Theory Audio SB25 Speaker System Review

[speakers4me]

So just one more FYI, I used the internet way back machine and found the manufacturer's spin data for the older version of this speaker's DSP preset (v1.4). I am almost certain this was the current version when Amir tested it. I think the manufactuerer posted the spin data for the new version (v1.6) long before they actually pushed that version out to the ALC-1809 via download.

 

[LPH]

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 $1,699 each and amplifier, US $5,999. Sorry for stock pictures:
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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:
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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:
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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:
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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:
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And maybe that slight peaking around 4.2 kHz.

I forgot to measure the port response in our near field driver measurement:
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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:

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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:
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Despite how bad this looks, again, bass response was surprisingly clean.

Horizontal directivity is very nice:
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Vertical though, is messy as expected with dual woofers:
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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:
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Finally here is the step response:
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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/

Hello Amir,

Thank you for measuring our sb25 loudspeaker. We noticed that the prices you've quoted are in error and quite high. The actual US MSRP of the sb25 is $1095.00 each, and the ALC-1809 US MSRP is $4950.00 each.

I can assure you that our published data is not manipulated. I'm happy to share our Klippel database with you confidentially, if you're interested.

Lastly, thank you for bringing objective evaluation to the crazy field of consumer audio where it is much needed.

Paul Hales
Theory

 

[amirm]

Thank you for measuring our sb25 loudspeaker. We noticed that the prices you've quoted are in error and quite high. The actual US MSRP of the sb25 is $1095.00 each, and the ALC-1809 US MSRP is $4950.00 each.

My pleasure. Thank you for correct prices. I edited the review.

 

[amirm]

I can assure you that our published data is not manipulated

I didn't mean to imply that you manipulated the NFS data. NFS allows for setting the per octave resolution and I suspect the value is set low to get such smooth graphs as you have posted.

 

[LPH]

I think they're extremely pricey at $3398/pr, especially when you can get a pair of Neumann KH 150's for $3500 with full amplification and optional DSP for another $300. The Neumann's will outperform these guys in every single way that can be measured, I don't imagine they'll sound worse either.

ASR had the prices incorrect in their original post. The sb25 US MSRP is $1095 each. Amir has updated the prices in his review.

 

[amirm]

ASR had the prices incorrect in their original post. The sb25 US MSRP is $1095 each. Amir has updated the prices in his review.

I went by what I could find online: https://acoustipower.com/product/sb25/

"Theory Audio SB25 Surface Mount Speaker -Each
Original price was: $1,999.00 $1,699.00"

 

[LPH]

I went by what I could find online: https://acoustipower.com/product/sb25/

"Theory Audio SB25 Surface Mount Speaker -Each
Original price was: $1,999.00 $1,699.00"

No worries. But Acoustipower is in Canada, so those are Canadian dollars they are showing. Even still, that doesn't track US MSRP which is $1095. We got it straightened out, so it's all good.

Very shortly Theory will be available from Audio Advice at the US MSRP for anyone interested.

 

[Speeddeacon]

Very shortly Theory will be available from Audio Advice at the US MSRP for anyone

That’s great news Paul.

 

[Brucemck2]

These are great speakers. I have used these (and other from the same manufacturer for several years). I’ve gotten great customer service too.

The price of the total package is more cost effective for multichannel applications because the amplifier can handle more than two speakers - you can spread the amplifier cost across more than two speakers.

 

[xavierjohn]

I listened to these speakers at CEDIA 2024, and they sounded impressive. The spinorama appeared unusually smooth, which I attributed to some DSP magic similar to the Grimani systems, but they likely used the low setting.

The amp is 9 channel and not 8 as mentioned in the review. I don’t know if it can power their sub. I was interested in knowing how a 9.4.4 configuration would look like.

 

[Speeddeacon]

I listened to these speakers at CEDIA 2024, and they sounded impressive. The spinorama appeared unusually smooth, which I attributed to some DSP magic similar to the Grimani systems, but they likely used the low setting.

The amp is 9 channel and not 8 as mentioned in the review. I don’t know if it can power their sub. I was interested in knowing how a 9.4.4 configuration would look like.

The ALC-1809 is an 8 input channel amp that has a duplicated mono channel for powering a second sub. So 9 amp outputs for 7.2 configuration (or 5.2.2). Two 1809s amps can then do a 9.4.4 config with 300w each to four subs, 300w to the LCR and 100w to the remaining channels.

 

[xavierjohn]

@LPH I listened to Theory Audio at Definitive Audio in Bellevue,WA , but it didn’t sound as good as it did at CEDIA. Were the speakers at CEDIA a new version, or is the room at Definitive Audio not set up correctly?

 

[TallMartin]

I'm in the midst of building out a Theory 9.6.6 system in a dedicated room using the Theory IW25 (the in-wall version of the SB25) for base layer, the IC6 for height, and the IWS 12-6 subwoofers. I'm in the SF Bay Area, and would be happy to have someone subject them to measurements (in the name of SCIENCE!). ETA on system completion is ~3 weeks. I'm working with Matt Poes on acoustic design, and with Daniel Fitterer on system A/V calibration

https://planner5d.com/v?viewMode=3d&key=e68a64062f3f402118f61c200d3f1146
Storm ISP Elite 24 Analog MK3 receiver
MadVR Envy Extreme Mk2 video processor
JVC NZ800 projector
r_volution PlayerOne 8K local network streamer
21TB Synology NAS for video storage
nVidia Shield Pro internet streamer
Amazon Echo Link music streamer
Panasonic DP-UB820-K 4K Blu Ray Player
Stewart Studiotek 130 G4 THX Ultra 138" 16:9 screen

Details on room construction (including wall and ceiling composition) here: https://docs.google.com/presentatio...zbx4pb_aeLxgk8/edit#slide=id.g28ab549acde_0_0

 

[amirm]

I'm working with Matt Poes on acoustic design, and with Daniel Fitterer on system A/V calibration

Matt should be more than capable to measure them. Please post them when have the system running.

 

[LPH]

@LPH I listened to Theory Audio at Definitive Audio in Bellevue,WA , but it didn’t sound as good as it did at CEDIA. Were the speakers at CEDIA a new version, or is the room at Definitive Audio not set up correctly?

I have not heard the Definitive room but I believe they used an EQ scheme, DIRAC or TRINNOV, which we don’t recommend. If they did, it would definitely not sound like our setups, which have minimal additional processing.

If you want to learn more about my (our) view on so-called “room correction” schemes you should listen to the Soundstage! Podcast from a few weeks ago with me and Jorden Guth. I go into it a bit and we’re going to do a follow up podcast to discuss the topic in more depth.

 

[xavierjohn]

They are using your amplifier and Trinnov.


I will checkout the podcast

Marrying Hi-Fi with Pro Audio - Paul Hales | Pro Audio Technology Origins | What Matters

This week, host Jorden Guth is joined by Pro Audio Technology owner/president L. Paul Hales to discuss his history in audio, how audio research has guided the development of his speakers over the years, what really matters in audio and what doesn’t, and why most consumer speakers fall short in...

www.podbean.com

 

[xavierjohn]

@LPH
I listened to the podcast. It seems the secret sauce is after the 1-hour mark—no one likes a flat curve, and no one can pinpoint what it should look like. I think it might be linked to genetics and upbringing. Observing friends from various backgrounds, I’ve noticed the same pattern with food preferences. Was there a specific curve applied to the demo room at CEDIA?

On a different note, I also dabble in drums. I got a Roland VDrum to keep the noise levels down and avoid getting thrown out of the house. Also, “Invincible” from Tool sounds intriguing—thanks for the introduction!

 

[LPH]

@LPH
I listened to the podcast. It seems the secret sauce is after the 1-hour mark—no one likes a flat curve, and no one can pinpoint what it should look like. I think it might be linked to genetics and upbringing. Observing friends from various backgrounds, I’ve noticed the same pattern with food preferences. Was there a specific curve applied to the demo room at CEDIA?

On a different note, I also dabble in drums. I got a Roland VDrum to keep the noise levels down and avoid getting thrown out of the house. Also, “Invincible” from Tool sounds intriguing—thanks for the introduction!

That's the point - there was *no curve* applied at CEDIA. We took the speakers out of the box, installed them and played them. That's just what they all sound like. If you're speakers are good, you don't need any EQ.

(Except the room was the second worst possible shape you can have : 1/2 of a perfect cube. It was 30' x 30' x 15'. We placed a single parametric filter at 42Hz on the subs only to knock out a HUGE resonance at that frequency due to the square room. No other EQ was used).

Even in a horrendous room, that's what our products sound like.