Options for a transparent sounding splitter for the subwoofer needed

[living sounds]

I've got a new subwoofer (Adam Sub8) and don't like what it does to the signal passing through it (85db filter on or off). There's a loss of detail and some annoying midrange aggressiveness added.
Would a simple Y-Cable work to avoid the signal going to the mains passing the subwoofer (where I guess it is forced through something like TL72s)? Or is there a good way to DIY a passive splitter using transparent transformers (Lundahl?)?

Thanks for any suggestions!
Gregor

 

[living sounds]

Anyone?

 

[Sleeper]

There are some very nice Jensen and Cinemag trafos that will split a signal very transparently (and I'm sure Luhndahl makes one too)  They are on the higher end of the cost scale. 
Some people just use a Ycable and are fine with it. 
The transformer is going to have a small bit of insertion loss and it's going to sound like the transformer (which in the case of Jensens, Luhndahls, Sowters and Cinemags or UTCs or whatever) is good. Oh yeah, and it's overkill.
I'm actually using a transformer to split with one side feeding my monitors and the other my AD.

If your input impedences are fairly high you should probably just Y cable it.  BUT...Once you split it there you lost the crossover in the subwoofer package.  This will work fine, but you should adjust the response of the sub to cross over with the real roll-off point of your monitors. Works best if you have an RTA (because the speakers are going to roll off a little bit differently based on where they are installed in your room) but you can do it OK by looking at the frequency response curve of your monitors.
Sleeper

 

[living sounds]

Thanks Sleeper!

I'll try the Y-Cable first. Those are all line connections, but there is a passive attenuator inbetween. We'll see. Having the low-cut would be cool, but I absolutely hate what the sub does to the signal. Where's the point in getting good converters when the signal has to pass what are probably some JRC5XXX opamps before you hear it?
Good transformers might be an option, but I prefer to have the monitoring as uncolered as possible.

Could try and build a passive high pass filter myself, using good components like Wima metalized polys...

And there's a helmholtz resonance box to be build for the sub to really show it's potential.

So much DIY...

 

[Sleeper]

Maybe this would help your rolloff
http://www.muzique.com/schem/filter.htm
http://hyperphysics.phy-astr.gsu.edu/hbase/electric/filter.html#c1

 

[living sounds]

Thanks!

 

[living sounds]

So, I finally made the Y-cable (took some time with all the other projects). Works great! Finally the detail is there again! I've also had a look inside the A7, and the small board is stuffed with JRC5*** crap opamps. And the same cheap chinese poly caps I've seen in the condenser mics. I probably won't risk modding it, but it's sorta tempting...

 

[1954U1]

Gregor,

I am in your same boat.. 
I too have a sub8, and was thinking of doing the Y cable split,
and modding the sub so the [remotely adjustable via IR] pot  will work
only with a cap in a passive lowpass RC filter, no further things done to the audio signal.
Or try to change also the pot with a better quality one.

Is this a stupid idea?

 

[living sounds]

Gregor,

I am in your same boat.. 
I too have a sub8, and was thinking of doing the Y cable split,
and modding the sub so the [remotely adjustable via IR] pot  will work
only with a cap in a passive lowpass RC filter, no further things done to the audio signal.
Or try to change also the pot with a better quality one.

Is this a stupid idea?

I haven't looked inside the sub, so I don't really know what is going on in there. I don't care that much about signal degradation on the sub's side, since in my case it's only very low frequency audio (below 50-60 Hz) so fast attacks and low distortion don't really matter that much. I don't see much point in changing the pot really. I can say that using the Y-cable and no filter on the A7s sounds way better than going through the sub with the filter engaged. The amount of clarity and punch that is lost in the sub really makes me wonder about how to improve the active filter/amp in the A7...

 

[living sounds]

Stupid question: Would there be an impact on impedance if I just used a 1:1 line transformer for the y-cables way to the sub (where quality doesn't matter much) but still feeding the nearfields directly?