Bypassing the amp of my active sub for an external one. Is it feasible?

[MCH]

Hello,

I have two SVS SB-1000 (non pro) subs and for different reasons, i am starting to think on the possibility of bypassing its amp and instead use an external one.

- The idea is to do it the less intrusive as possible: I would leave the original amp plate in its place and use the speaker level connections to pass the signal from the external amp to the driver. I just need to connect the driver directly to the speaker level terminals in the inside. I have checked and the terminals are very accesible (picture below). I would not even need to solder anything, and most importantly, no need at all to make a hole to pass any cable.

- I do the xovers and eq externally anyways.

All this idea is highly hypothetical, and before wasting more time thinking about it instead of looking at the rain outside, just wanted to ask: Am i missing something? Is this something i should never ever do for this or that reason or is it perfectly feasible?
If the later, what sort of amplifier should i be looking at? (Must be balanced, and remember, we are talking about two subs. One stereo amp would be preferred)

Thank you for your help and comments and remember this is the newbie/beginner forum

 

[levimax]

Hello,

I have two SVS SB-1000 (non pro) subs and for different reasons, i am starting to think on the possibility of bypassing its amp and instead use an external one.

- The idea is to do it the less intrusive as possible: I would leave the original amp plate in its place and use the speaker level connections to pass the signal from the external amp to the driver. I just need to connect the driver directly to the speaker level terminals in the inside. I have checked and the terminals are very accesible (picture below). I would not even need to solder anything, and most importantly, no need at all to make a hole to pass any cable.

- I do the xovers and eq externally anyways.

All this idea is highly hypothetical, and before wasting more time thinking about it instead of looking at the rain outside, just wanted to ask: Am i missing something? Is this something i should never ever do for this or that reason or is it perfectly feasible?
If the later, what sort of amplifier should i be looking at? (Must be balanced, and remember, we are talking about two subs. One stereo amp would be preferred)

Thank you for your help and comments and remember this is the newbie/beginner forum

View attachment 226762

I think it is feasible but there are going to be some issues to be aware of:

1. These small sealed subs are heavily EQ'd to get LF extension so you are going to have to recreate that so you will need a measuring microphone and REW and a way to create filters like REW / Rephase as well as a way to use the filters (some type of player that supports convolution).

2. You will need a powerful amp that can handle a wide range of loads. Probably a class D amp based on Hypex, Purfi, ICE.

3. The stock system has a lot of built in "safety features" to stop you from burning up your driver. This is going to be difficult to duplicate if you are using powerful external amps .... not sure if you can tell by "listening" if you are overstressing things so I would think about that and at least be careful.

SVS are pretty good as is so not sure why you want to do this but it if you keep the above in mind it should be possible.

 

[MCH]

Thanks a lot for your comments! See some answers below:

I think it is feasible but there are going to be some issues to be aware of:

1. These small sealed subs are heavily EQ'd to get LF extension so you are going to have to recreate that so you will need a measuring microphone and REW and a way to create filters like REW / Rephase as well as a way to use the filters (some type of player that supports convolution).

Yes, i will use, well, i already use, a mic, REW, eq, external dsp to apply eq and xovers and a 4 channel dac to feed mains and subs.

2. You will need a powerful amp that can handle a wide range of loads. Probably a class D amp based on Hypex, Purfi, ICE.

Any specific suggestions? (on the cheap side, but must be balanced).

3. The stock system has a lot of built in "safety features" to stop you from burning up your driver. This is going to be difficult to duplicate if you are using powerful external amps .... not sure if you can tell by "listening" if you are overstressing things so I would think about that and at least be careful.

Good point. My intention was to level match the subs to the mains when i do the measurements playing with eq and gain in the dsp. My thinking was: if i don't blow the mains, i won't blow the subs, if they are level matched. Am i missing something?

Thanks again!

 

[FeddyLost]

If the later, what sort of amplifier should i be looking at?

Ideally you need some touring amp with DSP and all safety features like those used with passive subs.
Maybe without DSP, but still PA/touring rated not less than "original" amp.
Like i.e. QSC GX5 or GX7 maybe.

But personally I see not much of benefit in changing amp in a budget subwoofer. Everything will stuck in a driver and enclosure.

 

[levimax]

Good point. My intention was to level match the subs to the mains when i do the measurements playing with eq and gain in the dsp. My thinking was: if i don't blow the mains, i won't blow the subs, if they are level matched. Am i missing something?

Whether your subs will burn up before or after your main speakers when level matched is not knowable as they are not related. It also depends on the music of course.... EDM is going to stress the subs much more than "girl and guitar" music. If you use common sense I think you would be OK but a EDM dance party could be a problem. I also don't see why external amps are required to use DSP with the subs... if you can feed an external amp a line level signal with DSP why not just feed the line level signal to the sub woofers? I run RCA cables 15 ft to my SVS Subs and it works well.

 

[MCH]

Whether your subs will burn up before or after your main speakers when level matched is not knowable as they are not related. It also depends on the music of course.... EDM is going to stress the subs much more than "girl and guitar" music. If you use common sense I think you would be OK but a EDM dance party could be a problem. I also don't see why external amps are required to use DSP with the subs... if you can feed an external amp a line level signal with DSP why not just feed the line level signal to the sub woofers? I run RCA cables 15 ft to my SVS Subs and it works well.

EDM won't be a problem, not ateast until my kid grows up, and hopefully also not then!
Yes i know i can do dsp with the sub as it is, as i mentioned bedore i already do it and works fine. My reasons to think on doing this are different and not really relevant.
Thanks for your input. I understand that doing it carefully and level matching subs and mains should be no problem provided the amp has enough juice and i stay away og EDM
What about the impedance of the naked driver and all that? Not an issue?

 

[levimax]

What about the impedance of the naked driver and all that? Not an issue?

As long as you have an amp that can handle 4 ohm loads easily you are going to be OK. You may be able to find specs on the driver used to double check.

 

[MCH]

You may be able to find specs on the driver used to double check.

I wasn't. But the peerless xxls 12 used in its sibling is 4 ohm, that should be ok for most amplifiers (?)

 

[levimax]

I wasn't. But the peerless xxls 12 used in its sibling is 4 ohm, that should be ok for most amplifiers (?)

yes