Hi all! I don't mean to sound like I've made up my mind, this is just the path I'm on that makes sense to me.
As always, I'm open to advice, help, and scrutinizing.
Thanks, Al.
As always, I'm open to advice, help, and scrutinizing.
Thanks, Al.
the USB has a much longer horn than those designs you've posted, so dont expect them to fit the bill any better.
I only recomended the usb because you were looking for a kick drum sub. I dont know of any kick drums tuned to 40hz.
if you are going to need a full 40hz extension, forget about insane spl out of a single 18" unless you go with a sizable horn or expensive driver/amp combo.
the best performing, semi budget design would be arts keystone loaded with a 18tbw100. this is a 45x22.5x26.5 box and a 375 dollar driver. extension to just shy of 40. capable of around 130db 1 meter 2 pi
the cheap dayton I posted can also be used in jbells SS18 variant (message forum member trackzilla for the plans). Still pretty large, but a much cheaper driver, and only one sheet of material (so, Lightish). extension to 40ish limited to around 120db output (due to low xmax)
the 18tbw100 in a bass reflex box tuned 40ish hz would be a good option for a small sized box with decent output. the more expensive dayton I posted (the 465 i think) may also be suitable for this, but it has a very high mmd to be considered f0r a very effiecient BR tuned around 40hz (lighter cone would be better)
I only recomended the usb because you were looking for a kick drum sub. I dont know of any kick drums tuned to 40hz.
if you are going to need a full 40hz extension, forget about insane spl out of a single 18" unless you go with a sizable horn or expensive driver/amp combo.
the best performing, semi budget design would be arts keystone loaded with a 18tbw100. this is a 45x22.5x26.5 box and a 375 dollar driver. extension to just shy of 40. capable of around 130db 1 meter 2 pi
the cheap dayton I posted can also be used in jbells SS18 variant (message forum member trackzilla for the plans). Still pretty large, but a much cheaper driver, and only one sheet of material (so, Lightish). extension to 40ish limited to around 120db output (due to low xmax)
the 18tbw100 in a bass reflex box tuned 40ish hz would be a good option for a small sized box with decent output. the more expensive dayton I posted (the 465 i think) may also be suitable for this, but it has a very high mmd to be considered f0r a very effiecient BR tuned around 40hz (lighter cone would be better)
Thank, sine.
I was looking for a smallish box with some horn loading to help efficiency. Maybe I should get my mind out of the gutter and settle in with 50Hz or so? LOL
Thanks, Al.
I was looking for a smallish box with some horn loading to help efficiency. Maybe I should get my mind out of the gutter and settle in with 50Hz or so? LOL
Thanks, Al.
Al,
Back in the 1980's I was an EV dealer, mainly to satisfy the needs of my sound company, the PA systems had over 250 EV drivers when I sold it.
Built lots of TL boxes (one for the guitar player in Manhatten Transfer) they work nice.
None of the EV cabs you are looking at go down to 40 Hz.
The variant could, if tuned low.
The Keystone goes about 10 Hz lower (37 Hz F3) than any of the EV designs (loaded with EV drivers) you are considering and would eat them for breakfast as far as output potential.
That said, Vd is volume of displacement Sd (cone area) times Xmax (linear displacement), a single Lab 12" has almost exactly double the Vd of a pair of EV12L (13mm Xmax compared to 3.3 Xmax, 659 cc Vd compared to 166 cc Vd).
A single Lab 12 in a ported cabinet can do around 121 dB to below 40 Hz.
A pair will do 127 dB (outdoors) driven with your Phase Linear 700. Indoors, could be louder depending on the room and speaker location.
If you don't want to make any sawdust, I have a pair of these
FREE SUB PLAN: Dual Lab12 (Front Loaded) by Welter Systems
available for about the cost of the drivers and wood.
Art
P.S. Also have one nifty little 2x12" band pass box design I call the "Bow Tie" available, it is 26.5" x 22.5" x 15", it didn't quite make 100 Hz as the sim predicted, but would work well with your TL 12s around 80-90 Hz.
Output between the WS 2x12" and the BT compared below.
The BT has really small back chambers which keeps excursion low below Fb without requiring a HP filter.
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unless the horn is very long, then it wont be "ruler flat" down to 40. an 80 hz horn requires half the path length of a 40hz horn. if its a FLH and you are only using 1... it wont be ruler flat regardless. tapped horn has potential though.
Arts dual lab 12 box might be a great choice... although it will go lower than you require.
Thanks, guys.
That dual Lab12 is looking good. I just down loaded the builders plans.
Art, for the "Bow Tie", my old Pioneer active only goes down to 125Hz. I can go 6, 12, or 18. The mid bandpass slopes have a flat position available. Maybe I could run the low cut on the TL 12s flat (no cut)?
Thanks, Al.
That dual Lab12 is looking good. I just down loaded the builders plans.
Art, for the "Bow Tie", my old Pioneer active only goes down to 125Hz. I can go 6, 12, or 18. The mid bandpass slopes have a flat position available. Maybe I could run the low cut on the TL 12s flat (no cut)?
Thanks, Al.
The TLs will flap with no low cut, but with a 12 dB per octave slope with the Bow Tie run a little hot (so it does a Metal "Loudness Contour" 🙂) there would be no gap to speak of.
You have a 1/3 octave EQ, so you can sculpt the response to what you like, room modes usually are a bigger problem than speaker response.
Art, that sounds great!
I see the Lab 12's are available in 4ohm with slightly different specs. Would these work correctly in your design as well?
Thanks, Al.
I see the Lab 12's are available in 4ohm with slightly different specs. Would these work correctly in your design as well?
Thanks, Al.
I have the Lab12 driver. 6 ohm. I put it in a sealed cabinet. I don't like to cross them higher than 80Hz. My other horn drivers are much more efficient. Make me wonder if this driver should be in a horn or not.
Al,
The Lab 12C TS parameters are close enough they should "work" in any design that would use a Lab 12.
It does appear to have less output in the 50 Hz range though.
The "4 ohm" Lab12C has a DCR of only 3.1 ohms compared to 4.29 for the Lab 12, and the impedance minima in most cabinet designs is pretty close to the DCR.
With one per side on a Phase 700 the 12C might be a little low impedance, it seems to be aimed at the car audio market that use amps that are optimized for very low impedance speakers.
The good/bad thing about the Phase Linear amps is they have no current limiting, which makes for great peak headroom, but allows them to let out the magic smoke from the output transistors (dumping the full DC supply to the loudspeaker) when current exceeds what the output device can handle.
The series II lightened up the transformer and capacitors quite a bit so there is less juice available to blow things up, but "a word to the wise"- don't tempt fate.
And if you ever blow the speaker fuses, make damn sure to check for DC on the outputs before you plug your favorite stereo speakers back in after replacing them.
I still miss the pair of Jordan 15" I sacrificed learning that lesson...
Art
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I was thinking of two 4 ohm Labs per side in series for a happy 8. (one cab per side). Why not? I like PBJ's! Besides, I have never had to 'turn down' for metal. LOL
Thanks, Al.
Thanks, Al.
I would like to venture off topic slightly now.
In the RaneNote titled "Why Not Wye", Dennis Bohn writes:
"The input impedance is really quite low and requires 600 ohm line-driving capability from the crossover, but this should not create problems for modern active crossover units".
I would like to fool around with this circuit, but this concerns me for my old 1980's equipment. I have long lost the manuals and spec sheets for my heap, but I do have some limited reproductions coming from Rick at Stereomanuals.
I'd rather not burn it down playing. Tell me to stay out of the sand box if need be! LOL
Thanks, "unmodern" Al.
In the RaneNote titled "Why Not Wye", Dennis Bohn writes:
"The input impedance is really quite low and requires 600 ohm line-driving capability from the crossover, but this should not create problems for modern active crossover units".
I would like to fool around with this circuit, but this concerns me for my old 1980's equipment. I have long lost the manuals and spec sheets for my heap, but I do have some limited reproductions coming from Rick at Stereomanuals.
I'd rather not burn it down playing. Tell me to stay out of the sand box if need be! LOL
Thanks, "unmodern" Al.
OK, back on topic. That insatiable 18" hard on I seem to have has got me thinking about that "variant" box I posted earlier. It looks like a "tapped short horn bandpass" box to me. But what do I know? Someone said with the right tuning, this box may have bass extension. Now, does that mean altering the box dimensions or choosing the correct driver (or both)?
Wish I had the faculty and gear to find out rather than pester you guys.
Thanks, Al.
Wish I had the faculty and gear to find out rather than pester you guys.
Thanks, Al.
Two drivers in series (assuming two equal size boxes) will end up the same sensitivity as one, -3dB power, +3 dB from mutual coupling of double the cone area.
Loose the 18" hard on, a big (long excursion) 10" can also get the job done 😉.
Someone (me) said the "variant" box (which is a combination of front loaded offset horn with bass reflex ports) could be tuned low (er), which would only require the ducts to be lengthened.
The short horn output will be louder than the port output, the cabinet will have a rising upper response like the EV boxes you mentioned, unlike the rising lower response of the WS 2x12 and Bow Tie. Being much larger, it also will be louder.
The lower it is tuned, the less output the ports have.
Try covering one or two of your TL ports (EV called that "step down mode") to hear the difference in tunings. You can extend response and boost the LF to make up for the sensitivity hit the lower tunings impose.
Assuming you have a Windows computer, you could download the free Hornresp program and compare various designs substituting different drivers and wiring configurations.
They all will adhere to Hoffman's Iron Law: low, loud, small- pick two.
Art
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I was thinking two 4 ohm drivers in the same box wired in series would be an 8 ohm load.
I was thinking the variant with tuning may be a 18 dream come true.
I know who it was.
I'll take a look, but I don't remember seeing any 'ducts' on that variant. It's hard for a smuck like me to keep up.
I see those EV boxes climb like monkeys.
The EV step down refers to nothing more than a piece of plywood that you can cover the center section of the EV port. If you don't have a center section of port, well, you don't have a genuine EV TL806.
I don't know who Hoffman is, I find his Iron Law credible. I am printing a quote to frame, with his acknowledgment of course. He explains so much in so little words.
Thanks, Al.
I was thinking the variant with tuning may be a 18 dream come true.
I know who it was.
I'll take a look, but I don't remember seeing any 'ducts' on that variant. It's hard for a smuck like me to keep up.
I see those EV boxes climb like monkeys.
The EV step down refers to nothing more than a piece of plywood that you can cover the center section of the EV port. If you don't have a center section of port, well, you don't have a genuine EV TL806.
I don't know who Hoffman is, I find his Iron Law credible. I am printing a quote to frame, with his acknowledgment of course. He explains so much in so little words.
Thanks, Al.
Hoffman's Iron Law was named after J. Anthony Hoffman, the "H" in KLH speakers.
The shelf duct (similar to the TL box ducts, though this one is not divided in three) in the offset FLH/BR horn is 85mm deep by 45mm wide and 536mm tall (the cabinet height).
Increasing the duct depth deeper than 85mm would lower the Fb (box tuning).
Lower tuning (Hoffman's iron law) with the same box size ("step down") means less LF output.
However, at Fb, excursion is at minima, so with more power you can boost level until the coil burns up, which is most likely at Fb because the impedance is lowest, so power draw is maximized, and with less cone movement heat is not dissipated as well.
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Hey Art, please allow me to thank you for hanging with me. I have picked up on so many things thanks to you. You inspire me to keep on. Although I have not met you in person, I consider you to be a Friend. You must have a tree trunk sized neck to hold up that amazing data bank you call a head. And a heart of gold to share it with someone like me. Thanks Art!
Alright, enough hugs and kisses.
I was searching for a pic of Wayne Johnson strumming through your Thiele to post here with no luck.
If my mule came in like a train I would build both your Lab 2x12 and my variant so as to compare with a pair of ears. Well, that train derailed somewhere in Washington I think.
I like to hear with my eyes as well. I picture a big gnarly reverse loaded 18" tapped short horn bandpass box sit'n in the corner in all it's glory with it's balls hanging out.
To me, that would sound incredible before I even turned it on. Don't hate me.
I would like to build one (actually half of one). Unfortunately I have no dimensions or driver spec's that variant was designed around. Maybe you could help?
I speak from the heart in Truth.
Thanks, Al.
If I had the outboard gear and knowledge, I wouldn't have to turn myself out and ask for help.
Alright, enough hugs and kisses.
I was searching for a pic of Wayne Johnson strumming through your Thiele to post here with no luck.
If my mule came in like a train I would build both your Lab 2x12 and my variant so as to compare with a pair of ears. Well, that train derailed somewhere in Washington I think.
I like to hear with my eyes as well. I picture a big gnarly reverse loaded 18" tapped short horn bandpass box sit'n in the corner in all it's glory with it's balls hanging out.
To me, that would sound incredible before I even turned it on. Don't hate me.
I would like to build one (actually half of one). Unfortunately I have no dimensions or driver spec's that variant was designed around. Maybe you could help?
I speak from the heart in Truth.
Thanks, Al.
If I had the outboard gear and knowledge, I wouldn't have to turn myself out and ask for help.
Well, you brought back Wayne J. to my memory- what a talent!
I do miss the Minneapolis music scene, but not the weather.
Half of the offset dual 18" ported cabinet would be a bit underwhelming, the horn is already not doing much below 100 Hz, cut the mouth size in half and pfft.
That said, you have the dimensions in mm, just divide by 25.4 and away you go, the box is 48" x 30" x 22.5". The speakers look like they might be some JBL 18".
The Keystone would kick it's butt, you could forgo the grill if you want it to look more gnarly.
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