The new budget speaker king?

[archie2]

Bought these JBL L-19 crossovers and was wondering how they would do in the Presiarians. To Zilch: I read one of your posts saying to close off the port for better bass. That surprised me. I've done that before on other speakers but didn't think it would work on the Presidians.

 

[Zilch]

Bought these JBL L-19 crossovers and was wondering how they would do in the Presiarians. To Zilch: I read one of your posts saying to close off the port for better bass. That surprised me. I've done that before on other speakers but didn't think it would work on the Presidians.

The bass is "Better" based upon nearfield measurements, which do not sum the port output; I'll have to measure that as well to see. It also varies depending upon which woofer is used, and location.

Generally, I'm trying for the most bass extension from these, and closed-box alignment may help. The plugs I'm using are shown in earlier posts. For now, try it both ways and trust your ears on this one. We're certainly doing better than typical mini-monitors with these.

I'll fire up the Mighty Presidians once again tonight for testing with L-19 crossovers.... :thmbsp:

 

[Zilch]

Not sure what tweeters you're using right now, so I worked with the stock ones. I left the woofers connected to the spring terminals, ran leads from the tweeter out the port, and plugged the port with the wires there. :

Green and green/black are the woofer leads, and yellow, yellow/black the tweeter. Results are not very good just using the N19 stock, crossing at 2.5 kHz:

The Zobel is wrong for the Presidian woofer. Remove the 18 uF non-polar electrolytic on the terminal strip and replace it with a 6.8 uF metallized polypropylene Dayton. Short out the 5-Ohm resistor, also on the terminal strip, by bridging across it with wire.

Better?

Attenuation control set to "5", we're crossed at 3.1 kHz, and the woofer hash is well and duly buried:

 

[analog addict]

Heh...

This is starting to remind me of the old Stone Soup fable....

 

[archie2]

Not sure what tweeters you're using right now, so I worked with the stock ones. I left the woofers connected to the spring terminals, ran leads from the tweeter out the port, and plugged the port with the wires there. :

Green and green/black are the woofer leads, and yellow, yellow/black the tweeter. Results are not very good just using the N19 stock and crossing at 2.6 kHz:

The Zobel is wrong for the Presidian woofer. Remove the 18 uF non-polar electrolytic on the terminal strip and replace it with a 6.8 uF metallized polypropylene Dayton. Short out the 5-Ohm resistor, also on the terminal strip, by bridging across it with wire.

Better?

Attenuation control set to "5", we're crossed at 3.1 kHz, and the woofer hash is well buried:

I'm using the stock tweeter. Only have a very small inventory of caps. May not have a 6.8 uF. How close do I need to come? I may have a 6.2. Thanks Zilch.

 

[Zilch]

I'm using the stock tweeter. Only have a very small inventory of caps. May not have a 6.8 uF. How close do I need to come? I may have a 6.2. Thanks Zilch.

6.2 will work fine. Doesn't bury the woofer hash quite as deep above crossover, is all.... :thmbsp:

This is starting to remind me of the old Stone Soup fable....

The Mighty Presidian....

 

[Zilch]

Pic of temporary N19 mod for Presidian.

Additional 3 uF cap at left (disconnected) is used for Tang Band AR4x, with the Zobel resistor reconnected. Ignore it for now:

 

[archie2]

Pic of temporary N19 mod for Presidian.

Additional 3 uF cap at left (disconnected) is used for Tang Band AR4x, with the Zobel resistor reconnected. Ignore it for now:

Where did the 7.5 uf cap on the left come from and what's it's purpose? Did I miss something?

 

[Zilch]

Where did the 7.5 uf cap on the left come from and what's it's purpose? Did I miss something?

On the right? When you asked if 6.2 uF would work in lieu of 6.8 uF, I tried it before saying so. I also tried 7.5 uF, and that's what's still on there now, is all, burying the woofer hash a bit deeper.

What's important is hearing how the sound improves when the woofer is shut down above the appropriate frequency, and the tweeter is actually employed as one.

Again, this simple mod lets N19 work with the stock Presidian, as you requested, but the circuit I developed earlier in this thread is better, and N19 is perhaps more suitably used for an AR4x Tang Band upgrade.... :thmbsp:

 

[archie2]

Sometimes I don't know my left from my right caused by a true mixed dominance I have. Yes, on the right. What kind of inventory you must have to be able to make all these permutations and combinations. I thought you were simulating most of these tests.

 

[Zilch]

I thought you were simulating most of these tests.

If it's a sim, I say so. Otherwise, you can count on it being the real deal.... :thmbsp:

 

[stangbat]

Found a pair of these today for $15. Gonna Zilch mod them just for the fun of it. I just got done building the Zaph ZDT3 so I guess I need another project.

 

[Zilch]

Cool!

There's gotta still be some out there at R/Ss.

Looks like folks bought up all the $12 Tang Band tweeter closeouts, alas:

http://www.partsexpress.com/pe/showdetl.cfm?Partnumber=264-823

These are now on sale for $9. Haven't tried them, tho:

http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=264-804

I now have three more woofer types here to try, JBL 506G and two different ones by Gefco, one with a 1.5" voice coil.... :thmbsp:

 

[stangbat]

I did the mod on one speaker and AB tested them. Night and day difference. This is a perfect example of how proper crossover design can make all the difference. The underwater sound and overbearing midrange is gone.

I need to do the second one, but in a way I don't want to because then I can't compare the old to the new anymore.

 

[Zilch]

I need to do the second one, but in a way I don't want to because then I can't compare the old to the new anymore.

If you REALLY wanted to, you could probably still find another pair of the originals out there....

 

[jcmanic]

Bastards.... I bought 2 sets today. And they've been reduced to $10 now. STEAL!

 

[Zilch]

"Deval" price now $10.47, $11.33 the pair out the door.

Your local R/S's computer knows where they are, #40-5053.

Five more pair in SF East Bay stores they want rid of right now.... :yes:

 

[w1jim]

Cripes, and you guys probably thought we were done talking about the Presidians. I bought a pair a few months ago and was so intrigued that I got a second pair. I replaced the tweeters with a pair of the M&K soft dome tweeters (#17500 - $12 ish) that are frequently available on ebay, put in a Jamo 661 crossover (3k - $20/pr ebay) and stuffed them with some fiberglass. I have these in my basement workshop system and the rears on my AV system.
I'm impressed; well maybe that doesn't mean much but I'm certainly not depressed, which counts for plenty.
I really do like these tweeters; I scored a pair of B&W DM560 speakers locally for short money. I figured B&W, they had to be great; ixnay - the metal dome tweeters where deadly. I pulled them out and mounted the M&Ks in the same spot behind the diffuser. Looks stock / sounds great (versus grate). Another DIY'er miracle.
JimB

 

[braxus]

My buddy in Seattle picked up a set of these for me and I got them in the last month. I finally hooked them up into my seconday system (computer A/V system) which is run by my Denon PMA-900V amp. Its 120 wpc so I don't want to overdrive these little guys. They won't stay in this system for long as Im getting some Energy C200 speakers to put in here. Anyway I decided to try the Rad Shack speakers out. Very bass heavy with a boxy kind of sound. I had to turn up the treble just to hear any at all. Your right- these speakers do need to be modded. I have a crossover from a 2 way speaker waiting to be used and I may replace the paper woofers with polypropelene ones I bought from Rad Shack years ago. Not a bad looking little speaker though. Eventually they'll go into my main system to be used for surround sound speakers.

 

[braxus]

I finally got what I needed to get the swap going. I got the crossovers and 6.5" woofers I had packed away out. I took the Presidians apart. As you can see from the pics there is not much to these speakers. The 3rd pic is the replacement Radio Shack woofer I bought in the late 90s. These woofers are much better built then the paper cone ones the speakers came with. The only difference is the polycone woofer is only rated to 40 watts. The 5th and 6th pic is the crossovers I got off Ebay. They were from a speaker which I forget, but when I did check it out that speaker set did use the 6.5" woofer, so these crossovers should be a better match then another generic set. I temporarily stuffed the crossovers in the top corner of the speaker box. If they work out ok, I'll get the box cut from those crossovers to drop in. So I hooked up the tweeter and put it back in, and then placed in the better woofer. Then got some stuffing material to insulate the box. Put it all back together. When hooked up to my Denon, the one speaker did cut out partially at times, so I may have a loose connection. That or my Denon needs work as this is also the first time I've used that amp. But after some playing the distortion that cut out the sound a little stopped. The last pic is the after pic next to the before. Now to the sound.

The mids and high end came back which was very noticable. The sound is more open now, but the bass is still a bit shy on some songs. More bass heavy music sounds ok, though as expected the low low end isn't great. The box still has a resonance even after being filled. The sound still sounds somewhat congested, compressed, and boxy. Haven't noticed much in a 3D sound quality yet. All in all it was fun to play with, but I'm happy these speakers will end up for surround duty on an old Kenwood Surround sound processor from the late 80s. But I must say the woofers make the speaker look much better.