New sub design? Constricted Transflex, simple build (series tuned 6th order)

BeauB,
Here is another sketch with some more explanation and details of measurements on the ML-TRANSFLEX for the Eminence 15 (special run) ...:key:

.....
:bulb:
I think i might arrange version 2 of the 50 liter cabinet for the Alpines in this same manner, with the constriction/port placed at the top right of the internal divider/baffle panel ... The cab sims a little better that way, and gives us slightly more path length while only increasing the total cab size by a few liters... This arrangement is also more likely to place any additional bandpass resonance (developed by the small chamber being energized from rear of the cone) closer to where it is needed which will be between the 3rd and 5th harmonic of the box's main pipe resonance...
 

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I'll most likely give the weather stripping a go tomorrow once it is rock solid (the PL), I want to hear it pretty badly :). If this goes well I have a whole plethora of plans (including stockpiling lab 15's).

Craft EVA foam sheets from craft stores or craft section in Walmart works very well as gaskets for drivers and enclosures. I cut to strips and glue in place with rubber cement (removable). Comes in all sorts of colors and is thin but enough compressibility.
 
Founder of XSA-Labs
Joined 2012
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BeauB,
Here is another sketch with some more explanation and details of measurements on the ML-TRANSFLEX for the Eminence 15 (special run) ...:key:

.....
:bulb:
I think i might arrange version 2 of the 50 liter cabinet for the Alpines in this same manner, with the constriction/port placed at the top right of the internal divider/baffle panel ... The cab sims a little better that way, and gives us slightly more path length while only increasing the total cab size by a few liters... This arrangement is also more likely to place any additional bandpass resonance (developed by the small chamber being energized from rear of the cone) closer to where it is needed which will be between the 3rd and 5th harmonic of the box's main pipe resonance...

I might have to build a model in AkAbak to check this out. Looks really interesting. It is similar to half a PP slot loaded bandpass but I am surprised the vent is so short. I think that is where the TL comes in to get the bass extension. Have you thought about doubling it into a push pull design to reduce 2nd harmonic distortion and double SPL? You can just make it twice as wide and put drivers side by side in PP with one flipped in. Or, put them side by side with drivers having separate chambers on back and common chamber in middle with a cutout facing front plane of drawing as exit port.
 
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BeauB,
Here is another sketch with some more explanation and details of measurements on the ML-TRANSFLEX for the Eminence 15 (special run) ...:key:

.....
:bulb:
I think i might arrange version 2 of the 50 liter cabinet for the Alpines in this same manner, with the constriction/port placed at the top right of the internal divider/baffle panel ... The cab sims a little better that way, and gives us slightly more path length while only increasing the total cab size by a few liters... This arrangement is also more likely to place any additional bandpass resonance (developed by the small chamber being energized from rear of the cone) closer to where it is needed which will be between the 3rd and 5th harmonic of the box's main pipe resonance...

Thank you - I printed your prior version and wrote in the dimensions.

BTW - your new version looks much nicer than my hand-annotated version.

Again, I appreciate your efforts.
 
Accidentally hit backspace and I'm retyping this..
Used gasket tape to seal driver.
Sound on is official, limiter set up today to 34 volts and HP/LP at 48/24 BW/LR 32/90hz respectively. Seems to have great sound quality from what I can tell (comparing to my T60 folded horn, at low power). It appears to be fine down to 33 or so Hz (well I have it HP'ed so that makes sense) corner loaded. Will need to let roomates wake up so I can power test.
 
Power test is in but I haven't run measurements because don't have a huge backyard, will be going to a friends to test the sensitivity and what response outdoors.

In a word, beautiful - sub audible distortion playing music even close to max. Not going to do a 35 Hz sine wave test because my house rattles a ton even with music going.

Sound quality is comparable to the T60 even up to max volume (preliminary testing). Will be building more of this design, it trumps my MFW 15 in output and sounds a lot better. To think I only spent 100 bucks to build it (including 40 bucks in parking at meters/tickets), It blows my mind. I dare someone to build something with more SPL to 35 Hz in a <4 cu.ft. box in 5 days that sounds just as good as this thing.

1 word, awesome.
 
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Founder of XSA-Labs
Joined 2012
Paid Member
Power test is in but I haven't run measurements because don't have a huge backyard, will be going to a friends to test the sensitivity and what response outdoors.

In a word, beautiful - sub audible distortion playing music even close to max. Not going to do a 35 Hz sine wave test because my house rattles a ton even with music going.

Sound quality is comparable to the T60 even up to max volume (preliminary testing). Will be building more of this design, it trumps my MFW 15 in output and sounds a lot better. To think I only spent 100 bucks to build it (including 40 bucks in parking at meters/tickets), It blows my mind. I dare someone to build something with more SPL to 35 Hz in a <4 cu.ft. box in 5 days that sounds just as good as this thing.

1 word, awesome.

Congrats!!!
:cheers:

What driver are you using - I missed it somehow, because the LAB was more than $100.
 
What driver are you using - I missed it somehow, because the LAB was more than $100.

XRK,
The Alpine SWE-10S4 driver is what he used in that small box, (correct me if i am wrong Saba) , i know he was considering some of the SWS 10s as well .... The cab is a slightly scaled up version based on a 50 liter (net) cab ...

The special edition Eminence Lab 15 works in a 135 liter version of that same design ...
 
Hi Sabaspeed521,

Post #110: "...I dare someone to build something with more SPL to 35 Hz in a <4 cu.ft. box in 5 days that sounds just as good as this thing."

Sadly, time has not been my friend lately, so I cannot take you up on your challange ( :) ). You might take a look at a MLTL as proposed numerous times by bjorno, it seems to suit this driver, and comes in @ a Vnet=90.6 L v. the ML-TP's Vnet=135.676 L.

The MLTL will accept a little higher input power before reaching Xmax, and may have the edge when it comes to group delay.

Maybe you can knock out one of these too, and let us know how they compare. :)

Thanks for sharing your experience, and letting us know that the ML-TL is a success.

Regards,
 

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I primarily chose the ML-TP because the design is easy to build, not that I'm opposed to difficult builds and honestly I also chose it because it had IMO a more complete drawing for me to go off of (novice CAD user here). I'll look into the MLTL designs some day (after the MLTP Lab 15).

Yes matthew is correct the first two subwoofers use the SWE 10s4 because I got them for 50 bucks shipped and they fit the needs of my original customer.

Corner loaded output is absolutely awesome for it's size, and it doesn't "sound like a small driver" whatever that means (I've never been convinced that 18's are better than 10's or 12's I just know that I can tune a bunch of 10's and 12's in small boxes that will sound just as good to my ear for cheaper :)).
 
Have you thought about doubling it into a push pull design to reduce 2nd harmonic distortion and double SPL? You can just make it twice as wide and put drivers side by side in PP with one flipped in. Or, put them side by side with drivers having separate chambers on back and common chamber in middle with a cutout facing front plane of drawing as exit port.

XRK,
This design could certainly be adapted to PP with two drivers... Keep the same path length, double the internal airspace and scale up the constriction's "area" :)
 
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NEW VERSION OF THE ML-TRANSFLEX 10S4 BOX !

Here is the fully updated 40hz ML-TRANSFLEX version 2 for the Alpine SWE-10S4.



  • I moved the constriction up the path some, and i extended the total path as well by a small amount.

  • Added a few more inches of height. Shaved off a little depth. The added internal airspace amounts to 4 more liters in this version, but a flatter response with a little more output are gained from these changes so it is a worthwhile compromise in my opinion.

  • Better damping (less "saddle" and also less peak at FB. These improvements often associated with reduced group delay means a more natural sounding roll-off on the bottom end).

  • There is more detail in the sketches now and the proportions are more accurate.

  • Simplified Hornresponse inputs by removing an unnecessary segment.


Enough "splitting hairs" for now ... I think i am satisfied for the moment with this Box's level of fine tuning :D..
 

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XRK,
This design could certainly be adapted to PP with two drivers... Keep the same path length, double the internal airspace and scale up the constriction's "area" :)

I'm seriously considering putting two subs side by side to accomplish this with drivers opposite mounting. One day I'll have a reason to. Thing is the distortion is so low to begin with it may not be worth it unless in a large room where you're driving max power at low frequencies really loudly (which would require ~4 subs imo).

Also, ran some frequency response measurements and here is the "tamed" frequency response of "just ML-TP" and ML-TP + T60 where the T60 is LP at 32 Hz keeping it's standard HP of 25 to blend in with the TP. It'll make more sense looking at the picture :).

I didn't boost the low end at all and in fact my room required a 10 dB cut at 43 Hz (room resonance). Ignore the crazy dip at 90 that's also room as verified by my running a sweep with my T60 running full bandwidth (which has a naturally rising response) and it showed the same massive dive so clearly it's a room issue.
 

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