"" VELODYNE HGS-15:
These two self powered subwoofers are in front of the main speakers and in side firing position.
It crossover at 78Hz. I do some tweaks in the circuit for a better quality sound reproduction and I changed the internal wiring that connects the woofer to the internal amplifier ( 50-60cm ), the original is a very bad zip cord one that I changed with Kimber Kable KCAG that I soldered directly to the woofers and directly to the amplifiers: with no connectors in between.
The power cord comes from Analysis Plus and is soldered directly to the inside subwoofer switch on/off with out no single connector kind ( at both sides/ends of the power cord ) and the IC cable is the Silver Oval by Analysis Plus too.
I change too the internal electrical power wires that goes from the subwoofer switch on/off to the Subs amplifier, I'm using KCAG by Kimber Kable.
Both subwoofers are " seated " over three Van Slike footers/isolators along with inverted Tip Toes ( position ) over these Van Slike isolators, so the subs are around 15-20cm. from the floor. Both subs have a dead-weight ( on top ) of 40kgs.
NOTE: I'm not using the subwoofer internal crossover or an external electronic crossover to send the signal to the ADS L 2030.
The crossover function ( high-pass. ) happens inside the two modified Levinson 20.6 mono-blocks at its input through a WIMA FKP1 cap and a single nude 0.001% Vishay 2575 resistor.
In this way the signal from the preamp goes normally ( pure and clean ) to the 20.6s and to the loudspeaker with out any additional electronic stage or cables/connectors and the signal was taken directly from the Essential 3160 by the Velodynes. ""
That's came from my virtual system details.
Now, there are several advantages/benefits to the room/system quality performance levels when we use two good self powered subwoofers ( for stereo music and at one seat position that is where normally we all listen the system 2 subs are way enough if are good designs and are well integrated to the main speakers. ) but perhaps the more critical an important is that, it does not matters if planar or dynamic speakers as mine, the IMD goes way lower exactly where that kind of distortion makes more harm that's a woofer or planar element handling at the same time frequencies as low as 20hz and intothe 200hz-400hz and even higher frequencie range.
This creates/develops really high IMD including the harmonics of the reproduced signal and this kind of distortions modulates for the bad all the quality sound that goes out side our beloved speakers and not only that but due to that high IMD the THD goes higher too.
When the main speakers are liberated from the bass excursions of frequencies below 80-100hz we can hear it no matters what because the quality improvement is really huge.
You can be sure that in the next example always things will goes as I stated:
if you own ( example only. ) a pair of Wilson Maxx3 that you are handling it through the top CH or Dan'gostino amplifiers those speakers will performs really good but if if you adds a pair of self powered subs crossed at around 80hz the differences for the better will be higher that any MAXX3 owner can imagine it.
This is the other critical and important advantages subs gaves us it does not matters if our passive speakers are full range and this advantage other that the one explained is that now those bass frequencies that are the foundation of MUSIC will be handled by a dedicated speaker designed in specific to mate/fullfil those bass frequencies needs along a dedicated amplifier too that makes the same.
Those MAXX3 never can performs better with out those subs that with them integrated to.
And believe me that difference is almost nigth and day.
R.