Single resistor in 2B TL x-over

gmcman

Which holes to use when using Gimpod's boards? Using a single resistor in place of the 2.7 & .5 ohm.

Use one location and a jumper or reach a single resistor to both locations...if the latter is even possible.

F1nut

You would use a jumper in place of the .5 ohm and use the single 3.2 ohm resistor in place of the 2.7 ohm.

gimpod

Same place where you would put the 2.7 holes B & G, Also don't forget to put a jumper across S1.

Personally I don't recommend doing this because this is not the way the crossover was designed. If I were you I'd start with a 0.2 Ohm in place of the polyswitch (S1) and go from there, If the tweeter seams too bright up the resistance a bit but don't go over 0.5 Ohms.

BTW here's a link that might help SDA 2B/CRS+ Parts Placement

gmcman

I will start with a .2 and work up. Just for the sake of interest, would using fewer resistors have a more positive effect on sound quality, or would it even be noticeable? Just curious.

gmcman

I had ordered a .15 as well as a few others so I started with the .15 and this made quite a noticeable difference. I need to give it a little more time for me to adjust to it but could be just ever so slightly on the bright side. The details in the higher passages are much more evident, granted this is in my setup but I want to speculate the 198 is capable of being allowed to reproduce these details cleanly without sounding overly harsh...I think the .5 mills may keep the 198 from showing it's true potential based on my initial observations.

I will give the .15 some time and see if the .22 does any better.

On3s&Z3r0s

I'm gearing up to make some more XO modifications on some previously upgraded 2BTLs. The big change is going to be new inductors, but I was thinking I would pull out all the stops and upgrade the Mills resistors to Dueland Cast Carbon/Silver resistors while I was at it. Since they're running over $50 a pop I thought no way I would spend that on the resistors replacing the polyswitches and was instead considering going to a single 3.1 ohm resistor instead of the 2.7 and jumpering the other location. I can see from the schematic that it's not electrically the same, but I was wondering if anyone had tried it? Maybe I should try it with cheap resistors before dropping the cash on the Duelands?

Is it stupid to replace just the one 2.7 Mills resistor with a 2.7 Dueland and leave the other Mills in place?

gmcman

On3s&Z3r0s wrote: »

Is it stupid to replace just the one 2.7 Mills resistor with a 2.7 Dueland and leave the other Mills in place?

I had asked this recently and the consensus was all or none. After what I had just gone through I would change out the .5 for a .22 working up to a .33, if you like the .33 then maybe use the 3 ohm in place of the 2.7 and a jumper for the .5 if you prefer a singe resistor.

I would try this before you go with the Duelunds.

I pulled the .15 and replaced with a .22, the .15 was just slightly bright. I think the .22 is almost right about where it needs to be, especially for the B&K components. These speakers sound completely different now and I am very much enjoying them.

I'm not an expert but lowering the resistor value doesn't seem to taper the upper end, but change the overall tonal quality. Everything that the .15 affected was bright, even the male singers voice sounded slightly pitchy. The .22 brought the entire upper spectrum down a notch from the .15 and I'm fairly certain the sweet spot will be somewhere between .22 & .33, total resistance roughly 2.9-3 ohms.

Time will tell but I can say this has changed the speakers dramatically for the good. I will give the .27 & .33 a try as well. Another issue I have with this room is certain spots have a void of bass and the speakers are naturally bright but that's only a few areas.

On3s&Z3r0s

I was afraid that was going to be the answer. Unfortunately Parts Connexion doesn't even stock the Dueland Cast resistors in values lower than .5 ohms and that's a 5 watt 10% resistor. It just seems like I'd be better off with a jumper in that case. I've heard lots of people sing the praises of the Duelands but it seems like it would be a trick to get something that would be just right.

I totally agree with you with respect to the values of the resistors in general. I have a B&K amp driving my 2BTLs also, and .22 seems to be a good value with the Mills. I did try just a jumper instead and things were a little bright for my taste but not terrible. I tried the .5 Mills also and thought that tamped things down too much, hence my hesitation to go with the .5 with 10% tolerance even if it is a Dueland.

gmcman

On3s&Z3r0s wrote: »

It just seems like I'd be better off with a jumper in that case.

Duelund has a 3 & 3.1 Ohm, I think that would be the ticket using a jumper in place of the smaller resistor location. I would personally be hesitant to go above 3 Ohms total. I believe Vr3 may have done this already, not 100% sure but someone did.

I believe regardless of which resistor you go with, 3.2 total Ohms is too much. I would love to hear mine with a set of Duelund's but it's an expensive gamble for sure to get it right. If I had to pull the trigger on one today it would be a 3 Ohm.

gmcman

This is something I have been digging up in other threads and I am curious about how the crossover frequency may be altered. Say for example I use a jumper in place of the .5 and use either a 3 ohm or 3.2 ohm where the 2.7 normally is...doesn't this alter the crossover point?

Reason I ask is if my setup sounds right with 3 ohms of resistance in the tweeter, 2.7 + .3, would this be different than a jumper at the .3 and a single 3 ohm at the stock 2.7 location? Just trying to learn the system and not reinvent the wheel...

headrott

On3s&Z3r0s wrote: »

I was afraid that was going to be the answer. Unfortunately Parts Connexion doesn't even stock the Dueland Cast resistors in values lower than .5 ohms and that's a 5 watt 10% resistor. It just seems like I'd be better off with a jumper in that case. I've heard lots of people sing the praises of the Duelands but it seems like it would be a trick to get something that would be just right.

I totally agree with you with respect to the values of the resistors in general. I have a B&K amp driving my 2BTLs also, and .22 seems to be a good value with the Mills. I did try just a jumper instead and things were a little bright for my taste but not terrible. I tried the .5 Mills also and thought that tamped things down too much, hence my hesitation to go with the .5 with 10% tolerance even if it is a Dueland.

The Duelunds are more transparent than the Mills, plus the Duelunds are more neutral sounding than the Mills as the Mills are pretty warm sounding. I would not be too afraid to try a .5 ohm Duelund for the polyswitch as I don;t think you will find it tames the highs as much as the Mills. I have two .5 ohm Duelund resistors for replacing the poly, but decided to simply instert a jumper after reading Ray's comparison results between a resistor ad a jumper inplace of the polyswitch. Maybe one day I will try the .5 ohm Duelund resistors in the jumper spot in my 2.3TL's....... Not today though.

headrott

gmcman wrote: »

This is something I have been digging up in other threads and I am curious about how the crossover frequency may be altered. Say for example I use a jumper in place of the .5 and use either a 3 ohm or 3.2 ohm where the 2.7 normally is...doesn't this alter the crossover point?

Reason I ask is if my setup sounds right with 3 ohms of resistance in the tweeter, 2.7 + .3, would this be different than a jumper at the .3 and a single 3 ohm at the stock 2.7 location? Just trying to learn the system and not reinvent the wheel...

This is what Tony was gtting at in his post above. He would certainly be able to answer better than me as he designed the crossover boards you are installing the resistors into. But, I don't think trying to increase a resistor value in the tweeter position would be a good idea for the crossover point. I think you are correct in assuming it will negatively affect the audio (if I understood you correctly).

F1nut

It's been so long that I forget, but I believe I was the one that realized compensation was needed when removing the poly.

On the subject of 2B's, I put a .5 ohm in place of the poly in my 2BTL's, sounds perfect. I suspect the results will vary depending on the gear and the way you hear things. I'm very sensitive to high frequency hash and anything less than .5 ohm sounded too bright while a .62 ohm sounded dull.

There is no hard fast rule here, so use what suits your tastes, but keep in mind that most find the .5 ohm to work best.

F1nut

Let add that I personally would not do what I posted in #2, just answering the man's question.

Toolfan66

There is no reason to use anything more then the .5 and I tried a handful just for **** and g1ggles, and the .5 worked the best, so when I ordered my Duelunds I did so without hesitation..

Also why use a 3 or 3.2 in the 2.7 position? Am I reading that right?

Never mind, just looked at the schematics, I see what your trying to do, and I now understand F1's post above, I agree with him I personally would not do that either..

If your trying to same money, forget about the Duelunds and stick with the mills...

gmcman

headrott wrote: »

This is what Tony was getting at in his post above. He would certainly be able to answer better than me as he designed the crossover boards you are installing the resistors into. But, I don't think trying to increase a resistor value in the tweeter position would be a good idea for the crossover point. I think you are correct in assuming it will negatively affect the audio (if I understood you correctly).

Correct, I definitely do not want to alter any crossover points. Was going with the idea on fewer components in the circuit path may possibly improve sq, and if 3 ohms sounded better than 3.2 total ohms then why not use a single resistor. Upon further research and what others have stated that this would alter the crossover point when bypassing with the 5.8 cap. So whatever I chose to do it will be with two resistors.

Toolfan66 wrote: »

There is no reason to use anything more then the .5 and I tried a handful just for **** and g1ggles, and the .5 worked the best, so when I ordered my Duelunds I did so without hesitation..


If your trying to same money, forget about the Duelunds and stick with the mills...

Yeah, not going with more than .5 as this value is already on the cusp of being dull in my setup.

The money isn't much of a factor with using the correct Duelund, it's just the cost involved in trying 2 or 3 different values. With the Mills that's about $25, with the Duelund's we're approaching $325...ouch. Being the fact they are more transparent changes things as well, sounds like the .5 Duelund will do much better than a .5 Mills.

Of course we have to consider using all Duelunds so may not hurt to try a .5 Duelund to start then add the 2.7 later. I have no problem keeping a handful of Mills lying around but the Duelunds, that's some serious overhead....

F1nut

Just a thought.....if you are use to the SL2000 replacing it with the RD0198-1 will sound mellow in comparision and adding a .5 ohm in place of the poly will mellow it out a bit more, but at least to me it ends up sounding a lot more natural. Screw that ultra detail transparent crap, live music doesn't sound like that.

gmcman

F1nut wrote: »

Just a thought.....if you are use to the SL2000 replacing it with the RD0198-1 will sound mellow in comparision and adding a .5 ohm in place of the poly will mellow it out a bit more.

I honestly forgot what the SL2000 sounded like, wasn't in the cabinets long before I TL'd and recapped the speakers.

My progress is I went with a .33 Mills and I'm still hearing some forwardness in the tweeter, not much change from the .22 but naturally a larger change from the .15. Doesn't seem to be a linear transition and I did recheck the .5 Mills I removed and they are right at .5 ohms give or take a few hundredths.

A lot of material sounds great, but some recordings sound very bright and I keep asking myself, basically what you said about live music....that it wouldn't sound that bright in real life.

I have a set of AQ Crystal for the mains that are in a shotgun bi-wire configuration when I was using them for the RT800's. Instead of completely undoing the bananas and spades, I just attached both terminations on the 2B's..one spade and one banana utilizing both wires for one terminal. I removed one of the leads from the speakers and ran another REW measurement and from about 1kHz on up, there was a drop in attenuation across the board, ran a second test and was roughly the same drop.

Interesting findings but I think I will try the .5 again and compare notes....fun stuff albeit tedious.

gmcman

Something I forgot to mention is when I was taking individual speaker measurements about 12" from the speaker, there was a sharp spike at 2.7kHz in both speakers, Is this normal? I can't post the graphs as of yet as my laptop is on the fritz.

Face

I would try measuring further back. Also, any chance your tweeter is wired backwards?

gmcman

Face wrote: »

I would try measuring further back. Also, any chance your tweeter is wired backwards?

I did measure back a few more feet, I believe room acoustics changed things somewhat but the spike was still there just not as pronounced.

I thought the polarity could be changed but I checked and double checked, I will check again. I do have the black wire on the red tab but that's not to say the black may be negative but I'm certain I had checked this at the X-over.

gmcman

Not to say something isn't wired correctly, here's the x-over and the left is the same.

gmcman

Better view, both sides are the same, was before I secured them with zip ties.

gmcman

What if my meter isn't capable of measuring capacitance correctly and these are in fact 5.6 uf bypass caps instead of 5.8? I consulted with Soniccraft when I opened the box about the issue before I soldered them to the board and they said there was a lot of misprinted 5.8's. Whether they were actually 5.8 or just the fact the way they were printed since the "8" looked awfully like a "6".

My meter was reading right at 5.8 give or take a few hundredths but it could be the error in the meter as well.

Face

5.6 vs. 5.8 is such a small difference that I wouldn't worry.

gimpod

I have to agree with face on the cap, there's probably more CRS+/2BTL's with 5.6uf cap's than 5.8uf.

From your pictures it looks like you have everything where it should be. Tweeter harness looks right and you said you have the black wire going to the tweeter terminal marked with red paint so that's right. As far as the crossover's go the only thing I can think of is check for a lose or cold solder joint.

Did you notice the 2.7kh spike before you disconnected the extra lead, if not I would hook it backup and retest and if the spike is gone start look elsewhere it's not in the speakers.

nspindel

I used a .5 Dueland in place of the poly. Love it.

gmcman

I went back to the .5 mills just to see how well it works with the new mids, and rule out any brightness associated with the smaller resistors. I cannot run any graphs as of yet with my laptop on the fritz, but the brightness is still present. I even swapped the 198's for the SL 2000's and it's bright....very odd.

Mathematically, what does the 5.6 do in comparison to the 5.8?

Solder joints look good, I can hit them again to be sure.

F1nut

How many hours do you have on the crossovers? If less than 200, anything you hear now doesn't count.

gimpod

gmcman wrote: »

I went back to the .5 mills just to see how well it works with the new mids, and rule out any brightness associated with the smaller resistors.

New Mid's ? did you change the 6.5" driver's ? if you did what one's. They should be a MW6510 or MW6503 for the stereo driver and a MW6511 for the dimensional driver.

gmcman wrote: »

I cannot run any graphs as of yet with my laptop on the fritz, but the brightness is still present. I even swapped the 198's for the SL 2000's and it's bright....very odd.

How many hours do you have on the crossovers, remember it can take up to about 400 hours for the caps to burn in and settle down, They will change all over the place from good to bad and back again. you shouldn't be making any changes until they've had sufficient time to fully burn in.

gmcman wrote: »

Mathematically, what does the 5.6 do in comparison to the 5.8?

I wouldn't worry about it as it's only 0.2uf difference well with in the +/- %10 margin, This is so small of an amount of capacitance that I doubt if anyone would be able to tell the diff.

gmcman wrote: »

Solder joints look good, I can hit them again to be sure.

Unless you got really sloppy with the solder and managed to make some solder bridges (Which I doubt from the looks of the pics very nice job, One thing though I would use some hot glue on those inductors to help with any vibrations), I think your problems are elsewhere, What kind of gear are you running?

Also remember not all recording's (Analog or Digital) are created equal, It all depends on how they were mixed & mastered.

gmcman

gimpod wrote: »

New Mid's ? did you change the 6.5" driver's ? if you did what one's. They should be a MW6510 or MW6503 for the stereo driver and a MW6511 for the dimensional driver.

MW 6503 for stereo, MW 6511 for dimensional, purchased through Polk.

gimpod wrote: »

How many hours do you have on the crossovers, remember it can take up to about 400 hours for the caps to burn in and settle down, They will change all over the place from good to bad and back again. you shouldn't be making any changes until they've had sufficient time to fully burn in.

I would put them at 5-600 hours very conservatively, finished them 2 years ago almost to the day.

gimpod wrote: »

Unless you got really sloppy with the solder and managed to make some solder bridges (Which I doubt from the looks of the pics very nice job, One thing though I would use some hot glue on those inductors to help with any vibrations), I think your problems are elsewhere, What kind of gear are you running?

Solder joints look real good, I'm running:

Denon 2910-BJC Digital coax-B&K Ref 50-BJC 2' XLR to B&K 200.2, then AQ Crystal to 2B's