passive crossover and biamping, peavey 3020 speakers

[spottyaudio]

my eventual solution is going to be to get the jacks replaced, but i have a specific show in 1.5 weeks that i got these for, so i just need them to work for that show like this and then i'm going to tear into them and do it right. i dont want to put any more money into these than i have to, and i am pretty sure i wont be keeping them for a long time, though i must admit that putting a 2 driver and horn is damn tempting, if only because i already have such a combo that'd probably fit if i cut the cabs up, but then i'm committed to that path, and i think i'd rather just run em fullrange with stock drivers most of the time and call it a day.

[spottyaudio]

these are older, with the xlr fullrange input on them btw.

[Unalaska]

I'd have the original crossovers repaired by a qualified tech, triamping these has basically no benefit and could lead to major amp failures. Could be a choke coil became dislodged, could be the 1/4" inputs went bad. It's worth the hassle. Have both serviced at the same time too.

[spottyaudio]

well, i will update with, andy was right about the ground being common across the two terminals. if i did the test right, which i'm guessing i did because how can you really muck up a continuity test, there is definite signal between the grounds of the low input and the fullrange input, but nothing between the possitives, which i expected.

i dont think i have time to service the crossovers before the gig so i am going to get in there and just hard wire the fifteens to the 1/4 jack, which should be interesting as it appears the 1/4 jack is an integral part of the crossover circuit board, and it may prove impossible.

any other suggestions to make this work before next tuesday? i have the amps to triamp the system if only for this gig but not the dsp...

is there a way to bypass the low input jack with hard wire to make it so the fullrange input drives the fifteens without the option of triamping? its not ideal but it sure would simplify the amp rack. also, it appears the only way to get at the crossover is to pull a fifteen, remove the padding inside, and then go from there..doesnt seem like much fun to me but i gotta do what i gotta do at this point because the drivers/horns i slated for my custom built mid tops are sitting idle while i find a competent carpenter who want run off with my parts and deposit like last time..

[spottyaudio]

i opened them up today, the 1/4 jacks are all board mounted so taking it apart in a way that can be easily put back together is going to be a true pain in the ass. my goal was to see if i could figure out how to simply bypass the low input jack so the fifteens used the crossover, negating the need to triamp. if anyone can give me a pointer on how to do this, wire between traces on the board? anything..i want to be able to undo it though, and fix the crossovers properly after the show.

[agedhorse]

Not an easy operation, and depending on how it's implimented, I'm not sure I could even walk you through it.

Was there continuity between the low and high input's sleeve terminals, not just the full range and low inputs sleeve's?

[spottyaudio]

i didnt check for that, i did some quick modding that will solve my problem effectively and be really easy to revert back to stock.

i removed a fifteen, pulled the passive network, used a chissle to make a 1/2 wide by about 1/6 deep channel under the crossover in the wood. i laid 12 gauge wire through this, one end connected directly to the fifteens and the other coming out the back of the cabinet above the jacks. this way the crossover can be tightened down and not pinch the wire. ,and the divit in the wood can be filled with puddy later. it looks crude, and it is. but, i can now run a speakon to the cabinet which will look so much cleaner than three 1/4 cables, and use one amp to drive the fifteens, and the other to drive the fullrange input to the tens and horns.

when i have time, after vacation/the gig, i want to pull the crossovers and have them serviced. i dont want to attempt this myself, to much hot metal, but i think i might have someone locally..maybe a few hours away, whom we all know and love who might tackle it for the right price.

[Dogoth]

I worked for a place that had somethoing like 12 of those boxes (as well as a few of their baby brothers the 1510s). These were distributed among several different venues. The HT94s would fail on a regular basis. Sometime after the 15th dia replacment, we just gave up. The general public never missed the high end and in reality the rest of the speaker never sounded that good anyway. I ended up with a couple of those pigs when they finaly upgraded. I guess the best thing I could say about them is they would get loud and looked impressive (2 handles on each side - great for garage bands :-). I parted out the scorpion drivers and made a few bucks but the boxes were terrible (they would resonate somewhere in the low 100hzs). I MAY still have the crossover (they worked fine when dissasembled) burried somewhere. I'll look. If I find them, you can have them for the cost of shipping. I'll PM you if I find them and you can decide. FWIW I really like Peavey as a company and think most of their products are underated in the industry but every company makes their lemons ;-).

cheers

[Yuuki]

I have run 3020s for many years during the late 80s and throughout the 90s, I also ran them with two bridged CS-800s all night long, held every ounce of it easily. 400watts program is the RMS value in music power which even at that is conservative. They held all of the 1000+watts of power to each I gave them running every genre of music out there. There has yet to be a single cabinet speaker system to beat them in my opinion. Now adays you have to make 10 trips to move everything that could equal the sound. I know this is an old thread, but dang, why cant Peavey make a great product once again. Now that technology is so much better, Imagine what they could make now.

 One thing I did notice, was a mistake made by so many people among other DJ companies, is that they used too small of an amplifier, and constantly burned out the HT94s. They were clipping their amps constantly in larger venues, and they wondered why they were burning out those Super tweeters. 

I never once had to replace a HT94 with my bridged setup. I felt sorry for the people driving speakers that required a big block engine, but the ignorant minds that used tiny single CS400 and CS800 amps. Its amazing how many do not realize that distortion from a low power amp kills more HT94s than too much power from a high power amp. I used and still do tell them, you wouldnt use a 4cylinder engine to pull a house, when it needs an 8cylinder.  

 

It seems today, that is not a problem compare to yester-years amps. I would love to get my hands on a set of 3020HTs again, heck, I would settle for a 3020 or better yet, a 3624 from Sonic and do driver and crossover upgrades.

 

-Kimiko

[agedhorse]

Yukki, the good ol days were not as good as you remember. Also, a cs800 is not 1000 watts into that speaker, lucky for you. You speak as though you understand the truth but what you say is just an opinion that is IMO inaccurate and does a disservice to others here.

[Yuuki]

The CS800 produced ~1050watts BRIDGED into 4ohms, 900 into 8 ohms that is how I ran them, and that is Spec per Peavey also. I read it with a meter to verify with students from University of Tennessee Electrical Engineering dept.

Please dont bash without realizing the information provided, which I guess could be an oversight on your part. It makes you have an unreliable knowledge base, which is the real disservice to everyone here.

[agedhorse]

 

Yukki, the new versions are current limited into 2 ohm stereo (4 ohms bridged) in order to get higher 4 ohm power, though all versions i am aware of are rated much lower at 2 ohms than 4 ohms. The older versions do about 800 watts at 4 ohms bridged. This is for USA versions. Some versions do not support 4 ohm bridged as well for regulatory reasons primarily. I would not recommend bridging the cs800 into 4 ohms as well.

 

Newbies should not be so disrespectful when they come onto a new forum.

edit:

I looked at my service manuals and I am not mistaken...

The version from 1976 uses 5 output transistors per rail and uses essentially a single slope VI (essentially just a current limiter) set at roughly 2.5 amps per device (which matches pretty well with the devices SOA and amp's Vcc) for a maximum current of 12.5 amps peak or 9 amps RMS. Calculating this out, that's about 160 watts into 2 ohms, but with some slow-down caps and curve sloping & droop, I would expect that in practice to be a bit over 200 watts. As a check of this, it should do about 320 watts into 4 and factoring in the above adjustment it ends up around 400 watts which is what it's rated for.

Later versions used slightly lower rail voltages but slightly stiffer rails, they also use much better power transistors, only 4 per rail and a more sophisticated VI limiter allowing for slightly more power with 1 less transistor pair.

I designed my first power amp in 1980-81, so I am pretty familiar with what was happening around this time in power amp technology. Today's devices, as well as a better understanding of device behavour and new operating classes have allowed us to get considerably more real world power out of 4 pair of devices.