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Using SUBWOOFERS internal crossover...

Just this week, I decided to try this hookup with my system. Pre out to sub line in....sub high pass line out to power amp. Power amp to speakers.

Schiit Freya preamp / VTA ST120 Dynaco Tube / Node2i / Gustard X16 DAC / KEF LS50 Meta / SVS 1000 subwith line in / high pass line out....

Feeding the signal through the sub and back to the power amp totally destroyed the sound imaging and stage of my system.

Large symphony music became small symphony music pieces. Piano solos lost all the air around the piano. 

On one particular track, Rolling Stone "Symphony For The Devil".....When the power amp is directly into the LS50 speakers, the piano is way right of the right speaker. Its so freaky that you would swear there is another speaker to the right of you. 

When the signal is routed through the subwoofer, the piano moves TO THE LEFT of the left speaker and seems to be coming from behind the stage! a total reversal of the image! And huge collapse of sound stage.

I tried it back and forth many times. Checked and rechecked my wiring. Used the PHASE control on the subwoofer in every conceivable position (Its variable on this subwoofer)...And the results are always the same. I had three other people listen to it to be sure it wasn't MY ears playing tricks on me.

I'm totally convinced that taking a great audio signal, and routing it through yet another piece of equipment and then back into the power amp and to the speakers is a bad idea. At least on this sub it is.

I have  "barrel" RCA  80Hz High Pass filters that I can insert before the power amp feeding the LS50s......This does not do anything to imaging or sound stage....but with LS50 it muddies up the upper bass. The LS50, IMO, want to be played full range with a subwoofer and let the natural 50Hz roll off play into the sub with the sub crossed over at 70Hz.....Not so with my Magnapan MMGs....They love the bass totally removed under 80-Hz with these barrel connectors......But using the subwoofers crossover the same sound stage and imaging destruction exists....

Different speakers want different subwoofer set ups.

anyone else experience this situation?

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rbertalotto
bdp24's avatar
bdp24
9,964 posts
 

@rbertalotto, I believe the m7-hp is for use with the Vandersteen amps and Model 7 loudspeakers, themselves rather expensive. Richard for years offered a much simpler and cheaper version for use with his Model 2 loudspeakers and subs. That version often comes up for sale used for a few hundred dollars.

Roger Modjeski of Music Reference was making a simple passive 1st-order x/o for a very reasonable price, but he passed away a few years back. If you can solder, Danny Richie at GR Research will sell you the parts you need to make the same thing yourself. Just a cap and resistor in most cases, which you can either install on the input jacks of your amp powering the loudspeakers (inside the amp), or put in a little box with input and output jacks. He just needs to know the x/o frequency you desire, and the input impedance of your amp.

rbertalotto OP
138 posts
 

Thank you! Very helpful...

 

ozzy's avatar
ozzy
7,542 posts
 

The old phrase "it's only as good as the weakest point" applies.

Run your main amps direct. Do not run them off of your subwoofers! Use a Y cable from your preamp if you must.

I use the JL Audio CR-1 crossover.

ozzy

 

musicaddict
372 posts
 

I need some help here on the concept of ‘Y’ ing out the signal to two different devices.

I have tried to Y out from the pre-amp to the left input of a DSPeaker unit as well as to the two left subs. Then I ran the Y out from the preamp to the right input of the DSP unit and to the right side subs (mere convenience).   BUT I am getting some type of feedback to a mono signal though my main speakers with this set up. It may be the DSPeaker unit but how can I cleanly feed it, and subwoofers from the single pre-amp output provided? I was using simple dual adapters (one male, two female plug).

For now I’m forced to run the entire audio-band through the DSPeaker and then Y out to the power amp and the subwoofers to maintain stereo main speakers. I really wanted to high pass the Raidhos as they have sufficient help down low with a DBA setup. But, on their own, those D2s will try to play near flat at 31Hz and that’s a waste of energy that I’d like really like to free up for the upper ranges.

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