes the speaker an easy load.
"MTM" configuration is not great for horizontal directivity but produces a lot more power, or said inversely, less distortion at the same power:
Finally here is the step response:
AV123 X-CS Listening Tests and Equalization
First impression wasn't too bad. I think this is because the average response is not too far off. At first I wanted to stop there as attempting to manually clean up that on-axis response seemed daunting.
But I thought it is important to do and see the impact of the various response errors. I don't claim high accuracy here but the result was a definite improvement:
As you see, it took quite a few filters to deal with all the response errors. Once there, there was more body in bass response and much improved clarity in high frequencies. Indeed with the filters in place, the sound was quite clean and would delight from time to time with its clarity of high frequencies and openness of it.
Testing for dynamic power, the mid-woofers handle a fair bit until they develop a gradual crackle which scales up with volume. In a home theater setting, they would be high pass filtered which would remove this issue, allowing to play quite loud.
Sub-bass response was barely there and somewhat distorted but not as bad as I see with ported bookshelf speakers.
Listening to a number of soundtrack such as Arrival was a joy with EQ and aiming directly at tweeter axis.
Conclusions
We can start with how much our money bought back 15 years ago! Such a solid speaker with beautiful hardwood veneer for just $199? Even in today's money that would be a steal. Alas, what was shipped was a faulty and unfinished design. Clearly the speaker had not benefited from proper objective measurements and analysis. If the GR research is continuation of the same, it means that sin is still being committed even today! Misleading measurements show a speaker that has no flaws where in reality it has plenty.
It is a shame really as the platform -- the woofers and tweeter -- seem quite capable in that large and solid cabinet.
I can't recommend the AV123 X-CS and by implication, GR Research X-CS Encore kit. However, if you are in a position to develop proper set of filters to it, then it can be turned into something worthwhile with a level of build that you don't see in commercial speakers anywhere close to these prices.
-----------
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/
Speaker is long discontinued (reviews date back 2007). But it seems the designer (?) Danny Ritchie is selling a kit based on the same (GR Research X-CS Encore) for $239 (driver+xover only). Old prices I can find are just $139 for plain finish and $199 for the gorgeous sample I have:
As noted, the speaker weighs 33 pounds which is quite heavy. This is likely due to the very deep cabinet and heavy construction.
The grill is unusual: it is a very thick gage metal piece screwed to the cabinet using very long stand offs. Since it was fastened such, I assumed it was part of the design and performed my testing with it in place.
AV123 X-CS Speaker Measurements
As usual we start with our "spinorama" (CEA-2034) standardized frequency response measurements:
Man, that is a rough response although overall average is not bad. Major thing that stands out is the resonance around 420 Hz and sloping down before it. There is no measurements of the AV123 speaker but GR research provides one for their kit:
Typical of GR research measurements, they look good at first blush until you realize low frequency is cut off at 200 Hz. Due to heavy gating (to remove room reflections), low frequency is massively smoothed so doesn't show the large anomaly we see in upper bass/midrange. It does show the peaks and valleys at higher frequencies but again, 1/3 octave smoothing helps hide them more (my measurements are 1/24 octave). These aside, GR measurements validates what we see more or less.
We can confirm the issues we see with our near-field driver responses:
The woofer clearly has a resonance around 420 Hz and then another post 2 kHz. The tweeter shows the same ups and downs which could be due to the grill but then again, we saw them in GR research which I assume is without grill. Either way, the flaws are very obvious with the design.
Early/important room reflections are smoothed a bit but otherwise, are messy:
Resulting in predicted in-room response that has a lot of ups and downs:
Building an EQ by eye is going to be difficult for this speaker but I took a shot at it (see Listening Test section).
The two mid-woofers cancel each other ("beam") once the wavelength of the sound gets close to their distance as you shift left and right:
Which as we know is not a good thing for a center speaker. Best to stay close to the center of the tweeter or flip it up vertically if your display/screen allows it:
Here is our vertical which is naturally much cleaner since the drivers are aligned in that axis:
Impedance and phase show the clear resonances we have seen in the response:
GR research measurements again don't show these due to large vertical scale (and likely lack of overall resolution):
Minimum impedance of 6 ohm makes the speaker an easy load.
"MTM" configuration is not great for horizontal directivity but produces a lot more power, or said inversely, less distortion at the same power:
Finally here is the step response:
AV123 X-CS Listening Tests and Equalization
First impression wasn't too bad. I think this is because the average response is not too far off. At first I wanted to stop there as attempting to manually clean up that on-axis response seemed daunting.
But I thought it is important to do and see the impact of the various response errors. I don't claim high accuracy here but the result was a definite improvement:As you see, it took quite a few filters to deal with all the response errors. Once there, there was more body in bass response and much improved clarity in high frequencies. Indeed with the filters in place, the sound was quite clean and would delight from time to time with its clarity of high frequencies and openness of it.
Testing for dynamic power, the mid-woofers handle a fair bit until they develop a gradual crackle which scales up with volume. In a home theater setting, they would be high pass filtered which would remove this issue, allowing to play quite loud.
Sub-bass response was barely there and somewhat distorted but not as bad as I see with ported bookshelf speakers.
Listening to a number of soundtrack such as Arrival was a joy with EQ and aiming directly at tweeter axis.
Conclusions
We can start with how much our money bought back 15 years ago! Such a solid speaker with beautiful hardwood veneer for just $199? Even in today's money that would be a steal. Alas, what was shipped was a faulty and unfinished design. Clearly the speaker had not benefited from proper objective measurements and analysis. If the GR research is continuation of the same, it means that sin is still being committed even today! Misleading measurements show a speaker that has no flaws where in reality it has plenty.
It is a shame really as the platform -- the woofers and tweeter -- seem quite capable in that large and solid cabinet.
I can't recommend the AV123 X-CS and by implication, GR Research X-CS Encore kit. However, if you are in a position to develop proper set of filters to it, then it can be turned into something worthwhile with a level of build that you don't see in commercial speakers anywhere close to these prices.
-----------
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/
