OP
dtbrown
10+ year member
CarAudio.com Elite
- Thread Starter
- #61
Here is todays results done by Jordan and my friend Mike. I'm just relaying results they got. First the stock alternator really seemed to hurt power since full tilt voltage was anywhere from 11.4 to 11.8v clipping the amp a little.
Let me explain and make this clear that yes we ran the amp at 1ohms and it's only running this way due to the equipment we have and the box design and size. Under most circumstances I don't recommend running these amps at 1ohms unless you know exactly your impedance rise and how you plan on running the amp daily. 1.5ohms no problem but if you want to ever run an amp at it's below rated impedance feel free to ask me or make a post and the knowledgeable people on the forums will tell if you if it's doable or not with your application.
With this set up the impedance rise was to 4ohms from 1ohms and that's why I ran the 4k2d at 1ohms because I knew that if we ran it at 2ohms with these particular subs and the size of box the amp would be seeing over 8ohm and we wouldn't have gotten much more then 2000w from the amp. So I hope that makes sense for the guys that where always wondering if you can run these amps lower or not. Very much depends on application.
Ok now for some numbers. The entire goal from the beginning was to have a 149-150db capable music vehicle and we met that goal. Even though Jordan will rarely listen to it that loud for extended periods of time he wanted to be able to listen to around 145-146db with out stressing subs or equipment and this set up is perfect for that.
Port ended up being best tuned at around 10" over all length.
Here is the spl from 40-48hz with the tuned port.
40hz 149.0db
43hz 149.5db
44hz 150.0db
45hz 149.9db
46hz 149.7db
47hz 149.3db
50hz 148.0db
60hz 143db but xover on at 63hz
So right where we wanted it tuned at for the type of music Jordan listens to. And still plays over a 148db in the 35-40hz range for when he plays some rap and what not. Nice and tight clean and loud.
Here is test for the box efficiency with power.
250w 34.7v and 7.2amps 140.8db @ 44hz
997w 65.6v and 15.2amps 146.2db @ 44hz
2709w unclipped102.6v and 26.4amps 149.7db @44hz
Here is power results but again with stock alternator voltage was anywhere from 11.5-11.8v at the back battery and .5v higher at the front battery
44hz 111.4v and 27amps @ 4.12ohms=3008w voltage 11.5v at the back battery. Not bad considering rating is 2800w at 4ohms at 12.6v.
So as you can see voltage was killing power again due to stock alternator. And I think there was a post on here from an owner of an xterra that said the stock alternator is weak which I agree. Easy 500-1000w gain with alternator. And I'm honestly not to sure about how strong the Kinetik's are.
Last test is full tilt street beating music over 10min with spl from 146-149+db on meter
Amp temp was 120 degrees. Subs carbon fiber dust cap temp was 95 degrees and outside air temp was 64 degrees. If we had better voltage amp would have been cooler no doubt but this is the result of running an amp lower then rated impedance full tilt for a period of time. Since Jordan 95% of the time listens to system at around 146db temperature isn't a problem but if someone where to run full tilt for an extended period of time at below rated impedance then this could potentially be a problem.
So that's why in this application running the 4k2d at 1ohms works fine.
Over all we set a goal and it was met on first try. We could make a box that is more efficient and louder but it wouldn't sound as good as this one does. So for anyone that asks "why it isn't louder" our goal wasn't just spl. Next is to clean it up and make it look better. Fell free to ask question.
A little spl in the kick test.
Let me explain and make this clear that yes we ran the amp at 1ohms and it's only running this way due to the equipment we have and the box design and size. Under most circumstances I don't recommend running these amps at 1ohms unless you know exactly your impedance rise and how you plan on running the amp daily. 1.5ohms no problem but if you want to ever run an amp at it's below rated impedance feel free to ask me or make a post and the knowledgeable people on the forums will tell if you if it's doable or not with your application.
With this set up the impedance rise was to 4ohms from 1ohms and that's why I ran the 4k2d at 1ohms because I knew that if we ran it at 2ohms with these particular subs and the size of box the amp would be seeing over 8ohm and we wouldn't have gotten much more then 2000w from the amp. So I hope that makes sense for the guys that where always wondering if you can run these amps lower or not. Very much depends on application.
Ok now for some numbers. The entire goal from the beginning was to have a 149-150db capable music vehicle and we met that goal. Even though Jordan will rarely listen to it that loud for extended periods of time he wanted to be able to listen to around 145-146db with out stressing subs or equipment and this set up is perfect for that.
Port ended up being best tuned at around 10" over all length.
Here is the spl from 40-48hz with the tuned port.
40hz 149.0db
43hz 149.5db
44hz 150.0db
45hz 149.9db
46hz 149.7db
47hz 149.3db
50hz 148.0db
60hz 143db but xover on at 63hz
So right where we wanted it tuned at for the type of music Jordan listens to. And still plays over a 148db in the 35-40hz range for when he plays some rap and what not. Nice and tight clean and loud.
Here is test for the box efficiency with power.
250w 34.7v and 7.2amps 140.8db @ 44hz
997w 65.6v and 15.2amps 146.2db @ 44hz
2709w unclipped102.6v and 26.4amps 149.7db @44hz
Here is power results but again with stock alternator voltage was anywhere from 11.5-11.8v at the back battery and .5v higher at the front battery
44hz 111.4v and 27amps @ 4.12ohms=3008w voltage 11.5v at the back battery. Not bad considering rating is 2800w at 4ohms at 12.6v.
So as you can see voltage was killing power again due to stock alternator. And I think there was a post on here from an owner of an xterra that said the stock alternator is weak which I agree. Easy 500-1000w gain with alternator. And I'm honestly not to sure about how strong the Kinetik's are.
Last test is full tilt street beating music over 10min with spl from 146-149+db on meter
Amp temp was 120 degrees. Subs carbon fiber dust cap temp was 95 degrees and outside air temp was 64 degrees. If we had better voltage amp would have been cooler no doubt but this is the result of running an amp lower then rated impedance full tilt for a period of time. Since Jordan 95% of the time listens to system at around 146db temperature isn't a problem but if someone where to run full tilt for an extended period of time at below rated impedance then this could potentially be a problem.
So that's why in this application running the 4k2d at 1ohms works fine.
Over all we set a goal and it was met on first try. We could make a box that is more efficient and louder but it wouldn't sound as good as this one does. So for anyone that asks "why it isn't louder" our goal wasn't just spl. Next is to clean it up and make it look better. Fell free to ask question.
A little spl in the kick test.
