Boomer1950

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

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.

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.

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 😉 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

Thanks so much for the reply. You've given me some things to think about.

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?

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?

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.

I'm recently retired & I'm spending even more time listening to my home theater system with my wife. We use my system for movies & TV 60% of the time & music 40%. I bought most of my current speakers 13 years ago. I have Polk Monitor 70s up front - Monitor 50s as surrounds - I recently upgraded my center channel to a Polk CSiA6 (from a CSiA3) - I added 2 height speakers - Polk RTiA1s - last summer. The only subwoofer I've ever owned is the Polk PSW12 - a "powerhouse" 12" ported sub with 100W. My house was struck by lightening last summer & blew up all of my electronics. I had a surge protector, but it had gotten too old to save my system. The good news is I was able to replace my TV with a 65" TCL 4K TV - replaced my AVR with a Sony STR-DN1080 - a Sony UBP-X700 4K Blu-Ray player replaced my Blu-Ray player - and an Apple TV 4K replaced my old Apple TV. I moved into the 4K/DolbyVision/HDR/DolbyAtmos world suddenly. The new receiver improved the sound of my main speakers dramatically (this is my 3rd AVR in 13 years). Unfortunately, it has also exposed my subwoofer as being woefully under-performing. I have a tough room to work with in some ways. It's 16' x 17 with a ceiling that starts at 9' on one side of the room & reaches 14' on the other side. One wall has a double doorway leading to a small home office - another wall has a double doorway leading to the kitchen/dining-room & it also includes a pass-through window that's 60" x 32" - another wall has a stairway leading to upstairs & a hallway to 2 bedrooms. One wall is solid, but it has a large window on it. So... I'm forced to use a corner placement for my TV & my couch is diagonal in the room - parallel with the TV. I'll add some pics to this before I post it. Given the awkwardness of my room, my speakers are positioned fairly symmetrically for my listening position. Everything looks & sounds better than it ever has, except for... We are both retired, so an unlimited budget isn't in the cards. My wife enjoys movies & music on my system, but she doesn't appreciate what we're NOT hearing on the low end. She hears "better subwoofer" only as "even louder music & explosions". I have a slight uphill battle for this project, so keeping it as "stealth" as possible is important - I'm thinking down-firing or dual-opposed end-table or coffee table. I probably need to keep total driver cost around $400-$500, but I'm open to suggestion. I believe DIY is my best option & I'd love a flat pack. But I have a friend who makes cabinets for a living, so a custom design is doable. However, I'm lost as to whether I'd be better served by two 12" or 15" drivers as opposed to one 18" driver. Or, I'm torn between ported & sealed, of course. I lean toward sealed, but I appreciate what a well-designed ported sub can do. I don't feel compelled to get below 20Hz. Getting down to 20Hz would be wonderful. I'm further handicapped by the fact that I only own a MacBook Pro, so most of the common subwoofer design programs are apparently unavailable to me. I need you to put your best thinking caps on. My problems are slightly different than the ones Ricci faces ("As usual with me it's not about the most I can get out of a single driver or for the least amount of cash but what can I get out of X amount of cubic volume for application X using whatever means necessary. Can't help it it's just what I find interesting anymore."). I need to spend as little as possible, but receive the most performance possible. Everything's easier when that pesky "cost" constraint is removed.