Joe X
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Posts posted by Joe X
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Let us know how it went or if you have any questions later on.
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The sundown U12s play rather peaky, you can either build a box with a net volume lower than recommended or use damping material inside the box like polyfill or dacron, sometimes an inefficient port can help with a peaky output (long port or lower port area) but if you didn't like the results the box is already made. the most effective solution is build a large sealed box, secondly use proper subs, or the methods mentioned above.
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Reading a bit your first post very much looks like your alternator is underperforming or is plain insufficient, fixing that would be first in my list. no amount of extra batteries will help, also verifying all your power and signal wiring is a must, the location where you install the amp should transmit a lot of vibration to it.
It's very important that you ask for an explanation on the mode of failure of the amp, Ideal installation location is a ventilated amp rack (isolated from the sub box) and keep your voltage at the amp terminals at at least 12V under any conditions. gains should be set properly. Installation issues frequently end up equipment damage.
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Do you know that amplifier has a remote turn on signal?
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Provided that you paid a lot of attention on correctly entering all your data and make sure the units correspond to what is specified by the manufacturer you do get some insight of what actually want to build and what don't additionally:
1 your subsonic can both prevent sub damage and hurt your output if not set exactly right WinISD lets you create filters and see the effect on excursion.
2 after building and sealing the wall + deadening your resonant frequency has gone up.
3 with those not to common wall builds on sedans suspension sometimes has been affected, may be a good ideal to get lighter wood or other measures you
might think of.
4 at this point talking to competitors would be most beneficial for you.
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On 6/1/2023 at 11:49 AM, mel80 said:
6 will bump me into a class i dont want to be in due to cone area rules , i did figure out how to do a slot port though and still be able to drop the tunning on the fly , i.e build the high tune port into the box and then make an insert i can drop into the port to extend it for the low tunning i want for daily use. 2.5-2.7cft is the sweet spot for theese to get them to be louder down low over what i have now not that they arent loud down low now but the increase in box volume will deff pick up the low end a good bit. i got plenty of time though so im not rushing this , next week ill prolly go pick up some wood and start on a front baffle to just start playing with layout and go from there
i am having troublke deciding were i want the port though i.e passenger side /ds / center or do i wanna put it at the top/bottom
A couple of things:
1) to confirm your suspicions on how the subs will react use modeling software to get insight on, A ) if Xmax is passed either below or above tuning on intended power and box specs B ) what's the proper port area. WinISD will suffice for that. Once you confirm your box specs then.......
2) Get yourself a SPL meter before starting your tests, there are many decently priced like the SSA, those are like $300 or so for the basic models I believe.
Wish I had more time these days like you to play with car audio gear. have fun.
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You can easily do 6 subs, port across the center, > 160 square inches 3 subs above 3 below, still at 2.25 net and 26 square inches of port per driver, easier to power, two subs or 3 per amp. Not that I don't get what you are getting at giving 2.7 is just that some DD audio 612s are some of the ones born to work like that.
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That is not normal. Your car is possessed most likely.
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Ok then, check this company, see if it has something for your vehicle:
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If you go the route of finding components compatible with your vehicle (or at least know the sizes) check out this:
https://www.crutchfield.com/S-CdX0cfruDY6/ymm/2004-Honda-Pilot-Speakers-Stereos.html
That's what I'd do if lacking time to work.
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Average power is V rms x I rms you cannot use R as the tweeter is not a resistor.
V rms and I rms are obtained by direct measurement bearing in mind your multimeter is a "true RMS" one otherwise the readings will be invalid.
Also VERY important that you don't mention is that your high pass filter must be set high enough to meet it's operating frequency range, if you play frequencies lower than what the tweeter is meant to play it will get destroyed, so to be safe you need to set amp gain AND high pass filter BOTH, furthermore, the highpass filter need to be set before measurements ar4e taken and gains are set.
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Skar gives in their website box suggestions are those no good for you? Explain a little more your situation.
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Yes, you shouldn't get any port noise as you are running the same port area per driver as before, Bottoming out could be more of a real possibility if you were to up power with new amps and not bring down internal volume, (entry level subs generally are not expected to have overly stiff suspensions). As far as ports go the longer port is less efficient than the short one, for a given port area and length two ports are less efficient than a single one, the port with flares is way more efficient than the one without them likely up to 3dB. If you can't find proper port area round ports octo is a possibility, you just build many of them to rapidly swap them. BTW wall and deadening change your resonant frequency, likely will higher.
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Red - 4 solobaric S15C (round solobaric from mid 2000s) in a 6 cubic feet net sealed box, D4 subs coils in series subs in parallel. Final load 2 ohm.
Yellow - 2 JL Audio 12W7 in a 4.5 cubic feet net box tuned to 33Hz 3 ohms single coli subs wired in parallel. Final load 1.5 ohm.
For a constant power amplifier such as Rockford Fosgate HDCP amplifiers:
For a non constant power amplifier the lower final load option will be at an advantage.
As ti stands the 12W7s are louder in the relevant range, say 28-45Hz.
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Those subs indeed need their space 4 to 6 cubic feet per driver is what they usually are given for ported use, if will use those in your room rather than a car tuning should be in the mid 20s not in the mid 30 which is what is given for car use.
It all depends on the application, you will need to be more specific on your dimensions, music you play, or movies or whatever you are doing with them, how are you powering the subs, etc.
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Port area depends on the driver itself, box size, power and tuning frequency. No params are available for the drivers SO just guessing, you were doing 26 square inches per driver last time, with the 12" port it's like 28 square inches so you know maybe, flares help a lot, what's too large is the box size, more than 2.5 net per driver, on a lot of power those drivers are going to bottom out below tuning very likely. Also I would do double layer in the baffle and probably the rear wall and a bunch of cross braces between them.
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The SALT 4k can put out 6106W uncertified @14.3V so let's say 3000W per driver:
Box: tuning is 32Hz net volume 2cubic feet per driver.
As you can see you hit Xmax at 23Hz, going over Xmax produces distortion and likely coil heating.
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As before I don't have enough information to tell your current box is the problem, make sure you read and check all the causes for lack off bass I left you. Also I recommend building a cardboard test box to make sure the real box can get inside your trunk once built. Best of luck.
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100% you need your subsonic engaged, the SALT 4K will put out more than 4K, not only will protect your subs but can also reduce the amp operating temperature among other benefits.
The frequency you set your subsonic filter is calculated as 0.75 x tuning frequency of the box.
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You cannot do the test with subs because the impedance of subs changes with the signal frequency, You should get a clamp, there are some inexpensive alternatives. You can calculate with it along with the voltage (measured under load at amp terminals) input power at whatever level you are playing.
Bottom line you are not going to get accurate numbers the way you measure, assuming a 13.8V input voltage under load and your fuse rating P=13.8 x 80 = 1104 Watts input power so that the fuse won't blow.
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You need a clamp to see the actual current going through the cable that has the 80A fuse.
To reach rated RMS power you need to feed a sinewave and you set the amp gain to get it's output to the threshold of clipping ( scope or DD-1 needed to measure) and using a resistive load. you measure the voltage across the power terminals of the amp as you do the test not when there is no load and the current with the clamp and do the math with that data. Most systems people have run like yours, far below their theoretical limits.
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You can absolutely use it and it will work but likely a modern car DSP will do everything better and you can control it wireless from your smartphone and with some models you can stream directly to it. Those were pretty rare, if in good condition it may still be worth a lot to some people.
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The worst case scenario is that your rear battery is discharged, malfunctioning or whatever and you want the alternator to be able to source the full current draw of that amp at full output so you want two 1/0 wires going back there and two 1/0 ground wires to ground since that's the amount of terminals the amp has on it.
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To answer the question anyways you have to take a look at hybrid Audio's own website:
Their solution to a 3 way setup is adding the U2x-W to the passive crossovers you already own like it shows in the picture above, you can see then that the crossover frequencies are as follow:
mid woofer 500Hz and below.
mid 500 to 5200Hz
tweeter 5200Hz and up
The link to the passive crossovers on the left (that make the setup 3 way passive) is as follows:
https://hybrid.audio/product/unity-u61-2v2/
From this I already can tell you that the B2 crossovers are not what you are looking for as the crossover frequency between mid and tweeter in those is 3.5 Khz, much lower than what your tweeters are expecting.
If you have a 4 channel amp you can implement the 500Hz crossover point with it and in the 500Hz and up channels connect your passive crossovers there to drive the mids and tweeters. Hopefully it makes sense.
Need help with Aero or slot port design (Going for more bandwidth than SPL)
in Subwoofers / Enclosures
Posted
Really controlling port area is not necessarily the preferred method to reduce a peaky response, reason being at high volume you may get port noise and at lower volume does nothing to help the peaky response,
Here is the U12 v1 in orange without damping and in yellow with heavy damping:
Box is 2 cubic feet net per driver @ 35Hz.
As you can see you get a sharp drop in the peak and a somewhat softer rolloff, additionally it doesn't change (up) your tuning as cutting volume would do.
If you are not listening to lower frequencies enough then just tune lower as needed..