Originally Posted by lovnblack
Thank you for your suggestion. But because of where I live (in Europe very far away from US), Chanes looks difficult option for me. This question still confuse me (sorry for my bad english) :
- now buy an amp which will be enough and good match for your current passive subwoofer, in next months buy an active subwoofer
- now buy an amp which will be enough for your current passive subwoofer and in next months make a DIY passive subwoofer and drive both of passive subwoofers with that amp
Do I need to match both of subwoofer's watt ohm and dB specs and maybe inches too ? (my receiver have 2 subwoofer output) If they need to be match, then by which one catching that match will be easier (with active or DIY passive subwoofer) ?
And if we decide to go on with 2nd passive subwoofer and drive them enough power amp, then cheaper (behringer km750) will be enough? Why Im asking this question again; because I just realized that expensive one looks lower watt output at 4 ohm -its weird-- I really cant understand, can you please check following compare table for them (plz see fan details also) :
It says at 4 ohm cheaper one gives 400W per channel, but expensive one gives 300w per channel. If DSP create that price difference then the question is do I really need DSP or not ? Second certain difference between them cheaper one Class AB, expensive one Class D...its really getting confusing
Please help me to decide...
You are reading the specs correctly, the Behringer KM 750 has more power. One of the reviewers said the fan is quiet, which is a plus for home use. Buying this and making a second DIY sub would be the cheapest solution by far.
Regarding DSP you would not need it if your receiver has room correction, which yours does, but it is a proprietary product that I have no experience with. So I really don't know how good it is. You could always try it, and if it's not great, get something like the minidsp if you want to do your own adjustments later.
A second DIY sub doesn't have to match your existing exactly, but building something similar would make the most sense if you think that would be enough for you. In other words I wouldn't spring for an 18" to match with a 12". If you think you need more output I would go with 2 18"s and dump the 12, or save it for nearfield duty.
Regarding your two sub outs, what you would most likely do is use one sub out to your Behringer input, and run both of your subs off of the same signal. There are times (placement driven) when you might not do that, but that's what you'd generally do.
If you want to pursue powered sub options, let us know your budget, room dimensions and listening habits.