Electronic Crossover for L300

[rbnjr]

Are there any recommendations on equipment that would best match the L300 summit speaker?
no budget constraints.

thank you.

[speakerdave]

Something to be aware of: In the 4333a, which was factory wired biampable, the signal shaping and frequency division elements of the high pass were left in the circuit when switched to biamp mode. Also the zobel was left across the woofer. These were done because both were necessary to achieving the design goal frequency response of the system as a whole. Therefore the external crossover only needed to provide low pass at 800Hz. As I recall, the L300 was not built biampable. The answer to your question depends in part on what modifications you have made to make yours biampable.

[rbnjr]

Something to be aware of: In the 4333a, which was factory wired biampable, the signal shaping and frequency division elements of the high pass were left in the circuit when switched to biamp mode. Also the zobel was left across the woofer. These were done because both were necessary to achieving the design goal frequency response of the system as a whole. Therefore the external crossover only needed to provide low pass at 800Hz. As I recall, the L300 was not built biampable. The answer to your question depends in part on what modifications you have made to make yours biampable.

as of this date i have not made any crossover mods to the L300. I wonder if the 4333a has similar design elements and the 4333a crossover will be able to be used.

thank you.

[speakerdave]

It's the same speaker.

[rbnjr]

It's the same speaker.

your reply indicates you do not have a clear image of my design concepts. other jbl speaker crossovers may work in the L300 and models with bi amped cross overs are the ones im looking for.

[macaroonie]

I am of the opinion that while the L300 / 4333 is a great speaker in it's original form , with modern DSP crossovers etc it can rise to another level not attainable with passive
networks.
To get there forget about the old crossovers and trying to integrate them with electronic filtering. I can be done but it not an elegant solution

You did mention in your original post the there were no price constraints , however
I will give you a bobby basic line up that will do your job.

DBX260

stereo power amps x3

6 core speaker cable

protection caps for the MF and HF drivers. There is a little table published by JBL which I have. I'll post that later

You know the x/o frequencies and slopes so you can copy that in the software of the X/O as a starting point.

Simply put the x/o will give you LF MF and HF outputs that you then allocate to the power amps. You absolutely need to keep track of your hook ups TAKE NOTES !!

In the L300 the mid horn driver as I recall is out of phase with the bass unit but you will not need to do that as the delay available in the x/o will allow you to do that digitally.

From there on in it's a matter of getting the basics set up and running then you can start refining the system bu using measuring tools . The X/o has loads of EQ options
that you will need to learn to get things dialed in properly. It will take you a while but straight out of the gate you will notice a significant improvement in dynamics , clarity , imaging etc . Almost as good as having you ears syringed

Read this: http://www.audioheritage.org/vbullet...ding-The-Build

I was able to lower the LF/MF crossover point to about 650Hz but I had provided for that with the bigger horn and a 2" driver. The 2235H is not really that well suited ti playing at 800Hz.

[tonymontana168]

Hello I have original L300 with nelson pass xo but only for the highs. for the sub I am active. I have 2 amps. I have 2 outputs on my preamp!
1 output goes to active crossover that has a 24db slope!
2nd output goes to the nelson pass passive xo and does to mid and tweeter.

BUT BUT... I think the nelson pass is 12db octave and my electronic active crossover is 24db oct.

Is that bad? should I be using my second output on my preamp?
Should I cross my active crossover at 1200hz? 800hz? Im really lost. It sounds good but not like it used to with original xo and active at 800hz.

Should I cross it at 1200hz now? should I get another active xo that has -12db oct slope?
I take mesurements but many people say they are not accurate here is the pic of high low and full range frequencys

[Mr. Widget]

Im really lost.

I see that.

Oh, welcome to the Lansing Heritage Forum!

What you are trying to do requires a fair amount of knowledge, skill, and patience if you want it to sound better than stock. Do you still have the parts to return it to original? If you do, I’d suggest you get it back to stock and then you can take a measurement of the stock system at 6’ or so. It’s important that you carefully balance the mid and tweeter l-pads to make the system as flat as possible.

If you still feel compelled to mess around with your speakers, keep this measurement as a baseline and have at it.

Regarding your question about slopes and crossover frequency, in some ways there is no wrong answer as long as you don’t damage anything and you like the results. I would try to get it to work with a 800Hz crossover frequency. Also if you hear highs coming from the woofer at an appreciable level, you’ve likely hooked up something incorrectly.


Widget

[tonymontana168]

triamp is really amazing I just put caps for protection and wow what a difference it made so much clarity! I crossed at 800 and 8500@24db with the new 3Rd Gen sublime crossover. it's great at the price. the bass really slames and goes really deep. I am using my 3 McIntosh amps 2x mc2200 and 1x mc2120 for my 4x tweeters 077!
I added 2 rear fire in 077 (ambience tweeters)