Added a subwoofer to Audioengine A2 but now I hear distortion in certain songs

[leoblack9]

Hi guys, I'm leo and I've been a long time lurker here at this forum.
 
I'll get straight to the point - I've hooked up my trusty A2's to a Velodyne VA 907 using the subwoofer's built in crossover (at 120hz) to help alleviate the A2's notorious bass issues. Right from there I've noticed a dramatic change in the sound coming from the A2--I've experienced an increase in ear fatigue while listening to them (I use them as computer speakers, arm's length max) and a noticeable distortion (crackle sound) in heavy rock (3:53 onwards  in This will Destroy You - Threads, here the sound of the cymbals are just drowned out by the crackle) and in other heavily layered songs with synthesizers in it.
 
This setup, however, played simpler songs reasonably well -- contemporary pop songs, bass-laden edm (party music) and surprisingly it plays classics phenomenally well (Queen, AC/DC, Led zeppelin to name a few), the songs would just feel alive, wow.
 
Now I've never experienced fatigue while listening to A2's on their own before so this is a new thing for me. I've set the audio knob on the A2 on the 12'o clock position and at 7'o clock at the Velodynes (6'o clock position is the lowest). I control the sound level via the computer audio mixer and connected the sub from the built in soundcard from the computer via a 3.5mm connector to RCA cable. I could not go beyond 25 in the computer's audio mixer without experiencing said fatigue, 50 is already enough to fill the whole room (and my room is barely 4x4 meters).
 
Right now my setup is a mess but I'll sort that out soon enough -- I'm trying to find out first what's causing the crackle / distortion here. I've singled them out to the ff.
1. The recording and compression of the song
2. Connectors - Cheap cables that came from home theater systems
3. Source - Built-in soundcard
4. Bad sub amp
 
If it is the recording of the song I would then resort only to high fidelity format versions of the song (flac/wma)
If it were the connectors I'd buy better quality audio cables (I'm vying for the Quiklock rca cables at the nearby audio shop)
If it is the source - I'd test it with another source that is not a computer (like a cd player), but I have none of those at the moment so I would buy an DAC/ODAC immediately - Audioengine D1 or a JDS labs ODAC is something I've been having in my mind.
And if it was a bad sub amp, I have to bid farewell to this sub then.
 
Could anyone chime in with a similar setup? I've never found anything extensive regarding the VA 907s considering it is a 20 year old sub but I bought it because it had quite a reputation at its time and quality audio gear lasts ages. I'd appreciate any form of comment or insight, I'm purely using this setup for music listening, light movie viewing with the occasional video editing.Thanks

 

[PurpleAngel]

Your assorted audio is really not designed to work together.
And I'm not the expert.......but.
 
The on-board sound card does not have a 2.1 output setting,
it does have a 2.0 or 5.1 setting, either setting really should not work with the connection you are trying.
 
I would say to try running a connection from the on-boards sound card''s Front Speaker jack to the line-output (RCA) jacks on the Audioengine A2+
Then run a connection from the A2+'s line-output (RCA) to the line-input (RCA) on the Velodyne's
or run a connection from the on-board audio (Front Speaker), to the RCA inputs on the Velodyne, then run a connection from the Velodyne's RCA output, to the RCA inputs on the A2+
With both setups, set your on-board audio, in the control panel, to 2.0 Speaker.
and use the controls on the Velodyne to balance the sound.
see if one setup works better then the other.

 

[leoblack9]

  Your assorted audio is really not designed to work together.
And I'm not the expert.......but.
 
The on-board sound card does not have a 2.1 output setting,
it does have a 2.0 or 5.1 setting, either setting really should not work with the connection you are trying.
 
I would say to try running a connection from the on-boards sound card''s Front Speaker jack to the line-output (RCA) jacks on the Audioengine A2+
Then run a connection from the A2+'s line-output (RCA) to the line-input (RCA) on the Velodyne's
or run a connection from the on-board audio (Front Speaker), to the RCA inputs on the Velodyne, then run a connection from the Velodyne's RCA output, to the RCA inputs on the A2+
With both setups, set your on-board audio, in the control panel, to 2.0 Speaker.
and use the controls on the Velodyne to balance the sound.
see if one setup works better then the other.

 
Thanks for your input PurpleAngel. Yes to a degree you are correct, these devices were made in different periods. I doubt the Velodyne engineers envisioned their sub being used in conjunction with small speakers like the A2 in nearfield listening.
 
I've used this method of connection because this is how the Audioengine engineers designed the A2 when being used with a sub. Their S8 subwoofer unit was meant to be wired this way when used with the A2's, that is source -> subwoofer (via line in) -> A2 (via line out / crossover).
 
I want to avoid feeding the A2 the full range of the audio because of its mid-bass amplification which causes its low end distortion (which is mostly a physical limitation) so your advice on connecting it through different outputs on the computer is out of the question.
 
edit:
I tried using my laptop as a sound source, the crackle is much less from the said heavy rock song. Is it the source? Or is it because the speakers / sub combo was simply cool enough, since I just woke up and its morning here. My laptop also doesn't have any form of equalization which my desktop did have which could have brought out the crackle as well.