Bypass Surgery

[Scooter]

Greetings,

I have just finished connecting 10 .01 microfarad caps to my L110 networks, and there is a noticeable benefit--removed some of the sibilance from the 033, and gives a generally cleaner, clearer sound. A friend concurs, so I have dismissed the placebo effect. I used the Dayton film and foil caps. Got ten for just over six bucks.

I still need some input on some other possible changes. One expert says that it is better to cascade the caps in increments to reach the desired value rather than do what I have mentioned, as it will avoid a "discontinuous" sound. I am open to experimenting, but I do not know which type of cap to use (try) in place of the electrolytics. Suggestions please. What might be the effect of using different inductors? It is not my intent to stray too far from the original sonic character, but I would like to try some different things, with the hope of finding desirable enhancements. I would appreciate any comments too on the sonic differences in caps as well. I have been considering Audiocap, Kimber, Crescendo, Zen, Clarity and Solen.

Thanks,

Scott

[Ian Mackenzie]

Scott,

Trying different capacitors can be fun, like wine tasting.

In the end you get what you pay for the pure grape is better than a blend imho, Perhaps just a small drop of something else helps.

In other words spend the maximum you can afford...there was a good link to a cap review in another thread , try a search. The Mundorf supremes bypassed with a certain 0.01 were the bees knees as I recall .

Ian

[jandregg]

On my 2123 mid I use a 12db low pass with 20mf as the second component. I built using all Dayton caps from parts express. It is comprised of a 16mf and 2 2mf with a .1 bypass. Yesterday I recieved a pair of 2mf audiocaps. Replaced one of the 2mf daytons in each speaker. Played them last night. Didn't have to listen for the difference, it was right there. Now the 20mf consists of three dayton and one audiocap. It is very much improved sound. At $14 each for two caps it cost $28. Best bang for the buck of all my upgrades. Now I simply must try charge coupling.

Anyone know a good (and cheap) brand of cap for charge couple filters?

John

[4313B]

The Daytons bypassed with the AudioCaps sound good charge-coupled.

"A friend concurs, so I have dismissed the placebo effect."

JBL doesn't believe in placebos. If it wasn't valid they wouldn't waste the money on bypass caps.

"One expert says that it is better to cascade the caps in increments to reach the desired value rather than do what I have mentioned, as it will avoid a "discontinuous" sound."

Holy hand grenade Batman! We've been listening to all these JBL's and suffering their discontinuous sound! :banghead:

Seriously though, do what you want and what sounds best to you.

[Earl K]

Anyone know a good (and cheap) brand of cap for charge couple filters?

John, if I was you, I'd continue on the path that you are presently on.

ie; Charge-Couple ™ using Daytons as your base cap, plus add in some portion/value of AudioCap to achieve the final "uf" total. Maintain the ratio ( of Dayton to AudioCap ) that you just implemented (assuming you can afford it ) . If that investment is too "rich" - then dial-down the investment and use "AudioCaps" as only small value bypasses .

See Bypassed and Biased Capacitors (http://audioheritage.csdco.com/vbulletin/showthread.php?t=3555) for more info on bypassing .

regards ,> Earl K

[Earl K]

One expert says that it is better to cascade the caps in increments to reach the desired value rather than do what I have mentioned, as it will avoid a "discontinuous" sound.

Hi Scott

A good, comprehensive "capacitor sound-off" or rerview ( the one Ian referred to ) is located here. (http://home.zonnet.nl/geenius/Cap.html)

Regarding your question on "cascading" ( and/or obvious, sonic discontinunities ) ;

- The only obvious "discontinuity" that I've run across when bypassing caps , is when I used Solens as the base cap. I've never had great success with the standard bypass formulas ( .01uf Film & Foil PolyProplylene, .005 Film & Foil PolyStyrene ) as applied to Solens MPP caps. Though, I have been able to better integrate the above mentioned bypass caps, by adding into the matrix, some very small value (.022uf ) Mylars. ( Who would have thunk it ? ) This whole combo is still pretty "hot" , 3K and up - but it does have better integration and balance than without the Mylar bits .

- I cascade to some degree - but not according to any formula . The link I posted mentions ASC MPP caps in oil . These are essentially high voltage HVAC caps of the 60hz motor-run variety. I tried these ( actually the Mallory variety ) about 15 months ago - without much success. My comments are somewhere around here in a thread called "Capacitors". About a month ago , I gave them another try - based on the linked "review" of the ASCs and a more evolved approach to bypassing. These HVAC caps do provide a great base, upon which to buildup larger values. "Raw", I find them incredibly dull sounding. Their biggest strength is that they integrate well with almost anything and everthing . I use a 50/50 mix of these to dry-film MPP types ( I figure my noname surplus caps are comparable to the Daytons ) and lots of small value bypass caps . I even add .47uf of Solen MPPs to enhance the "brilliance" area of this multiple cap combo. After a month of listening - I'm quite satisfied . The point ?, if you need to build up some large value caps, try the ASCs or the comparable GE, CWC or Mallory types. You can obtain them quite inexpensively on eBay here (http://search.ebay.com/_W0QQgotopageZ1QQsassZmachinery13QQsorecordsperpag eZ50QQsosortorderZ1QQsosortpropertyZ1) or here (http://stores.ebay.com/Capacitor-and-Craft-Farm_W0QQsspagenameZl2QQtZkm)

Some education about this class of motor cap is required because they are not all MPP ( Metallized PolyPropylene ) - in oil .

regards <. Earl K

[Scooter]

Thanks guys for the input--and the sarcasm too.

I think that the placebo effect is real. Desire can taint objectivity to a degree, at least on the hobbyist level. I'll bet that JBL is aware of the effect, but I cannot say if it factors in to their reasons for rigorous testing. Also, I did not specify that JBLs have a discontinuous sound. I was referring to one man's opinion on a certain type of bypassing--a general reference. I am a comparative "dummy load" when it comes to crossover design, but I am learning. Sorry if this is annoying to some. I read about the discontinuous sound on George Short's North Creek sight. There is a considerable amount of information there, although none of it, as far as I know, relates directly to JBL products.

I like the capacitor/wine tasting analogy. My hunch is that the N110 can be modified so as to improve the overall resolution and transient response of the system. Time for more parts and a written log of the results. This is something I'll enjoy.

I recently heard from my brother, and he says that he can get me a pair of 15 inch, 2-way Cabaret cabinets (in rough shape) with the original 2425s and E-140s. I am trying to picture them next to my television...

Scott

[Zilch]

I recently heard from my brother, and he says that he can get me a pair of 15 inch, 2-way Cabaret cabinets (in rough shape) with the original 2425s and E-140s. I am trying to picture them next to my television...Envision them somewhat AWAY from the sides of your TV, unless its a plasma or LCD type immune to magnetic fields.

Sounds like Cabaret 4691(B), a fun 4.5 cu.ft. box with 2370 rectangular flat-front biradial horn. A popular "workhorse" two-way sound reinforcement box, they'll play LOUD, but for home use, you'll find the highs are not very high, and the lows are not very low.

HOWEVER, they're the right size box for lots of fun playing around. Put 2235's in them and retune, then use 4430 crossover topology to extend the VHF of the 2425's, OR, add a UHF driver and crossover to make killer 3-ways out of them.

Don't want to mess with all that? Then, as is, they'll rock the entire neighborhood at your next yard party, no sweat. Well suited also for garage band vocals, but check your local noise ordinance first. :p

See also my earlier thread on making Sub1500 subwoofs outta them.

Footnote: Find also a pair of the same-size 4625 subwoof boxes. Install your UHF drivers in the blank baffle space above the 15's in them. Stack your 4691's with mids upside down on top of them. Call them "Project Scooter." Heh.

[Scooter]

Project Scooter? A humble, yet worthy title indeed!

Despite all the intriguing possibilities, I had to pass on those 4691Bs. Like a magnet drawn to the refrigerator, I tend to go off on idea tangents and not finish the current project, which for me would be my L110s. I had a pair of those Cabarets back in the fog of the 1980s. I had the E-140s reconed to 2225s. I kept them in my house for at least a year. A couple of my closest friends always wanted to hear Stevie Ray cranked-up through them. Another project was to modify a couple of Carvin cabinets that each held two 15s, two eight-inch mids, and a compression horn on top. I did some cutting and strengthened the cabinets, then did all JBL: Two 2225s, two 2119s and a 2425 on top. I had some networks custom built too. Metallica's Sad But True is forever etched in my brain because of those! Alas, then tinitis set in, and those days are no more. Time now to learn more about the qualitative aspects of speakers; networks in particular. I seem to have the patience for it now.

Scott