Sunlighten Amplify Full-Spectrum Infrared vs Sunlighten Signature Far Infrared
$5,999 against $4,999. Here is where the $1,000 difference actually goes.
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Higher lab score
Sunlighten
Amplify Full-Spectrum Infrared
$5,999
8.6 / 10
Indoor installs where a traditional sauna's moisture is not an option
Sunlighten
Signature Far Infrared
$4,999
8.2 / 10
Apartment and spare-room installs where 240V is impossible
Specifications side by side
| Spec | Sunlighten Amplify Full-Spectrum Infrared | Sunlighten Signature Far Infrared |
|---|---|---|
| Price | $5,999 | $4,999 |
| Lab score | 8.6 | 8.2 |
| Max temp | 170°F (mfr) | Not published (mfr) |
| Heat type | Full-spectrum (near/mid/far) | Far infrared |
| Electrical | 120V (20A dedicated) or 240V by model | 120V / dedicated 20A |
| Warranty | 7 years | 7 years |
| EMF | Low-EMF SoloCarbon heaters | — |
| Footprint | — | 1–4 person cabins (Signature I–IV) |
The verdict
Sunlighten Amplify Full-Spectrum Infrared takes the higher score here. The indoor infrared cabin that actually gets hot — 170°F, which most infrared cabins never reach. If infrared has disappointed you before, this is why.
The counter-argument for the Sunlighten Signature Far Infrared is straightforward: it costs $1,000 less. Plugs into a normal wall outlet on a dedicated 20A circuit. That single fact removes the $800–1,500 electrician line item that kills most indoor sauna plans.
Put plainly — if your constraint is budget, take the Signature Far Infrared and put the $1,000 toward installation, which is the line item most first-time buyers underestimate. If your constraint is that you want to buy once, the Amplify Full-Spectrum Infrared is the one you will not be replacing.
What each one is good at
Sunlighten Amplify Full-Spectrum Infrared
Strengths
- Reaches 170°F, closing most of the gap with traditional saunas
- Thick insulation and double-pane glass hold heat properly
- 7-year warranty is among the longest in the category
Compromises
- Priced within a few hundred dollars of a full 6-person outdoor thermowood barrel, before either one's electrical work
- 240V models still need an electrician despite 'plug-in' marketing on smaller ones
- Assembly is a two-person half-day job indoors
Sunlighten Signature Far Infrared
Strengths
- 120V operation on a standard dedicated circuit — no panel work
- Far infrared only, which is all most users actually use
- Smaller footprint fits a spare bedroom or large closet
Compromises
- Far infrared only — no near-infrared or red light
- Lower maximum temperature than the Amplify
- Basswood is functional but plain next to cedar
Read the full ranking
Both products are placed in context, against the whole field and with the installed cost worked out, in these guides:
- The best home saunas of 2026: indoor, outdoor and the $2,099 exception
- Red light sauna: what the term means, and what dose you actually get
- Infrared vs traditional sauna: they are different appliances, not price tiers
- How hot should a sauna be? Temperature by sauna type, measured at the bench
- Sunlighten sauna review: the three models, priced, and who each one is for
More head-to-heads
- Sunlighten Amplify Full-Spectrum Infrared vs Sunlighten Solo System (portable)
- Sunlighten Amplify Full-Spectrum Infrared vs Sun Home Saunas Pod 1-Person Indoor Red Light & Infrared
- Sunlighten Signature Far Infrared vs Sunlighten Solo System (portable)
- Sunlighten Signature Far Infrared vs Sun Home Saunas Pod 1-Person Indoor Red Light & Infrared
Prices captured September 2026 from manufacturer and retailer pages and subject to frequent promotion. Confirm before buying. See our testing method for how lab scores are assigned.