1point21gigawatts
-
Posts
3740 -
Joined
-
Last visited
-
Days Won
93
Content Type
Profiles
Forums
Events
Media Demo
Store
Collections
Videos
Posts posted by 1point21gigawatts
-
-
3 hours ago, SuzukiGS750EZ said:
Thanks for the explanation. I may have tuned to 40hz but since I'm so used to 50hz with a DMM I think I just said that. I only used the o-scope once.
Can I test these clipping points off the RCA ends if I wanted to install on my HU and put everything back together or is it better to do at the source?
Can I open the filters to fully open and set the filters on the HU itself? And if so, do I set them before or after tuning up the Amp gains. Do I need to retune my sub Amp after installing my speakers Amp and why(just trying to learn, not questioning your intent)?
You can test the clipping points on your rca ends. No problem. On your head units filters, which I’m guessing you are speaking of the EQs, those have to be flat, at zero, when you are tuning and then left like that after tuning or if you don’t like that sound, then instead of zero on certain frequencies you can tune in the negatives below zero. But if you go above zero then you are introducing distortion to your setup. You don’t need to retune your subwoofer amp after installing your speaker amp. Just leave the subwoofer amps gain the same and leave it with your subsonic filter off or at zero and the lpf at 80hz. This is because the speakers amp settings don’t affect the subwoofer amps settings. They interact.
-
It’s impossible to tune by ear. You can get kinda close to correct tuning by ear. But there is no possible way to tune correctly by ear. You can find your head units distortion point with an oscilloscope since you said you have one. Make sure the eq’s are flat and the loudness and bass boost and other bullshit is off. And never tune the eqs in the positive after tuning. Only negative. Positive creates distortion at this point. Make sure you have some alligator prongs on your oscope leads and now it’s time to check the subwoofer rca pre outs and front and rear pre outs for distortion points. Clamp the positive lead of the oscope on the subwoofer rca prong coming out of the head unit and then clamp the negative on the circular part that goes around the prong. Play a 0db 40hz test tone then adjust the volume until you see the wave clip then back off until it’s smooth. Do the same on the front and rear rca pre outs on the head unit but on a 0db 1000hz tone and do the same with the oscope. Once you find the volumes you can safely play on subwoofers and speakers, if the volume numbers are different, then find you he number in between them 2 numbers and tune at that volume on your head unit. Tune your subwoofer amp on a -5db 40hz tone and your speaker amp on a -5db 1000hz tone. Before tuning, the filters on each amp have to be set as so, hpf or subsonic filter off or turned all the way down and lpf turned all the way up. That 50hz test tone tuning on a subwoofer amp is when you are tuning with a digital multimeter. But you don’t have to do that since you have an oscilloscope. Once your amps are tuned, now it’s time to set the filters. Since your subwoofer enclosure is sealed, there is no need for a subsonic filter. Turn that off. Turn the lpf to 80hz. Then on your speaker amp, turn the amp on hpf and tune it to 75hz so you don’t miss a frequency and it overlaps instead of gaps on frequencies. You can find frequencies points on filters on your subwoofer amp using a digital multimeter. But it doesn’t work on on speaker amps. The best thing to do is actually use a cc1 and dd1 to do these tunings, but if you don’t have the money, then just guesstimate on the frequency on the hpf on the speaker amp but make sure it overlaps with the subwoofer amp. If you accidentally set it to like 50hz or 60hz hpf, the fugh it and it would work. Just set the speaker amp on hpf and try to tune it to 75hz. But if you don’t want to stress about that then just set your filter to full instead of hp or lp and you won’t have to worry about setting your speakers filter capabilities. It would work but it wouldn’t sound as good as a nice crossover or small overlap setup. It would sound like the speakers you have now but louder and clearer. Because the speakers you have now are playing the same frequencies as your subwoofers. If you are fine with that sound but just want louder, then just click that speaker amp switch to full and and say fugh it. That’s what I’m having to do on my taramps 800.4 because it doesn’t play hpf lower than 90hz and I need my speakers to play below that. But when I get a crescendo s4, I’m gonna tune it to 50hz-60hz hpf. I have to wait to test my subwoofer enclosures bandwidth accurately once installed.
-
What is you subwoofer amp filters set to an what is your enclosure tuned and net volume of that enclosure and port volume. I need to know subwoofer enclosure specs to determine a rough estimate on your subwoofers capable bandwidth. Once I figure that out, I can help you set the filters on both your amps.
-
You are clipping. Turn your amps gain down to begin with or your subwoofers are gonna need to be reconed. Then invest in a dd1 and tune your amp correctly to save money on fixing and replacing gear. Then your gear wouldn’t crap out.
-
1
-
-
That would be sufficient if you had that d3100 as a secondary battery and another agm under the hood with a big 3 upgrade. And you won’t be pulling 415 amps of current. No where near. Those current readings are readings done at the lowest impedance stable and on a sinusoidal signal, not music. Music current draw is around half that value. Then you have to factor in impedance rise which minimizes the current draw as well. There are fluctuations in impedance rise and in music that there would be at times quick bigger current draws. Then you have to factor in the current the alternator does at idle and at certain rpm’s. And xs makes an agm battery that would fit in your vehicle factory battery slot. That and a big 3 upgrade would work just fine. What brand of alternator are you using?
-
You have to factor in subwoofer displacement and bracing displacements then add .95 cubic foot then do the ported section 2.85 cubic feet with about 46 square inches of port area.
-
You are gonna have to buy marine grade plywood because even if you bedliner spray it it would still get damaged by the weather. Do a 3:1 ratio and 16 square inches of port area per cubic foot. So if the ported section is 3 cubic feet the multiply 16 square inches by 3 cubic foot which would equal 48 square inches of port area. Make the port as close to a square as you can. Not a slot. And make sure wherever the subwoofer is mounted that you factor in the subwoofer displacement. Say the subwoofer is .1 cubic feet of displacement and the section the magnet is gonna be facing needs to be 1 cubic foot, then you add in that .1 cubic foot subwoofer displacement and whatever bracing displacements, let’s say it’s .03 cubic feet, and it would equal 1.13 cubic feet and that’s what that section has to measure to net 1 cubic foot.
-
What type of vehicle is it going in?
-
The length of the port is measured down the center of the port, not on the port walls. Add up the middle length. Since the port is 3” in width, the measurement down the middle would add 1.5” on each port wall. So that’s 3”. 13.75”+14.75”=28.5”+(3”)=31.5”. The tuning is 32.76hz and net volume is 2.29 cubic feet after bracing.
-
And you would cut that second port piece as 14”, even though that wall is 14.75” because the way the port elbow connects adds an extra .75” to the length. So the piece should be 14” in length but that wall is 14.75” in length.
-
And 32.75” was a misprint. I meant to put 32.25”. Lol my bad! All the other cuts measurements I used 32.25” as the width to do my calculations but I accidentally wrote 32.75” instead of 32.25”.
-
-
-
33 minutes ago, akuma4u said:
Ok sounds good. Thanks
You are welcome!
-
I’ve been swamped with work. Almost every day I long for sleep. I’m gonna have it finished this weekend.
-
On 7/29/2020 at 4:33 PM, armyvet68 said:
Meade is useless I tried contacting them and no answer no return email. useless
That’s a major thing to say about somebody. Just because somebody doesn’t answer you doesn’t make them a bad person nor useless. There’s no such thing as a useless being, substance or essence. Everybody and everything has worth and a purpose.You have to think beyond what’s irritating you and realize people, places and things all function differently and just because they don’t put you in their function doesn’t mean any insult, ill intentions or harm to you. Also, what if he has been doing his own thing and not really focusing on some stuff because he is going through something and handling his own life. You can’t be mad at somebody about that. Quit being like that dude. Chill out and bass on.
-
Your enclosure now is already small and you want louder and harder hitting bass on the same rms, which is minimal rms after rise for that subwoofer. The only thing that can be done in this case is increase the net volume. You are thinking too hard into this. And that straw and toilet paper tube analogy wasn’t used correctly. Of course more air velocity is generated throw a smaller tube on the same amount of rms. But if the rms is too high for that tube’s diameter then there would be port noise because the air would be traveling too fast. You don’t want high port velocity. You have to stop looking too hard into this because you are gonna keep running into contradictions and become more indecisive.
-
Leave the amps high pass filter at 80hz.
-
I’m not understanding what you are saying. What volume level does distortion occur on the subwoofer rca at 40hz and what volume level does distortion occur on the front or rear rca at 1khz?
-
I’m gonna reference the numbers of the new enclosure in multiple programs and calculators before I draw up a cut sheet.
-
I just noticed that Torres calculates end correction factors port width plus half of port width instead of just half of port width. Idk why he calculates end correction factors like that. Only half the port is added to the physical length to find the effective length of the port. End correction factoring is added because the end of the port shares a common wall with the enclosure making the subwoofer see a longer port. Only an extra half the width of the port is what the subwoofer sees as port length as long as the end of the port isn’t the width of the port away from the side wall which would add more effective length. I’ll calculate them specs to reference. Because port length is not something to miscalculate.
-
55 minutes ago, akuma4u said:
thanks.. i had to increase my max dimensions a tad bit so i hope it will fit. i may have to use some crisco and lube the hell out of it to slide it in LOL damn trunk is too tight.
all i need is the cut sheet/blueprint so i can send it off to my builder and then i can let u know in a week or so how it turned out.
btw, my current box which does sound pretty good is like this:
That’s the specs of the enclosure you are using now?
-
I’m gonna holler at you tomorrow. Peace out dude.
-
I can just draw up that slot port design you did. It’s good. Plus you can tell people who hear how good it sounds that you designed it.
v2 100.4ab crossover, lpf, hpf setup
in SKAR AUDIO - (READ ONLY ARCHIVE)
Posted
I looked at that Skar amps filter settings and it’s crazy that it has a subsonic filter and a hpf. Those are the same exact thing. Lol! Im saying this because it’s on the same side as the hpf settings which doesn’t make sense because if it was there to be used in conjunction with the lpf on subwoofers if somebody wanted to use that amp on subwoofers then it would be on the same side as the lpf setting. Then on the subsonic filter on that amp, it has a range that begins at 10hz and the hpf has a range that begins at 50hz. It’s gonna be hard to tune that amps filters unless you have a cc1. So what I would do is just set that amp switch on full which allows any frequency to play to them speakers. If you have tweeters in that circuit, then just put 3.3 microfarad 100v non-polarized capacitors on the posited feed on each tweeter to block lower frequencies. If you have external passive or active crossovers, then you don’t have to worry about capacitors/bass blockers.