Speakerplans X1
18″ bass by Rog Mogale for the P.Audio SD 18 – with f3 31/119 Hz, 102.5 dB and 800 W according to the title block. Enclosure type not stated.
Primary source checked; some values are missing from the source or still open.
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Specifications
Link to section “Specifications”Every value with its provenance. If a value is missing from the source, it reads “not available”.
- Drivers
- 1 × P.Audio SD 18 Designer
- Enclosure type
- Enclosure type not specified
- Low-frequency extension
- 31 Hz (-3 dB) Designer
- Sensitivity
- 102.5 dB 1 W/1 m Designer
- Max. SPL
- 131.5 dB continuous · 135 dB peak Designer
- Power handling
- 800 W Continuous power (standard not stated) Designer
- Impedance
- not available
- Dimensions (H × W × D)
- 770 × 606 × 800 mm from drawing, Front view (sheet 4) Designer
- Volume
- not available
- Tuning frequency
- not available
- Weight
- not available
- Recommended high-pass
- not available
External dimensions from the front and side views; the front view additionally gives an internal width of 570 mm.
Description
Link to section “Description”In brief
An 18-inch bass for a specified driver. The title block gives cut-off frequencies, sensitivity, maximum SPL and power handling.
The X1 is an 18-inch bass by Rog Mogale for the P.Audio SD 18. Unlike most plans on Speakerplans.com, it has a title block with scale (1 : 10), material and performance data.
What the title block states
Link to section “What the title block states”- f3 points: lower 31 Hz, upper 119 Hz
- 102.5 dB at 1 W / 1 m
- 131.5 dB continuous and 135 dB peak level
- power handling 800 W
- material: 18 mm birch plywood with 13 plies
The driver sits on a baffle inclined at 22.5°. It is installed through a removable panel in the rear wall; the drawing shows cut-outs for this. The plan does not name an enclosure type, so we do not classify it by appearance.
Drivers
Link to section “Drivers”-
Original driver
1 × P.Audio SD 18
Woofer
Enclosure
Link to section “Enclosure”- Enclosure type
- Enclosure type not specified
- Shape
- Rectangular box
- Ports
- not stated
- Material
-
- Birch plywood, 18 mm – specified: Birch plywood, 13 plies (“13 Laminate 18 mm Birch Ply”)
Build plan
Link to section “Build plan”We link to the original plan and do not host other people’s drawings.
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Open original document
X1 – Plan-Seite mit Zeichnungen auf Speakerplans.com (englisch)
Official source · accessed on 13 September 2026
Rights of use not stated – we only link
Plan access: Free
Curves in the original document
The drawing includes a frequency response graph (“P Audio SD 18”). It does not say whether it is measured or simulated. We do not read any values from it.
Pros and cons
Link to section “Pros and cons”Pros
- Complete key data in the title block
- Drawing to scale (1 : 10)
Cons
- Designed for one driver only, no alternatives named
- Enclosure type is not stated
Sources
Link to section “Sources”-
Tier A · primary source
Speakerplans.com – X1 (Sub Plans)
Rog Mogale · Speakerplans.com · 2004 · accessed on 13 September 2026
Four drawings with title block (© 2004 Rog Mogale, scale 1:10). No statement on usage rights.
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Tier B · secondary source
Speakerplans.com – Speaker plans (overview)
Rog Mogale · Speakerplans.com · accessed on 13 September 2026
Overview with Horn Plans, Sub Plans and Mid Top Plans. The plans are embedded as images (drawings) on the individual pages.
Usage rights of the plan: Rights of use not stated – we only link. Added on 14 September 2026, last updated on 14 September 2026.