Fluance XL7F Floorstanding Loudspeaker Measurements and Analysis
Impedance / Phase Measurements of the Fluance XL7F
The Fluance XL7F speakers appear to be tuned at around 40Hz, but the saddle points are quite asymmetric. This indicates two things: the system is tuned a bit lower than the driver's resonance frequency and smallish box volume would benefit from, and the midrange drivers running without a HPF essentially lower the impedance of the 32Hz saddle point. I measured the impedance of the MTM and bottom woofer separately and, when combined their parallel equivalent, you get (20 ohms and 9 ohms, respectively) equals 6 ohms. I understand why Fluance did this as they were relying on the real usable bass extension the dual 6.5” woofers provide down to the 50Hz range to supplement the bottom 8” woofer but I caution anyone pairing these speakers with a modestly powered A/V receiver. The impedance dip to 4.5 ohms at 20Hz and 45 degree phase shift from 100Hz to 200Hz can trip the protection circuits in some receivers at high listening levels. I found this to be the case when powering these speakers on my Marantz PM-11S2 integrated amp at very LOUD listening levels. The manufacturer rates these speakers as “4 to 8 ohms” but I’d say calling them 6 ohm speakers would be generous.
Calibrating my measurement system so that it sent out 1 watt into a 6 ohm load (2.44Vrms), I measured system sensitivity and found the XL7F's measured around 89dB 1 watt/meter which is what Fluance claims for this product though they don’t declare at what power level since their impedance spec is rather vague.
XL7F In-room 1/2 meter SPL vs Frequency Response (1/12th
green trace: on-axis; yellow trace: 15 deg off-axis; red trace: 30 deg off-axis
I measured Fluance XL7F loudspeaker with grilles off. The speaker produced generally excellent on/off axis horizontal response +-3dB from 200Hz to 20kHz on-axis with a gradual tapering off above 2kHz off-axis. I measured both speakers and found they measured similarly indicating good quality control between the samples.
Fluance XL7F In-room 1/2 meter Listening Window Response (1/12th octave smoothed)
took a total of 7 measurements (on-axis +-15 deg & +-30 deg
horizontal and +-15 deg vertical) and averaged the response to more
accurately represent what the listener will actually hear. As you can
see, the speaker’s linearity is quite excellent.
did find a peculiar suckout 15 deg up the vertical axis from the
tweeter between 1.2kHz and 5kHz, indicating that perhaps more work
could have been done in the crossover to optimize the response. Though, the dip was somewhat over exaggerated by the close proximity of the measuring mic and typical for what we see measuring multi-driver speakers like this.
XL7F Bass Response (1/12th
Green trace: MTM ½ meter ; purple trace: bottom woofer ½ meter groundplane
I was curious to get a better look at bass response of the XL7F’s so I measured the MTM separately from the bottom woofer. The MTM was measured at tweeter height ½ meter and the bottom woofer was measured groundplane ½ meter between the woofer and port. I level matched the outputs of both as closely as possible to get an idea of how much bass extension the bottom woofer adds. As you can see below 50Hz the bottom woofer really adds significant bass extension to the system (+10dB or so at 40Hz). I did find the crossover frequency of the bottom woofer set too high (around 800Hz). This caused too much combined upper bass energy which at times I felt made the speaker sound a bit boomy. I personally would have liked to see the bottom woofer crossed over at 200Hz and can only figure Fluance chose a higher crossover frequency for cost purposes since it allowed them to use a smaller value filter choke.
Fluance XL7F In-Room THD Distortion Measurement (1/2 meter)
Using the OmniMic system from Dayton Audio, I positioned the mic about ½ meter away from the XL7F’s tweeter to do a frequency vs distortion sweep. This is a similar test to how the NRC does distortion. In my opinion this doesn’t come close to giving you the whole picture on actual audible distortion since it’s a single tone sweep and doesn’t account for modulation distortion if for example a midrange driver is running fullrange without a HPF (like this speaker). This measurement does tell you of any obvious flaws or problems with the speaker system. I drove the XL7F’s at fairly high output (more than my ears could take for any duration of time) and they produced nice clean results as you can see above. If you want to convert the THD to physical #’s you can subtract the SPL sweep (black) from the distortion sweep (blue) at corresponding frequencies and convert the numerical # to a percentage as follows:
|dB Below Test Tone||% Distortion|
For example at 1kHz, the XL7F SPL was roughly 95dB while the THD level was 45dB. 95dB – 45dB = 50dB or 0.316% THD.
Like any budget-minded speaker, compromises must always exist in order to hit a certain price point. The Fluance XL7F tower speaker system is far from being perfect, but it does so many things so right at this price that it’s hard to be too critical of them. From a design standpoint, I would have liked to see Fluance cross the bottom woofer over at a much lower frequency (200Hz instead of the current 800Hz configuration). I believe this would have reduced the somewhat bloated bass response I was hearing with some music. As an experiment, I switched over to my Denon rig and bass managed the XL7F system, biamping and running the bottom woofer crossed over at 200Hz and the MTM at 50Hz. This did a great job at reducing the overly energetic upper bass response and also seemed to improve midrange definition and clarity. The only other real gripe I have with these speakers isn’t related to the speakers at all, but the company itself. Fluance appears to have a little bit of an identity crisis. They are generally not a well known company and visiting their website reveals a rather disconnected product line offering. They currently don’t have matching center and surround speakers for the XL7F towers, but informed me they are in the works. At the prices they are offering their products for, I hope this review gets them their much deserved attention and they also take the time to consolidate their product line and tweak their website accordingly. In my opnion, Fluance needs a "look" and a brand. Right now they come across as a smorgasbord of mismatched products that don't share any sort of design philosophy or company identity.
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Recent Forum Posts:
exlabdriver, post: 975338
Post #19 - a thread on Fluance turns into major brand bashing again…
The post you're alluding too was made 05/15/12….just to set the record straight.
exlabdriver, post: 975350
How many time do we have to see virtually the same post with the same pictures?
It is out there numerous times & in multiple places. Brand bashing at its finest, IMO…
Sorry, I guess I'm not active enough on the forums anymore to catch multiple instances of the same post. Still, is the content incorrect? I'm not trying to take sides, but if the content isn't untrue, it really doesn't matter how many times it shows up.