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Advent Prodigy Tower Crossovers

Uncle Paul

Uncle Paul

Super Member
Anybody know the component values or where I can get them?

I've identified a 300uH inductor, 5uF cap, and 1 ohm 5 watt resistor from the original. The remaining inductor and cap values (one each) are unknown due to lack of markings and/or covered in glue.

I'd like to build new ones with upgraded components as part of a refurb project.
 
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The other cap is a 13uf at 50v + or - 20 percent but, like you I am unable to read the inductors. Do you need new crossovers or are you just trying to upgrade? I have a pair from a pair of towers, I scraped for parts.

Clyde
 
Clyde,
Thanks for the info. The stock crossovers are in great shape, I'm looking to upgrade. I could just recap, but I also want to replace the terminal cup with one that has binding posts. I figure it's better just to leave the stock ones alone and build new ones.

The remaining inductor looks measurable due to it's orientation in the circuit. I may have to hunt down an LC meter somewhere to get the answer.

In the mean time I'll continue to Google away and see if I can find a schematic somewhere.

Paul
 
I measured the inductors and have the following values:
L1 = 300 uH RDC=2.4 Ohms
L2 = 200 uH RDC=1.6 Ohms
C1 = 5 uF
C2 = 13 uF
R1 = 1 Ohm 5 Watt

I plan on using Dayton (Bennic) film and foil bypassed with Audio Cap Thetas.
I've added series resistors to the 20 gauge Jantzen inductors to match the DCR of the original inductors. Cost for the improved crossovers is ~$30.00 each
 

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Hi Uncle Paul - I know that this is an old thread, but I'm wondering if you did the mod, and what the results were.

Thanks,

John
 
Prodigy crossover in attached photos. I just replaced the caps. In the end I was disappointed in their sound. I don't remember their specific shortcomings.
 

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johnbachel said:
Hi Uncle Paul - I know that this is an old thread, but I'm wondering if you did the mod, and what the results were.

Thanks,

John
Click to expand...

I did make the mod using the parts listed, about $60 at the time. It did make a difference which improved the longer I ran them. I used a pair of JBL L46's as a baseline for sound quality, since I figured any "improvement" might be due to the placebo effect. My conclusion is that it did make an audible improvement, but the tweeter in them can only be taken so far. I'll see if I can find some pix of the crossovers later today.
 
thanks - Not sure whether it's worth trying this based on what you say. Mine sound pretty good with the stock crossovers, but the highs are a little overly sharp/coarse.
 
All in all I think the money is better spent on a better speaker than better crossovers. I had about $160 into the Prodigies including crossover. It was really just a learning project (also refoamed the woofers). There is no way an additional $60 could make these any way near as good as my $220 JBL 18Ti's.
 
I would agree. I replaced just the caps in mine with Erse caps and was so disappointed in the sound, I pulled them back out.

Just not as good of a speaker as I thought they could be.
 
Uncle Paul said:
Anybody know the component values or where I can get them?

I've identified a 300uH inductor, 5uF cap, and 1 ohm 5 watt resistor from the original. The remaining inductor and cap values (one each) are unknown due to lack of markings and/or covered in glue.

I'd like to build new ones with upgraded components as part of a refurb project.
Click to expand...
 
In stock form they were significantly better than my JBL L26's, EPI 100's, AR15's, Dynaco A-25's, ar2ax which I A/B'd for a considerable period of time. They do need a tad bit of help with the woofer back wave cancellation. Original stuffing was marginal in terms of material and quantity. Fixing this drastically improved the lower mid and brought the low bass in line with almost no transients. Tweeter in fine and compares well to the T27 in my LS3's. Have seen some people add a ribbon or air motion transformer as a super tweeter sitting on the top of the pecan wood top.
 
taineasy said:
In stock form they were significantly better than my JBL L26's, EPI 100's, AR15's, Dynaco A-25's, ar2ax which I A/B'd for a considerable period of time. They do need a tad bit of help with the woofer back wave cancellation. Original stuffing was marginal in terms of material and quantity. Fixing this drastically improved the lower mid and brought the low bass in line with almost no transients. Tweeter in fine and compares well to the T27 in my LS3's. Have seen some people add a ribbon or air motion transformer as a super tweeter sitting on the top of the pecan wood top.
Click to expand...
So what got out of this is leave the crossover stock and add a little stuffing to combat transients.
 
Honestly, I think they are worth an upgrade.
The Jensen era Advents had very good drivers and cabinets, but the crossovers were as cheap as they get.
Additionally they also skimped on sound isulation.
I have 2 sets of Prodigies and did the upgrade in several steps, comparing the new upgrade to the other prodigy that didn't have it (AB testing). A sucessful upgrade as then transitioned to the other set.

It is possible to improve the sound quality significantly for maybe $40 or $50.

1) Add additional sound insulation. Make sure the back wall, side wall, and top/bottom have a layer of insullation. I have found adding too much muddies the sound, so don't over stuff it, but do make sure the sides and top/bottom are covered.
2) The electrolytic caps should be replaced with metalized polypropylene caps. The poly caps are only in the tweeter circuit, but will improve the clarity of the high end. Note that poly caps take some time to break in. At first power they sounded awful, but after 3 hours, the sound quality improved tremendously.
3) The inductor is the only component in the woofer circuit, there is also one in the tweeter circuit. I upgraded to inexpensive iron core inductors that were physically larger and while I didn't notice much improvement in the high end, the bass became much better defined.

My next experiment will be to see if air core inductors sound better than the iron core.
 
Some cabinet bracing would also help. Not worth sticking a bunch of money into. They were sort of designed for the Lawrence Welk/Percy Faith crowd.
 
I agree that its not worth sticking a bunch of money into this ; however, the upgrades mentioned aren't expensive.

Here is a picture of an upgraded crossover from a Prodigy (its the one sitting behind the blown Prodigy crossover - I guess someone had cranked up their Lawrence Welk too loud). I used Solens, but You can do this with Daytons for about $12 per speaker for the caps. Inductors are more, it you change out the woofer inductor only; that would add $3.25 per speaker - I didn't see a big change in upgrading the inductor in the tweeter circuit but if you did figure another $3.

Keep in mind that the electrolytic caps used are over 20 years old (electrolytics have a limited life) and the least expensive poly cap will out perform any of these electrolytics.
 

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Hello

old thread but curious if anyone is paying attention and could help me

I picked up some Prodigies for 20 for my office and they look great and my wife likes the way they fit the room. The have been re foamed and seem to be in good shape. I want them to last as the wood matches the furniture in my office. ‘I’m tempted to start buying backup parts including extra set of treaters and maybe crossovers. Is this stupid if they are presently working fine and I’m not driving them super hard? Are those likely to be parts I’ll never need? If the tweeters and cross overs seem to be working I have no context for when or what would make them not. Any advice on how you have handled this scenario is welcomed. I don’t want to put much money into speakers I paid $20 for yet I do want them to last ( and they are perfect now)
 
I'm a big Advent fan and have owned several sets of Prodigies. I still have a set, a Prodigy II. If they are playing fine, just enjoy them. They are a great speaker and nearly bulletproof. And since Advent made a lot of them, used replacement parts are available.

If you decide you want to enhance them, they are simple. The crossover consists of two inductors, two capacitors, and resistor.

Another cheap upgrade is to add some additional sound insulation.

None of this work is required - they are a great sounding speaker as is.

Do keep the pecan wood panels oiled every now and then.
The wood can dry out and start to split or delaminate.
I oil mine about every 6 months with Old English.

Enjoy the music!
 
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