Diy network 43xx

[bldozier]

my next question has arose, with the intended pre amplifier id like to use its tube section as well as biamp the system,
pretty much just like the older network switches,

if using an active external i won't have access to the majority of the tube preamp, so building a network is the avenue I'm aware
of using the section from it.

so my question is would i need to increase the filtration for the low section using two 12" 2203,

also can someone explain network DCR in conjunction with speaker.
thanks.

[hjames]

also can someone explain network DCR in conjunction with speaker.
thanks.

In a word --- No
... its not really a DIY, as-you-fly design thing.


if you are trying to pick up tips from JBL's classic monitor designs and don't have any design/engineering chops of your own,
its really best to start with a SIMPLE design, get that right, and maybe go from there. Find a 2 or 3 way and use that concept.
An alternative is to clone one of the more famous JBL 3 or 4 way designs.

But jumping into a 5 way design is not for the faint of heart -
please notice how many JBL 5 ways are on the market ...
really, go with a 3 way or 4 way design - getting all those crossover points to blend smoothly in an affordable manor is quite a task.

Ok, ... as you were ...

hi,
im building a second system, for the my room in my humble apartment, its for a stereo console with will house tube equipment an
a small 40" 4k, internal external switch,

using tube preamps with an active equalizer would decrease the output the the pre stage, for the active network, devaluing my
investment...

i have listend to Jbl comparisons, with original stock studio monitor's an they revised and updated counter part, the output from he original
networks, has always proved, for me just better from 200hz forward,

id like to build a fiveway, cabinet, 2203/2121/2420/2440/2405, something like a 4351 with an added horn, to work out to in my living room. JK.
.

[bldozier]

i just don't want to use the external, maybe someone else can help.
thanks heather for your help with the thread then. i will try an move forward,
even with little to zero ability, should de fun.

[bldozier]

There are essentially two kinds of bi-amping.

In the first, which is far more common in the hifi world, the full range output of the preamp is sent to two stereoamplifiers (or pairs of mono blocks). Each amp delivers the full range output to a section of the speaker. The high frequency half of the speakers passive crossover filters all of the low frequency content and provides any other additional balance adjustments required. Likewise, for the low frequency section. No active crossover is used with this method of bi-amping. To use this approach, you'd want to get your EV passive crossovers rebuilt anyway.

In the second, an active crossover is used between the preamp and the amplifiers. Each amplifier is directly connected to the component in the system that it is driving with no intervening passive components. The active crossover provides frequency band separation and sometimes more sophisticated functions like phase-shift or EQ. You can get any number of analog or even digital active crossovers to perform this function. To do this with your EVs, you'd be able to remove the old passive crossovers entirely and would not need to rebuild them, but since you have three drivers, you'd need a three way crossover and three pairs of amplifiers. You'd also need to ensure the active crossover performed all of the EQ functions included in the passive crossovers. That looks like a constant directivity horn in there and those require EQ to work correctly.

You could probably take a hybrid approach where you just split off the low frequency section and use a passive crossover for the mid/high section. The mid/high crossover could be a clone of the existing passive crossovers design, but with the high pass filter removed, as that function would be performed ahead of the amplifier by your active crossover. This would allow the horn EQ from the passive crossover to continue to function. The low frequency section would likely just be a straight wire from the low frequency amp to the woofer, with the low pass function performed by the active crossover. Essentially, you mainly want to avoid the scenario where you are using an active crossover and then following it with a passive crossover in the same band. This will result in excessively sharp roll offs and potentially ringing or phase issues

this is a quote from an alternate site,
i ventured out to read up on passive biamp,
my guess is i would passive biamp the low dual 12" section directly to mono block amplifiers. the hybrid approach.
is this correct.

[DES-1]

I find that writeup rather oddly worded. It seems to skirt the central issue of passive vs. active. My take on this - Once you decide to employ multiple amplifiers it seems illogical (to me) to use passive crossovers. Passive crossovers effectively reduce the usable power of the amplifiers, are a bit of an art to design and build, potentially introduce distortion, and lack the ease of adjustment of an active system (active crossover or DSP). But, each hobbyist has a different objective and preference so there is no 'right' way.

[bldozier]

so to adjust the network id be able to design it utilizing the pdf files for the k110a/2420/2440/2405, connecting
the dual 2203 directly to the amplifier, retaining the a preamplifier section.

[hjames]

so to adjust the network id be able to design it utilizing the pdf files for the k110a/2420/2440/2405, connecting
the dual 2203 directly to the amplifier, retaining the a preamplifier section.

When I biamped my 4341 4 ways, I used the old crossover, but did not connect the low pass to the woofers. I only connected it to the Mid-bass driver, the LE85 Horn Assy, and the 2405 slots. Thats not the best way to go - its best if you build a new passive for just the upper drivers, but I had the old crossovers and was on a tight budget.

I took the output of my preamp, ran it into an Active 2 way stereo crossover (Originally a JBL/UREI M552, later an Ashly XR1001). I set the Active crossover point to 290Hz.
The Low pass side of the Active crossover went into a power amp - (JBL-UREI 6260 originally, later an Adcom GFA-555) and that tied directly to the 2 woofers, Left and Right
The High pass side of the Active crossover went into a second power amp (Usually best if it matches the other in tone) and the output of that amp fed the old internal passive for the 3 high drivers.


I put the money into good amps.

[bldozier]

id love to see that old setup in action.

isn't that what i wrote though

connect the low pas to the to the amps, and construct a passive network based of the 4 mentioned mids/horn/uhf/

do i have to use a active filter on the low pass?
thanks

[Challenger604]

id love to see that old setup in action.

isn't that what i wrote though

connect the low pas to the to the amps, and construct a passive network based of the 4 mentioned mids/horn/uhf/

do i have to use a active filter on the low pass?
thanks

Did you pay your debt to Larry?

[rusty jefferson]

....Once you decide to employ multiple amplifiers it seems illogical (to me) to use passive crossovers. Passive crossovers effectively reduce the usable power of the amplifiers, are a bit of an art to design and build, potentially introduce distortion, and lack the ease of adjustment of an active system (active crossover or DSP). ......

I agree with this statement, for what it's worth. No reason to reinvent the wheel.

Also, (most) tube preamplifiers have pretty high output impedance and don't do well driving multiple amplifiers, especially solid state amps with low(ish) input impedance. Of this, I have first hand knowledge.

[bldozier]

I agree with this statement, for what it's worth. No reason to reinvent the wheel.

Also, (most) tube preamplifiers have pretty high output impedance and don't do well driving multiple amplifiers, especially solid state amps with low(ish) input impedance. Of this, I have first hand knowledge.

i would yes you but i can't dispute this article.
maybe you can review my original question as to would connect the low pass section directly to the amps.
anyone have an answer to the question.

[bldozier]

i just thought maybe the condition I'm having deciding over the network & along w/ the comment
on the tube preamps not actively responding to multi-amp environments, i thought about the L-212 &
and le10/2420/2440/uhf in a pair of cabs w/ the a powered Sub box.

may fit better as well.