This is my first DIY sub, and first post on the forum. After 3 weeks of messing around in the garage I came up with a decent result. Output so far seems great, but I may need some adjusment on the HPF. When testing the sub using the opening explosion in Hurt Locker and opening scene in War of the Worlds it bottomed out a few times. Not prolonged, but audible.
I think I need some guidance at this point. I modeled this using Unibox. Here are the particulars:
2.5L
Tuned to 22hz +/-
4" x 25.25" port flared on both ends
F3 of 20 hz or so
According to the modeling this will hit XMAX around 19hz. The Bash 300 comes with a stock 17.7 HPF that I thought would be sufficient to avoid XMAX. But maybe not......I was not sure if I created the HPF circuit using Bagely's circuit designer program correctly, when I imported it into Unibox. I am using the LFE input and have it crossed over at 80hz on my Marantz reciever. Here are my questions:
1. Does the LFE input bypass the 17.7 HPF on the Bash 300? If so I guess I need to used the Line Level Inputs in order to use the HPF.
2. If it does not, then it sounds as if I may need to raise the HPF. Right?
I welcome all thoughts and advice. Thanks in advance...
I think I need some guidance at this point. I modeled this using Unibox. Here are the particulars:
2.5L
Tuned to 22hz +/-
4" x 25.25" port flared on both ends
F3 of 20 hz or so
According to the modeling this will hit XMAX around 19hz. The Bash 300 comes with a stock 17.7 HPF that I thought would be sufficient to avoid XMAX. But maybe not......I was not sure if I created the HPF circuit using Bagely's circuit designer program correctly, when I imported it into Unibox. I am using the LFE input and have it crossed over at 80hz on my Marantz reciever. Here are my questions:
1. Does the LFE input bypass the 17.7 HPF on the Bash 300? If so I guess I need to used the Line Level Inputs in order to use the HPF.
2. If it does not, then it sounds as if I may need to raise the HPF. Right?
I welcome all thoughts and advice. Thanks in advance...
oops
Not sure what I was thinking or not-
The enclosure is 2.5 cubic ft or about 72 Liters.
Thanks for the responses thus far.
Not sure what I was thinking or not-
The enclosure is 2.5 cubic ft or about 72 Liters.
Thanks for the responses thus far.
Hmmm. I thought so. Does the LFE bypass the HPF then I wonder on the Bash 300?
I'll post a some pics when I hit 5 posts and my restrictions are lifted.
Hi cptnjosh, you should be able to post pics whilst still under moderation. Just click the Go Advanced button, and you should be able to upload pics 🙂
Tony.
Tony.
PICS
The finished is rolled on. If I could do it again I probably would have put some vinyl on it. The grill is a JL Audio Grill that was slightly modified to fit. No fasteners, just friction. I had to add an extra plate on the back for the Bash, as PE lists the wrong cutout dimensions on there website.
Overall I am pleased with my first project.
The finished is rolled on. If I could do it again I probably would have put some vinyl on it. The grill is a JL Audio Grill that was slightly modified to fit. No fasteners, just friction. I had to add an extra plate on the back for the Bash, as PE lists the wrong cutout dimensions on there website.
Overall I am pleased with my first project.
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Based on some adivice from another forum, I ran down to Radio Shack today and picked up some resistors and a soldering iron.
Made the modifications to increase the HPF to 20.4hz with 1db of boost in the 31-35hz range. Well, good news is I didn't screw it up. It still works, but my fine soldering leaves something to be desired.
Bad news is, it still seemed to bottom out during the explosion at the beginning of the Hurt Locker. The volume was no more than normal listening level. I am not sure what to think of this.....
My Outlaw Audio LFM-1 Compact which uses a Hsu 10" driver with inferior specs does not do this, even at Reference levels.
Maybe I need to contact the folks over at CSS. Any suggestions?
Made the modifications to increase the HPF to 20.4hz with 1db of boost in the 31-35hz range. Well, good news is I didn't screw it up. It still works, but my fine soldering leaves something to be desired.
Bad news is, it still seemed to bottom out during the explosion at the beginning of the Hurt Locker. The volume was no more than normal listening level. I am not sure what to think of this.....
My Outlaw Audio LFM-1 Compact which uses a Hsu 10" driver with inferior specs does not do this, even at Reference levels.
Maybe I need to contact the folks over at CSS. Any suggestions?
IIRC, the built-in high pass on the amp is second order so it won't be as effective.
i would say the box is too big. i have the adire koda 10(sdx10 is the next gen. of this sub) and bash 500. i went from a 3.0 cuft @26 to 1.5 @32 and now its perfect. get a 15" for under 30hz.
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I have found with smaller XBL drivers (FR125 & SDX7) that when they reach their limit it is abrupt, and disturbing -- sounds like what you are describing. So when i went to choose boxes for my quad od SDX10 i chose sealed. With room gain and maybe a bit of boost i should get 20 Hz no problem.
You might try stuffing the port with someting like open cel foam to make the box aperiodic.
dave
You might try stuffing the port with someting like open cel foam to make the box aperiodic.
dave
Ok-Thanks for the replies guys. I was worried about the enclosure being too large. It looks ok on paper but maybe not in reality.
Today I made a dummy plate and wired my Bash 250 from outlaw sub to it. I was able to replicate it with second amp. So no amp issues. Must be driver or enclosure design issue.
I was also wondering if the flow of air in the enclosure is such that it might be throwing the cone out of alignment ever so slightly.
Anyway, I think I will try plugging the port and see what difference that makes.
I wish i had a spare smaller enclosure to try this in. Back to the drawing board I guess. In the mean time, it is playable but is not what I was going for.
Today I made a dummy plate and wired my Bash 250 from outlaw sub to it. I was able to replicate it with second amp. So no amp issues. Must be driver or enclosure design issue.
I was also wondering if the flow of air in the enclosure is such that it might be throwing the cone out of alignment ever so slightly.
Anyway, I think I will try plugging the port and see what difference that makes.
I wish i had a spare smaller enclosure to try this in. Back to the drawing board I guess. In the mean time, it is playable but is not what I was going for.
+1 !!
I used the older TRIO8 (same XBL motor) in a ported sub design and even though the design was conservative and would not approach the manufactures xmax spec, I found that the sub would bottom out at less than 60% of what is rated at. Besides not having a bumped back plate, I think that the xmax specs on all the TRIO and SDX drivers are only about half of what is listed on their spec sheets.
I replaced the TRIO8 with a 8"TB sub (same amp and enclosure) that actually had less spec'd xmax than the TRIO8 and everything works perfectly - can drive it to full rated output without bottoming the driver
I'd build more than one of these. A single 10" isn't going to move a lot of air... you might just be expecting a bit much from one SDX10.
I don't believe this to be the case at all... it's the motor technology. XBL2 motors don't soak up power after Xmax quite like others - they push harder after that point than those using older ceramic tech. Which tends to make them more sensitive to issues like the highpass not being set correctly.
Found this out the hard way once I fired up my dual SDX10 16Hz tapped horn for the first time. The drivers bottom out easily if I mess up my highpass. Ask me how I know 😉
I am leaning toward the driver being the issue as well. The enclosure size is not much bigger than the Quartet 10 design. Same HPF listed in the specs. of that design. I am not sure what to do at this point. Try an alternative HPF, exchange my SDX10 for another one, build another enclosure, or return the SDX10 and get a HIVI sp10 or a Seas L26Roy.
Oh, i tried plugging the port and it seemed to make things worse.
How should i proceed?
Hi cptnjosh,
If you have another SDX10 you could try mounting both in this same box (maybe the second one in the back?), and connecting the drivers in series. Even without retuning you should get a very nice subwoofer with a lot less driver excursion for a given input voltage level.
Regards,
If you have another SDX10 you could try mounting both in this same box (maybe the second one in the back?), and connecting the drivers in series. Even without retuning you should get a very nice subwoofer with a lot less driver excursion for a given input voltage level.
Regards,
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