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Boomer1950

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  1. Ricci - the plan is to have the port & driver on the 20 x 26 side, as you thought.
  2. About the suggestion of having two subs - I can't do it right now. I understand the advantages, but it is unaffordable at the present time. This sub will be such an improvement over what I've been listening to for the last 13 years that two subs are not very appealing to me.
  3. Thanks for your comments, @SME. Because the problem you mentioned with arranging 3 Precision Ports on the front of my box is virtually unsolvable, I'm going to go with a slot vent. This construction is a little more complicated than using pre-made ports, but I don't think it will be beyond my capabilities. I've settled on a 7ft^3 box with a 70 sq.in. port that is about 40" long which I hope gives me a tuning of around 24Hz. I will be dividing the port into 3 pieces for added support & to give me the possibility of closing one or two of the ports. I assume dividing the 70 sq.in. port into 3 ports will lower the tuning, but that seems fine to me. I plan to start working on the box in the next few weeks. I'll keep you posted as to my progress. If there are additional comments or suggestions, I'd love to see them. Thanks again to everyone's help.
  4. After further consideration I've made another adjustment to my plan. If I leave the box @7ft^3 & change the tuning to 20Hz, the port length drops to 22.25" - removing the need to curve the ports. Plus, blocking one port should take it into the teens for HT, if I've understood properly. If I get this type of performance from my first DIY sub, I'll be thrilled.
  5. Thanks, Ukko. I noticed the sweep elbow you mentioned when I was looking for components for the ports. It looked preferable to the 90ยบ angle piece. I will be able to source the pipes & fittings locally. I haven't tried Wine to run WinISD. I'll give it a try.
  6. After working with some box modeling software I've come up with a new design. To the basics: I'm planing to use a 15" SI SQL-15 driver (with dual 2 ohm voice coils) & a Crown XLS1002 amp, 1100w bridged @4 ohms. My plan now is to build a 7 cu.ft. box (26'" x 20" x 29.35") with two front-firing 4" ports tuned to 16Hz. The ports will be 36" long - necessitating a curve in the PVC ports. I have a friend in the cabinet business & he will cut all of the MDF for me. I plan to assemble the box & ports myself. I've decided to put this sub between my L&R speakers & under the center channel. This will allow me to hide most of the box from view, but this location has restricted me to 20" high & 26" wide. The depth is variable. Because I only have access to a MacBook I've been unable to do any modeling using the driver I've selected. I don't know if tuning the box to 16Hz is reasonable for this driver, amp or box size. I'm not ready to start cutting MDF, so I'd like to know where I may have gone astray and/or made unreasonable assumptions. https://subbox.pro/en/b/wikqDKNb2 - the mock up of my current design. This program doesn't give the option to move the ports to the front or to indicate a curve in the port. Based on my research the length of the ports should be 36" - not the 33.83" indicated in the box design program. All feedback is appreciated - even if it (once again) exposes my ignorance. I have so much yet to learn.
  7. Hi guys - I did a bunch reading since my last post. Shoulda done it before I posted that last message. I'm more educated about the relationship of the size of the box, diameter of port, number of ports, and the tuning of the sub. I knew so little when I started researching DIY subs that I'm constantly amazed at what I still don't know. I guess it's a good thing that I don't mind laying out my ignorance in front of all you more knowledgable people. I'm back at the "drawing board" to decide how low I'd like to tune my sub, how large of a box will be acceptable in my room, how many ports am I planning & the diameter of the ports. So, until I can get my head around the various parameters left for me to determine, I'll be working on these variables. It's like I've been thinking from the beginning - answering a few questions (how big of a driver, which driver, how much power, ported or sealed) just opens the door to additional questions. I'm glad I enjoy solving puzzles.
  8. Thanks for the advice. Dgage, I would have never been satisfied with the tuning used in my first attempt. I went back to the modeling software I found & set the port tuning to 16Hz & it generated new plans. I'll upload them. I wish I could afford to build 2 subs right now, but it's not feasible. I need to build one sub & try to maximize its performance. SME suggested using 2 ports - that's probably a good idea. The revised plans I'm uploading indicate one 3" x 16.87" port. If the port length is correct, will 2 ports 3" x 8.44" produce the same result? I am very aware that the port length may not have been calculated well, so any confirmation will be appreciated. SQL-15 Ported Sub.pdf
  9. Everybody"s input has been very helpful to me. To get an additional viewpoint, my long-awaited (not really a "long" wait) visit to Stereo Integrity happened last week. Nick met me in the parking lot & called me over to the back of his Jetta. He lifted up the hatch & showed me his new 15" SQL-15 he had mounted into a remarkably small box he bought for $20 for on Amazon. He had a 1000w amp driving the sub. He also had one of his mid-range woofers & tweeters on each door (he's now discontinued those speakers). He cranked up the volume & actually played some pipe organ music for me first. It was impressive. The vibrations from the extremely deep bass hit me hard in the chest (& everywhere else). Nick said one note was 16Hz. I believed him. It was very deep & loud. My poor wife was in the back seat & during the demo she told me her hair was blowing from the air being moved by the sub. It's not a big surprise. The Xmax on this driver is 28.4mm. That's not 38mm Xmax like his HST-15 mkII, but it's pretty damn good. Air was being moved - a lot of air. Anyway... after a long & enjoyable demo ( including every type of music) & me quizzing Nick about every bass topic I could think of, we began to say "Good-bye" - but even that took a few minutes. He's just a really nice guy. In addition, he was incredibly patient & knowledgable. Of course, I left knowing I would buy one of those babies. They won't be ready to ship until late December, but I'm in no hurry. Now I need more specific advice. I've decided to build a ported sub with ST's 15" SQL-15 driver. Nick recommended 1000w for the amplifier & I'm considering a Crown XLS 1002 with 1100w @ 4 ohms bridged. From SI's website: Ported = 3.75 ft^3 tuned to 29 Hz. I have a Mac & no easy access to a PC, so my access to speaker design software is limited. I found a limited web-based subwoofer design program, but I'd appreciate any feedback on the sketch I'm u ploading. I like the idea of a "pipe" port, but I have an open mind. How many braces should I add inside? All suggestions are welcome.
  10. Thanks, Max. I think the number of variables involved in the selection of a subwoofer are somewhat overwhelming. Your suggestion to determine a rational budget seems simple, but I think my problem is much more basic. I have very little listening experience when it comes to various subwoofers. The numerical expressions of how low, how loud & how accurate each subwoofer can reproduce bass don't mean much to me because I haven't heard a sufficient variety of subs with differing capabilities to understand the numbers. But, I'm hoping to take a big step forward soon. I haven't been able to go to Stereo Integrity yet, but I'm planning to go soon. I'm excited about hearing a few different subs with someone who actually knows what he's talking about. I won't be surprised when I decide to buy a SI driver after a visit, but I'll know it was an informed decision, at least.
  11. You guys are so helpful. I was afraid my problem wouldn't get any attention, since I wasn't planning to build four 21" subs ๐Ÿ˜‰ In my recent travels around the subwoofer universe I had discovered Stereo Integrity. Everything about their drivers looked great - if expensive - to me. They became my "aspirational" choice. The truly amazing thing is I live less than 2 hours away from SI. I'm a NC guy - born & bred. Do you know whether visitors are welcome at their facility? I don't plan to be a pest, but the opportunity to see one of the best driver manufacturers in person is very compelling. I'm in no hurry to buy a driver. I'm enjoying the research. But, I would dearly love to be able to end up with a sub from SI. It's more than worth it to me to wait until they release their new subs later this year. Thanks again, dgage
  12. Thanks so much for the reply. You've given me some things to think about.
  13. Dgage, one other thing... Do you have a 15" driver you prefer. I realize you don't use 15" drivers much anymore. Is the Ultimax 15" a good choice?
  14. Thanks, dgage. That question of two smaller subs vs. one larger sub has been a difficult issue for me. I thought two smaller ones were preferred, but it's nice to have that confirmed. For some reason the idea of dual opposed 15" drivers in a "coffee table" appeals to me. The table would sit parallel to my seating position with the drivers firing to the left & right. Neither driver would have any obstructions near it. The idea of having a relatively vibration-free coffee table/subwoofer has grabbed my attention. Will this configuration provide any of the benefits of having two separate 15" subwoofers?
  15. Thanks for the advice, Peniku8. I have been sorely tempted by the Marty Sub Cube. It really convinced me to go DIY - the cost/benefit was clear. I thought the logistics of getting one of their flatpacks is somewhat complicated. They like to ship 4 Marty subs to a customer & he tries to find someone to buy a couple in order to share the freight costs. Call me hornery, but I don't like that process. I was impressed with the build of a MartySub & the kit is great with the interlocking structure. It's not out of consideration.
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