jbl 4406 monitors

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Jonkan

Well-known member
Joined
Jun 7, 2004
Messages
733
Location
Sweden
I read somewhere that someone had modded these monitors to sound better.

I cant find any details on this, so im wondering if any of you could perhaps take an educated guess as on what a mod on this speaker might be?

Change caps in the crossover? Completely replace the crossover?

I have the schematic lying around somwhere, but im not shure where to start.

/Jonas
 
The guys at http://www.audioheritage.org/vbulletin/ should have the answer. But maybe you already searched in it?
 
ok, bringing this old thread back to life.


I found the schematics for the crossover network for these speakers.

Going to read in my aes speaker bible about crossover networks soon, to see if i can actually understand anything about the design..
:green:

I also asked jim williams at audioupgrades about it. He basically recommended just changing the components to better quality ones.

Is there any point in changing the stock mylar caps to quality polypropylene caps instead, or will the difference in quality probably be negligable?

What else could make the biggest difference? Better inductors perhaps?

What are your experiences?

/Jonas
 
small changes can make large differences with speakers
this can take great skill and/or test equipment to quantify

as with mics
capacitor changes can be subject to personal taste

if the original inductor is well made and of the required spec for the mod then a new inductor is not likely to make much difference

I generally use extra winds on the inductor and then un-wind ... one turn at a time ... until I get the desired spec and or sound.

speakers and passive crossovers are an art
 
Ok, sound like fun! But since i dont have any test equipment (or skill) it could be hard to know when an improvement has been made.. except for the obvious placebo effect that is.

The big mylar caps are bypassed with 1000pf polyester caps. I might try changing these for polystyrene or polyprop caps instead and see if i notice any difference at all.

How high voltage will these caps generally recieve from an 150w amp?

(Im asking because i have lots of 1000pf/63v polystyrene caps, but the originals are rated at 200v.. Im guessing 63v wont cut it ?)

Also generally speaking, will polypropylene caps be more transparent than mylar?

/Jonas
 
[quote author="Jonkan"]Ok, sound like fun! But since i dont have any test equipment (or skill) it could be hard to know when an improvement has been made.. except for the obvious placebo effect that is.[/quote]
yep
that's the point

but for a fun exercise ... go for it

I don't think 63 volts is anywhere near enough. I like to see upwards of 200 volts for stuff like this.

A very big power amp can have 100volt rails ... pos and neg ... 200 volts.
800 W into 8 ohms ... 105 Volts ...
:roll:
sorry if my math is wrong there - I can't be bothered looking it up

150 W ... ?? 68 volt rails ??
whatever
more than 100 volts
and I often use 500 to 600 volts


at random from google
http://www.soundlabsgroup.com.au/audioconsulting/audio_consulting_capacitors.htm

audio_consulting_capacitors_nos_4uf.jpg

NOS Paper in Oil Capacitors for Audio

Made in Switzerland, these NOS (New Old Stock) paper in oil capacitors are only available in limited numbers and values.

4 uF / 800 VDC / 400 VAC NOS paper in oil capacitors, 135 x 55 x 30 mm.


C-td.gif

+/-10% tolerance. Non-inductive self healing
windings. Axial Leads. 630 volts working
Ideal for vintage radio and guitar amplifiers.

orange716.gif

Ultra high quality, copper leads -
Ideal for Hi-End Audio & Guitar Amps.

micacaps.jpg

For Guitar Amplifier and Hi-End Audio use.
500 volt working


I like stuff that looks like the yellow ones for speakers as it provides for up to 10uF and they seem to hold together even in the demands of PA

I think the HiFi boys like this brand
solen.JPG

http://www.welbornelabs.com/solen.htm
 

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