September 18, 2014

AV8 - home theatre speaker

AV8 is an 8" home theatre speaker with high output and sensitivity in a compact form.

PSE-144 white complete with bass module

PSE-144 white with bass module

Red Spade Audio Reference 18 sub

This is the first sub now available from Red Spade Audio assembled and finished - Reference 18.

Features a high excursion 18" sub driver and a 32mm MDF cabinet. 1 kW amplifier.

Finished in satin black (2 pack) as shown in the photo. Also available in various veneers in satin or high gloss finish as well as high gloss black.

Dimensions: 550 mm W x 600 mm H x 500 mm D.

Includes grille and solid rubber sub feet are provided as standard.

Why bring a sub to the market?

The market is flooded with 12" subs but I am finding that many of my acoustics clients appreciate something more. For many the option to go beyond existing subs on the market leads to multiple subs and it starts to become more expensive. This sub will do the work of around four 12" sealed subs without costing four times the price. I developed this sub as an option for my clients.

August 24, 2014

PSE-144 active DSP crossover - how does it measure

PSE-144 active version measured outdoors.

This is an outdoor gated measurement that has been elevated to around 4m. The mic was placed at a larger than  usual distance to capture baffle effects - this is not a near field measurement. 


July 31, 2014

PSE-144 in black

In the first exclusive run of PSE-144, black as seen here was by far the most popular.

July 1, 2014

Room Analysis case study

This is an example of a room analysis job for one of my PSE-144 customers. This client built two subs of my design - T20, intends to build multiple large 18" bass boxes along with my horn. The goal here was to figure out the best treatment scheme along with a suitable bass arrangement.

You can see there is a lot of brick in this room, which could be a recipe for disaster in the bass, if not for a large window across the left wall and some openings.

For testing here I used an old Wharfedale speaker with a 12" woofer in a sealed box, powered by a DSP amp. EQ is used to get it flat when measured nearfield:

After confirming the extension and smoothness of the test speaker, different listening positions were tested:

Listening positions: Orange: rear left, Pink: rear right, Green: middle front

Here you can see the two seats against the rear wall, with a third position with another chair in front, centred on the couch.

This measurement might lead you to think that the left rear seat is the one to choose. However, in reality much of the bass will play through both main speakers and only one is shown here. Summed mono, the combined bass is expected to even out the response.

Left (grey) and right (black) bass bins shown for the left seat

Now in the right seat, we also see the two bass bins:

Green = right bass bin, pink = left.

Again, when these are combined, we expect the dip will be smoothed out and we will see a fairly flat bass response with a hump around 40 Hz. Both of these seats end up with a similar bass response.

What we see here is that the combined bass response of the two main bass bins is expected to be good. We see no major need for a more complex multi sub arrangement.

Next we moved on to testing sub positions.

The results cover a 50 dB range.

The best overall sub position was the centre of the front wall (black), which is compared to the middle of the ceiling, such as may be used in an infinite baffle sub.

 Black - sub in middle front wall vs ceiling centre (green).

Below 40 Hz, the ceiling position has around 10 dB less output, and significant nulls. The main area of interest for a sub position here is below 60 Hz, as the horn in question is best operated below that point.

Basically, the central mid wall position in this room has the best mix of extension, output and smoothness.

The recommended treatment scheme here includes a little more focus on diffusion due to the dispersion control. There is less off axis energy from the horn. Hence, here I suggest retaining more of that energy in the room with a little more later arriving reflections at a lower level. This will retain some natural ambiance in the room and maintain spaciousness.