PG "All System" Tri Mode Passive Crossover Network

bigdwiz · Post by **bigdwiz** » Mon Oct 25, 2010 6:01 pm

I was just curious how rare these are? I'd like to build a system around one of these and have not seen many on the market. I was able to find a PAC-100, but the PG looks much nicer. I guess I could build one with a terminal strip and the chokes and caps....

Any insight?

12voltjunky · Post by **12voltjunky** » Mon Oct 25, 2010 6:06 pm

the pg units don't come up for sale very often. i have seen just a couple in the last 12 months.

Pillow · Post by **Pillow** » Mon Oct 25, 2010 6:08 pm

I have a used one if you need it. No plexi cover though.

30 shipped... If serious I will take some photos.

It is a cool old school item for sure!

bigdwiz · Post by **bigdwiz** » Mon Oct 25, 2010 6:16 pm

Pillow wrote:I have a used one if you need it. No plexi cover though.

30 shipped... If serious I will take some photos.

It is a cool old school item for sure!

Yes, I am VERY interested! I don't need the plexi cover, but as long as it functions properly, I'll take it!

bigdwiz · Post by **bigdwiz** » Mon Oct 25, 2010 6:24 pm

Pillow, PM sent....

Pillow · Post by **Pillow** » Mon Oct 25, 2010 8:41 pm

PMed back, it is yours!

Post by **ttocs** » Mon Oct 25, 2010 9:16 pm

they were neat systems but the lack of tunabilit is what I think killed them. I would love to know what kind of power they ate up as well..

bigdwiz · Post by **bigdwiz** » Tue Oct 26, 2010 4:24 am

Pillow wrote:PMed back, it is yours!

Payment sent! Thanks!!

bigdwiz · Post by **bigdwiz** » Tue Oct 26, 2010 4:30 am

ttocs wrote:they were neat systems but the lack of tunabilit is what I think killed them. I would love to know what kind of power they ate up as well..

Pardon my ignorance, but can you explain "tunabilit"?

I've used passive crossover networks in the past and the most significant loss I've noticed is in the low's. I did a side by side comparison of a Punch 45HD using a choke, then using an active crossover and the difference was very noticeable. If I could make an educated guess, I'd say it robbed 25-30% of the low end power. It would also be interesting to hear a scientific answer!

Thanks.

Post by **ttocs** » Tue Oct 26, 2010 6:13 am

forgot the "y" on tunability. Sorry you pay the price for my fast, badly done typing

....

When you power it up, what ya got is what ya get. You can adjust the bass/treble controls but the lack of being able to adjust the subwoofer seperate from the mids/highs, along with the amount of power the x-over itself eats is what I think made them go away. I mean they look beautiful and the idea of driving everything off of one amp should have taken off, if they sounded as good as we wanted them too.

Post by **fuzzysnuggleduck** » Tue Oct 26, 2010 7:55 am

The "tunability" in these units can be somewhat controlled via the impedance of the drivers you select, right? Doesn't that change the xover points somewhat?

Post by **ttocs** » Tue Oct 26, 2010 8:59 am

changes everything from the sensativity to teh signal to the cross over points. Most people would rather turn a dial then start swapping out speakers to get the right sound.

Post by **fuzzysnuggleduck** » Tue Oct 26, 2010 10:05 am

ttocs wrote:changes everything from the sensativity to teh signal to the cross over points. Most people would rather turn a dial then start swapping out speakers to get the right sound.

No doubt, swapping speakers is definitely not the same kind of "tuning" as with active processors.

bigdwiz · Post by **bigdwiz** » Tue Oct 26, 2010 12:16 pm

Not to mention the increased availability of 4 and 5 channel amps with built-in-xovers make all the tweaking easier. But where's the fun in easy?

Pillow · Post by **Pillow** » Tue Oct 26, 2010 6:20 pm

I forgot I had this video...

tri mode in full effect! Powaed by an M50 to boot!

http://www.youtube.com/watch?v=tvzmQ53b8YY

No laughing at the goof-ball narrator

FWIW the M50 is FS now as well. I just haven't posted a FS yet.

bigdwiz · Post by **bigdwiz** » Wed Oct 27, 2010 3:33 am

Pillow wrote:I forgot I had this video...

tri mode in full effect! Powaed by an M50 to boot!

http://www.youtube.com/watch?v=tvzmQ53b8YY

No laughing at the goof-ball narrator

FWIW the M50 is FS now as well. I just haven't posted a FS yet.

Nice...I watched this video months ago and just had to get me an Audio Authority Power Supply. I was able to score a 100A model 978 for my test bench. Funny, my friends joke that I dim the lights in my neighborhood when I'm doing my bench testing!

I didn't want to spill the beans too early, but I plan on using the tri-mode crossover with my custom designed "old school" boombox. I'm planning on using a Punch 45HD, Boston Pro 5.4 separates, and either a Polk DB8, JL 8W1 or MTX 10" Blue Thunder sub. I also have an Alpine 7903, but I think the CD mechanism is no longer working, so I may use a newer Alpine with iPod and MP3 capability. I've found it is possible to get 3+ hours of HIGH VOLUME playback using a 4lb 12v 11ah sealed lead acid battery. I'd like to make the box out of fiberglass, but I've never worked with the stuff, so I may do plywood and finish with veneer or truck bedliner material (spray on kind).

I'll keep everyone updated and have some other videos on Youtube under "bigdwiz". Most are RF videos up to this point and one video of my first iteration of a "toolbox boombox". I've since updated this project as well, just haven't posed the updated video. This stuff is TOO MUCH FUN!!

Pillow · Post by **Pillow** » Wed Oct 27, 2010 4:30 am

Sounds awesome! Pics are mandatory

bigdwiz · Post by **bigdwiz** » Wed Oct 27, 2010 4:58 am

Pillow wrote:Sounds awesome! Pics are mandatory

I will have plenty of pics and a video to go along with it.

In the meantime, I have put up a video of my first toolbox boombox, (since updated with MB Quart 6.5's and an Alpine 9813 HU....) BTW, a plastic toolbox is not the best enclosure for SQ...

http://www.youtube.com/watch?v=f6k4fWWmTz8

Enjoy!

Post by **smgreen20** » Wed Oct 27, 2010 1:58 pm

To clarify the power consumed by a passive network, the general rule of thumb is for every order/6 dB the slope is, it's ~5% of the power wasted.

1st order/6 dB= 5% loss
2nd order/12 dB= 10% loss
3rd order/18 dB= 15% loss
4th order/24 dB= 20% loss

Remember that this is in general/on average.