How to safely over power a sub ? Smallbox recommendations

[ManzKea 152]

Ok so I see a lot of conflicting answers regarding a small box if you plan on over powering your sub. Be believe in it, others say it's a lie. My question is if you're gonna over power a sub. What would be considered smaller ? I'm thinking about 2 15s. They call for 3-4 ft3 but I'm thinking of putting them in a 5 ft3 box. After displacement and port.  

 

Im looking into the  sp4v2 and putting them on a hd8k. I know they are underrated. And the taramps is over the rms slightly. So I wa wondering if this will work out well. The reason why I'm asking is because I don't wanna sacrifice more space for my box. And seeing how the 8k is more than enough for the subs, I assume I could get away with a smaller box.  Well thanks for all inputs guys. 

 

Aloha. 

[frogcase2002 393]

I think if your not crazy with the volume knob all the time you wont mess the subs up. Most people messing up subs are clipping real bad and a smaller box isnt going to help with that. I would still go with what is recommended for the subs . Friend of mine is running 2 sp4s on 9k with no problems and his enclosure is on the larger side of whats recommended.  But has the electrical for the 9k

[ManzKea 152]

Sweet. How are they? What's he tuned too? Does it play lows and also kill the higher notes? 

[Travis 82]

I know I'm in a small box (5 cubes tuned to 35) and I'm stinking the he'll out of my level 6 on my ns1. The damage may already be done and I've tuned by ear. By multimeter. And it doesn't seem to matter. I think my voltage is causing me to clip. I need to pull my sub and see what's going on. There may be a recone in my future. Everything I've tried isn't helping so I'm assuming it's my voltage. Scratching my head and a little frustrated. Had a couple shops try to tune it ect. I don't know it all and I don't pretend to... But very frustrating honestly.

Edited September 26, 2017 by Travis

[Tirefryr 1,742]

35 minutes ago, Travis said:

I know I'm in a small box (5 cubes tuned to 35) and I'm stinking the he'll out of my level 6 on my ns1. The damage may already be done and I've tuned by ear. By multimeter. And it doesn't seem to matter. I think my voltage is causing me to clip. I need to pull my sub and see what's going on. There may be a recone in my future. Everything I've tried isn't helping so I'm assuming it's my voltage. Scratching my head and a little frustrated. Had a couple shops try to tune it ect. I don't know it all and I don't pretend to... But very frustrating honestly.

Your answer is in your question, or lack-there-of.  You're reaching the thermal and/or mechanical limits of your driver in your application.  The ONLY way to remedy this is to find the root and fix it.  Change the driver, the application, the power, or the user.  

[Tirefryr 1,742]

9 hours ago, ManzKea said:

Ok so I see a lot of conflicting answers regarding a small box if you plan on over powering your sub. Be believe in it, others say it's a lie. My question is if you're gonna over power a sub. What would be considered smaller ? I'm thinking about 2 15s. They call for 3-4 ft3 but I'm thinking of putting them in a 5 ft3 box. After displacement and port.  

 

Im looking into the  sp4v2 and putting them on a hd8k. I know they are underrated. And the taramps is over the rms slightly. So I wa wondering if this will work out well. The reason why I'm asking is because I don't wanna sacrifice more space for my box. And seeing how the 8k is more than enough for the subs, I assume I could get away with a smaller box.  Well thanks for all inputs guys. 

 

Aloha. 

You can build the enclosure smaller;it will effectively be a heavier spring on the driver, but with a vented enclosure it's or that simple.  This is especially true when you factor in unloading.  When a driver runs below tuning, the vent unloads and the waveforms cancel.  It's effectively become a free-air driver at that point and you're now at the mercy of the driver mechanically and electrically.  You're enclosure is no longer a factor.  The ONLY way to figure out what may work fit you is testing.  There are far too many variables to accurately model this.  It you.  

 

Let me ask you this. . .    Why are you wanting to "overpower?"  

[ManzKea 152]

Well I'm saying overpower because Im planning on picking up an 8k. These are rated at 3500 a piece. So I decided to go with the 8k since that's the closest size to the amount of rms these will total too. im syre my voltage won't hold a steady 14.4 so I won't consistently see the 8k+ it says it'll do. But just figure I'd ask. Also it'll help for future purposes. 

 

Im actually trying not to build the box bigger because I don't wanna sacrifice any more space. So I'm hoping I can get away with a slightly shrunken down box if I add more power to it. It calls for 6ft3 for two 15s. That's on the small side. And I'm able to give it 5.5ft. 

 

Ive also read that the bigger the box the more efficient the driver will be. So you could get loud with less power. So I'm figuring if I keep it on the smaller side having more power won't harm the sub as much

49 minutes ago, Tirefryr said:

You can build the enclosure smaller;it will effectively be a heavier spring on the driver, but with a vented enclosure it's or that simple.  This is especially true when you factor in unloading.  When a driver runs below tuning, the vent unloads and the waveforms cancel.  It's effectively become a free-air driver at that point and you're now at the mercy of the driver mechanically and electrically.  You're enclosure is no longer a factor.  The ONLY way to figure out what may work fit you is testing.  There are far too many variables to accurately model this.  It you.  

 

Let me ask you this. . .    Why are you wanting to "overpower?"  

 

[ManzKea 152]

1 hour ago, Travis said:

I know I'm in a small box (5 cubes tuned to 35) and I'm stinking the he'll out of my level 6 on my ns1. The damage may already be done and I've tuned by ear. By multimeter. And it doesn't seem to matter. I think my voltage is causing me to clip. I need to pull my sub and see what's going on. There may be a recone in my future. Everything I've tried isn't helping so I'm assuming it's my voltage. Scratching my head and a little frustrated. Had a couple shops try to tune it ect. I don't know it all and I don't pretend to... But very frustrating honestly.

Oh man that's not good to hear. Especially a lvl 6!? Dang. I thought those would be beasts. But I guess it's the same with my zv5 15. I got it on a taramps 5k and it starts to smell over a long period of play time. Idk I see lots of videos where people say the zv5 takes power. Lol. 

[///M5 2,833]

11 hours ago, ManzKea said:

Ok so I see a lot of conflicting answers regarding a small box if you plan on over powering your sub. Be believe in it, others say it's a lie. My question is if you're gonna over power a sub. What would be considered smaller ? I'm thinking about 2 15s. They call for 3-4 ft3 but I'm thinking of putting them in a 5 ft3 box. After displacement and port.  

That is because there are a lot of stupid people.  The goal of "over powering" is already dubious adding an enclosure change to rationalize it being okay is downright ridiculous.

Larger amp = lower gains if you want your stuff to live.  Doing something else is absurd.

[Travis 82]

2 hours ago, Tirefryr said:

Your answer is in your question, or lack-there-of.  You're reaching the thermal and/or mechanical limits of your driver in your application.  The ONLY way to remedy this is to find the root and fix it.  Change the driver, the application, the power, or the user.  

I've got a couple ideas but not an easy task to wrestle it around solo. 

[altoncustomtech 773]

I ran a pair of 10” DCON’s on an Arc XDi2000 at one ohm, 2.5x their rated power in a bad sealed enclosure. Never hurt them thermally but did cause a little trouble mechanically. The prefab sealed enclosure started to come apart. 

I honestly feel that if the enclosure hadn’t started to leak they would probably have been just fine. Like I said I never hurt them thermally, the coils still look like new. 

As a result I started designing a ported enclosure around using them on my SAZ-2000 in my Grand Prix. According to the modeling, with 25hz tuning and an enclosure slightly larger than the maximum recommended size they should handle the power mechanically. By manipulating the enclosure size and tuning I managed to put the drivers’ peak impedance right where the xmax peaks allowing them to not exceed their rated xmax even on 2.5x rated power. 

Of course it’s all theory and modeling so real world results are going to vary to a point but I plan on trying it out at least. My point is that if everything is good with the voltage, clipping, distortion, etc. I wouldn’t be nearly as worried about thermal damage especially if you’re talking a single 8k on the two subs, you’re only 500 watts over with the ratings and that’s never going to even be noticeable. 

[frogcase2002 393]

5 hours ago, ManzKea said:

Sweet. How are they?whats he tuned too? Does it play lows and also kill the higher notes? 

I love how they sound . Hes runnin 2 18s In almost 16 cubes tuned to about 27 Or so On an ampere 9k . Im real Surprised how good It does on the higher notes . Pretty flat response from like 25 to In the 50s . Hes hiting 151 at 35 In his escalade

[Jimi77 0]

On ‎9‎/‎26‎/‎2017 at 10:52 AM, ManzKea said:

Well I'm saying overpower because Im planning on picking up an 8k. These are rated at 3500 a piece. So I decided to go with the 8k since that's the closest size to the amount of rms these will total too. im syre my voltage won't hold a steady 14.4 so I won't consistently see the 8k+ it says it'll do. But just figure I'd ask. Also it'll help for future purposes. 

 

Im actually trying not to build the box bigger because I don't wanna sacrifice any more space. So I'm hoping I can get away with a slightly shrunken down box if I add more power to it. It calls for 6ft3 for two 15s. That's on the small side. And I'm able to give it 5.5ft. 

 

Ive also read that the bigger the box the more efficient the driver will be. So you could get loud with less power. So I'm figuring if I keep it on the smaller side having more power won't harm the sub as much

 

Subs have a thermal rating, if you exceed that for an extended period of time, you'll toast the coil.  That thermal rating is independent of the enclosure.  The smaller enclosure will act as a "heavier" air spring, which can increase mechanical power handling, but won't increase thermal power handling. 

[ManzKea 152]

The thermal rating is the rms correct? Oh and mechanical your talking bout bottoming out and sounding all funky from too much power

[jesh4622 0]

http://linkwitzlab.com/thor-intro.htm

Theory and stuff is linked after the little blurb. It's also hard to argue with the guy.

Edited October 3, 2017 by jesh4622

[Jimi77 0]

On ‎9‎/‎29‎/‎2017 at 3:31 PM, ManzKea said:

The thermal rating is the rms correct? Oh and mechanical your talking bout bottoming out and sounding all funky from too much power

Thermal is the RMS rating.  The mechanical is Xmech which isn't often disclosed.  Mechanical is when you bottom out or otherwise exceed the mechanical limits of the sub (tinsel lead slap would be another common one).  You cannot "increase" the RMS rating by putting the sub in a smaller enclosure.  You can make it less likely that you'll reach the sub's mechanical limits by putting in a smaller enclosure.

 

[ManzKea 152]

12 hours ago, Jimi77 said:

Thermal is the RMS rating.  The mechanical is Xmech which isn't often disclosed.  Mechanical is when you bottom out or otherwise exceed the mechanical limits of the sub (tinsel lead slap would be another common one).  You cannot "increase" the RMS rating by putting the sub in a smaller enclosure.  You can make it less likely that you'll reach the sub's mechanical limits by putting in a smaller enclosure.

 

So when people online shrink their enclosure to add more power what are they actually doing? Like what's their purpose of doing so ? 

[ManzKea 152]

Another question that's off topic but figured I'd post here to avoid adding another topic. 

 

What would be louder , 3 12s or 2 15s. Of the same model of course. I know they say surface area is king. But the 2 15s are slightly larger than 3 12s. But the 3 12s could handle more power. So I'm not sure how that works out. 

 

I was looking at the sp4. Thinking bout 2 15s . I picked one up from a buddy already. And I was gonna run a 10k on  em.  But I noticed I could fit the 3 12s in the same box as the 2 15s. Then I added up the total rms. Which would b 7k for the 2 15s. Or 10.5 for the 3 12s. But with slightly less surface area. So. Chime in fellas. Much appreciation. 

[frogcase2002 393]

3 hours ago, ManzKea said:

So when people online shrink their enclosure to add more power what are they actually doing? Like what's their purpose of doing so ? 

They are doing that cause they see It online

[///M5 2,833]

1 hour ago, frogcase2002 said:

They are doing that cause they see It online

Yep, same reason that idiots are building useless 4th order bandpass boxes.  Either trying to copy or be unique, but almost always a monster failure.

[ManzKea 152]

5 hours ago, ///M5 said:

Yep, same reason that idiots are building useless 4th order bandpass boxes.  Either trying to copy or be unique, but almost always a monster failure.

You don't say!!!??  Yea I noticed a lot of people vouching for the 4th orders. Then got those special few that wanna kick it up a notch to 6th orders lol.  What makes em useless? People say it plays wider range because of the sealed and ported portions etc. 

[ManzKea 152]

7 hours ago, frogcase2002 said:

They are doing that cause they see It online

Oh no that's me!!! Lol 

[///M5 2,833]

19 minutes ago, ManzKea said:

 People say it plays wider range because of the sealed and ported portions etc. 

Umm, no.  People are lemmings.  The name should give it away for you: Bandpass.  By definition (verbatim from Websters lol) :a filter that transmits only frequencies within a selected band.  In other words, the box in this case becomes a filter and reduces the low frequency & high frequency output.  Wider range is laughably stupid as it is the exact opposite.

There is only 1 logical use for a 4th order BP and that is when you have the port fire into a cabin instead of the box into the trunk.  Some cars are bass traps and you need to do that.  Other than that, one could argue if you had no processing that you can use the mechanical filtering of the box to improve your overall sound but in the modern headunit there is always sub processing so that reason seems pretty ridiculous.

[ManzKea 152]

Yea i remember seeing bandpass boxes back in the day and knowing those type of boxes were garbage. I'm talking those boxes with the plexi glass showing the subs. And then the two aero ports.   Is that what the 4th order basically is?

[ManzKea 152]

And how bout my other question on 3 12s or 2 15s same model. Which is louder