Prodigy panels only, digital crossovers

[Watchdog]

I would like to run the prodigy panels I have without any passive crossovers. I own a Tact preamp capable of crossovers and room correction. I would just like to build whatever I need to run the Panel only. I know it will still have to plug into the wall but can I build that. Thanks in advance for any advice.

 

[C.A.P]

Without the power supplies and step up transformers its gonna be a difficult project. Can it be done? YES in the most capable of hands . Someone who has a electrical engineering background and can design them. Martin Logan is pretty closed fist about selling just parts of that nature. Its probably something proprietary. With out owning them and dissecting them its gonna be tough to start out fresh. I am not sure they will even sell you panels with out a serial # to start with.

Why and what are your reasons for this ?

 

[jtwrace]

I would like to run the prodigy panels I have without any passive crossovers. I own a Tact preamp capable of crossovers and room correction. I would just like to build whatever I need to run the Panel only. I know it will still have to plug into the wall but can I build that. Thanks in advance for any advice.

This will be a start if you are unable to purchase the products direct. http://www.plitron.com/audio_elec.asp

 

[FISH_MAN]

I would think about selling them before you brake them.you could then put the money towards a complete speaker

 

[JonFo]

I would like to run the prodigy panels I have without any passive crossovers. I own a Tact preamp capable of crossovers and room correction. I would just like to build whatever I need to run the Panel only. I know it will still have to plug into the wall but can I build that. Thanks in advance for any advice.

Hi and welcome to the club!

First, you’re on the right track, with a TacT pre, you definitely need to explore active crossovers. Once you do, there’s no going back.

If all you have from the Prodigies is the the panel (no electronics), are they used panels taken from someone who just updated theirs? If so, it might not be worth the effort to get them running again. As they were probably updated for a reason.

However, if they are in excellent condition, then yes, there are ways of building out an ESL energizer and the audio-step up is pretty simple (commercial products available).

But before you embark on any of this, what’s your level of comfort with electronics, soldering, etc.?

For a taste of what might be involved, please read my SL3XC build thread, as there will be some similarities and you’ll get a feel for the level of tech you’ll need to be at for this. But I'll be around to help as well

 

[Watchdog]

I hope this answers any questions from above.

I have a working pair of 8 year old Prodigy's. I am ordering new panels for them and would love to buy the hardware to hook up just the panel. I would run 300 watts from a digital tact setup to the panel and send 300 watts to a line array for the mid\lows. I will use the sub out of the Tact for 4 15inch infinite baffle subs that play into attic eclosures. The Clarity and efficiency from eliminating all analog crossovers with the all digital amp and preamp system, and the look and sound improvement of the panels freestanding alone is what I'm after. I am willing to do alot of work I just don't know the electrical portion.
Thanks

 

[Watchdog]

It looks like you have a very nice setup and lots of experience with martin logan. I have plenty of soldering skills. I have worked in the audio business for 14 years and own my own Home Theater Company. I am not scared to try anything.

 

[JonFo]

Sorry watchdog, finally getting back to this one.

If you have Prodigies, and are upgrading the panels, that a great start.

Since you have the electronics in the Prodigies, then just use those. As you saw in my mods for the SL3XC, it’s ‘easy’ to bypass all the passive crossover components and just use the ESL step-up (audio and voltage) components.

So no new parts required. It’s all there in the Prodigies.

Now, if you want to remount the panels in some new structure, go right ahead and engineer something strong, stable and with a place to mount the energizing board (and ESL audio step up transformer).

If combining this with a companion line-array (wonder where I’ve heard of that before ), then I’d recommend building a common mounting solution, as the line array should be as close as possible to the Panel (and at least as long, but could extend a 14” or so above and below if more mid-bass is desired or if using small drivers (e.g. 4”) ).

Now, for crossovers, I’ve not measured a prodigy panel, but I’m guessing that much like the other panels, it starts loosing output capabilities (at higher SPL’s) around 250Hz. Please note that even the much larger Monolith panels I use are crossed over above 250Hz (around 315hz right now).

So, I’d start by setting the TacT pre to send anything above 250hz to the panel using a 48db/octave slope. Send 60 to 250hz to the line array with 24 db slope low-pass at 250Hz and a 48db high-pass at 60Hz. Sub obviously low-pass at 60Hz with a 48db slope.

The reason for recommending a shallower slope on the 250hz mid-bass low-pass is that we want a bit more output in the upper mid-bass to come from the line-array to help compensate for the dipole cancelation that the panel will have at those frequencies.

Use the TacT measuring system to ensure that all speaker phases are correct independent of each other (turn off their respective amps or disconnect them), if you can control delays in the TacT, then set them based on physical distance (or better - measured impulses responses).
Ultimately, the TacT measurement system will phase and time-align the results, but best to start with something close to right.

Which TacT gear do you have?