Looking for diresctions for a typical 12 " woofer
Hi BudP your ground plane tweak has made me a believer in your studies/publications....well done. Now I'd like to tackle this EnABL process.
Is there a a way to apply your pattern (in a reversible way) on the exterior surface of a 12" woofer? I tried going thru the various threads but they are overwhelming in scale....so I thought I would directly. I remember reading about applying stcky back tape in various patterns. This sounds reversible (if I don't like it).
Anyway I look forward to any feedback you could provide.
Hi BudP your ground plane tweak has made me a believer in your studies/publications....well done. Now I'd like to tackle this EnABL process.
Is there a a way to apply your pattern (in a reversible way) on the exterior surface of a 12" woofer? I tried going thru the various threads but they are overwhelming in scale....so I thought I would directly. I remember reading about applying stcky back tape in various patterns. This sounds reversible (if I don't like it).
Anyway I look forward to any feedback you could provide.
G'day Frank,
Nice work on the ports!
You are now reaping benefits that some have emphatically claimed are impossible. 😀
Next thing to try is adding some additional tape EnABL patterns:
- on the baffle immediately around the port opening
- on the inside circumference at the opposite end of each port
- around the outside circumference at the opposite end of each port
You can expect more kick and speed in mid-bass transients and bass that sounds deeper and more textured.
Let us know your impressions if you get around to doing these.
Next on the list would be using the tape pattern for treatment of baffle edges, cabinet sides and internal panels.
With all these in place, the squarest and boxiest of cabinets can be rendered invisible to the naked ear.
Cheers,
Alex
PS: Glad to hear the calculator was useful. 🙂
Nice work on the ports!
You are now reaping benefits that some have emphatically claimed are impossible. 😀
Next thing to try is adding some additional tape EnABL patterns:
- on the baffle immediately around the port opening
- on the inside circumference at the opposite end of each port
- around the outside circumference at the opposite end of each port
You can expect more kick and speed in mid-bass transients and bass that sounds deeper and more textured.
Let us know your impressions if you get around to doing these.
Next on the list would be using the tape pattern for treatment of baffle edges, cabinet sides and internal panels.
With all these in place, the squarest and boxiest of cabinets can be rendered invisible to the naked ear.
Cheers,
Alex
PS: Glad to hear the calculator was useful. 🙂
I fired up the system after doing the ports and my very first reaction was, "We have to figure out why this is working!" Easier said than done.
My lower crossover point of 150 Hz and large drivers don't give me any noticeable point source for the bass. It's just 'in the room'. It would be a big mess to pull the cabinets apart sufficiently to pattern the inner ends of the ports. I took Bud's advice and thinned the interior damping material and that has been sufficient to restore balance in the lows. [I removed about a grocery bag full of fiber between the two cabinets.]
Meanwhile, Bud, I realized that the 2" domes of he LE8Ts were still not quite tame. I began to hear them break up on certain passages, particularly that one with the pesky oboe played in a slightly reverby space. I added a mid-dome EnABL ring and that has me smiling big time. In addition to separating the oboe from it's reflected sound, all female vocals are now a touch sweeter. And to my delight, percussion is even cleaner than before. Really good stuff. Listening is more relaxing, and high volumes (even well into 'insane') are just effortless.
Frank
I had exactly the same reaction the first time I treated a port with tape. That was late 2007.
A few years and a few thousand blocks later and I'm still just as excited.
Makes you grin on the inside don't you think? 😀
The same lack of point source effect can be achieved for all other frequencies with additional of baffle and cabinet edge treatment.
Cheers,
Alex
Alex I have experimented with ENABl patterns on woofers with success but room corners is new to me. In one post you said the pattern was 6+ cm high in another 2 feet. Please help me understand. And you applied to a plastic (rigid?) sheet that stands or is glued to the corner? Please say more
Just keep in mind that you still have the same thermal limits as before EnABL. When younger and dumber (as if) I ran a multiway system, with Vifa 6 inch mid woofers, so hard that the voice coils caught fire, just because it sounded SOOOOO GOOD!!! Don't push those drivers any harder than you did before they stopped announcing their distress.
Bud
Hi Bud,
Those Vifa's sacrificed themselves to save your hearing. I hope you buried them with honors.
😀
BTW: Haven't seen you in awhile, I hope you got over the flu, or whatever it was that you had.
I should be done painting the drywall by Monday! Then I can clean up, break out the soldering iron and get going.
Best Regards,
Terry
G'day theob,
Initially, the pattern height was 60cm (2 feet) so that it was the same height of the speakers I was using (to hide it from my other half).
IME the greatest benefit comes from extending the pattern from floor to ceiling in all available corners. Highly recommended.
The blocks are applied to strips of clear contact (self-adhesive stuff used to cover books - a.k.a contact paper) which are wide enough to accommodate the pattern with a one block width margin on either side. The tape I used for the blocks is about twice the thickness of a good quality PVC duct tape (or approx 3 times the thickness of the clear contact). The strip needs to be long enough to reach from the skirting board to the bottom of the cornice. Each strip is then stuck directly onto the wall - two for each corner.
Yes, I was given permission to do this in my lounge room. 🙂
I'm convinced that more can be gained with the application of two circumferential patterns around the entire room - one just above the skirting boards and another just below the cornice.
No, I did not get permission to do this. 🙄
Cheers,
Alex
Last edited:
Thanks so much Alex I tried a mini version of room ENABL and was playing so loud w/o distortion I toppled one of my tube traps which fell on my Logans which fell over and bent the e-panels. New panels will be ordered today. Oh well at least I will get new panels but wife not happy that house improvement funds now get diverted.
Ouch! Sorry to hear about the panels. I take it that you had the volume cranked way above your normal listening level?
I appreciate the thoughtful advice Bud - but life is short! 😛 ...and JBL 2235 15" woofers should be quite comfortable with the 125 or 150 high current watts I can throw at them... Actually, I'm impressed how the woofer EnABLing has made that amount of power more than sufficient for even the ridiculously deep club grooves. The woofer amp heat sinks barely break a sweat.
I thought I'd check in with a little update on the JBL LE8T-H drivers with which your help was so pivotal. They were dialed-in to perfection for my Twisted Pear Buffalo II DAC / Legato I/V stage / balanced amps. I had been hoping to add the optional shunt regulated power circuits (called 'Tridents') to the Buffalo DAC. Finally a new batch became available last week - mine were installed by Thursday. The effect of the shunt regulators on the analog signal 'coherence' (for lack of a better term) sounded *identical* to the the effects of EnABLing the midrange drivers! That was pretty cool except - unfortunately - the LE8Ts weren't dialed-in any more! Significant 4-5kHz resonance was killing all the listening pleasure. With enough sampling I isolated the problem to the 2" aluminum midrange domes so I added another ring pattern in the 16 mm untreated gap. This resolved 85% of the resonant misbehavior. The last ~15% I erased with a mid-cone ring pattern at the edge of the rear damping material, as we had discussed previously. Now the drivers sound no brighter than before all of the 're-tweaking', but they coherently manage a signal that is truly 'put together'! The 'wall of sound' illusion (etc.) took a quantum step. The shunt regs for the DAC were a surprising upgrade. I'm glad I had to go back and re-tweak the drivers because the sound is becoming nigh unto breathtaking - at least until I've worked through my music collection a couple of times. For reference I attach photos. A) the current dome treatment, B) the current cone treatment, and C, the little glowing 'heaters' on the DAC.
All the best,
Frank
Attachments
Hi Frank,
Really nice workmanship! Can I talk you into laying a ruler across the LE8T and taking a picture of the whole driver please? That would allow me to develop a set of ring application guides specific to the driver, so others with slightly less native courage can benefit.
I would bet that one more ring set, on the LE8T drivers, will eliminate all of the remaining "slightly uncomfortable" output. I have just recently been back to a driver / Fonken box combination I had not listened through for perhaps 10 months. Mark Audio has released a series of drivers, of which I was able to treat and listen to the Alpair 7. These were dealt with using the techniques that arose from George Soon's investigations four years ago. Being the tap test you have been introduced to, though George was much more incrementally thorough in his treatment of a Jordan JX92s driver, with ever greater in diameter and ,or, number of EnABL pattern rings, made from toothpaste.
Addition of one more ring set to a Fostex F 127eN driver pair I have had here, has completely removed ALL drawbacks to a single full range driver use of these delightful little speakers. The last three upper register piano notes that were not perfect, the removal of a blurring to the leading edge of ride cymbals and another level of depth of field and placement of instruments within, has resulted from adding just one more ring set to the cone and dome. You have done the dome, but it may be useful for you to investigate the area, between where the backside glue left off ring set is applied and the final outer ring set. Having had success with five different drivers, including the F 200 A with adding this fourth ring set, I suspect you will find a useful improvement. One of diminishing returns, compared to the initial success, but one adding a final improvement and a finish to your investigations of this driver.
For the 126 and 127 fans here I have attached a PDF set of additional and original ring patterns to this post. The three additional rings, added since the origianal treatment years ago is almost unbelievably worthwhile. These little drivers will become fault free from a musical perspective, without suffering any drawbacks in output.
Bud
Really nice workmanship! Can I talk you into laying a ruler across the LE8T and taking a picture of the whole driver please? That would allow me to develop a set of ring application guides specific to the driver, so others with slightly less native courage can benefit.
I would bet that one more ring set, on the LE8T drivers, will eliminate all of the remaining "slightly uncomfortable" output. I have just recently been back to a driver / Fonken box combination I had not listened through for perhaps 10 months. Mark Audio has released a series of drivers, of which I was able to treat and listen to the Alpair 7. These were dealt with using the techniques that arose from George Soon's investigations four years ago. Being the tap test you have been introduced to, though George was much more incrementally thorough in his treatment of a Jordan JX92s driver, with ever greater in diameter and ,or, number of EnABL pattern rings, made from toothpaste.
Addition of one more ring set to a Fostex F 127eN driver pair I have had here, has completely removed ALL drawbacks to a single full range driver use of these delightful little speakers. The last three upper register piano notes that were not perfect, the removal of a blurring to the leading edge of ride cymbals and another level of depth of field and placement of instruments within, has resulted from adding just one more ring set to the cone and dome. You have done the dome, but it may be useful for you to investigate the area, between where the backside glue left off ring set is applied and the final outer ring set. Having had success with five different drivers, including the F 200 A with adding this fourth ring set, I suspect you will find a useful improvement. One of diminishing returns, compared to the initial success, but one adding a final improvement and a finish to your investigations of this driver.
For the 126 and 127 fans here I have attached a PDF set of additional and original ring patterns to this post. The three additional rings, added since the origianal treatment years ago is almost unbelievably worthwhile. These little drivers will become fault free from a musical perspective, without suffering any drawbacks in output.
Bud
It's a pleasure to collaborate with you on these older drivers, Bud! 😉
It was quite surprising to me that the LE8T-H drivers could be playing absolutely smoothly and beautifully, whereupon after adding shunt regulators to the DAC circuit board the 'leading edges' of the signal became so challenging that the signal caused pervasive resonances in the midranges! The tweeters remained fine as they were. I think this demonstrates that the tweaks one might want or need are definitely dictated by what's on the other end of the speaker cable. So it's a step-wise process of refinement, as your approach clearly shows.
Since that last communication I did add one more ring to the cone but it was as near as feasible to the dome. The test track that I find most revealing by far is the Allegro from Bach's Concerto for 2 harpsichords, oboe, strings and continuo. [Track 11 - https://www.hdtracks.com/index.php?file=catalogdetail&valbum_code=HD00028947419921 (88kHz, 24 bit)] That oboe signal is *tough work* because there seems to be a resonant surface near to the oboe in the recording area. The latest inner cone ring on the LE8Ts smoothed out pretty much all of the little resonant trills. I like what I hear and would like to listen critically to a lot of different samples now before I decide on more paint. Piano, cymbals, bandoneon, tenor sax, (Willie Nelson's voice? 😛 ) ... everything else is completely mesmerizing.
[BTW, I have some raw F 126s that are just waiting their turn - no rush just now.]
On the photo I needed flash so the dome is tricky. The inner cone ring is somewhat obscured by a little bleeding of black dome glue solvent, but you can see it on the left side. I agree with what you said earlier that there are some strong advantages to a larger diameter midrange IF they are well behaved because you can cross them into a woofer almost anywhere you want at the demands of room acoustics and woofer performance. That's rather a luxury...
I wish you could drop by and hear this thing! (I wish my dad, who when I was a kid let me help build his Heathkits, were around to hear it.) A friend of a friend came over last night totin' some HD FLAC files he knew well. As they played, he kept laughing out loud because he could hear so much or because a coherent, punchy transient would shift him in his seat... 😛 So I'm deriving really great enjoyment from the process you have developed. IIRC, was it Terry O who once referred to LE8Ts as the 'holy grail of midranges'? With these mods I couldn't disagree...
All the best,
Frank in Minneapolis
It was quite surprising to me that the LE8T-H drivers could be playing absolutely smoothly and beautifully, whereupon after adding shunt regulators to the DAC circuit board the 'leading edges' of the signal became so challenging that the signal caused pervasive resonances in the midranges! The tweeters remained fine as they were. I think this demonstrates that the tweaks one might want or need are definitely dictated by what's on the other end of the speaker cable. So it's a step-wise process of refinement, as your approach clearly shows.
Since that last communication I did add one more ring to the cone but it was as near as feasible to the dome. The test track that I find most revealing by far is the Allegro from Bach's Concerto for 2 harpsichords, oboe, strings and continuo. [Track 11 - https://www.hdtracks.com/index.php?file=catalogdetail&valbum_code=HD00028947419921 (88kHz, 24 bit)] That oboe signal is *tough work* because there seems to be a resonant surface near to the oboe in the recording area. The latest inner cone ring on the LE8Ts smoothed out pretty much all of the little resonant trills. I like what I hear and would like to listen critically to a lot of different samples now before I decide on more paint. Piano, cymbals, bandoneon, tenor sax, (Willie Nelson's voice? 😛 ) ... everything else is completely mesmerizing.
[BTW, I have some raw F 126s that are just waiting their turn - no rush just now.]
On the photo I needed flash so the dome is tricky. The inner cone ring is somewhat obscured by a little bleeding of black dome glue solvent, but you can see it on the left side. I agree with what you said earlier that there are some strong advantages to a larger diameter midrange IF they are well behaved because you can cross them into a woofer almost anywhere you want at the demands of room acoustics and woofer performance. That's rather a luxury...
I wish you could drop by and hear this thing! (I wish my dad, who when I was a kid let me help build his Heathkits, were around to hear it.) A friend of a friend came over last night totin' some HD FLAC files he knew well. As they played, he kept laughing out loud because he could hear so much or because a coherent, punchy transient would shift him in his seat... 😛 So I'm deriving really great enjoyment from the process you have developed. IIRC, was it Terry O who once referred to LE8Ts as the 'holy grail of midranges'? With these mods I couldn't disagree...
All the best,
Frank in Minneapolis
Attachments
Last edited:
hmmm - I ran across some Cecilia Bartoli vocals that were not quite right. Will investigate a range of other female vocalists and reevaluate. I wonder if the transition at the inner edge of the glue joint to the foam surround (on the back of the cones) may now need more control. If I were to want another ring pattern between the existing outer two, it makes me wonder if perhaps adding a 'half pattern' to one of the existing pairs of radii might not be sufficient? (e.g. make the outer pattern a triplet of 3 radii?) When might one prefer to add a pattern to the rear of the cone vs. the front?
Depends upon what is going wrong. If it is the legato compression, as emphasis to a note begun more softly, you might get away with some of the blue glue added to the inner side of the surround and brought over that glue joint onto the glue already on the cone back side. If that starts to take care of the problem add more of the glue onto the previously blue glued surface, but only about 1/3 of the way from the surround to the glued start on the cone.
If, instead of the power compression opening out and causing a non tonal blat, it is a glassy covering, then that ring set between the outer two will need to be placed. Just do a full set spaced right between the two already laid down. You may still have to add damping to the joint of cone and surround, on the back side, assuming it will adhere to the material already applied to the back of the surround by JBL.
Placing ring sets on the back side of the cone can be.... interesting. The cone will become more transparent to reflections from within the cabinet. It is entirely possible that this is the actual problem and placing rings back there without knowing how to deal with the wave fronts will make the problem pretty overwhelming.
On the other hand, backside ring sets will provide another 30% of transparency into the depths of the music. We would have to discuss what is back there in detail. It is quite possible to equal open baffle performance in a closed box, with rings controlling both surfaces and you probably already have the hand skill needed.
If this driver is mounted open baffle already, and I act dumb only so I don't have to go back and read all of our conversations again, then you likely will have to EnABL the baffle surfaces.
There, that should be enough to start to think about the problem with. But, do consider the basket and motor as possible elements in the problem. The more transparent the cone becomes the more important things that were already wrong, but covered over by problems now removed, will become.
Bud
If, instead of the power compression opening out and causing a non tonal blat, it is a glassy covering, then that ring set between the outer two will need to be placed. Just do a full set spaced right between the two already laid down. You may still have to add damping to the joint of cone and surround, on the back side, assuming it will adhere to the material already applied to the back of the surround by JBL.
Placing ring sets on the back side of the cone can be.... interesting. The cone will become more transparent to reflections from within the cabinet. It is entirely possible that this is the actual problem and placing rings back there without knowing how to deal with the wave fronts will make the problem pretty overwhelming.
On the other hand, backside ring sets will provide another 30% of transparency into the depths of the music. We would have to discuss what is back there in detail. It is quite possible to equal open baffle performance in a closed box, with rings controlling both surfaces and you probably already have the hand skill needed.
If this driver is mounted open baffle already, and I act dumb only so I don't have to go back and read all of our conversations again, then you likely will have to EnABL the baffle surfaces.
There, that should be enough to start to think about the problem with. But, do consider the basket and motor as possible elements in the problem. The more transparent the cone becomes the more important things that were already wrong, but covered over by problems now removed, will become.
Bud
G'day Frank,
Just a couple of thoughts:
1) Try tap testing absolutely everything on the driver - surround, legs, bezel, spider, magnet etc.
IME, when the cone has been EnABL'd, underlying problems caused by 'non-cone' parts of the driver can become audible and annoying.
2) Have you applied any treatment (felt or similar) to the inside of the basket legs?
3) Damping and stiffening of legs and bezel can also be of great value.
Cheers,
Alex
Thanks Bud and Alex!
A couple of follow-on points...
1) If there is still a problem in the driver per se, I want to base any decisions on the best possible data so I added a lovely reference to my library: Esperanza Spalding's "Chamber Music Society" (in 96/24). ...lots of reference potential in this well-made jazz recording.
2) Extensive survey of female vocals last night - nnnnnot much of a 'problem'! I also repeated the C. Bartoli tracks (redbook). This time I could hear more clearly that the opera singer was occasionally overwhelming the acoustics of the studio. [Plus, I'm willing to bet that I've figured out that oboe reference track. I think it's a music stand causing the reflections, because I can now clearly imagine when the oboist would look up at the conductor and clearly hear when they turn to look over at the violin soloist.] An inch away I can hear a tiny bit of smearing by the surround, but not from normal distances. The domes are bright but oh-so-clear. There might be a little 'glassy' halo around the sharper voices, like Christina Aguilera or India, or Misia.
3) Rear reflections within the sealed cabinets are a real possibility but they would have to come from the spider or baffle free edge. Everything else is quite shut-down. But I could damp and/or EnABL the inner baffle edge.
4) Every previous ring pattern I have added has helped. I'm getting tremendous energy transfer from these drivers! (...and tremendous energy 'packaging' by the DAC!) Today I'll add the 'in between' edge ring, follow up on Alex's suggestions, and possibly experiment with EnABL patterns on my left ear canal, which seems to have a higher impedance than the right. 😛
A couple of follow-on points...
1) If there is still a problem in the driver per se, I want to base any decisions on the best possible data so I added a lovely reference to my library: Esperanza Spalding's "Chamber Music Society" (in 96/24). ...lots of reference potential in this well-made jazz recording.
2) Extensive survey of female vocals last night - nnnnnot much of a 'problem'! I also repeated the C. Bartoli tracks (redbook). This time I could hear more clearly that the opera singer was occasionally overwhelming the acoustics of the studio. [Plus, I'm willing to bet that I've figured out that oboe reference track. I think it's a music stand causing the reflections, because I can now clearly imagine when the oboist would look up at the conductor and clearly hear when they turn to look over at the violin soloist.] An inch away I can hear a tiny bit of smearing by the surround, but not from normal distances. The domes are bright but oh-so-clear. There might be a little 'glassy' halo around the sharper voices, like Christina Aguilera or India, or Misia.
3) Rear reflections within the sealed cabinets are a real possibility but they would have to come from the spider or baffle free edge. Everything else is quite shut-down. But I could damp and/or EnABL the inner baffle edge.
4) Every previous ring pattern I have added has helped. I'm getting tremendous energy transfer from these drivers! (...and tremendous energy 'packaging' by the DAC!) Today I'll add the 'in between' edge ring, follow up on Alex's suggestions, and possibly experiment with EnABL patterns on my left ear canal, which seems to have a higher impedance than the right. 😛
Well... my goodness, Bud! More "polish" is a nice way to refer to the effect of that last ring pattern on the driver itself. But that doesn't begin to tell the whole story. The listening "comfort envelope" has been significantly expanded - in the dimension of managing poorer quality recordings and in the dimension of being able to enjoy more volume or energy when the music calls for it. And these last 'details' in the iteration of mods, though seemingly small, are having a logarithmic impact in imparting the emotion and artistic impact of the music. I seem to be enjoying music more and forgetting to listen critically to the sound. 😀
Alex, the 4 basket legs are 8mm X 30mm cast aluminum - i.e. broad and stiff. For lack of anything better on hand, I padded them with about 8 mm of folded cotton medical gauze. I think it helped that touch of smearing I heard near the surrounds. Thanks for the suggestion. Now I am clearly up against the design limitations of my flat-sided DIY enclosures. That's the way we'll stay until I have time for a thorough literature review because my old bag of tricks is not that full.
Courage, all you would-be speaker EnABLers! You can do it too!
Best,
Frank
Alex, the 4 basket legs are 8mm X 30mm cast aluminum - i.e. broad and stiff. For lack of anything better on hand, I padded them with about 8 mm of folded cotton medical gauze. I think it helped that touch of smearing I heard near the surrounds. Thanks for the suggestion. Now I am clearly up against the design limitations of my flat-sided DIY enclosures. That's the way we'll stay until I have time for a thorough literature review because my old bag of tricks is not that full.
Courage, all you would-be speaker EnABLers! You can do it too!
Best,
Frank
