Last edited:
Buck
5,000+ posts
little alien on campus
I'm willing to bet the manufacturer recommendations are probably what someone should use for a daily setup, and just tune the box where you want to try and peak. That Fs is quite high for today's times, at least from what I'm used to. I mean it's a high power, high Fs sub, low Qms, not a terribly high Mms for that power level, some subs at around 3k have 400, 600+, but with 4" coils. That relatively lower Mms for that wattage handling plays into the higher Fs, some. These are gonna move a lot of air at high frequency, and they're probably gonna peak hard at higher frequency, like 50-60+ hz or the sub's Fs combined with cabin resonance, idk what that would be. You could try tuning in the lower to mid 30's to try to drop the harshness of that over 45 hz hard peak it's probably going to have. I mean that's 6kw resonating hard, so I'd just tune as low as you need to hit the lowest you want to play, and the rest is going to be the rest. Probably do 5 cubes with 80 in^2 port area, but it should always be modeled to make sure. Maybe tune to 32-35 hz for an average daily. If you tune these subs low, you wanna model it to see if the port air velocity drops way off, because you might can shrink port area. Idk a good designer will be able to see things like that, lower tuning and smaller port can help musicality and controlling woofer cone, especially if you're going to fire forwards, but I'd only recommend that if you seal off the cabin, but I'd still try to do it in the trunk rear or firing up or something.
These come across to me as pretty stiff, high throw subwoofers, so they might resonate hard around Fs. I wish the Cms unit made sense; you can reverse engineer that sometimes with winisd Alpha. Idk what a m mm/N is. Cms is suspension compliance, as in how far the suspension moves when a force is applied, so it should be in m/N or mm/N one, which is millimeter/Newton, how many mm the suspension travels one way with a Newton of force applied, shows direct stiffness (compliance) of suspension. And that Vas is low, too (stiff).
Last edited:
Wish I would have saved the graph, can't find the file and forgot to save the parameter's SMH... but agree, vent velocity was close in the smaller-ish (6 gross) but was able to get decent response tuned to around 33hz, VV looked good too. Using a 6.25 cu ft (gross) enclosure (Vb) 5.06 cu ft, 32hz, I wrote down that I got a vent of 10"x6"x24.5", or a slightly smaller box, say around 6 gross, Vb 5.14, 4x10x15.25 port. Did it in BassBox 6 pro.
I think he's pulling out the top half of the back seats, firing everything into the cabin.
I think he's pulling out the top half of the back seats, firing everything into the cabin.
Last edited:
- Thread Starter
- #24
...
Last edited:
Buck
5,000+ posts
little alien on campus
Ports seem like too little in^2 for 2 subs, I'd have to model to say what I'd do. I have dozens of self inputted woofer t/s and hundreds of individual models saved for every person I modeled for starting at certain point lol. I save it all.
The subs together is gonna be about 26" wide, so you need to make sure you have enough width for a proper port. 30" width doesn't leave you hardly any room for a port, especially not an aero, like if you plan to stuff it in between that opening (giggity).
Last edited:
Yeah, the smaller one did seem a bit on the smaller side. but the larger one was close to 1500 cubic inches?? Anyway, will try again, see what happens. I think he plans on using the full width of 39", up to 14", 15" high, deep as needed. Thinking tipple baffle of 2.25", sufficient bracing, bit of a monster but, should get to where he's trying to go.
Buck
5,000+ posts
little alien on campus
Buck
5,000+ posts
little alien on campus
I meant to ask too, or say this, you can port through the rear deck. Sound-wise that would work better firing forward IMO, as long as the proper space and clearance is there. Also takes port out of the box which saves internal space, somewhat. It's not easy to do, though, but you def can do it sometimes and make it awesome. Just a thought, I've literally had to think about this so much with all the systems I've designed for. Like I usually get some of the most ridiculous box requests because I'll try to do them no matter what. Just depends on how hard you wanna go.
Last edited:
- Thread Starter
- #30
...
Last edited:
Old_Slapper
CarAudio.com Elite
People didn't like ported boxes because the port noise and needing a bigger box. Therefore, instead of 1-sub in a ported, they would go with 2-subs in a sealed box. The complaints were hollow sounding bass and the air turbulence sound coming from the port.
Back in 1997, I started messing with parted enclosures. This was a time when sealed boxes were the common design for SPL competitions. After sitting and listening to a ported enclosure, I realized how to fix the ported issue. The hollow sound comes from the plastic pipe reverberating the sound as it travels down the pipe. Same thing as screaming down a plastic pipe and sounding like a robot on the other end. The rushing air noise comes from a mass pressure of air trying to flow out of a small port. So, the fixes were simple. Design a port that doesn't vibrate and is large enough to allow air to flow easier. Also, it dawned on me (DUH) that sound was coming from the port, so if I made the port bigger, more sound would come out. My box design caught the attention of a few manufactures, such as Rockford Fosgate, JL Audio, and Kicker. My box designs also started to dominate the DB drags in my area. A single sub, in a ported box, out performed 3 of the same subs in a sealed enclosure. At the time, I worked at DOW Stereo in San Diego.
With that said, I would go with a large port opening that is made using, at the least, 3/4" MDF. A square port put out more sound than the slash port. Tune it around 40 hz. that will give it a really nice bump in the octives.
Back in 1997, I started messing with parted enclosures. This was a time when sealed boxes were the common design for SPL competitions. After sitting and listening to a ported enclosure, I realized how to fix the ported issue. The hollow sound comes from the plastic pipe reverberating the sound as it travels down the pipe. Same thing as screaming down a plastic pipe and sounding like a robot on the other end. The rushing air noise comes from a mass pressure of air trying to flow out of a small port. So, the fixes were simple. Design a port that doesn't vibrate and is large enough to allow air to flow easier. Also, it dawned on me (DUH) that sound was coming from the port, so if I made the port bigger, more sound would come out. My box design caught the attention of a few manufactures, such as Rockford Fosgate, JL Audio, and Kicker. My box designs also started to dominate the DB drags in my area. A single sub, in a ported box, out performed 3 of the same subs in a sealed enclosure. At the time, I worked at DOW Stereo in San Diego.
With that said, I would go with a large port opening that is made using, at the least, 3/4" MDF. A square port put out more sound than the slash port. Tune it around 40 hz. that will give it a really nice bump in the octives.
Activity
No one is currently typing a reply...
Similar threads
- Started by Emilis
- General Car Audio 2 3
- Started by Maddoxp07
- General Car Audio
- Started by Brad Eli
- General Car Audio
About this thread
- Start date
- Participants
- Who Replied
- Replies
- 30
- Views
- 5,223
- Last reply date
- Last reply from
- Old_Slapper
New threads
-
-
-
-
-
Need information on testing passive crossover capacitors.
- Started by masterblaster1
- Replies: 20
-