Which is the best avenue for powering a passive sub?

[suttondesign]

I'm building a passive subwoofer. I am debating between using a MiniDSP 4x10HD with a plain-vanilla, used outboard amp versus a good subwoofer plate amp with lots of control flexibility. The sub will be incorporated into a speaker setup already dependent on a MiniDSP 2x4HD, which I would replace with the 4x10HD if I go with the MiniDSP option.

Which is the better choice? I keep leaning to the MiniDSP system since I can upgrade just the amp later.

 

[Lorenzo74]

Seems a nice idea but why not making the extra mile pointing to a full band active stereo speakers with digital Xover?

you can play with minidsp 2x4HD, Adding two purifi 6.5 and two seas DXT or Blisma t25(A,S,B depends on budget) and I believe you have top quality set 30-20kHz: no subs regret.

or if you want to keep your speakers just add 2 subs passive or active depends on how much time you have to invest on it keeping 2x4HD.

the minidsp 10HD is (IMHO) for HT or multi way active stereo speakers.
what do you think?
My Best
L.

 

[suttondesign]

In effect, I am using multi-way active stereo speakers -- Linkwitz LXmini, requiring 4 channels of amplification. I just finished building them, so they are there to stay. To add one more channel for a sub requires a step up to a 4x10. That would make the whole rig an active, three-way system, in effect.

 

[jhaider]

No plate amp is going to be as flexible as miniDSP. I prefer that way because you can later use both processor and amp for another purpose.

 

[somebodyelse]

Since you're already DIYing things, the FusionAmps come pretty close to being as flexible as the miniDSP and a separate amp since you can take the amp and DSP boards off the plate and box them separately later. It seems like a marginal call to me though, and probably depends on your priorities.

I assume you're not going for any of the usual Linkwitz subs since both the open baffle and linkwitz transform are outside the capability of generic sub plate amps.

 

[misterdog]

No plate amp is going to be as flexible as miniDSP

Apart from a mini DSP plate amp.

https://www.minidsp.com/applications/plate-amplifiers/209-pwr-ice125-subwoofer

I use 2 x 12" subs from the 500W plate amp.

https://www.minidsp.com/products/plate-amplifiers/pwr-ice250

All controlled from my laptop, via ethernet.

Superb.

 

[suttondesign]

Hey, I didn't know MiniDSP even had those! The 125 is a steal.

 

[misterdog]

Why more people do not use them for subs I have no idea, though as you say many probably do not know they exist.

 

[jhaider]

Hey, I didn't know MiniDSP even had those! The 125 is a steal.

Note they sell backboxes for them too, so you don't have to mount them inside the cabinet.

 

[suttondesign]

I saw that. Fortunately, I can just save the money and just screw one to a plywood panel which conceals the other amps located under the stairs. Makes it easier for me to plug into the ethernet port on the plate amp too.

 

[suttondesign]

Decide to use the 2x125 for now. It's so inexpensive that I can save up for the 4x10HD and a 6-channel Hypex-based class D for the whole system when I'm rich again. Thanks, forum members! You solved my problem.

 

[suttondesign]

the minidsp plate amp is working out great. i can manipulate dsp on the fly through my laptop. after getting to know the lxmini, i could shut those off while listening to just the new homemade sub, and it became quite clear where to low pass the sub and what slope to use. i will test that out in rew, but the initial work has boosted the extreme low end of the potent 9” sub at 20hz in a cabinet tuned to about 35 while letting it slope 2d order downward from 75hz.

in my large living room, the lxmini are petering out below 100hz, but esp. below 50 or 60 at my listening positions. i am getting a pretty nice balance by letting the sub fill in. i am building a second sub now to sit behind the other lxmini and even out the response. the plate amp allows a stereo hookup too, so the fexibility is great. two hidden, potent little scan-speak 9” subs limited to 20-75hz make a full range system almost invisible when the subs are disguised as books in a bookcase. that is a reason to go this route rather than lx521!