Could I build a highly efficient sub?

[Papermaker85 5,000+ posts]

you want to build a sub? good luck not having to proper equipment..

second the idmax is no more efficent than alot of drivers on the market and don't sound nearly as good when ported..

the higher your bl the higher your inductance and back emf... this means higher distortion.. the most output is not always the highest efficiency woofer..

if you want to use 1500 RMS with 4 to 6 cubes a pair of 12s is your best bet..

matching transfer function and phasing are much more important...

 

[sundownz Pro Seller]

Not the original one. The original nightshade was built to take a ton of power and have SOME sq. It is a compromise woofer. It will get loud, but it's only like 85db @ 1w/1m

SPL output 1w/1m is really not an important specification for a sub-woofer driver... a driver with a lower sensitivity tends to have MORE low-end output, actually. It comes a bit more in to play on SPL burps -- but as far as getting real SUB-BASS it's not something to really pay much attention to.

As for the original topic... sure you can -- the reason most "big boy" woofers are power hogs is because that is what people WANT. They want their sub to HANDLE power... they don't ask "How can I get the loudest with the least power?" -- they ask... "Can you make me a sub to handle 5000 watts ?!"

 

[Kross6622 10+ year member]

you want to build a sub? good luck not having to proper equipment..second the idmax is no more efficent than alot of drivers on the market and don't sound nearly as good when ported..

the higher your bl the higher your inductance and back emf... this means higher distortion.. the most output is not always the highest efficiency woofer..

if you want to use 1500 RMS with 4 to 6 cubes a pair of 12s is your best bet..

matching transfer function and phasing are much more important...

When i say build my own sub, I mean find a motor, basket, and get the proper softparts made. Im not trying to really make my own subwoofer, rather just take pieces and put them together you could say.

And to Jacob, your kind of the reason i started this, because i follow you on SSA and noticed how much louder you made the v2 Z series from the v1... i was basically going off this idea, but with a little more extreme approach.

Im glad I started this because i got some of the answers im looking for.

Now my next question, what type of motor would I be looking, what size coil gap, etc..

Thanks for the help, really appreciate it.

 

[SPLaudio 5,000+ posts]

people think it's cooler to have a pair of 12s in a crappy box and do a 140 with 5000 watts. times have changed,power is cheap....

 

[sundownz Pro Seller]

When i say build my own sub, I mean find a motor, basket, and get the proper softparts made. Im not trying to really make my own subwoofer, rather just take pieces and put them together you could say.
And to Jacob, your kind of the reason i started this, because i follow you on SSA and noticed how much louder you made the v2 Z series from the v1... i was basically going off this idea, but with a little more extreme approach.

Im glad I started this because i got some of the answers im looking for.

Now my next question, what type of motor would I be looking, what size coil gap, etc..

Thanks for the help, really appreciate it.

The Z v.2 is basically what you are looking for.

1) Around 70 grams less moving mass in the 15" size than the Nightshade v.1

2) Around half the inductance of the NS v.1 due to half the wire layers AND double shorting rings (not to mention more linear inductance over stroke)

3) Softer suspension than NS v.1 to get moving a bit easier and to keep FS down after reduced MMS

4) In order to "make up" for the reduced coil winding thermally a much more advanced air cooling system was implement for the voice coil -- thermal power handling is practically unchanged from the NS v.1

5) The motor force factor was kept nearly identical to the NS v.1 as well despite less coil layers.

Maximum mechanical power handling is down a bit due to the softer spider... but the NS v.1 stock suspension was good for 3000+ watts "daily" so to speaker so there really is no need on a driver rated for 1500 RMS -- plus the suspension on the Z v.2 has a progressively stiffening curve towards the end of linear stroke to act like a safety net on the softer suspension.

If you model the NS v.1 15" vs the Z v.2 15" in the same 3 cube box @ 35 Hz the curves are nearly identical but the Z v.2 will be a bit louder at a given power input level -- I have tested this in real life so it's not theoretical.

In theory you could keep doing what I did... keep reducing mass and keep softening suspension in unison so FS doesn't go through the roof and end up with a really efficient woofer -- but if you kept the motor strong at the same time you would progressively lose low-end output. I tried to balance it as best as possible in the Z v.2 model design.

 

[SPLaudio 5,000+ posts]

so burping at 3k which is louder ns v1 or z v2?

 

[JimJ 5,000+ posts]

Due to this an efficient sub is not good for music and only for burps.

Not really.

The only thing stopping you would be the size of the enclosure - Hoffman's Iron Law. In order to maintain low frequency extension, you'd end up with an enclosure much larger than a lower efficiency design. But it'd be just as musical.

As mentioned before, with multi-kW amps being as cheap as they are in 12V, there's no reason to do it.

 

[sundownz Pro Seller]

so burping at 3k which is louder ns v1 or z v2?

Z v.2

 

[SPLaudio 5,000+ posts]

thats impressive...

 

[mendon mafia 10+ year member]

indeed it is. I might try a pair myself. to bad i just purchased another 3k amp i guess i can sell it now.

 

[supermaxx123 10+ year member]

Not really.
The only thing stopping you would be the size of the enclosure - Hoffman's Iron Law. In order to maintain low frequency extension, you'd end up with an enclosure much larger than a lower efficiency design. But it'd be just as musical.

As mentioned before, with multi-kW amps being as cheap as they are in 12V, there's no reason to do it.

anyhting over 1000rms cost a lot, at least to me lol.