FUSION 3
Copyright 2018 © Troels Gravesen
DISCONTINUED, now open kit.
Download Kit Instruction
here.
CROSSOVER DRIVERS CABINET CROSSOVER LAYOUT SPEAKER-KIT SOUND
This page describes the third version of the FUSION speaker. We here have a Hypex FUSION FA252 plate-amp with DSP and two power amplifiers, one running the bass driver, the other running the mid-tweeter section with a simple crossover between the two. The benefit of this is two-fold, you don't need any power amplifier and we can omit the midrange high-pass section, which saves us a lot of expensive capacitors. Below you see what's going on:
The Hypex software comes on a memory stick together with the Hypex modules from Jantzen Audio and contains the low-pass filter in three gain settings to adjust to your pre-amp, streamer, etc. with a volume control and line output, being either single ended or balanced. Most likely you will have RCA sockets (phono sockets) and you need a pair of cables going from single ended (SE) to balanced (XLR) as seen below. The XLR plugs must be male XLRs like seen below.
Hypex FUSION plate amp/DSP
Click images to view large
Download HYPEX FUSION manual
here.
Download Hypex Filter Design
here.
Go to page 31 to read about the FUSION
modules.
Download Hypex Filter Design 4.97 software from
Hypex website.
Download FUSION-3 software here.
More on FUSION FA252 programming HERE.
Click images to view large
Download specs: SNAcoustics TW29RN-B ScanSpeak 18M/8631T00 BMS 12N630
CABINET: Go to
FUSION for details
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Above the very simple mid-tweeter section
providing the low-pass section for the midrange driver and high-pass
section for the tweeter.
Another advantage of this is the we can tune this as high as the
midrange driver allows and not having any resister in series with the
driver as we can adjust gain of the amplifier running the mid-tweeter
section to match the 12" bass driver.
Basically the mid-tweeter section is tuned to 90 dB sensitivity
(2.8V/1meter).
Useful links (Please read before writing!):
http://www.troelsgravesen.dk/tips.htm
http://www.troelsgravesen.dk/crossovers.htm
http://www.troelsgravesen.dk/LCR-RC.htm
http://www.troelsgravesen.dk/Inverted-Polarity.htm
FAQ (Please read before writing!):
You cannot change cabinet front panel dimensions and drivers' placement
without needing a new crossover - and I cannot help.
You cannot use any other drivers with the crossover specified.
http://www.troelsgravesen.dk/crossovers.htm
http://www.troelsgravesen.dk/choices.htm
MEASUREMENTS
Above the response of bass, mid-tweeter and
summed response. Not included is the contribution from the ports.
CROSSOVER LAYOUT
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I'm having an extra resistor for R1 to try out different tweeter levels.
Place the crossover on rear panel above the ports.
As the HYPEX software comes with channel 1 inverted polarity, connect the midrange driver with positive polarity and tweeter with inverted polarity.
The HYPEX FA252 mounted on rear panel. Note the speaker terminals are no
longer used here.
Connect channel 1, red (PLUS) and black wire (MINUS) to crossover board.
Connect from channel 2 blue (PLUS) and grey (MINUS) to bass driver.
Speaker wiring
Note tweeter connected with inverted polarity!
The 8 Ohm bass driver can be had from various
sources, e.g.:
http://www.lean-business.co.uk/eshop/bms-12n630-12-600-watt-neodymium-speaker-8-ohm-p-2566.html
(217 £)
https://www.thomann.de/de/bms_12n6308_ohms.htm?ref=search_prv_6 (246
€)
Both very reliable dealers to my experience.
With my Anthony Wilson 45 rpm Jack Of
Hearts on the platter, precision and clarity from a pitch black
background was what came to mind firing up the FUSION-3. This LP cut by
Bernie Grundman (link to YOUTUBE interviews) is a phenomenal
recording, and in particular I was surprised by the clarity and
transparency of the midrange and treble.
After some fine-tuning of treble level -
the usual procedure - things fell into place and I could fully enjoy the
sound of these NCORE Hypex modules that truly puts my tube affection to test.
I'd say these Hypex modules are closer to very good solid state
amplification than tubes and in the end it's all a matter of taste. The
convenience of this construction is hard to ignore. Line stage or any
receiver, DAC or streamer/network-player with volume
control - and you're running. No power amplifier required!