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karina
07-31-2010, 04:16 AM
I have great L300 and recently i think of renew thier crossover.
As understand this is must specially in this part.

From reading the L300's crossover planned to work with massive SS amp , I love tubes:)
So my question is any one redeisgn the L300's crossover and improve it?
I hate the Lpads and they are not necessary for my daily use.

I'd like to order the parts and asks for opinions for the design for new crossover.
From reading JBL used autotransformer in some other PRO series,Do you think implementing such autotransformers in the crossover can do good with the speakers?


Thanks for reading

hjames
07-31-2010, 06:12 AM
I have great L300 and recently i think of renew thier crossover.
As understand this is must specially in this part.

From reading the L300's crossover planned to work with massive SS amp , I love tubes:)
So my question is any one redesign the L300's crossover and improve it?
I hate the Lpads and they are not necessary for my daily use.


Thanks for reading
Since the L-300 is, in effect, the consumer version of the 4333 Pro monitor, why not build some up-to-date 3133 crossovers? I know one of the members here posted updated 3133 equivalent crossovers (http://audioheritage.org/vbulletin/showthread.php?166-4333-S300-L300-equivalent-bandbass-circuit&p=1042#post1042) a few years back. I built a pair and they work well (http://www.audioheritage.org/vbulletin/showthread.php?15317-Looky-What-I-just-got-Those-Darned-L200-Cabs-%28from-Aberdeen%29&p=268763&viewfull=1#post268763)in the L-200s cabinets I've upgraded to 3-way specs in my upstairs room ...

If you are a technical, D.I.Y type person, there is also a Charge-Coupled 3 way design for that speaker here:
http://www.audioheritage.org/vbulletin/showthread.php?22280

Another perspective - have you considered biAmping them? With biamping, you use a high quality active crossover and low-split off the woofer signal, feeding that with a powerful amp to handle them best, then you could feed the high-split side to your tube amp for the horn and slot drivers ...

Just a couple thoughts - things I've seen folks here do with other speakers ...

One other thing, the L-300s generally have such high resale value most folks don't modify them much.

4313B
07-31-2010, 06:32 AM
I hate the Lpads and they are not necessary for my daily use.It's really simple to replace them with fixed resistors. Use multiples of fixed resistors to increase their power handling capacity.
Do you think implementing such autotransformers in the crossover can do good with the speakers?No. I'm not going to go into why they were used, suffice it to say, don't use them. Use fixed resistors, or use high efficiency low frequency transducers to mitigate the efficiency disparity, or do as Heather suggested, bi-amp them.

karina
08-01-2010, 02:42 AM
It's really simple to replace them with fixed resistors. Use multiples of fixed resistors to increase their power handling capacity.No. I'm not going to go into why they were used, suffice it to say, don't use them. Use fixed resistors, or use high efficiency low frequency transducers to mitigate the efficiency disparity, or do as Heather suggested, bi-amp them.


Thanks 4313B,

I read many of your posts (:applaud:) and i would really appricate your help.
Can you please explain why not using auto transformer in the l300?
What are the disatvantage is such design?
I have search a lot for renew/resdesign my L300 and not clear what is the best way.
I have also the hand updating the crossover with new caps and etc will give good results?
I find L300 great speaker and even better then many of very expensive recent speakers
but is not detailed as i want.
BTW- Bi Amp the speakers is not something i want(dont have place for more amps).


As it look my options are :
1.Design new crossover - with charge coupling design ORAutotransformer - which not understand why it's not good idea...

Renew the exiting one- case you think that would bring the best results.can you focus me what exactly i need replace?

Thanks for the help!

4313B
08-01-2010, 03:16 AM
Why use an inductive voltage step down device (tapped autotransformer, and you are going to have to deal with that inductive reactance) on a compression driver when you can use a non-inductive fixed resistor pad instead?

Better yet, just bi-amp. The compression drivers and ring radiators just don't need a whole lot of power.

karina
08-03-2010, 11:29 AM
Do you know TANGO SA300?

see:
http://www.av-forums.net/plus/viewthread.php?tid=46828&page=5

4313B
08-03-2010, 12:40 PM
Yes. Why bother with them?

karina
08-04-2010, 01:29 PM
I understand these tangos are really good for such configuration,I see many people finding the implementation of auto trans in crossover is really good.I understand your point but I read that tango are really great for such use,for your advice -I like simple thing so bi amp it's not for me-I just want to get better sound and more details out of the l300...by 2options or building new crossover or renew the original one