The Philharmonic Audio, BMR Philharmonitor by Dennis Murphy
If you have been looking for a loudspeaker that plays orchestral music very well, you might look to a designer who plays violin in the Washington DC Philharmonic Orchestra. While complete systems from Dennis are on hiatus, you can build your own copy of this incredible monitor right now.
This is the newest member of the Philharmonic family. Dennis has developed this new 3-way design using the same RAAL ribbon tweeter.found in the New Philharmonitor. The mid-range is an innovative Balanced Mode Radiator (BMR). The woofer chosen is the 7″, Scan Speak 18W/8545.
The bass response extends to 34 Hz in a bass-reflex cabinet thanks to the optimization done by Paul Kittinger – an expert in mass-loaded transmission line design. The BMR midrange and RAAL tweeter provide exceptional lateral dispersion and an expansive sound stage. The 17-element crossover uses the same high-quality parts found in our more expensive speakers and blends the three drivers seamlessly.
The most unique feature of the new design is the Balanced Mode Radiator, midrange driver. Conventional drivers function in simple pistonic fashion across their frequency range. Eventually, the response becomes chaotic as severe breakup modes develop from the applied mass of the voice coil interacting with the driver mass, which greatly restricts the usable range of operation. The BMR is a flat-diaphragm speaker that uses strategically placed weights in the diaphragm to counteract the mass of the voice coil at higher frequencies.
The BMR driver operates as a piston at lower frequencies, but shifts to a bending wave motion mode in the lower treble, and to a second bending mode in the upper treble. The result is greatly reduced breakup and extremely broad dispersion above 2,000 Hz. This driver is used as both a midrange and tweeter in several commercial applications. Although the BMR can function acceptably in this fashion, its true strength is upper midrange performance. The highest frequencies are much better served by the RAAL ribbon tweeter.
Bass frequencies are handled by a recently improved version of the classic Scan Speak 8545 7-inch woofer. This driver has long been noted for its superior bass reach and low harmonic distortion. The large volume of the BMR cabinet and expert port tuning by Paul Kittinger allow the Scan Speak woofer to provide a useful bass response to 34 Hz. This means you can experience the power of a pipe organ or bass drum without the expense of a tower speaker or the complexity of a subwoofer.
- Freq. Response – 34Hz- 20 Khz
- Sensitivity 85dB (dB/2.83v/1M)
- Dimensions 20″ H x 8″ W x 12-1/2″ D
- Impedance 6 ohm
See the Audioholic’s review here
The basic Bare Bones kit includes:
- 2 x RAAL, 64-10 Ribbon Tweeter – We may have delays in getting the tweeters.
- 2 x BMR 2.5″ mid-range
- 2 x Scan-Speak, 18W8545-1 Paper-carbon cone woofer
- 2 x Inductors specified by Dennis
- 2 x Audyn Capacitors (pictured) – or upgrade
- 2 x Sand-cast Resistors – or upgrade
- Directions and build plans
The optional Full Kit add-on parts include:
- 2 x Choice of terminals
- 2 x 16ga Internal Hook up wire
- 2 x Crossover mounting board and solder lugs
- 2 x All mounting hardware
- 2 x Internal damping materials
- 2 x Precision Ports
Extra optional items include:
- Assembled crossovers Option
We are happy to customize this kit for you – different capacitors, etc. – even if we don’t normally stock them. Just let us know your preferences and we can quote accordingly. Some component upgrades are listed above in the drop-down when ordering.