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!