clamping "actual" power. impedance rise in relation to amp set up.

  • 4
    Participant count
  • Participants list

devin171moto

CarAudio.com Regular
So. this may be a dumb question.
But im running 2 sa-12's in a 4.5 cu ft box tuned a 30hz. 61in of port area.
I know its more efficient because of its size so i can expect more cone movement and impedence rise on less power.

my question is due to me finally attempting to tune by ear on an amp that does 3k.

I know the voltmeter method is bs because of rise. according to my voltmeter at 1 ohm I'm pumping 45volts which is equivelent to more than 2k. but clamped at 24hz im only doing like 400watts with plenty of xmax to spare. I unload pretty hard at 21hz so I dont play that low really.

ive I set the gain to give me as much clamped power at posibble withing mechanical limits do I run the risk of amp clipping or over stressing the subs?

I have a feeling they will take a "real" 1000w clamped without hitting xmech from 24-40hz. but don;t know if thats pushing the amp or softparts too hard.
 
What amp do you have? Amp's a big factor in playing below tuning frequency in relationship to sub control.

Also, there's a certain limit of how well a sub will play below it's Fs. Your box is bigger than what I would run for a SA. With what you appear to want to do, you might actually be better off going with a smaller box and a slightly smaller port and lower overall tuning. Bigger boxes are going to be harder on the amp because of the higher cone movement, ESPECIALLY when you start unloading. There's an amp statistic that will tell me how well your amp can handle the electricity produced by high excursion.

If you have that much power, and you only want to play 24-40 hz, you might do a series 6th. They take a lot of room, though. Just a thought.
 
What amp do you have? Amp's a big factor in playing below tuning frequency in relationship to sub control.

Also, there's a certain limit of how well a sub will play below it's Fs. Your box is bigger than what I would run for a SA. With what you appear to want to do, you might actually be better off going with a smaller box and a slightly smaller port and lower overall tuning. Bigger boxes are going to be harder on the amp because of the higher cone movement, ESPECIALLY when you start unloading. There's an amp statistic that will tell me how well your amp can handle the electricity produced by high excursion.

If you have that much power, and you only want to play 24-40 hz, you might do a series 6th. They take a lot of room, though. Just a thought.
Thanks for the reply buck.
It's two sa 12's powered by a taramps smart 3. I have a northstar agm up front in a gmc envoy with big 3, no alt. so I MAY have room for a series 6th.

Though if I'm gonna build a 6th order i'd prefer to dig even lower. Maybe 20hz. But i know cone area becomes a big factor here.
 
Thanks for the reply buck.
It's two sa 12's powered by a taramps smart 3. I have a northstar agm up front in a gmc envoy with big 3, no alt. so I MAY have room for a series 6th.

Though if I'm gonna build a 6th order i'd prefer to dig even lower. Maybe 20hz. But i know cone area becomes a big factor here.

You need an alt. You'll see your lows improve greatly.
 
Thanks for the reply buck.
It's two sa 12's powered by a taramps smart 3. I have a northstar agm up front in a gmc envoy with big 3, no alt. so I MAY have room for a series 6th.

Though if I'm gonna build a 6th order i'd prefer to dig even lower. Maybe 20hz. But i know cone area becomes a big factor here.

I've made 2 like 300 watt 8's play 25 hz in a 4th order. You can do it. Idk how low I would exaclty tune, maybe 25-26 at the lowest, personally.
 
You need an alt. You'll see your lows improve greatly.
I was really hoping this wasn't the answer lmao. But I guess it can't be helped. I was told I didn't need one from the guys here during my planning stage. Mines a 150amp.

So i can assume trying to give it more power is gonna starve the amp and cause issues? Or is it the fact that it can't push past the impedence rise without more stable power? Its honestly pretty loud now. I just didn't want to leave performance on the table.
I really didn't think I would need an alt under 2000w
 
I was really hoping this wasn't the answer lmao. But I guess it can't be helped. I was told I didn't need one from the guys here during my planning stage. Mines a 150amp.

So i can assume trying to give it more power is gonna starve the amp and cause issues? Or is it the fact that it can't push past the impedence rise without more stable power? Its honestly pretty loud now. I just didn't want to leave performance on the table.
I really didn't think I would need an alt under 2000w

It made a huge difference when I was running 2400w. Like night and day difference. Lows seem to take more energy to reproduce.
 
I've made 2 like 300 watt 8's play 25 hz in a 4th order. You can do it. Idk how low I would exaclty tune, maybe 25-26 at the lowest, personally.
I've always wanted a series 6th. Might experiment for sure. Would that be more or less efficient overall than a bass reflex? Id rather build a new box than pay 400 for an alt.
 
I've always wanted a series 6th. Might experiment for sure. Would that be more or less efficient overall than a bass reflex? Id rather build a new box than pay 400 for an alt.

You need the alt regardless IMO. You just aren't getting the power you think you are. Like I had no idea the difference between my factory 130a vs a 300 amp alt would make. I would invest in one 110%.
 
I even had my factory 130a built to 180a and the 300a still made a humongous difference. I got louder with the bigger alt's I had. I was probably doing about 2800w @ 14v. 2 amps strapped. It's close to what you're doing, except I had 18's and was tuned to 29 hz in a slightly oversized box.
 
I even had my factory 130a built to 180a and the 300a still made a humongous difference. I got louder with the bigger alt's I had. I was probably doing about 2800w @ 14v. 2 amps strapped. It's close to what you're doing, except I had 18's and was tuned to 29 hz in a slightly oversized box.
you got videos of your builds? youtube?

im starting to see the selling point of efficient subs lmao. my 350 dollar impulse purchase for two sa 12's turned from what I thought would be a 1,000 project to 2,000 lmao.

I'll heed your advice reluctantly.

I was wondering why I couldn't get voltage to drop below 13.6.
that's what made me think I had the power.
 
Out of curiosity what wattage are you getting with pink noise?
Never ran pink noise through the amp before. Only really thought that was for sq calibration.
The 400 watts is honestly a guestimation from the gauge on the smart 3. (My clamp meter is fucked)
Subs not connected its like 3/4 filled. with them running its just shy of a quarter filled
 
I've always wanted a series 6th. Might experiment for sure. Would that be more or less efficient overall than a bass reflex? Id rather build a new box than pay 400 for an alt.

I broke down and bought the big alternator. It is worth it. My alternator cost more than my sub amp and head unit combined. Just "bite the bullet" and do it. If you don't power the light bulb, then, it won't provide light. Remember that, power = light and power = sound.
 
Activity
No one is currently typing a reply...
Old Thread: Please note, there have been no replies in this thread for over 3 years!
Content in this thread may no longer be relevant.
Perhaps it would be better to start a new thread instead.

Similar threads

No sweat. I was also going to suggest New England Providore (NEP Audio) but it looks like they shut down the shop.
11
76
Run the biggest AGM you can under the hood, the parallel runs to one of these - should be everything you need and then some...
5
137
What amplifier(s) are you using? What speakers? Is this your main battery or is it a 2nd battery? If it is a 2nd, how are you wired up? What if...
2
145
That’s the little single 6.5 inch enclosure. The Savard did just as well as the RDS. These subs do well in ported or 6th orders but not as well...
12
443
With 6500 rms.. you are still going to need some battery bank and/or supply for that demand
2
15

About this thread

devin171moto

CarAudio.com Regular
Thread starter
devin171moto
Joined
Location
Gilbert, AZ
Start date
Participants
Who Replied
Replies
17
Views
1,867
Last reply date
Last reply from
Buck
Screenshot 2024-03-07 184329.png

Doxquzme

    Mar 27, 2024
  • 0
  • 0
IMG_3075.jpeg

Daniel Lee

    Mar 27, 2024
  • 0
  • 0

Latest topics

Top