Hey everybody. I'm new to sub enclosures and have been using winisd. I keep getting a common problem with vented, 6th, and 4th order enclosures.
No matter what I do I cannot push the frequency lower. Either the drivers go into overexcursion or the port velocity is too high.
For example, if I make a 4th order, the enclosed volume largely dictates the frequency depth. However, if I make it larger no matter which driver I choose it seems to send it into over excursion down low. The only way to prevent this is a thin port, then port velocity is too high. I also don't know how to stimulate tapered waveguides or flares to make sure I don't wreck the drivers.
6th order just seems impossible for the same reason, but people obviously build them so I must be doing something wrong. Any ideas?
No matter what I do I cannot push the frequency lower. Either the drivers go into overexcursion or the port velocity is too high.
For example, if I make a 4th order, the enclosed volume largely dictates the frequency depth. However, if I make it larger no matter which driver I choose it seems to send it into over excursion down low. The only way to prevent this is a thin port, then port velocity is too high. I also don't know how to stimulate tapered waveguides or flares to make sure I don't wreck the drivers.
6th order just seems impossible for the same reason, but people obviously build them so I must be doing something wrong. Any ideas?
This was my first post so I posted here with the direct question haha. I'll post my design pics with the response curve over in the subwoofer section. Though I'll have to model up some different variations, I've been through a ton of iterations and just can't understand how people make boxes that are ported without overexcursion or port noise or how to model in flares (to get rid of chuffing, but also not reduce resistance and therefore overexert)
Thanks for your response!
Thanks for your response!
For a given LF cutoff, the required excursion in the pass band is the same whether you use 4th, 6th order or analogue or DSP EQ to flatten the response and is independent of box size. The excursion is a LOT less than a Closed Box with the same LF cutoff.
The price is the port. To reduce chuffing, make the port large, long & flared. For a sub, you don't have to worry about 'pipe resonances' in the port.
The price is the port. To reduce chuffing, make the port large, long & flared. For a sub, you don't have to worry about 'pipe resonances' in the port.
This is my current best, I tried a couple different drivers, and every style seems to have the same issue. No matter what I do with the port it can never get lower without the subwoofer going into overexcursion or the vent velocity being too high. The box becomes too complient with large ports, leading to too much subwoofer play, or the ports are too restrictive and they will chuff. I have absolutely no idea how to model in flaring the port, which I think would reduce the restriction and therefore push the sub too much. I've tried sealed, ported, 4th order, 6th order, just so many. The graphs here have pretty hefty use of high and low pass filters to control excursion below the red line and port velocitybelow 18m/s.
For reference, I'm an engineer, but not in this discipline so am BRAND new to this. I don't know where to find the equations to build my own spreadsheets for complicated designs.
My goal, get as low as possible for as little height as possible. Box volume doesn't tend to be the issue, with 42.5w x 26l x 2-4in high.
I have flirted with throwing in a 12in kicker L7T124 wired to 2ohm. My amp is LX1300.7 with 550w to the subwoofer at 2ohm and the sub could handle 600w. However, box gets up to 6-8in and that takes about 25% of the trunk space, especially because I need the top to be sealed to act as the new trunk floor. Trying for SQ not SPL so not too stressed if the levels aren't extraordinary. This is the wife's daily.
I also don't know how to model in downfiring. I imagine it acts as a 6th order bandpass with the rear wave being ported and the front wave having 4 incredibly short and wide ports.
If anyone has suggestions on how to enter in the data if I'm missing something or some advice that would be super appreciated!
For reference, I'm an engineer, but not in this discipline so am BRAND new to this. I don't know where to find the equations to build my own spreadsheets for complicated designs.
My goal, get as low as possible for as little height as possible. Box volume doesn't tend to be the issue, with 42.5w x 26l x 2-4in high.
I have flirted with throwing in a 12in kicker L7T124 wired to 2ohm. My amp is LX1300.7 with 550w to the subwoofer at 2ohm and the sub could handle 600w. However, box gets up to 6-8in and that takes about 25% of the trunk space, especially because I need the top to be sealed to act as the new trunk floor. Trying for SQ not SPL so not too stressed if the levels aren't extraordinary. This is the wife's daily.
I also don't know how to model in downfiring. I imagine it acts as a 6th order bandpass with the rear wave being ported and the front wave having 4 incredibly short and wide ports.
If anyone has suggestions on how to enter in the data if I'm missing something or some advice that would be super appreciated!
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kgrlee, thanks for the reply. I'm sort of confused though, I tried extending the port a lot and I still can't manage to push the graph to the left. However, I may have been widening the port and lengthening to a net no movement? I also adjust the height to account for box volume, increasing didn't seem to help. I have plenty more hours to play around with it, but have been spinning my wheels for days trying different drivers.
Are there key TS parameters that limit the minimum frequency? Maybe I can start looking for others. I've seen some Hexibase videos where he gets low low with 6th order and tapered waveguides that I just cannot replicate, but know it can happen and don't know where I'm going wrong.
Thanks!
Are there key TS parameters that limit the minimum frequency? Maybe I can start looking for others. I've seen some Hexibase videos where he gets low low with 6th order and tapered waveguides that I just cannot replicate, but know it can happen and don't know where I'm going wrong.
Thanks!