Power Sound Audio XV15 Subwoofer Measurements and Analysis
The XV15 was placed outdoors in a large field with the nearest large objects a minimum of 60ft or greater away from it, with the amplifier and port facing towards the microphone and the driver down firing as per normal orientation in room. The LFE input was used and the measurement microphone was placed on the ground at a distance of 2 meters from the nearest enclosure face of the XV15 and pointing directly at it unless otherwise specifically noted for all measurements. For more info on the testing equipment and procedures please see the article here.
Power Sound Audio XV-15: Effect of Low Pass Filter Settings
Above are measurements of the Power Sound XV15 with various settings of the internal low pass filter. Minimum, maximum, bypassed and at settings on the dial that correspond to the 9, 11, 1 and 3 o’clock positions on a clock. The filter roll off corresponds to about 45Hz at the minimum and 150Hz at the maximum settings and a roll off of 24dB/octave. This is a plenty wide range to accommodate most situations if the low pass filter in the subwoofer needs to be used.
Power Sound Audio XV-15: Basic Frequency Response as Tested
The response shape of the XV15 conforms pretty closely to that shown in the manufacturers graph but has a slight hump in response centered at 80Hz which is not present in theirs. This may be due to production variance in the drivers in the subwoofers or measurement and equipment differences. It is hard to know. Regardless it is not a large enough difference to be concerned with. Overall the response shape as measured here fits within a 6dB total window from 21-200Hz matching the listed spec exactly. The blip in response just above 200Hz is likely to be the port resonance. The response gradually and slowly trails off on the bottom end until about 7dB down at 18Hz and 10dB down at 16Hz. This response shape indicates that the subwoofer can be used low passed as high as 150Hz or potentially even higher if needed and that typical room gain should counteract the shallow roll off towards the low end to produce a flatter response. Indeed response to the 16Hz range in room is quite probable.
Power Sound Audio XV15: Group Delay
Power Sound Audio XV15: Water Fall Decay
The group delay plot for the XV15 shows good behavior with less than 1 cycle of delay until below 20Hz where it just breaks the 1 cycle mark at around 16Hz. It is very doubtful that anyone would be able to hear small differences in delay at such deep frequencies so the increase below 20Hz is of little consequence. Looking at the data presented another way in the waterfall plot indicates that the XV15 exhibits clean and rapid loss of 25dB of energy over most of its bandwidth within the first 150ms. As seen in the group delay plot the port tuning and high pass filter produce a little delayed energy below 25Hz. However the XV15 is rather well behaved in this regard compared to many other bass reflex systems.
Power Sound Audio XV15: Long Term Power Compression
Running the XV15 through the gauntlet of long term output compression testing provides the results in the graph above. The XV15 maintains excellent output uniformity through the 105dB sweep with less than 2dB over most of the range, but the 110dB sweep shows notable compression in the deep bass and signs that the limiter may have kicked in. This being a new product from a new company entering the market I wanted to see if they had done their homework with the protection circuits so the level was increased a further 5dB and a 115dB sweep was attempted. It resulted in little extra output indicating that the sub was clearly giving all that it could but otherwise it operated as normal and was unharmed. During the 110 and 115dB sweeps there was some port noise noted during the sweeps and the driver made a few grumbles during the 115dB sweep. This may have been the limiter heavily intervening near the port tuning as you can see the loss in output compared with the 110dB sweep near 18Hz. Otherwise there was no cabinet vibration or rattles and the XV-15 was inert throughout the testing. The XV15 exhibits substantial output during this test with roughly 110dB available from 40-90Hz and protection circuits that prevent any damage to the system from over-zealous knob jockeys.
Note on Output Compression Testing: This is by far the most demanding measurement type conducted on the subwoofers during our testing and will reveal any issues with overload, port compression, port noise, driver distress, creaks, rattles, buzzes, etc. Additionally the test is conducted outdoors with just the subwoofer operating so there will be no nearby walls or objects to vibrate and no upper frequency content from other speakers in operation. These would normally help to cover up or mask any objectionable noises from the subwoofer in a typical room. Any sort of audible distress or issues with the subwoofer are readily apparent in this environment.
Power Sound Audio XV15: Output Compression Magnitude
Looking at the only amount of compression exhibited by the XV15 during the compression testing it again can be shown that the sub was linear up through the 105dB sweep but was out of output completely by the 115dB sweep. The largest compression occurs near 18Hz and combined with the behaviors seen in a few other tests indicates that this is likely the tuning of the vent system in this subwoofer. Some compression of the output near vent tuning and a bit of port noise at full output is not unexpected with a single 4” port tasked with coping with a long throw 15” driver. However the flaring helps out a lot and other than with the certain scene in the movie Pulse I never heard any port noise during listening.
Power Sound Audio XV15: Total Harmonic Distortion
Power Sound Audio XV15: Distortion by Component
The distortion results for the XV-15 are shown above. THD is under control during the 100dB sweep and is under 10% over the subs entire useful range. By the 110dB sweep where the unit is being pushed very hard THD has grown drastically and reaches about 30% at 20Hz and 15% or more near 100Hz. However over the critical 25-80Hz bandwidth THD is still well below 10% for the most part. Looking at the component makeup of the distortion reveals that the THD is primarily composed of the second harmonic over virtually the entire bandwidth of this subwoofer. The general belief is that the second harmonic is the hardest to hear and the least offensive to the ear.
Power Sound Audio XV15: CEA2010 2 Meter Groundplane RMS Results
Power Sound Audio XV15: CEA2010 2 Meter Groundplane RMS Graph
The CEA2010 burst testing results for the XV-15 indicate that it offers a substantial amount of headroom for this price class of product. At 10 and 12.5Hz a passing output could not be recorded but at 16Hz the XV15 mustered up 98.1dB and at 20Hz 102.7dB so the XV15 has credible deep bass output capabilities into the 16Hz range. In room this output will usually see some positive reinforcement as well. From 31.5 to 100Hz the XV15 produces roughly 110dB or more. At 50Hz an SPL of 116.6dB which is getting to be loud indeed was recorded. The distortion profile follows the same trend as that shown in the distortion charts with increased distortion in the deep bass and around tuning and above 80Hz.The XV15 CEA-2010 output is amp limited from 25-125Hz and essentially is at 16 and 20Hz as well as the output meets the distortion thresholds at right about the same time as the limiter circuit clamps further increases in output. Power Sound tests their subs for CEA-2010 output internally and lists some of the information on the website. Comparing the averaged CEA-2010 output measured over 20-31.5Hz and 40-63Hz with that listed by PowersSound, shows that their listed results are a little higher, but still within 1.5dB which is well within the margin of error due to variance in: Production, equipment, calibration tolerance and atmospheric conditions.
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Recent Forum Posts:
billy p, post: 1048418
Yeah… the standard finish is quite nice, I've seen it in person….much nicer IMHO than the traditional flat or faux black finish you often get on competitors products. Curious to hear read your thoughts once you have it all set up.
Just a FYI, we can send out samples of the wood veneer AND the Black Satin free of charge. Just send me a note to one of our email boxed.
Power Sound Audio
Well I got the sub (very fast shipping BTW!) Here are some photos of the unboxing. While it was not double boxed it seems to have travelled well.
Congrats on the new sub…
Anyhow I was greatly impressed with the knowledge from the Chat person (can't recall the name).
Looking forward to picking my PSA sub, receivers (Denon AVR X-4000 and X3000) and my Panasonic projector (PTAE8000) up from the local Fedex store tonight!