This is a review and detailed measurements of the Theory Audio SB25 on-wall speaker with its companion 8-channel ALC-1809 amplifier and DSP. It is on kind loan from a member. Speaker costs US $1,095 each and amplifier, US $4,950. Sorry for stock pictures:
As you see, this is a very sleek speaker designed to be hung on the wall and comes with nice bracket. Built quality is excellent with the speaker feeling like a rock. Weighs as much too for its size! Unexpectedly for a system speaker, it is driven passively with the crossover being inside the speaker rather than DSP module. On the other hand, this halves the number of amplification channels needed which is a lot in a home theater/surround system:
Two configuration apps are provided. You can load up different profiles (DSP settings) into the Windows app using either. I opted for the "Flat" (I think version 1.4) profile.
Speaker was measured using Klippel Near-field scanner without taking the grill off. Company seems to have measurements using the same system showing exemplary response:
Let's measurement ourselves to see if we get the same response.
Theory Audio SB25 Speaker System Measurement
Let's start with our anechoic CEA-2034 series of measurements:
Bass response matches company measurements up to about 500 Hz. From there, there are small disturbances likely caused by the port. The treble response starting from 1.5 kHz seems slightly lower which could be intentional or difference in how they measured the speaker and tuned the DSP with it. It is not consequential though as you would want to dial your own in-room response anyway.
Despite the wide waveguide around the tweeter we see some directivity error. This is caused by the dual woofer interference with each other. We see this more clearly in our early window response:
We will revisit this in our directivity measurements. As noted, thick carpeting and ceiling absorption is advised (or high ceilings). This becomes the only failing in the predicted in-room response:
And maybe that slight peaking around 4.2 kHz.
I forgot to measure the port response in our near field driver measurement:
We see the same peaking around 4.2 kHz in tweeter response but otherwise, what we have is unventful.
The company's claim to fame is power handling and high SPL so let's see how it did in distortion department:
Considering how compact this speaker is, this is very good response. Notice how bass distortion never rises to the level of the output. Indeed, during frequency sweeps I was impressed by the clean bass response. Everything has a limit though. Here is 106 dBSPL:
Despite how bad this looks, again, bass response was surprisingly clean.
Horizontal directivity is very nice:
Vertical though, is messy as expected with dual woofers:
Dual drivers give you much more power capability but costs you in narrowing the response as the two drivers "beam" together, shrinking usable response to ± 10 degrees. Using it horizontally means narrow coverage unless you sit very far. Be sure to position the speaker in horizontal configuration as to point to listener as to maximize that 20 degrees. Vertically it should be fine but again, position the tweeter toward your ear and don't listen to them standing up!
Same resonances that we saw in distortion measurements show up in our waterfall:
Finally here is the step response:
I am sorry but I did not get a chance to listen to this speaker, nor measure the amplifier.
Conclusions
While company measurements seem overly optimistic/smoothed, overall performance of SB25 speaker system seems excellent for such a compact and family friendly speaker. The cost is high but I am told prices have increased substantially as of late. I don't have a recommendation for you since I did not get a chance to listen to the speaker but you should have the data to decide whether this system is for you.
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/
As you see, this is a very sleek speaker designed to be hung on the wall and comes with nice bracket. Built quality is excellent with the speaker feeling like a rock. Weighs as much too for its size! Unexpectedly for a system speaker, it is driven passively with the crossover being inside the speaker rather than DSP module. On the other hand, this halves the number of amplification channels needed which is a lot in a home theater/surround system:
Two configuration apps are provided. You can load up different profiles (DSP settings) into the Windows app using either. I opted for the "Flat" (I think version 1.4) profile.
Speaker was measured using Klippel Near-field scanner without taking the grill off. Company seems to have measurements using the same system showing exemplary response:
Let's measurement ourselves to see if we get the same response.
Theory Audio SB25 Speaker System Measurement
Let's start with our anechoic CEA-2034 series of measurements:
Bass response matches company measurements up to about 500 Hz. From there, there are small disturbances likely caused by the port. The treble response starting from 1.5 kHz seems slightly lower which could be intentional or difference in how they measured the speaker and tuned the DSP with it. It is not consequential though as you would want to dial your own in-room response anyway.
Despite the wide waveguide around the tweeter we see some directivity error. This is caused by the dual woofer interference with each other. We see this more clearly in our early window response:
We will revisit this in our directivity measurements. As noted, thick carpeting and ceiling absorption is advised (or high ceilings). This becomes the only failing in the predicted in-room response:
And maybe that slight peaking around 4.2 kHz.
I forgot to measure the port response in our near field driver measurement:
We see the same peaking around 4.2 kHz in tweeter response but otherwise, what we have is unventful.
The company's claim to fame is power handling and high SPL so let's see how it did in distortion department:
Considering how compact this speaker is, this is very good response. Notice how bass distortion never rises to the level of the output. Indeed, during frequency sweeps I was impressed by the clean bass response. Everything has a limit though. Here is 106 dBSPL:
Despite how bad this looks, again, bass response was surprisingly clean.
Horizontal directivity is very nice:
Vertical though, is messy as expected with dual woofers:
Dual drivers give you much more power capability but costs you in narrowing the response as the two drivers "beam" together, shrinking usable response to ± 10 degrees. Using it horizontally means narrow coverage unless you sit very far. Be sure to position the speaker in horizontal configuration as to point to listener as to maximize that 20 degrees. Vertically it should be fine but again, position the tweeter toward your ear and don't listen to them standing up!
Same resonances that we saw in distortion measurements show up in our waterfall:
Finally here is the step response:
I am sorry but I did not get a chance to listen to this speaker, nor measure the amplifier.
Conclusions
While company measurements seem overly optimistic/smoothed, overall performance of SB25 speaker system seems excellent for such a compact and family friendly speaker. The cost is high but I am told prices have increased substantially as of late. I don't have a recommendation for you since I did not get a chance to listen to the speaker but you should have the data to decide whether this system is for you.
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/
Last edited:
