Philharmonic BMR HT Tower Speaker Review

Philharmonic BMR HT Tower Introduction

For those in the know, Philharmonic Audio is one of the stand-out values in high-fidelity loudspeakers, but since Philharmonic doesn’t spend a penny on promotion and advertising, only those enthusiasts who are really tuned into the world of home audio loudspeakers would be familiar with the name. Their reputation stems purely from word of mouth and a few lucky reviewers who managed to spend some time with their products. Happily, Audioholics has spent some time with their speakers: see our reviews of the BMR Tower and the BMR Philharmonitor. In both instances, we were astonished at just how superb the engineering was, even irrespective of the affordable pricing.

Today, we have the opportunity to go over Philharmonic’s latest release, the BMR HT Tower. This speaker is Philharmonic’s foray into wider dynamic range applications such as home theater, as denoted by the ‘HT.’ As such, the design does take some significant departures from what we are used to from Philharmonic, although it does retain some key elements from previous designs. The questions we will be asking in this review are can the BMR HT Towers deliver the same sound quality that we have become accustomed to from Philharmonic, and how well does their formula serve home theater applications? Let’s now dig in to find out…

Packing and Appearance

The BMR HT Towers arrived at my home in a couple of heavy-duty cardboard boxes. They were double-boxed, and the speakers were nested in some polyethylene sandwiching pieces that covered the entire speaker. The speakers themselves were wrapped in soft cotton sacks to prevent scuffs. This is very good packing and it should ensure that the speakers arrive safely at their destination through all but the roughest shipping. Since the BMR HT Towers can only be had through parcel shipping, the packing had better be good, and Philharmonic has made sure that it is.

Once unpacked, we have a pair of gleaming tower speakers that are finished in a mirror ebony veneer. The BMR HT Towers can also be had in a satin Zebrawood veneer which I would also imagine looks very nice. The vertical edges are rounded and the horizontal edges have a slight rounding. The speakers have grilles that cover the entire front baffle. When the grilles are attached, the speakers look OK, but much of their character is lost. Once the grille is removed, we get to see the driver layout, and the speakers look a lot more interesting with the drivers exposed. The top half of the speaker has an AMT tweeter sandwiched by two BMR drivers with flat diaphragms, and the lower half has two bass drivers with unusual pleated surrounds that wind in a spiral pattern around the cones. The feet aren’t really visible, which helps to create a clean look. Also adding to the clean appearance is the absence of grille guides since the grilles use magnetic adhesion. The BMR Towers look high-end and would fit into luxurious decors without problem.

One odd aspect of all of this is that they are more geared for home theater applications, and many home theaters are installed in media rooms or ‘man caves’ where this type of high-end finish isn’t a requirement at all. I think Philharmonic might try a simple vinyl matte black as a lower-cost option for those who want to put these in a dedicated home theater, especially one using a projection system where reflective surfaces are undesirable.

Design Analysis

We have seen Philharmonic’s superb performance from their BMR loudspeakers in past reviews, but those speakers were intended for typical two-channel applications. So how do the BMR HT Towers crank up the dynamic range of Philharmonic’s celebrated BMR designs while still adhering to the same formula? Let’s discuss how the BMR HT Tower achieves that by starting at the top of the frequency band with the tweeter.

The BMR HT Tower uses a high-performance AMT tweeter from the celebrated audio equipment parts manufacturer Mundorf. It’s a wide dispersion tweeter that also has very low distortion. AMT tweeters are more robust than the ribbon tweeters that Philharmonic had previously used. Ribbon tweeters use a very thin aluminum strip that is set between two magnets, and it oscillates as an alternating current is sent through it thereby creating pressure waves of sound. Its advantage is that its dimensions gear it for a very wide dispersion pattern as well as an extremely extended high-frequency response without the bending modes of dome tweeter diaphragms. Their disadvantage is that the thin aluminum strip is fragile and has to be protected from playing low frequencies. For this reason, they are mostly found in three-way speakers or two-way speakers with relatively high crossover frequencies. 

AMT tweeters (AMT stands for Air Motion Transformer), on the other hand, are constructed by etching a metal film in a hard plastic resin (Polyethylene terephthalate or PET) that is folded into a pleated sheet. This membrane is mounted in a powerful magnetic field, and when alternating current is sent through the metal etching, the folds of the pleated sheet rapidly contract and expand which ejects and draws air into the fold cavities. This creates pressure waves of sound. A major advantage of AMT tweeters is that since the folds of the diaphragm are much deeper than they are wide, the air is ejected out at a much faster speed than the vibration of the diaphragm itself- as much as five times faster. That can move air very quickly, and that can equal high SPLs in upper frequencies. Another advantage is the very low mass of the diaphragm which makes it very easy to move and change direction since it does not have the momentum of the weight of a typical dome tweeter. These elements give AMT tweeters an extended response well into ultrasonic frequency ranges. Also, since AMT tweeters can have a relatively large surface coupled with the air, they can have a very wide dynamic range, and they are not as easy to break as ribbons since the polymer resin membrane is a lot tougher than a thin aluminum strip.

Moving downrange from the tweeter, we have the BMR midrange drivers of the speaker’s namesake. The BMR driver used in the BMR HT Tower is a newer, more powerful version of this driver design. The ‘BMR’ stands for ‘Balanced Mode Radiator.’ It’s not an expensive component but it is a sophisticated piece of engineering nonetheless. It is an extremely wide-band, flat-diaphragm, 3” driver that uses weighted rings on the diaphragm to dramatically reduce cone break-up. Cone break-up occurs when the excursion of the driver happens so quickly that the cone can’t keep a uniform shape and begins to bend in various ways. This happens to all drivers at high enough frequencies, and the results are that the response starts to get heavily distorted past a certain frequency. The larger the cone, the lower in frequency that break-up will start to affect the response, and this is one of the reasons why midrange drivers are smaller than bass drivers, and dome tweeters are smaller than midrange drivers. Filtering out break-up artifacts has always been a challenge for loudspeaker designers, so any driver that doesn’t have as much of a problem in this respect makes designing a good speaker much easier. The exact method that Tectonic uses to reduce break-up with their weighted rings is rather complex but is explained in this white paper: The Balanced Mode Radiator.

The midrange drivers are arranged in an MTM configuration with the tweeter (where MTM stands for midrange-tweeter-midrange).  One reason an MTM design is better than a traditional MMT (midrange-midrange-tweeter) is that by using two woofers that are both the same distance from the tweeter, the acoustic time alignment of the speaker is more centered on the tweeter. That gives this speaker a more predictable response on the tweeter axis in both the vertical and horizontal planes. Another reason why an MTM design can be an improvement over an MMT design is that MTM midranges will interact with each other in a predictable way, and this can be used as an advantage in reducing vertical dispersion minimizing the smearing effects of floor/ceiling reflections. If you are standing dead ahead of both midranges, the time-arrival of their sound will hit you simultaneously, but if you are standing at an angle that puts them at different distances, the time-arrival between them is different, and this difference causes interference with each other and can cancel output. The result in a speaker like the BMR HT Tower is that less sound is emitted at off-axis angles in the vertical axis, so there will be less acoustic reflections from the ceiling and floors.

The bass drivers are 6.5” Purifi drivers. These are state-of-the-art drivers that have been measured by multiple third parties to have extraordinarily low distortion. Purifi uses a few different design strategies to accomplish this. For starters, they use a specially designed pole piece that uses a magnetically saturated piece to combat intermodulation distortion. They also use a large and specially designed copper shorting ring to reduce inductance-generated problems such as shortened bandwidth and distortion products. They also use a specially designed surround that keeps the radiating surface area of the driver consistent as well as mitigating any effects on the cone that cause it to bend or deform under excursion. The assembly of these drivers is surely difficult and very expensive. Magnetizing a motor with such a large shorting ring and then trying to install a magnetized pole piece in an already powerful magnetic field sounds like a very involved procedure. Given the retail cost of these drivers (approx. $420 each), buying a set of speakers for $4.5k that has four of these drivers is a high-value proposition to the consumer, assuming the speakers are competently engineered, and from examining the design of these BMR HT Towers, the evidence suggests that these speakers are very competently engineered.

The crossover circuit blends the bass drivers with the BMR midranges at 700Hz using 2nd-order Linkwitz-Riley filters. The midrange-to-tweeter crosses over at 3.8kHz with 4th-order Linkwitz-Riley filters. Given the caliber of drivers used, that is a sensible design that should yield a very flat response. The crossover board itself has a slew of large 5% tolerance capacitors, resistors, air-core inductors, and a couple of steel laminate inductors, all adding up to a 21-element circuit. The components look high-quality and beefy and should be able to handle a good amount of electrical current.

The BMR HT Tower’s enclosure is not a typical ported design but rather a mass-loaded transmission line design. Mass-loaded transmission lines don’t use a cabinet with internal folds for a long, convoluted path like a conventional transmission line, but rather places the woofer and port at just the right locations and loads the cabinet with damping material at just the right points so that port produces output at a quarter-wave of the driver’s output instead of an entire cycle behind like a traditional vented speaker. The advantage of a transmission line is that the speaker can gain deeper bass extension and the driver is loaded more precisely for greater control over the cone’s movement. The front baffle of the enclosure is just over 1” thick, and it has two window braces that divide the cabinet into three sections. The BMR Midrange drivers get their own sealed compartments. The port has a 4” depth and 3 ½” diameter and is flared on the outside.

The stock feet are some narrow metal spikes that screw into the bottom panel. There are some small, nickel-sized metal pucks that the spikes can be set on to protect hard floor surfaces. To be blunt, they are not great feet or pucks, but the BMR HT Towers will be coming out with the option for more substantial feet attached to outriggers later in the summer of 2023. The stock feet do not extend out on some outriggers or a plinth, so they do not provide the BMR HT Towers with the same stability as outriggers or a plinth, although their tipping angle is not unreasonable. While I did not receive a sample of the upgraded outrigger feet, they will doubtlessly improve things. The stock feet look like spear tips, and accidentally setting the speaker down on one’s foot would be a brutal mistake. Contrary to audiophile mythology, spiked feet have never been shown to provide any audible benefit. Their only benefit is that they can plant the speaker a bit more firmly on carpeted surfaces. The pucks for the stock feet that Philharmonic provides to protect hard flooring are inadequate for their mission. They are so small that the user has to take great care in lowering the speaker onto the pucks or else the spikes will sink into the floor. If prospective owners are concerned with feet scratching the flooring, I would advise them to not even try the included pucks and just get the outrigger upgrade feet set or larger pucks from another source.

The grille uses some acoustically transparent fabric stretched over a wood frame. It uses magnetic adhesion, and the grip on the front baffle is fairly strong so that it won’t get knocked off by accident. The frame would certainly add some hard edges that would increase acoustic diffraction, but I couldn’t really hear any difference in my listening. The wire terminals are just a simple pair of five-way binding posts that jut out of the back panel. I do prefer it when they are sunk in a cup so that they can’t accidentally knock into anything if the speaker must be moved, but I think that these speakers look so nice that anyone who moves them is going to do so carefully, so that won’t be a problem.

Listening Sessions

In my 24’ by 13’ (approximately) listening room, I set up the speakers with a few feet of stand-off distances between the back wall and sidewall and equal distance between the speakers and the listening position. I angled the speakers to face the listening position. The listening distance from the speakers was about 9 feet. No room correction equalization was used. Processing was done by a Marantz 7705 and the amplification was done by a Monoprice Monolith 5x200 amplifier. Subwoofage was provided by the RSL Speedwoofer 12S. A special thanks goes out to Monoprice for swiftly providing this high-performance amplifier after my amp kicked the bucket (Audioholics review of the Monoprice Monolith amplifier).

Music Listening

“Gesualdo: Sacrea Cantiones” is a new release that should be big news for Renaissance music fans. Carlo Gesualdo was an innovative and experimental composer who, in the late sixteenth and early seventeenth centuries, pioneered compositional techniques that would not gain wide use until two-hundred years later. This album is a performance of the first collection of motets of sacred music composed by Gesualdo in 1603. This choral music is beautifully sung by the Il Pomo D’Oro ensemble, and I listened to it in a hi-res 24-bit/88kHz stream from Qobuz.

From the first track onward, I was struck by how realistic the voices of the choir were. This production is sublime, but very good loudspeakers are needed to fully exploit the resolution of the recording, and in this case, the BMR HT Towers are able to accomplish this. The singers sounded vivid and natural, and the speakers seemed to operate as a window into the original performance. The performers of the choir were imaged with remarkable precision. Sopranos and altos dotted the soundstage, with tenors on all sides. Bass voices occupied the lower right-hand side of this soundscape. The BMR HT Towers relayed the acoustics of the performance space, a Renaissance church in Italy called the Confraternita Dei Santi Rocco E Sebastiano, for a transportive effect where I could close my eyes and believe I was there in an aisle seat at a middle pew. A light reverb reached from outside the width of the speakers’ placement to create a sense of envelopment and immersion. The BMR HT Towers’ reproduction of this album was magnificent, and I am not sure how a sound system could improve upon this exquisite recording beyond what I heard. There may be different ways that the soundstage might be communicated by different loudspeaker designs, and the best of them may be able to equal these in a different manner, but I wouldn’t think that any of them could do better. 

For a demonstration of the BMR HT Tower’s capability with some lively orchestral music, I selected “Antonin Dvorak: Symphonies Nos.7-9” released last year on the Deutsche Grammophon label. Even though he is lauded as a major nineteenth-century composer, I only knew Dvorak from his famous “Slavonic Dances” and his more popular works written during his stay in the United States: “New World Symphony” and “The American.” After hearing a selection from this recording, I thought it would be a good time to give Dvorak a closer listen as well as revisit “New World Symphony” (Symphony No. 9). This album was recorded at the Walt Disney Concert Hall and performed by the Los Angeles Philharmonic. I also streamed this album from Qobuz in a hi-res 24-bit/96kHz stream.

This album is on the more dramatic side of classical music, which is why I thought it would better exhibit the BMR HT Tower’s dynamic range as opposed to calmer recordings, and the speakers were certainly up for the task. While I don’t listen at a very far distance from the speakers at nine feet, they were more than sufficient for recreating the power of a live orchestra to my ears. In a larger room or a much further listening distance, they may well not be capable of that kind of sound, but in my medium-sized room from my listening distance, they had a terrific impact. Of course, the near-field placement of the subwoofer I was using made a real contribution to the force of the sound, but the speakers had no problem keeping up with the sub. The crescendo in the finale to Symphony No.7 on track four produced fireworks from all quarters of the orchestra, and the BMR HT Tower brought all of these instrumental sections to fiery life. The soundstage imaged the instrumental sections with well-defined placement, and the tonality of the instruments sounded true-to-life. This album was reproduced with a worthy verisimilitude to the living experience of a full orchestra, and classical music fans will certainly dig what these have to offer.

While the BMR HT Towers are more intended to be used with subwoofers, I decided that parts of “Antonin Dvorak: Symphonies Nos.7-9” would be a good example to see how they would fare when run full-range without subs. In doing so, the speakers sounded surprisingly full by themselves. The timpanis didn’t sound quite as thunderous and room-filling, and the lower notes of the double bass weren’t quite as potent, but the resultant bass sound was still very good and more than acceptable. With a spec’d response of 38 Hz - 20kHz (+ 1.5 / - 3db), the BMR HT Towers should have a strong sound down to 40Hz at the very least. There isn’t that much acoustic music with a lot below 40Hz, although orchestral music does skim the waters of deep bass at times, so I do think that the inclusion of subwoofers does improve the sound of these speakers on this particular album. However, I don’t think that subwoofers would add much to most other types of acoustic music recordings. If your jam isn’t heavy-duty orchestral, pipe organ music, or bass-heavy electronic music, you could easily get by without needing to add subs to the BMR HT Towers. There are a lot of other tower speakers that claim to be full-range yet don’t dig any deeper than these, so these don’t really have abnormally shallow extension. They just don’t have as low-frequency extension as Philharmonic’s larger BMR Tower, which is truly full-range.

Taking a turn for something that is very much the opposite, I listened to “The Gift from Neon Planet'' by Sayohimebou. My other reviews of Philharmonic speakers featured albums from this very strange artist, so I decided not to break that trend. It’s difficult to classify Sayohimebou’s music into a genre, but try to imagine the most sugar-coated pop music broken to pieces and then reassembled by someone in the throes of an LSD overdose. This music is at once hyperkinetic and manic as well as spaced-out and psychedelic. It makes for a fun and wild listen, especially on a capable sound system, so I set out to see what it sounded like on the BMR HT Towers.

Listening to this album on the BMR HT Towers is like getting lost in WiIly Wonka’s Chocolate Factory after having suffered a serious concussion. I have always loved how the wide, expansive soundstage of Philharmonic Audio’s other speakers played with the bizarre and frenetic imaging of Sayohimebou, and the BMR HT Tower did not disappoint me in this regard. Low-fi pop music samples splashed back and forth between the sides of my room while rapid synths stabs rained down from the sky in synchrony with the time signature. The BMR HT Towers gave depth to the hypnotic ebb and flow of the sweeping synth pads of track 10. The soundstage presented on track 13 was a journey into an alien Candyland, and the imaging extended outside the boundaries of the speakers to an almost supernatural extent. Track 14 saw some wildly distorted vocals dance around the soundstage along with a dizzying array of percussion, but the imaging of BMR HT Towers gave clarity to the locations where these sounds originated. From start to finish, “The Gift from Neon Planet” was a delight to hear on such resolving and capable loudspeakers, especially ones that can throw such an immersive soundstage. Most people who buy loudspeakers that look and sound as impeccable as the BMR HT Towers probably aren’t going to experience an artist like Sayohimebou - but they should. It is loads of fun.  

To see how the speakers could handle some real stress, I threw on Current Value’s “Time Gap.” This is electronic breakbeat music from the harder end of the genre and is meant to be played loud. Current Value can always be counted on for finding some of the strangest sounds and then using them as the lead instrument in his music. His arrangements are usually very high in tempo but can be sparse at the same time, and it makes for an aggressive and futuristic sound. This bleeding edge of electronic music can be an experimental playground where new sounds are heard; indeed, Current Value has often been the first to produce music that has been imitated elsewhere in the electronic music world. Reproducing this music at a high level is a tough proposition for any sound system, so I set out to see how the BMR HT Towers could cope with it.

Once the drop on the first track hit, I knew these speakers had some muscle. Current Value’s searing lead synths soared on the BMR HT Towers. With help from the subs, these speakers were capable of putting out a bruising sound and they didn’t ever sound stressed or inhibited. Mid-bass percussion threw jabs that acted like combos with the uppercuts that the sub was delivering. Hi-hats and snares snapped, crackled, and popped like Rice Krispies on meth. Synths shredded like metal being torn. I found the limits of my ears before finding the speakers’ limits and had to back off to preserve what is left of my hearing. Listening to “Time Gap” at a high volume proved that these speakers could slam hard for those willing to endanger their hearing.

Again, I should state that my seating position doesn’t give me a large distance from the speakers: only about 9 feet, not an unusual listening distance for many sound systems. Could these speakers tackle a larger distance in a bigger room with the same kind of force? Philharmonic claims that the BMR HT Tower can hit 105dB at one meter. That is pretty loud, but it isn’t quite club levels at a typical listening distance in a normal room. In fact, clean 105dB peak playback at 12 feet in a 3,000 cubic foot room is required to attain THX Ultra certification, so that wouldn’t suggest that the BMR HT Towers could attain THX Ultra certification. That isn’t such a knock on the BMR HT Tower, since the dynamic range required to achieve THX Ultra is a high bar to clear. However, one factor that could enable the BMR HT Towers to have a wider dynamic range in practice than on a spec sheet is its wider dispersion. Many wide dynamic range speakers achieve their headroom by focusing their sound output within a narrow angle (think loudspeakers that use horns like Klipsch). The BMR HT Tower, on the other hand, has a very wide angle of sound output, and that means that more of its sound will arrive at the listener in the form of reflections than direct sound from the speaker. It could be that the total amount of acoustic energy emitted by the BMR HT Towers isn’t actually less than a speaker that has more power on paper, and that may be what is heard in a real-world situation.  

Movie Watching

Word of mouth has been good for “House of the Dragon,” the “Game of Thrones” prequel, so I was interested in giving it a try, even though “Game of Thrones” ended in a lackluster conclusion. I figured that it would be a good test of the BMR HT Towers’ ability to reproduce something cinematic and grandiose. With lots of scenes of dragon carnage, torrid romances, and political intrigue, all done with an unlimited budget, the sound mix is sure to be as good as money can buy. So, over the course of two days, I binged it with fingers crossed that it would live up to the hype and learn from its predecessor’s missteps.

“House of the Dragon” sounded superb on the BMR HT Towers. While much of the show is simple dialogue, the show did have its fair share of epic dragon scenes, and the beasts sounded fabulous on the BMR HT Towers. The speakers made their roar and fireball breath sound like the dragon was right in front of me. Of course, a fair chunk of the dragon sound was performed by the subwoofer, but the BMR HT Towers could keep up with the elevated volume that I listened at without issue. Another notable action scene with a striking sound mix was the knights’ tournaments. The jousting and brutal swordfights had a visceral impact, especially the sickly sound of bones breaking. Ramin Djawadi returns from “Game of Thrones” to compose another great music score, something that the first show never faltered with even though it stumbled dramatically. I don’t normally listen to end-credit music, but the score was so good, as was its rendition by the BMR HT Towers, that I watched each episode to the end. Dialogue intelligibility was never a problem. Some of the dialogue was performed with exotic accents with respect to the English accent of the main cast, but it was all easy enough to follow. “House of the Dragon” lived up to the acclaim, and it does hold promise for further seasons, but then so did “Game of Thrones.” Let’s hope it doesn’t squander the potential shown so far.

One new movie that has been gaining some buzz is the suspense thriller “Fall.” It’s not a mega-budget behemoth like “House of the Dragon,” but it looked like an engaging movie for its simple premise. In this movie, two thrill-seeking extreme climbers decide to climb an old, abandoned 500-meter radio tower. However, they become stranded at the top when the ladder they used to ascend the tower crumbles, leaving them with no safe way to get down. The sound mix for this movie looks like it could be interesting and certainly an opportunity for an adventurous sound engineer to create something special.

For someone who is not a fan of heights, “Fall” was a truly anxiety-inducing experience, and having the sound mix so vividly reproduced helped to increase that anxiety. The movie is brilliantly built up with close-up shots of structural decay of the tower that goes unnoticed by the characters as they ascend it. The creaking and grinding of the tower’s dilapidated components could be heard with sickening detail through the BMR HT Towers, and the suspense that it created was harrowing. Other effects noises included an approaching thunderstorm and circling vultures, and these were relayed with threatening fervor. Dialogue intelligibility was always crystal clear, and the terror of the cast’s quivering voices could be heard with utmost clarity. Tim Despic’s serviceable orchestral score heightened the tension, and it was exuberantly rendered by the speakers, although I think an interesting and potentially effective alternate choice the filmmakers could have gone with is simply omitting added music altogether and just using ambient effects sounds. That could possibly have heightened the realism and therefore the immersion. However, acrophobiacs already have enough to be apprehensive about in “Fall” and wouldn’t need the movie to be even scarier. “Fall” was truly an edge-of-your-seat thriller, and I recommend it be experienced with high-fidelity speakers like the BMR HT Towers for an extra nerve-racking experience.

Philharmonic BMR HT Tower Measurements & Conclusion

The Philharmonic BMR HT Tower speakers were measured in free-air at a height of 4 feet at a 2-meter distance from the microphone, with the microphone raised to an 8’ elevation that was level with and aimed at the tweeter center. The measurements were gated at 8 milliseconds. In this time window, some resolution is lost below 400 Hz and accuracy is completely lost below 200 Hz. Measurements have been smoothed at a 1/24 octave resolution.

The above graphs depict the BMR HT Tower’s direct-axis and horizontal dispersion out to a 90-degree angle in five-degree increments. Information on how to interpret these graphs can be read in this article. The measured responses by this speaker are beautifully neutral both on and off-axis. The BMR HT Tower on-axis response stays with a very tight window without any broad regions of elevation or depression which departs from neutrality. The off-axis responses hold a tight correlation with the flat on-axis response, so this speaker will have the same tonality over a wide angle of its front hemisphere. There is a small, sharp dip at around 1.8kHz that is much too narrow to have an audible impact on the sound. There is a roll-off in the top end of the response which is partly due to the measurement conditions where a windscreen was used. The windscreen helps to reduce noise contamination from wind gusts, but it does shave off some of the sound above 18kHz or so, so in reality, the upper-frequency response of this speaker maintains a stronger high-frequency response than what is shown here past 20kHz.

The bottom line is that the BMR HT Tower is a highly accurate loudspeaker that keeps its neutrality over a wide listening angle in front of it.

The above polar map shows the same information in the preceding graphs but depicts it in a way that can offer new insight regarding these speakers’ behavior. Instead of using individual raised lines to illustrate amplitude, polar maps use color to portray amplitude, and this allows the use of a purely angle/frequency axis perspective. The advantage of these graphs is they can let us see broader trends of the speaker’s dispersion behavior more easily. More information about interpreting this graph can be read Understanding Loudspeaker Measurements.

The BMR HT Tower shows a beautifully even dispersion pattern in this polar mapping of its horizontal responses. It maintains a strong and even response out to a 60-degrees to 10kHz before losing energy beyond that angle. That means that this speaker sounds the same over a wide listening area, and it also means that acoustic reflections from walls and other vertical surfaces will bear the same tonality as the direct sound from the speaker. This speaker would be very amenable to equalization both manually and also by automated EQ systems like Audyssey. It also doesn’t need a room stuffed with acoustic treatments to sound good; it should work well in any normally furnished room.

Unlike other Philharmonic speakers we have tested, the upper treble frequencies do narrow a bit above 10kHz, and part of that is likely to the windscreen used in measuring the speaker, but much of it is also due to the AMT Tweeter that Philharmonic has employed in the BMR HT Tower. The narrow RAAL ribbon tweeters of the previous Philharmonic speakers were well suited for achieving very wide dispersion even up to 20kHz, but the wider diaphragm of the Mundorf AMT can’t really match them in that regard. That is not a huge loss since there isn’t a lot of recorded content above 10kHz, and upper treble in that region typically becomes much more attenuated as an acoustic reflection anyway. Furthermore, the upper treble dispersion that we do get from the BMR HT Tower is broader than the vast majority of dome tweeter speakers that we come across. It’s definitely a worthwhile trade-off for the BMR HT Tower’s purposes; less high treble dispersion for more dynamic range. The RAAL ribbon tweeters would not be able to achieve the kind of output that the AMT tweeter from Mundorf can produce.

The above graph is a sampling of some of the vertical angle responses at and around the on-axis angle. Negative degrees indicate angles below the tweeter, positive angles indicate angles above the tweeter, and zero degrees is level with the tweeter. The BMR HT Tower holds the most neutral responses at and above the tweeter. In fact, the overall most neutral response occurs above the tweeter at around 5 to 10 degrees. None of this is problematic since the tweeter is mounted at a typical height of 37.5” (with feet attached), which is where many user’s ear levels would be in low-slung seating. Many chairs would probably boost the listener’s at around the height of the upper midrange driver, a 41” elevation. Few people would listen at heights below the tweeter. The vertical coverage of the BMR HT Towers is good and shouldn’t present a problem in any normal listening situation.

The above graph shows the BMR HT Tower’s low-frequency response captured using groundplane measurements (where the speaker and microphone are on the ground at a 2-meter distance in a wide-open area). The response is extremely flat down to 50Hz and then starts rolling off more steeply below its port tuning frequency of 40Hz. The rolloff isn’t very steep though, and it looks more like a 12dB/octave slope rather than a traditional 24dB/octave slope that we often see with ported loudspeakers. This is likely due to the transmission line tuning which doesn’t behave like a normal ported loudspeaker. The advantage of this is that it can take advantage of room gain without over-boosting the bass response, which is what may happen were the response flat down to deep bass. This speaker does not need a subwoofer for most music recordings and should provide a strong in-room response down to 40Hz. However, its home theater-centric design does call for the addition of a subwoofer for those who want powerful deep bass.

The above graph shows the electrical behavior of the BMR HT Tower. Philharmonic specifies this speaker at 4 ohms, and that is what we see. Impedance dips a bit below 4 ohms at 150Hz and 2kHz, but not by much and not accompanied by extremely steep phase angles, so monster amps are not needed to cope with this design. A decent mid-level AVR would be enough to make these speakers sing, but a well-built outboard amp would make them sing louder and take fuller advantage of their dynamic range capability. One interesting aspect to note is the relative evenness of the two peaks of the lower-frequency saddle shape, and that indicates that the resonant frequency of the driver is a good match for the resonant frequency of the cabinet. We can see that the enclosure was carefully tuned for these particular bass drivers, yet more evidence of excellent loudspeaker engineering.   

I measured the BMR HT Tower’s sensitivity to be 91dB at 2.83v at 1 meter. This is substantially different than Philharmonic’s own spec of 88.5dB. Philharmonic tells me that their own specification is very conservative, but even so, with a 2.5dB increase, my own measurement nearly doubles their sensitivity spec. Sensitivity measurement results can vary to a degree depending on the method used (read our article: Loudspeaker Sensitivity and Impedance Explained), so while my own measurements are rarely an exact match with loudspeaker manufacturers, it is usually not far off, with perhaps a +/-1dB variation on average. While I can’t fully explain the discrepancy between my measurement and Philharmonic’s specification, it’s safe to say that the BMR HT Tower is not a speaker that needs tons of power to get loud, no matter whose measurement is correct. 100 watts will be enough to make these things thunder pretty hard, and they can handle significantly more than 100 watts.

Conclusion

Before bringing this review to a close, I will briefly go over the strengths and weaknesses of the product under review, and, since I am the kind of guy who always wants the bad news first, I will start with the weaknesses. The Philharmonic BMR HT Tower only has one small weakness, and that is the stock feet which are sharp spikes with pucks that are too small to place the spikes on. Philharmonic is remedying this by releasing an optional outrigger feet upgrade later this summer, so even this one small complaint is being addressed. Outside of that small issue, there is nothing that I could fairly complain about.

Some might complain that the BMR HT Towers don’t have exceptional low-frequency extension, but that is the inevitable trade-off in having a speaker that is not huge yet still offers a wide dynamic range, so it is not a reasonable complaint. While there are circumstances that the BMT HT Tower can be used without a subwoofer without problem, it was engineered to be used with subwoofers for home theater applications. Those who want a tower speaker that can do deep bass should be looking at its less expensive tower sibling, the BMR Tower. But of course, that speaker does not have the dynamics range of the BMR HT Tower and is considerably larger. This is all a consequence of Hoffman’s Iron Law which states that you can have two of the following but never all three: efficiency, small enclosure size, or low-frequency extension. 

Moving on to listing the strengths of the BMR HT Tower, there are many. Firstly, the sound quality is impeccable, much as we have come to expect from Philharmonic Audio. I never heard anything that sounded errant or off in the slightest. The tonality is exceptionally accurate. As I have said about Philharmonic speakers in the past, this is another that is so dead-on accurate that it could be used in mixing and mastering music in a studio setting since it resolves the sound without bias. If you don’t want your sound system to interject its opinion on what the source material should sound like, the BMR HT Towers are a terrific option.

What is more, the accuracy of the BMR HT Towers does not only occur in a narrow beam in front of the speaker; it happens over a wide angle, so all listeners will be met with an even, balanced sound. This quality also does away with the need for lots of acoustic treatments, since the reflected sound will have the same neutrality as the direct sound. As I said before, this characteristic enables these speakers to work well in any normally-furnished room.

The BMR HT Towers also achieve their aim of a wide dynamic range. They played louder than I could bear yet did not audibly distort or compress. Those looking for some very high-fidelity speakers for head-banging as well as enjoying the nuances of Il Pomo D’Oro ensemble’s performances of Carlo Gesualdo’s Sacred Cantiones have a great choice here. Just add a subwoofer, and the listener is all set for a large, cinematic sound in the comfort of their own home.

In addition to aspects of its superb sound reproduction, the BMR HT Towers also look very nice. The mirror ebony finish is gorgeous, and the overall industrial design is tasteful enough to work well even in high-end interior decors. What really helps in this regard is their very reasonable size. They aren’t large towers and so will not dominate the room or become a major visible presence.

One point I want to mention is the pretty tremendous value that the BMR HT Towers present. The $4.5k/pair pricing is abnormally low considering the parts used. The Purifi drivers are $420 each at retail. The Mundorf tweeter is about $250. The BMR midrange drivers can be had for $40 each. The crossover circuit has to have at least $100 worth of components on it. When we add all of that up for two speakers, the cost is over $2,500 for drivers and crossover components alone. Philharmonic is certainly getting manufacturer discounts for buying larger quantities, but we still have not even considered the cost of the enclosure and its associated components like binding posts, feet, acoustic stuffing, and the multi-step labor of a mirror finish. The shipping packing is also commendable and can not have been cheap. When we consider the bill of materials for most loudspeakers is somewhere between one-sixth to one-fourth of the final cost, it is astonishing that Philharmonic can sell these at their present pricing. $4.5k for a pair of loudspeakers is not something that most middle-class people can buy on a whim, but when considering the parts used, these speakers are absolute bargains. 

The sum up the BMR HT Towers, they have successfully brought Philharmonic’s high-fidelity sound into a wider dynamic range. They have also kept their very aggressive pricing and only cost a few hundred dollars more than the regular BMR Towers. Among Philharmonic’s offerings, they are the ones to go with if the buyer is going to use subwoofers. I would guess that constitutes a large fraction of consumers shopping in this price and product class, so I think the BMR HT Towers are going to be seeing a hot seller for Philharmonic. These speakers certainly deserve high demand, and if more people appreciate the level of engineering that has gone into them, I think Philharmonic will have problems keeping them in stock because they will be selling out so fast. The BMR HT Towers are outstanding loudspeakers!

The Score Card

The scoring below is based on each piece of equipment doing the duty it is designed for. The numbers are weighed heavily with respect to the individual cost of each unit, thus giving a rating roughly equal to:

Performance × Price Factor/Value = Rating

Audioholics.com note: The ratings indicated below are based on subjective listening and objective testing of the product in question. The rating scale is based on performance/value ratio. If you notice better performing products in future reviews that have lower numbers in certain areas, be aware that the value factor is most likely the culprit. Other Audioholics reviewers may rate products solely based on performance, and each reviewer has his/her own system for ratings.

Audioholics Rating Scale

• — Excellent
• — Very Good
• — Good
• — Fair
• — Poor

Metric	Rating
Build Quality
Appearance
Treble Extension
Treble Smoothness
Midrange Accuracy
Bass Extension
Bass Accuracy
Imaging
Dynamic Range
Fit and Finish
Performance
Value