I'm looking to make a pair of 3-way bookshelf speakers to go deep (at least mid 30's, but the lower the better) but not terribly loud. These would be used ideally more for office, computer, and background music and are not intended for HT use.
I have a pair of Tang-Band W5 1138SMF's from a previous computer build that would do nicely. Those would be perfect if they didn't require so long of a port. It's impossible to fit that much port in a nice-looking bookshelf enclosure without folding the port a bajillion times (bad for sq and efficiency from my understanding). I've been experimenting with another box with a Dayton 5.25 PR on both the left and right side of the box. So far, I'm not terribly impressed, but I only have one box made and have yet to start tweaking.
Are there other options I may be missing to hit the 32Hz neighborhood in a bookshelf sized enclosure? I'm really not interested in going sealed and throwing EQ at it just yet as I'd like to hit my targets "naturally" using organic wood, cage-free drivers, and non-GMO ports. 😎
I have a pair of Tang-Band W5 1138SMF's from a previous computer build that would do nicely. Those would be perfect if they didn't require so long of a port. It's impossible to fit that much port in a nice-looking bookshelf enclosure without folding the port a bajillion times (bad for sq and efficiency from my understanding). I've been experimenting with another box with a Dayton 5.25 PR on both the left and right side of the box. So far, I'm not terribly impressed, but I only have one box made and have yet to start tweaking.
Are there other options I may be missing to hit the 32Hz neighborhood in a bookshelf sized enclosure? I'm really not interested in going sealed and throwing EQ at it just yet as I'd like to hit my targets "naturally" using organic wood, cage-free drivers, and non-GMO ports. 😎
Not so much the smallest sub but the smallest enclosure requirements.... Maybe try modelling the Tang Band W6 or W8 RBMs. The W8 RBM PE claims will hit 29Hz F3 in 0.77cuft.
Passive radiators can replace ports and take up very little cabinet volume. More expensive than a port, but something's gotta give if you are trying for low and small, and more level than a mouse fart 😉.
I'm having a hard time finding a suitable PR though. I'm typing this on my measuring rig and am in the middle of testing out my 2x Dayton 5.25 PR box right now. This is my first time with PR's, but from my understanding, you basically want "twice as much" PR as driver. My driver is the Tang Band 5.25" with 9.25mm xmax. dayton's new PR's advertise 9mm of xmax, so I figured 2 of those PR's would match 1 of my TB drivers nicely. Nope. The 5.25 TB can bottom out both of those PR's no sweat. We'll gloss over the fact that my TB is plugged into my iNuke 1,000 DSP, so I suspect it's getting more than 40w 😉. I wish they had a 6.5" version of those PR's, but the 5.25" versions simply aren't beefy enough to keep up and I'm having a difficult time finding a nice looking 6.5" PR with enough xmax to keep up.
Tang Band has what looks to be a nice 6.5" and 8" PR on their site, but I can't figure out where I'd go to order one...
I'm just not having any luck finding a good 6.5" PR that I could pair up. I may just suck it up and buy one Dayton RSS265-PR (10" aluminum cone with 24mm xmax) for each box. I really wish they had an 8" version though as 10" is way overkill for my build and I'd have to make the box bigger just to mount it. At that point, I should be using a larger driver and then it's becoming bigger than a 'bookshelf'.
Quick question on PR's. Do I need to pay attention to the physical location of the subwoofer in relation to the PR? If I'm mount a single PR on the side of a cabinet with the subwoofer on the bottom of the front baffle, the subwoofer will physically be much closer to one side of the PR than the other. Would this cause any disturbance to the PR caused by pressure waves hitting the PR at slightly different times?
Quick question on PR's. Do I need to pay attention to the physical location of the subwoofer in relation to the PR? If I'm mount a single PR on the side of a cabinet with the subwoofer on the bottom of the front baffle, the subwoofer will physically be much closer to one side of the PR than the other. Would this cause any disturbance to the PR caused by pressure waves hitting the PR at slightly different times?
Location of the PR will not matter. Unfortunately any time you need to tune a small box to a low frequency, an unreasonably long port is necessary, so this isn't a problem unique to the Tang Band W5-1138. Have you tried a pair of the Dayton SD175 PRs? With 8mm xmax, a pair should be able to keep up wi the W5-1138.
Have you TUNED the PRs to your requirements? You don't just stick a couple into a box in a 2 to 1 ratio.
PRs have to be tuned using mass(and/or vary the enclosure volume etc) exactly the same as a ported enclosure. A tiny enclosure often results in lots of PR excursion.
Did you plot a box at all or just randomly guess and now you have a random result...?
You would be far better off with EQ and sealed for a near field monitor.
PRs have to be tuned using mass(and/or vary the enclosure volume etc) exactly the same as a ported enclosure. A tiny enclosure often results in lots of PR excursion.
Did you plot a box at all or just randomly guess and now you have a random result...?
You would be far better off with EQ and sealed for a near field monitor.
Those Dayton 6.5" SD PR's look like they would be able to keep up much better. I have an SD 215A-88 8" sub that I'm very pleased with sonically. Unfortunately, the SD line looks rather cheap for this build. I want these to look super nice and the SD line just isn't quite as nice looking as I'm shooting for.
So, I'm wondering.... Just eyeballing, the PR excursion during sweeps/tones, it looks like it's peak excursion is around 32Hz, which is much lower than my simulated peak excursion at 38Hz with 37g added. If I sim adding an additional 15g (52g total), my sims show peak excursion at 32Hz and a frequency response that looks more similar to what I think I'm hearing. This has me wondering.... Does the advertised FS of PR's include the mass of the wingnut to hold the weights in place? I would imaging that's approximately 10-15g or so, but I'm not at home to measure for another couple hours.
So, I'm wondering.... Just eyeballing, the PR excursion during sweeps/tones, it looks like it's peak excursion is around 32Hz, which is much lower than my simulated peak excursion at 38Hz with 37g added. If I sim adding an additional 15g (52g total), my sims show peak excursion at 32Hz and a frequency response that looks more similar to what I think I'm hearing. This has me wondering.... Does the advertised FS of PR's include the mass of the wingnut to hold the weights in place? I would imaging that's approximately 10-15g or so, but I'm not at home to measure for another couple hours.
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Reviewing my sims, it looks like ported is still gonna give me a solid ~5Hz lower than PR. I may have to revisit my ported design. Well, time to sketch up revision 3. lol
Ports / passive radiators / Transmission lines are flawed.
Plus one!
Sealed box with Eq is superior full stop.
Plus one!
Sealed box with Eq is superior full stop.
Nature Vs marketing
Here Here!
The attached is very interesting as it explains the basic maths / biology behind the way we hear....
I had built lots of ported and ABR loudspeakers (first was a Hi Fi Answers kit, then a Practical HiFi kit ...1980's man!) and when I read the attached a few years ago I never looked back.
Pro drivers in sealed box's with powerful amplifiers and Eq .... OMG!
Soooo detailed and natural... bowed double bass / cello / left hand piano is a revelation.
All ports / delayed resonance systems now remind me of the bass you hear when the 18 year old bass ball cap dudes drive by in their ford fiesta's with a Kilo watt of amps driving 6 cubic feet of ported box.... Yuc.
Here Here!
The attached is very interesting as it explains the basic maths / biology behind the way we hear....
I had built lots of ported and ABR loudspeakers (first was a Hi Fi Answers kit, then a Practical HiFi kit ...1980's man!) and when I read the attached a few years ago I never looked back.
Pro drivers in sealed box's with powerful amplifiers and Eq .... OMG!
Soooo detailed and natural... bowed double bass / cello / left hand piano is a revelation.
All ports / delayed resonance systems now remind me of the bass you hear when the 18 year old bass ball cap dudes drive by in their ford fiesta's with a Kilo watt of amps driving 6 cubic feet of ported box.... Yuc.
I realize there's a place for sealed, and there's nothing wrong with that. That's just not my goal for this build.
Totally understand and all good.
I wish you all the best with your build but please do try a sealed option at some point in the future.
I wish you all the best with your build but please do try a sealed option at some point in the future.
I made a design very similar to where you are heading. W5-1138 Neo with 2x Peerless 830880 PRs or a single SD215-PR, known as Triumph or Biumph respectively. About 40Hz is all you can get in the 9" cubes I built, using the Peerless PRs with no added mass. In fact, the 1138 struggles to get lower than 40Hz in most compact alignments available. If you go overly large and EBS it like I did in my Compellurgy5, You'll get 20Hz as an F3, but the box is sized more for an 8-10" woofer by then, and you can't drive it very hard. The 1138 is also more prone to rocking modes in the suspension than the 1139, and makes more noise under longer excursions.
The W6-1139 is a lot more versatile, will achieve lower than your target rolloff, handle the power, and work in anything from 0.4ft^3 to 2ft^3.
Later,
Wolf
The W6-1139 is a lot more versatile, will achieve lower than your target rolloff, handle the power, and work in anything from 0.4ft^3 to 2ft^3.
Later,
Wolf
Yeah, I'm having difficulty getting PR's to go solidly under 40Hz with PR's as well. Vented seems to do much better, but I have to remember it is only a 5.25" driver. Still, in a 0.4 ft^3 vented box, it models an F3 of 32Hz, which meets my goals. If I didn't have the 1138 drivers already on-hand from the previous build, I'd totally go for the W6 for those reasons.
So, here's another (probably obnoxious) question. I'm looking to go with a rectangle port 0.75"H x 6.5"W x 21"L. In a 0.4 ft^3 (net) box, that's tuned to 38Hz and provides an F3 of 33Hz. Obviously, I'll have to fold the port, which affects tuning. My question is, is there an accurate way to predict the difference 'bending' a port will change the tuning? I'll just run it along the bottom, then go 90 degrees up the back to reach my length requirements (probably 2x 45's, but yeah).
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