Just finished the x-overs on my 2.3tl's

drumminman

A couple of observations:

Polk did not use exact value caps as called for in schematics.

In the right speaker I found the following:

Instead of 8uf - 4.4uf film bypassed by 4.2 electrolytic
Instead of 16uf - 12uf film bypassed by 4.2 electrolytic
Instead of 18uf - 12uf electrolytic bypassed by 5.8 uf electrolytic

In the left speaker:

Instead of 8uf - 8.4uf film
Instead of 18uf - 12uf electrolytic bypassed by 5.8 uf electrolytic

All other values were exact. Looks like a case of using up old parts as each speaker was a little different! :eek:

Doing the boards was not bad at all. I had already spent so much money with the RDO-198's x 6 and all the parts from Sonicraft that I decided not to go with Gimpods boards, though they looked really nice.

The second board went much easier than the first as the real trick is working out how to fit all those big film caps in a space not really designed for them. Fortuneatly, space inside the cabinet is not an issue. The only cap that was hanging off the board to any degree is the 27uf.

How does it all sound:

Upon firing up everything last night the left speaker was at about half the volume of the right, and then started distorting like crazy :frown: In my haste to get everything hooked up I neglected to turn off my power amp and blew a fuse. It's designed to be left on, and definitely doesn't reach its best sound unless its been powered up for at least a day.

Anyhow, I noticed that the sound from the speakers was a little more organic, a slightly deeper soundstage, dynamics that sounded maybe a little less forced. These qualities were present on some recordings, not so much on others. The bass is diminished, though still there. Looking forward to when these are fully burned in.

The 198s should arrive mid week and then I'll install those and finish the mods. Stay tuned!:biggrin:

headrott

Nice drumminman. Wait until the capacitors fully break in. They only get better. Right now, they don't sound nearly as good as a few hundred hours from now. Give them about 200 hours and you should be grinning from ear to ear (especially after you install the RDO-198's).:biggrin: Keep us posted.

Greg

george daniel

yep-- it's gonna' be a roller coaster ride with those speakers for sure(caps),things will settle in and I think you'll be pleasantly surprised.Enjoy.

drumminman

Or thereabouts. It was almost exactly that for my def techs when I did the same mod - actually I went ahead and replaced the inductors as well on those

I didn't play the system that much and I remember thinking maybe it wasn't worth all the time and trouble. And then one when I started spinning cds I was blown away. The change was profound and it stayed that way.

I got to speed up this process, that's for sure.

The caps in the 2.3 x-overs are alot older than those in the def techs, which may explain why the depth of soundstage has already shown a little improvement.

But I want my bass back! ! ! !

F1nut

But I want my bass back!

Bass response improves immediately after doing the upgrades, you've got something wrong somewhere. Check for air leaks.

drumminman

F1nut wrote: »

Bass response improves immediately after doing the upgrades, you've got something wrong somewhere. Check for air leaks.

I did the PR push test before and after the x-over mods. No real difference: the MW's extend and then slowly recede to about 1/2 way and hold for 5 - 10 seconds. Also, I plugged the bass brace holes on the back.

I was very careful to put the new caps in exactly the same spot on the boards as the old - or so I thought. Do you have any suggestions for x-over mistakes that might cause the loss of bass?

If I made a mistake I was very consistent as both L & R speakers have the same tonal qualities. I can hear the bass line, but it doesn't slam like it did before. The deep notes don't sound as deep either. They sound too polite

I have about 10 hours on these post mods.

Thanks,

Fred

george daniel

did you check your crossovers--wiring?

drumminman

george daniel wrote: »

did you check your crossovers--wiring?

I double checked each one. . . . .still I suppose I should pull them and have a look one more time.

Perhaps a bad solder joint? This seems unlikely as I would have to have a bad joint in exactly the same place on both boards.

Conradicles

Lack of bass is usually wiring out of phase somewhere...could be in the speakers, amp or actual speaker wires (which is uncommon). You will figure it out.

heiney9

Lack of bass is one of the side effects of new components. It should come back in 200-300 hours. Do you mostly notice the bass extension is less? As if a ball is rolling on a table and then it abruptly falls off the edge. Sort of like the bass notes are coming up a little short? That's typically what we talk about when we mention "less" bass.

If you are talking little, to no bass notes at all, then there might be a wiring issue, sealed cabinet issue, etc.

It takes time, so play 'em and let things settle in and then revisit.

H9

drumminman

Lack of bass is one of the side effects of new components. It should come back in 200-300 hours. Do you mostly notice the bass extension is less? As if a ball is rolling on a table and then it abruptly falls off the edge. Sort of like the bass notes are coming up a little short? That's typically what we talk about when we mention "less" bass.

Yeah, that pretty much describes it. The bass has much less impact. The notes seem to be there, but it's like that part of the frequency spectrum is muted.

I'm hoping a big part of this is everything needs more time to burn in.

Air leakage in the cabinets may be an issue, but the cabs haven't been altered. Since I was getting bass before the x-over mod there must be something else.

Perhaps I'll reverse phase on the speakers as C pointed out just to see what effect it has.

heiney9

Probably just the new components, but reversing the phase and listening certainly wouldn't hurt. But again, I wouldn't make a final determination that there is an issue until the parts have ample time to break in 200-300 hours. What you are describing is pretty much spot on when upgrading parts. I had this issue with my 5B's whne I recapped them, it all came back and more after ample break-in

H9

headrott

I agree with Brock. Let the caps burn in and the Bass should come back in full and much better (tighter and deeper than the original caps). There is a chance something else could be wrong (as F1nut stated), but the bass on both my 3.1TL's and 2BTL's was not as strong (to my ears) until the caps burned in. Also, the high end was more shrill, but then evened out. I cannot remember, did you put the 0.5 ohm resistor in the S1 spot (for the polyswitch)?

I think it's highly unlikely that it's a bad solder joint causing the problem, but wouldn't hurt to check. It would certainly take less than 200+ hours to check them. But, as H9 said, you may just need the caps to burn in to get the full bass response back.

Greg

drumminman

headrott wrote: »

I agree with Brock. Let the caps burn in and the Bass should come back in full and much better (tighter and deeper than the original caps). There is a chance something else could be wrong (as F1nut stated), but the bass on both my 3.1TL's and 2BTL's was not as strong (to my ears) until the caps burned in. Also, the high end was more shrill, but then evened out. I cannot remember, did you put the 0.5 ohm resistor in the S1 spot (for the polyswitch)?

I think it's highly unlikely that it's a bad solder joint causing the problem, but wouldn't hurt to check. It would certainly take less than 200+ hours to check them. But, as H9 said, you may just need the caps to burn in to get the full bass response back.

Greg

As of last night I now have 13 hours on them, and 2 on the new 198's which came and were installed last night. More on that later.

I tried reversing phase (from reverse back to normal - my pre reverses phase), and that was definitely not as good. So then I put on a Headhunters CD that has lots of quick low bass notes and percussion. The bass is definitely there and perhaps slightly more present last night.

The last CD I played was Diana Krall "The Look of Love". Among other things it has some nice stand up bass. I didn't have to focus on it to hear it, though again it's a little recessed in the soundstage.

So I'll just keep playing em and listening for the changes :biggrin:

drumminman

I played the aforementioned Headhunters (Herbie Hancock) CD and then installed them. Then I played it again. I know audio memory can be a little tricky, but I'm very familiar with both the CD and the speakers. No other changes were made - all the same equipment, cables, etc.

I was absolutely shocked at what I heard! :eek:

From what I've read on the board I was hesitant about ordering them as I thought the high end on these speakers was slightly on the dark side. Maybe not the dark side, but without the high end detail that I'm used to. I was concerned that the "smoother" RDO's might be a little too much so, a little too laid back.

A big THANK YOU to everyone on the forum who recommended them. From the first note I could hear more detail, more sparkle, more presence in voices (especially female), less thickness. It's like the tonal balance shifted to be much more neutral. And s-m-o-o-o-o-o-o-o-t-h

I'm so looking forward to hearing what they do when they're burned in.