Sirvalence's TPL-150 / SB23NRXS Point Source Horn

Here is cool speaker that I helped member Sirvalence with the design and he built them himself. He was too busy to post this but I thought folks might find this interesting.

A Beyma TPL-150 AMT tweeter is used in a straight wall expansion horn with some midbass injection provided by an SB Acoustics SB23NRXS45-8 woofer. The horn is about 52.5cm wide x 34cm tall at the mouth and 22cm deep (external dims) with a rectangular throat 25mm wide x 126mm tall. The angles are approximately 80 deg H x 30 deg V. The woofer fires through two 100mm x 23mm hotdog shaped ports located as close as possible to the throat such that the end of the port is about 35mm from the throat. The woofer is upfiring through the two ports and the backside rests on a large 30cm dia x 1m cardboard tubes which serves as both a stand and the bass chamber. The whole thing is active with a DSP crossover at about 1350Hz but sometimes plays them crossed low like a FAST at 550Hz. Yes, it is amazing that the TPL-150 can go that low. I think he uses basic TPA3116 Class D amps and runs these as a quadrophonic system.

Here was the foamcore pathfinder:


Then he made them in 18mm BB plywood.

Here are the four horns:

Side View Detail:

Rear View AMT mounting detail:

Woofer mounting plate detail:

Adpater plate detail:

He says they sound great. Still playing with the DSP crossover settings and taking measurements to refine. We will try develop a passive XO for this at some point.


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