Review Velodyne Acoustics SPL-X 10:Technology and features
- The cabinet is made of HDF with wall thicknesses between 25 and 35 millimetres. A front frame, into which the driver's mounting ring is clamped, adds a further 15 millimetres of material thickness at the front (Image: Velodyne Acoustics)
There are good reasons for this, although it does present challenges: where there is no port, there can be no ventilation noise. In addition, it is always advantageous to minimise the number of variables in the system. Resonance control is the key word here, with the basic rule being that closed enclosures allow more accurate impulse behaviour. On the other hand, the enormous forces at work inside a subwoofer need to be tamed, and this becomes all the more important when some of the sound energy cannot escape through a port. Product Manager Thomas Wolff puts it in a nutshell: "Every bit of energy that doesn't move the driver, the cabinet or the screws, translates directly into more precise impulse response. To ensure that the SPL-X enclosure behaves like the proverbial rock in the surf, the base, top and side panels are made of high-density fibreboard (HDF) with a wall thickness of 25 millimetres.
- A look inside the cabinet, without the back panel and supporting cross-brace, reveals the powerful magnet system (Image: AV-Magazin)
The baffle is made from the same material and is 35 millimetres thick, with a front frame adding a further 15 millimetres of thickness at the front. This frame, which is connected to the baffle, holds the driver's mounting ring in place; inside the cabinet there are further stiffening elements and a cross brace that supports the driver's extremely generously dimensioned magnet system, which weighs around fifteen kilograms.
Power is supplied by a MOSFET power amplifier in Class D topology, capable of delivering a full 1,200 watts of output power - and an impressive 2,500 watts at peak! Four-layer voice coils, 76 millimetres in diameter on the 10' and 12' models, double centering spiders and triple vented drive units are designed to ensure linear excursion of the carbon fibre cone and accurate impulse response even at very high levels - this capability was a top priority during development. To achieve this, it is not enough to simply use a particularly powerful drive unit; the dimensioning of the power stage, the driver, the magnet system and the voice coil have to be finely tuned to each other.
- Strong and light-weight: the diaphragm of the newly developed drivers is made of carbon fibre (Image: Velodyne Acoustics)
Connectors for every application
- Connectivity is complete, with balanced high level inputs and outputs. The XLR and RCA sockets for the left channel can accept and loop through LFE signals (Image: Velodyne Acoustics)
The rear connection terminal of the SPL-X woofers, equipped with sockets from Essen-based specialist WBT, leaves no wish unfulfilled, whether for classic stereophonic systems or more complex home cinema systems. For the latter, the LFE channel is particularly suitable, which can be supplied via an RCA connection and XLR cabling via the high-level inputs. On the output side, there is a similar configuration with RCA and XLR connectors that can output an LFE signal in addition to the stereo signal. This allows multiple subwoofers to be daisy-chained. For minimalist stereo systems using integrated amplifiers with no preamp or subwoofer output, the speaker level inputs are the only way to integrate a subwoofer into a two-channel system. The SPL-X 10's performance and maximum level make it ideal for home theatre applications, but those who want to use it for music and cinema can connect it in parallel and even switch the inputs in the app - an update is in the pipeline.