18" Subs That Can Handle Over 6000watts RMS

[CortezDTV]

And fi can add spiders to raise the fs on the sp4.... imo tho ur comments on the subs efficency and fs are just ignorant!

its a 4" coil its hard to be efficent when you have all that weight of the copper..... and I don't see how u can complain about efficency if you are gonna push 6k to a sub...........

the fs being to low..... I always looked at that as a good thing

I understand everything you've said and as far me being ignorant, you may be right. That's why I'm here to learn. Not trying to turn this into a vs thread, but I feel I need to explain myself with an example. The SP4 has a fs around 24hz and an efficiency around 88 SPL. If my box is tuned to 35hz and my vehicle peaks at 36-38hz, then with all other things being equal, why wouldn't I look for a sub with an fs around 35hz and a higher efficiency rating? Will it help? You could argue that it doesn't, but I don't think anyone would argue that seeking those numbers won't hurt me. If a DC level 6 has a fs of around 36 and an efficiency rating of around 91, taking those numbers off the top of my head....then how could it possible hurt me to choose that sub? Both subs have 4" vc, both are beasts, both will play all of the music and tones I need them to play.

So, explain to me why I should NOT look at those numbers and buy the sub that fits my application better?

Edited to say.... Not trying to be a smart ass dick with the last line there, I know it sounds that way, but seriously asking why I shouldn't seek those numbers.

I posted this cuz I was in a very similar boat a year ago I was gonna do 1 18 bandpass, with 10k. I posted a thread ill have to find it might help u with your decision....

But on ur comment, from what I have gathered about fs and efficency rating.... is this

Mosty you don't want to tune below the fs of the sub, fs also changes over time, and some like ia ray and a few other guys with extensive knowledge will say to basically ignore the #

with certin style boxes like tlines the fs then becomes very imporotant... you can't tune below the fs of the driver or " free air resonance"

Also with fs the fs changes over time, a sub with extra spiders will have different perameters as one with the original spider packs, I believe it goes more spiders ups the power handling lowers efficency and then raises the fs of the sub, also medium spiders will break in but after breakin and long long time of use will remain stiffer than the stiff spiders offered by dc... so I would prolly reccomend an extra medium spider rather than an extra, Stiff one kinda make sence?

As for the efficency your not going to be able to tell the difference between a sub with an efficency of 91 to 89... audiablly u might be able to hear a sub that 82 and 95 .... the lvl 6 and sp4 are just to close in that aspect....

If I was you sp4 all the way.... price is very good, and fi coils are argueably the best coils on the market..... they have the same curvature as the motors cooling, and there fore have superior cooling to any other coils on the market

Anyone some of my fs and efficency stuff may be off, hhr edd and people who build subs will be able to give. You a much better answer so feel free to correct me

[CortezDTV]

Not to insult steve but I don't think I've ever seen a clamped number from his truck..... might even be more than 6k, they are 2 15,000 watt amps.....

I think you got a little confused. It's not chickens truck, that's the one with the T15k's. Steves tahoe has 2 2500bdcps per 18.

I'll be tuned for the build though OP if you decide on it. Sounds nasty.

Im pretty sure he has 2 15ks in his tahoe.... I guess I may be wrong... steve care to share some clamped #s

But either way id like to see 2 2500s (strapped gain matched )doing 6k and I would wanna see voltage

[HHR Ed]

Not to insult steve but I don't think I've ever seen a clamped number from his truck..... might even be more than 6k, they are 2 15,000 watt amps.....

I think you got a little confused. It's not chickens truck, that's the one with the T15k's. Steves tahoe has 2 2500bdcps per 18.

I'll be tuned for the build though OP if you decide on it. Sounds nasty.

Im pretty sure he has 2 15ks in his tahoe.... I guess I may be wrong... steve care to share some clamped #s

But either way id like to see 2 2500s (strapped gain matched )doing 6k and I would wanna see voltage

It's 8 RF 2500CPs to 4 SMD 18s.

I have seen tested figures of just around 3000w rms out of one of those amps.

[CortezDTV]

^^^ thanks

Now am I correct on the technical part of the question?

[Captain Stupid]

And fi can add spiders to raise the fs on the sp4.... imo tho ur comments on the subs efficency and fs are just ignorant!

its a 4" coil its hard to be efficent when you have all that weight of the copper..... and I don't see how u can complain about efficency if you are gonna push 6k to a sub...........

the fs being to low..... I always looked at that as a good thing

I understand everything you've said and as far me being ignorant, you may be right. That's why I'm here to learn. Not trying to turn this into a vs thread, but I feel I need to explain myself with an example. The SP4 has a fs around 24hz and an efficiency around 88 SPL. If my box is tuned to 35hz and my vehicle peaks at 36-38hz, then with all other things being equal, why wouldn't I look for a sub with an fs around 35hz and a higher efficiency rating? Will it help? You could argue that it doesn't, but I don't think anyone would argue that seeking those numbers won't hurt me. If a DC level 6 has a fs of around 36 and an efficiency rating of around 91, taking those numbers off the top of my head....then how could it possible hurt me to choose that sub? Both subs have 4" vc, both are beasts, both will play all of the music and tones I need them to play.

So, explain to me why I should NOT look at those numbers and buy the sub that fits my application better?

Edited to say.... Not trying to be a smart ass dick with the last line there, I know it sounds that way, but seriously asking why I shouldn't seek those numbers.

I posted this cuz I was in a very similar boat a year ago I was gonna do 1 18 bandpass, with 10k. I posted a thread ill have to find it might help u with your decision....

But on ur comment, from what I have gathered about fs and efficency rating.... is this

Mosty you don't want to tune below the fs of the sub, fs also changes over time, and some like ia ray and a few other guys with extensive knowledge will say to basically ignore the #

with certin style boxes like tlines the fs then becomes very imporotant... you can't tune below the fs of the driver or " free air resonance"

Also with fs the fs changes over time, a sub with extra spiders will have different perameters as one with the original spider packs, I believe it goes more spiders ups the power handling lowers efficency and then raises the fs of the sub, also medium spiders will break in but after breakin and long long time of use will remain stiffer than the stiff spiders offered by dc... so I would prolly reccomend an extra medium spider rather than an extra, Stiff one kinda make sence?

As for the efficency your not going to be able to tell the difference between a sub with an efficency of 91 to 89... audiablly u might be able to hear a sub that 82 and 95 .... the lvl 6 and sp4 are just to close in that aspect....

If I was you sp4 all the way.... price is very good, and fi coils are argueably the best coils on the market..... they have the same curvature as the motors cooling, and there fore have superior cooling to any other coils on the market

Anyone some of my fs and efficency stuff may be off, hhr edd and people who build subs will be able to give. You a much better answer so feel free to correct me

Thanks for the explanation. Like I said, I'm learning here. One follow-up question. Fs test is free air resonance and sensitivity test is also measured free air, is it not? So it would stand to reason that the sensitivity number was likely measured at the fs frequency? Is that correct? If it is, then wouldn't a sub that has an fs substantially lower than where you plan to tune be losing sensitivity as it climbs the frequency ladder? In other words, if it is 88 decibels sensitivity at 25hz, wouldn't the sensitivity number be significantly lower at 35hz? Honestly wanting to know if my train of thought on this is correct?

[lifted_silverado]

I didnt read every post, but the SP Audio SP15X says its handles 6000 rms and now they will have an SP12X 6000w rms 4" coil

[CortezDTV]

Yes and yes

But because your not looking at the graph of each frequency you can't tell if a speaker is very smooth or peaky throughout its frequency range

And this is free air... not in a box... and the box has a huge effect on how the speaker plays and performs

Just curious why do you wanna go to 1 18 over the 2 you have right now?

[Chris Hammer]

I didnt read every post, but the SP Audio SP15X says its handles 6000 rms and now they will have an SP12X 6000w rms 4" coil

2-18"s

I think he has only said it 20+ times.

I wanna see some nice level 6's or sp4's go in that box. Im just in for pics. Only things I can say are reitterations of what more experienced people have said and none of it from personal experience. Still like the way lvl6's look..but the sp4 is sex too.

I would agree with you on specs... I would choose higher efficiency with a fs close to your tuning if you think both subs can handle the power equally as well.

[TRTC360]

I really dont think you should worry about the fs and spl rating on the sub, I've had a few very well recognized competitors/company owners tell me that they aren't really important. Are you specifically chasing numbers with this setup? If so i think you need to do some more testing with your vehicle instead of the enclosure or the subs

[img]

I try to stay away from subs that are inefficient at low wattage. I know that SPL number doesn't mean shit when the speaker is being pounded by 6000 watts, but if all other specs are the same, I will always go with the sub with the higher efficiency rating. It may be wrong to some, but that is what I look for spec-wise.

The SP4 is far from inefficient at low power, I ran my 2 15s wired stupidly high and they still managed to get loud. Yes efficiency is the key, but it doesn't stop at the sub, every other part of your install needs to be efficient.