- Manufacturer & Model
- Polk Monitor XT70 2-Way Tower Speaker
- $299.00 Ea
Floor Standing Two-Way Speaker
1” Terylene Dome Tweeter
(2) 6.5” Bi-Laminate Paper Woofer
(2) 8” Passive Bass Radiators
89dB Sensitivity (1 watt @ 1 Meter)
Frequency Response 35 Hz -> 40,000 Hz
200 watts power handling
The Polk Monitor XT70 is a lightweight floor-standing 2-way speaker with a simple, inclusive design aesthetic. There is good reach into the low-end provided by two 6.5” woofers and two 8” passive radiators. The waveguide-mounted dome tweeter has a frequency response extending beyond 40K Hz. Relatively sensitive and should be a good fit for use with smaller receivers/amplifiers.
A Story in Three Scenes
Scene 1: Sometime in 1986 – “Window shopping” in a long-defunct brick and mortar stereo shop in Arlington, Texas. I was looking for something new, and I spotted some unusually wide but somewhat shallow speakers. One of the speakers was sans grill cloth, and something struck me as different but interesting.
The speakers in question were a pair of brand-new Polk SDA-2A speakers. The salesman queued up a demo featuring a newly released CD, Harlequin by Dave Grusin and Lee Ritenour. I was literally “gobsmacked” and instantly enamored by the depth, separation, and sheer scope of the soundstage projected by those speakers. The sense of space, air, clarity, and definition was startling.
That same demo also convinced me that the CD format had merit.
I bought the SDA-2A’s ($1000 Pair) that day along with a $900 Sony CD player. I ran to Warehouse Sound in Dallas that same day and bought six of those new-fangled Silver Disks, including Harlequin and Picture Book by Simply Red.
I lived with those speakers for almost ten years and never fell “out of love” with the Polk’s.
Scene 2: Sometime in 1996 - With the proliferation of Home Theater, I started looking for something with more grunt on the low end and purchased a pair of Definitive Technology BP-2000s and a full complement of Definitive Technology Center, Surround, and Subwoofers to match.
Scene 3: Today – During the ten years I owned the Polk SDA-2As, I continued to be very happy and mightily impressed by them. So, thirty-five years later, and after going through three major iterations of speakers, I was offered by AV NIRVANA and Polk Audio the chance to revisit my audio past (kind of :-) and review a different sort of Polk speaker, the Polk Monitor XT70.
The Polk’s arrived via FedEx in relatively good shape. The tall (46” x 19” x 16”) boxes had the usual odd assortment of dings and dents but nothing serious.
The boxes were single-layer medium-duty cardboard, and the fully assembled speakers were capped with soft foam “cloth” toppers and then wrapped in a plastic bag. The captive Styrofoam endcaps tightly held the speakers in place within the box.
The only items in the box besides the speaker were the multi-language manual covering all the Monitor XT series speakers and a warranty/registration instruction card.
The speaker’s appearance conveys a simple utilitarian, industrial vibe with a plain black vinyl wrapper. The full-length black grille cloth is stretched over an ABS plastic frame held in place by twelve cup-in-pin fasteners.
The drivers and the passive radiators stretch from the top to near the bottom of the cabinet. A small “Polk” logo badge adorns the cabinet below the lower passive radiator, and another badge is attached to the full-length grille cover.
The fit and finish look very good and are appropriate for a speaker at this price point.
Construction and Design
The Polk Monitor XT70 is a two-way design featuring a 1” Terylene (artificial fabric akin to Polyester) Dome Tweeter mounted in a shallow waveguide. Two 6.5” bi-laminate paper woofers handle the critical Mid-range and Bass. The bass is further reinforced by a pair of internally air-coupled 8” passive bass radiators.
The Slender 9.25” Wide x 40.4” High x 12.5” Deep 35-pound cabinet is constructed of machined MDF. A hard rap with the knuckles, or my little rubber hammer, applied to almost anywhere on the cabinet surface produced a substantial ringing and a distinctly hollow sound.
Removing one of the 8” passive radiators revealed sides, back, top, and bottom of what appears to be ½” MDF and a front panel of slightly heavier 5/8” MDF. The attached base is constructed of ¾” MDF. All internal corners and side bracing are glued in place.
The cabinet contains a strip of Dacron (Polyethylene Terephthalate) batting for damping material. In addition, all wires were enclosed in a “Techflex” type of material. I’m assuming this is to minimize/eliminate any noise or abrasion caused by the possible movement of the wire bundle.
The simple 2-way crossover splits the frequency spectrum at 2700Hz (specified by Polk as the acoustic crossover point). While the topology of the crossover was not named, Polk stated that the low pass (LP) part of the crossover is designed to approximate the sharper roll-off (on the upper side) of a 4th order crossover to eliminate the possibility of lower frequencies destroying the tweeter. The crossover components seem to be of good quality and commensurate with the speaker's price.
The only component on the rear of the cabinet is a sturdy recessed plastic cup holding the 5-way, plastic capped, nickel-plated binding posts, the model number, and the speaker’s serial number.
Setup was straightforward, with the Polk XT70s replacing my usual right and left speakers. The speakers were toed-in, with the projected sound field crossing just behind my seating position.
I ran a full Audyssey calibration to dial in the speakers. As per my usual SOP, I initially limited the effect of the Audyssey calibration to 300Hz and under.
I sat back and gave the speakers a solid two weeks of run-in to acclimate the speakers, my ears, and my brain.
Using my UMIK-1, MacBook and REW, I made my standard set of measurements, with and without subwoofers in the mix, from 1 meter (Figure 1) and again at the listening position (Figure 2). All measurements were performed with the XT70’s running “full-range” and the Audyssey correction turned off (unless noted otherwise). The frequency range tested was 6Hz to 22.5kHz.
Disclaimer: Please note that my room is NOT an anechoic chamber or even a “quasi-anechoic” chamber. It is a minimally treated but revealing room that affects the overall measurements. All measurements supplied should be looked at with this caveat in mind.
From One Meter – (Figure 1 below) At the one-meter measuring position, the SPL vs. Frequency response shows a reasonably flat curve with no surprises. There is a gentle rise starting at 3kHz to about 14kHz, and then a gradual roll-off as the frequency continues beyond audibility. This curve indicator is a good indicator of extended high-end response. The low-end response is solid to around 40Hz with a fairly sharp slope and no real usable energy below 30Hz.
From the Listening Position – When moving to the listening position, the measurements (Figure2) told an interesting story. Measurements showed a bit more of a roll-off of the high frequencies starting around 10kHz than some of the other speakers recently tested in the same room.
With most speakers using dome tweeters, this would not have been too much of a surprise. However, since the XT70 utilizes a dome tweeter mounted in a waveguide, it was a bit puzzling. This test result leads me to have some doubts about the effectiveness of the waveguide, but results will undoubtedly vary depending on placement and room characteristics.
I re-engaged the correction program to see if Audyssey could fill in the upper end a bit. Running the correction full-range and using the Marantz Audyssey MultEQ app, the generated curve was edited/corrected to remove the normal Audyssey “dip” on the high end. The measured result was a much flatter curve (see Figure 3), indicating the tweeter could easily supply an extended high-end into my room with a bit of correction/help to overcome my normal room shortcomings.
A comparison of the bass response from the listening position vs. 1-meter (Figure 4) shows a smooth response curve with substantial bass energy starting around 50Hz. Polk lists “total response” in the specs as 35Hz to 40kHz. I see some bass energy at 35Hz, measured at the 1-meter mark, but very little at the listening position.
Off-Axis Response (Figure 5) – Going back to the one-meter position, I checked the off-axis response at 15˚, 30˚, and 60˚ from the on-axis point.
These measurements tend to confirm the expected beaming characteristics of the tweeter/waveguide combo.
No ± parameters were given for Polk’s frequency response claim of 35Hz to 40kHz. At one meter, I measured about a 24dB drop at 35Hz from the peak average of 74dB, and the high-frequency response remained essentially flat out to the practical limit of my measurement equipment (22kHz).
After two solid weeks of acclimation, I gathered the usual suspects together and began my evaluation.
Starting with the speakers running full range and the Audyssey correction constricted to 300Hz and below, I ran initial selections with Subwoofers off and then on.
First, I queued up the same CD that convinced me to purchase the Polk SDA 2A speakers those many years ago, the 1985 release of Harlequin from Dave Grusin and Lee Ritenour. This Grammy-winning recording offers lush and airy soundscapes that the right speaker can convey into the room. The Polk Monitor XT70 did a respectable job of bringing some of that airiness and lushness embedded in the recording but fell short in terms of the size and scope of the soundstage that I knew could be there.
The High-end was smooth, sweet, and present. Mid-range was clear and present with no hint of a bump or dip at the crossover point of 2,700Hz (the frequency response charts above reflect this as well). Low-end was well represented as solid, present, and reasonably tight. This presentation held up at lower and mid-level volumes, but higher volume levels didn’t fare quite so well. When pushed to more extreme volume levels, things started to compress, becoming a bit congested in the upper bass and tubby in the lower bass. Mid-range also became significantly more congested and constrained sounding. However, the high-end held in there and remained sweet and accessible at any volume.
Returning the speakers to “Small,” setting the crossover to 80Hz, and reinserting the subwoofers into the mix improved on everything above. With the subwoofers engaged, the soundstage became more open and less compressed, and the XT70s just seemed to “breath” a little easier. In addition, the speakers were able to operate at any reasonable volume level and maintain a pleasing, listenable presentation compressing only slightly at “bordering on insane” levels of volume.
Starting with the XT70’s running full range and the subwoofers off, I turned to Amazon Music Ultra HD for a quick listen to one of my go-to tunes that feature punishing bass. The Primus bizarro tune from the Pork Soda album, “Bob.” The unassisted Polk Monitor XT70s did well enough at low and moderate volumes, providing a measure of punch in the bass regions. However, the speakers fell apart at the telling higher volumes, and the bass became a globby mess. The “mess” was cured by, once again, returning the speaker setting to “small” and reengaging the subwoofers into the mix.
Next up was another CD purchased long ago, the 1985 inaugural release of Simply Red’s Picture Book. This album is another excellent recording with a stellar studio sound loaded with lots of space and “air.” Like the Harlequin CD, the Polk speakers conveyed a good portion of the desired soundstage, with a good balance and clarity at lower to mid-level volumes, falling a bit short only at higher volume levels. Adding the subwoofers back into the mix had the same effect as before, fixing, to a large extent, the issues previously noted.
I turned to two Windham Hill samplers to get a handle on the more delicate side of things. The 1987 release of “New Electronic Music” Soul of the Machine, and 1985s Windham Hill Records Piano Sampler.
Both recordings feature tons of studio-generated “air” and “space” and are well recorded and presented.
I sampled the first three tracks from the synthesizer-based Soul of the Machine. “Rizzo” by Mitchel Forman, “Time and the River” by Fred Simon, and “Water Trade” by Michael Whitely.
Each selection was rendered with good space and weight through the Polk speakers recreating the studio sculpted synth tunes with a solid center image and believable space and soundstage, but something was missing.
As in the previous selections, the bottom-end and imaging suffered and were only cured, in large part, by inserting a low-frequency crossover point and returning the subwoofers to the mix.
With a much clearer picture of the XT70s limitations, I decided all further listening would be with the speakers in the “small” mode while keeping the subwoofers in the mix and the crossover at a hard 80Hz.
After deciding to keep the subs in the mix, I listened to the piano music from the Windham Hill Records Piano Sampler CD. Sampling the selections “In Flight” by Michael Harrison, “Amy’s Song” by Peggy Stem, and “A Morning with the Roses” by Richard Dwarsky, the speakers presented the solo piano music with clarity and good weight. In addition, the top-end of the XT70 was clear, smooth, and warmly rounded, the mid-range was cleanly and concisely presented, and the bottom-end (subwoofer reinforced), when present, was full with appropriate weight and feel. Overall, the XT70s recreated the oft-hard to render full-range piano sound with warmth and appeal.
Switching to SACD and 5.1 Surround Sound, I sampled music from Nora Jones’s atmospheric inaugural release Come Away with Me and Pink Floyd’s effect-laden Welcome to the Machine.
When the surround was used as ambiance in the recording, the Polk’s sounded fine, blending well with my in-wall BG Radia SA-320 surrounds. However, when the surround channels were used as primarily effects points, hardpans highlighting specific instruments, noises, or effects, the XT70’s presented in a different timbre than my BG planar ribbon surrounds. If using the XT70s in a surround scenario, this timbre mis-match issue could be fixed by simply using timbre-matched Polk speakers for surround duties.
Video and Home Theater
Surprisingly, the timbre matching difference noted while listening to surround music didn’t present any issue with video and movie watching. The Polk XT70s performed well as my surround system’s right and left speakers.
Accuracy is not as important, in my opinion, at least for surround movies. Instead, I’m happy with a speaker that presents with excitement, dynamics, and clarity. The Polk Monitor XT70 speakers were just fine in that aspect.
I watched several episodes of season two of The Witcher on Netflix using my Apple TV 4K. The sound is Dolby ATMOS encoded with lots of atmospherics and subtle placement cues to the sides, and even overhead. The Polk’s, in this case, blended well with my side and rear surrounds and my overheads (Polk RC60 in-ceiling), and the effects tracked well around the surround sphere. Dynamics were very good at any level of volume.
The only speaker that the Polk XT70 failed to blend well with was my center channel, a BG Radia CC-220 featuring a planar ribbon tweeter and mid-range speakers working with conventional woofers and changing the Audyssey range on the center channel to “full range” fixed much of this issue. Swapping the BG for a Polk Monitor XT35, also on hand for review, "fixed" the balance/timbre issue but created a slightly different problem. The XT35 proved to be too small for my room and was not a good match for my system.
Next up were two episodes of the new series Hawkeye on Disney+. Again, this series is in Dolby ATMOS, and the surround cues and dynamics were well presented and tracked well.
Continuing with Disney+, I went with Jungle Cruise for a movie. Jungle Cruise was a fun ride using the Polk XT70s. This fun, sometimes silly, film presented well through the Polk’s with good dynamics and a solid connection to the visuals.
Listening in two channels to some YouTube talking-head style channels proved informative. As you may well know, the quality of this type of content is all over the map but can tell a story with many speakers. In this case, the Polk’s were not very forgiving, and even the better-quality YouTube content sounded chesty and congested with most content. With lousy YouTube content, it was considerably worse, and intelligibility suffered.
Summary and Closing Thoughts
These are, without a doubt, interesting speakers. They can easily stand on their own at low to medium volumes. They have a decent low-end with a good clear, smooth high-end with no harshness or ugliness evident. The mid-bass/lower mid-range is good but somewhat congested and tubby. Male voices (spoken word) suffer a smidgen when predominant. The Polk XT70s came off as a bit rounded and warm in the upper-mid-range and on the high end in my room. The speakers also seemed somewhat compressed and underwhelming at higher volumes when unassisted by subwoofers.
These are clearly speakers that operate better with subwoofers, and unfortunately, they fall flat in a large room and at higher volumes without some help. But that is OK. Most will naturally pair them with one or more subwoofers if used for home theater duties anyway.
But! And this is certainly a BIG BUT! They cost only $299 each!
So, please do not take this review as an actual criticism of the Polk Monitor XT70s! I am not “talking smack” or truly disparaging this speaker. In general, I am OK with a warm and rounded-sounding speaker. Many speakers are voiced with that characteristic in mind. Think thirty years ago, and it used to be that “warm” was a highly desirable and sought-after sound signature. Today, in our search for new speakers, we first look for a hyper-extended upper-end response in the specs. We prefer things crispy (or at least think we do...)! Can you have both high-end extension and warmth? Yes! Many speakers are still created and voiced with that desirable characteristic in mind.
And, keeping in mind, I was directly comparing this inexpensive speaker against my current reference speakers costing over 12.5 times more, and something becomes even more evident. These speakers are an extraordinary value and performance level, for $299.00 each!
So, did these speakers take me back to my fond memories of my Polk SDA 2A speakers in the past? Well, No! But should they? Again, no, not really!
Those same one-thousand dollars per pair of SDA 2A speakers would cost $2,580.00 in today’s money. So, you could buy five pairs of the XT70 today with that money (they are currently on sale at the time of this writing for $249.00 each). Also, considering that the XT70s are conventional speakers and are being compared to some rather revolutionary technology of the time the SDA 2As were manufactured (1980s SDA – Stereo Dimensional Array), they came off pretty well.
Interestingly the most expensive speaker Polk is now selling is a modern retelling of the SDA technology from the ’80s, the Polk Legend L800. The Legend L800 costs $2999.00 each and weighs 118 pounds featuring an updated and rethought version of the Polk patented SDA technology, SDA Pro®.
While the Polk Monitor XT70 speakers perform well with music or home theater, I think their strongest potential performance area is in home theater. Of course, they will need subwoofer support to realize their full potential. But given subwoofer support and they will perform admirably well within the context of home theater.
So, do I consider them comparable in performance to audiophile or home theater aficionado speakers exponentially higher in cost? Well, of course not! That is not what they are intended to be. Instead, the Polk Monitor XT70s are high-fidelity speakers at a friendly budget price.
Many consumers will be happy with the Polk Monitor XT70 as the heart of a low-cost home theater starter/family system or a bridge music system considering that they punch well above their comparative cost point. Sum everything into the equation, and I think they would easily work in many situations. I can easily recommend them for budget home theater systems or that weekend music system at the little cabin in the woods.
Polk offers excellent service with five-year parts and labor warranty.
Specifications: Polk Monitor XT70 2-Way Floor-Standing Speaker
- Driver Complement
- 1 – 1” (2.54cm) Terylene Dome Tweeter
- 2 – 6.5” (16.51cm) Bi-Laminate Paper Woofers
- 2 – 8” (20.32cm) Passive Bass Radiators
- Crossover Frequency: 2,700Hz (specified by Polk as the “Acoustic Crossover Point”)
- Sensitivity (1 watt @ 1 meter): 89dB
- Total Frequency Response: 35 – 40kHz
- Impedance: Compatible with 4 Ohm and 8 Ohm outputs
- Recommended Amplifier Power Per Channel: 25 watts to 250 watts
- Width: 9.25’ (23.5cm) - Height: 40.4” (102.6cm) - Depth: 12.5” (31.8cm)
- Weight: 35lb (15.88kg) Each