Contributor I

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Sonos Amp with Acoustic Landscape AS41SYS

Forum|Forum|7 years ago
April 23, 2019
21 replies
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I have been disappointed in the Sonos Amp and how it performs with an Acoustic Landscape AS41SYS. The AS4.1 consists of 4 satellite speakers and 1 sub that presents it's self as an 8 ohm load to the receiver. I previously had this system powered by a Yamaha RX-V667 receiver rated at 90w per channel @ 8 ohms. I had tried a Sonos Connect:Amp and it simply didn't produce enough volume. I recently purchased the Sonos Amp rated at 125w per channel @ 8 ohms and really I can't tell a difference between the Sonos Amp and Sonos Connect:Amp. The Yamaha RX-V667 produces more volume (albeit without all the Sonos features). It confuses me that the Yamaha RX-V667 rated at 90w per channel out performs the Sonos Amp rated at 125w per channel both at 8ohms. The speaker setup is the same when testing both receivers. Some of the runs are long (~200 FT) but I used all 12AWG oxygen-free stranded copper.

Sonos support is chewing on this, but I was wondering if others out there have tried this paring. I sent it the diagnostic report when asked and she said there were no obvious issues.

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Best answer by marky4556

I thought i would follow up before closing this topic. After working with Sonos tech support, we determined that the Sonos Amp was not faulty, but instead not the best pairing for the Acoustic Landscape AS4.1. This was in part because the Sonos Amp lacks the dynamic range amplification 8/6/4/2 ohms for 125/160/190/230W for Front L/R.

I ended up returning the Sonos Amp and buying a Sonos Connect and paired it with an Audio Control Rialto 400 amplifier at the recommendation of Origin Acoustics (maker of the AS4.1 system). I am much happer. While i wish i could have gotten down to one unit, the Rialto 400 does a much better job of driving the AS4.1 system and even allows me some room for growth in speakers.

I appreciate Sonos technical support team's help.

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L

lahey

Trending Lyricist II

I made a file of 1KHz tone at -40dBFS. When I played this through the Sonos Amp at maximum volume, I measured about 0.45V to 0.5V (RMS) from the amp. This would correspond to 45-50V RMS for a 0dBFS input, which would result in fairly severe clipping. Assuming my measurement with "True RMS" meter is any good, the Sonos Amp provides some gain overkill. So I don't know why the OP's system is not as loud as it should be.

K

Kumar

Note also that according to the OP:
No audible difference in sound levels between the 55wpc Connect Amp and the 125 wpc Sonos Amp.
The 90wpc Yamaha outperforms the Sonos Amp on sound levels.

Both above read together point to a defective Sonos Amp, IMO. If the OP observations are accurate and free of expectation bias.

Would any defect in the output stage/s be visible in a diagnostic?

pwt

Virtuoso

Both above read together point to a defective Sonos Amp, IMO. If the OP observations are accurate and free of expectation bias.

Quite possibly. It's not the only report of the Amp not being as loud as people expected.

4 x P:5 | Sub | 4 x P:1 | 3 x Connect | 2 x Boost | Connect:Amp | 2 x One | Amp | Move | Port | Era 300

K

Kumar

Quite possibly. It's not the only report of the Amp not being as loud as people expected.

But as far as I recall, those are from people not used to the linearity of the Sonos volume control, coming from amps that go loud very early in the control knob movement, and max out a little above 50%. The Connect Amp had a lot of complaints from such people, for sure, for that reason.
The linearity becomes a non issue at 100% of course; and to be honest, I have never run any of my Sonos kit at 100% ever, it would be too loud to bear. I understand that out of doors it may well not be so, so I don't question that the OP ran his at 100%. But if bias can be ruled out, I can't see any reason other than a defective unit.
You should know about the comparison with Connect Amp - by what levels on the volume controls does the Sonos Amp start going noticeably louder than the Connect Amp? - Note that OP found no difference at all.

pwt

Virtuoso

You should know about the comparison with Connect Amp - by what levels on the volume controls does the Sonos Amp start going noticeably louder than the Connect Amp? - Note that OP found no difference at all.

I didn't do any objective comparative testing. My subjective impression is that I use about 10% lower volume on the Amp compared to the Connect:Amp, at least at 'active listening' volumes above 50%. Like you, I've never had the need or the inclination to run either amp at 100%, but I got closer to doing so with the Connect:Amp.

4 x P:5 | Sub | 4 x P:1 | 3 x Connect | 2 x Boost | Connect:Amp | 2 x One | Amp | Move | Port | Era 300

L

lahey

Trending Lyricist II

[
But as far as I recall, those are from people not used to the linearity of the Sonos volume control, coming from amps that go loud very early in the control knob movement, and max out a little above 50%.

Is the volume control really linear? It seems to be fairly ordinary to me (that is to say I would have thought it is logarithmic). I am not sure I would notice though since I'm using a slider on my phone.

edit: also, wouldn't it work the opposite way - a linear control would get very loud right from the beginning? But I don't doubt that the the Sonos control could have a more gradual increase in perceived loudness than other amplifiers.

M

marky4556AuthorAnswer

Contributor I

I thought i would follow up before closing this topic. After working with Sonos tech support, we determined that the Sonos Amp was not faulty, but instead not the best pairing for the Acoustic Landscape AS4.1. This was in part because the Sonos Amp lacks the dynamic range amplification 8/6/4/2 ohms for 125/160/190/230W for Front L/R.

I ended up returning the Sonos Amp and buying a Sonos Connect and paired it with an Audio Control Rialto 400 amplifier at the recommendation of Origin Acoustics (maker of the AS4.1 system). I am much happer. While i wish i could have gotten down to one unit, the Rialto 400 does a much better job of driving the AS4.1 system and even allows me some room for growth in speakers.

I appreciate Sonos technical support team's help.

K

Kumar

Good to know that your problem is solved.

It is curious though that this has been done via an amp specified by the manufacturer to be:
Power Output (8Ω): 100W per channel
Power Output (4Ω): 200W per channel

Which is marginally less powerful than the Sonos Amp.

I can't see a reason for this, other than a defective Sonos Amp or a dishonest power spec for the Sonos Amp by Sonos.

M

marky4556Author

Contributor I

I wouldn't go as far as dishonest. My guess is that across certain frequencies the AS4.1 system presents itself as something less than an 8 ohm load and at that lower value, the Sonos Amp cannot adequately drive the system. I didn't have a network or spectrum analyzer to actually sweep the AS4.1 system. The manual for the AS4.1 says 8 ohms nominal, but i suspect it operates lower than that. The Rialto pushes up to 200 watts at 4 ohms. There are no stated specs for the Connect Amp at anything lower than 8 ohms.

Just a guess. The system is substantially louder. In fact i have to dial down the gain on the Rialto to avoid over driving the speakers.

L

lahey

Trending Lyricist II

Likewise the Sonos Amp provides 200W into 4 ohms (see measurements in link below). Strange that Sonos support would say that this amp was not up to the task. I wonder if he/she just gave up on trying to figure this out.

https://www.audiosciencereview.com/forum/index.php?threads/review-and-measurements-of-sonos-amp.6957/

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