rocky500 Posted August 2, 2012 Share Posted August 2, 2012 (edited) I have some series crossovers in my speakers that I have been changing parts over for better quality ones. I did a Cap change to better known quality caps. It also had those cheaper white square resistors(5watt and 7watt), so decided to change them over to Mills 12watt for 2 of them because of size and the one on the midrange to a Mundorf 20watt. Now I have one speaker with the original resistors next to the one with the new Resistors. It has been played for at least 48hours and I can not hear a difference between them. Maybe slightly the midrange but it is hard to pick. I actually swapped out a different value for the Mundorf one. 3.9 ohm to 2.7 ohm, thinking to increase the midrange slightly. The others were on the tweeter. 1 was 1.5 ohm (used the same value mills) the other was 2x 33 ohm in paralel to give 16.5 ohm.(replaced with a 1x 20 ohm mills) I have a ECM 8000 mike and attachment to use REW but have not set it up yet. Is it worth trying to get any readings before changing the other speaker? Also normally how far a value to need to go to hear a change? Edited August 2, 2012 by rocky500 Link to comment Share on other sites More sharing options...
davewantsmoore Posted August 2, 2012 Share Posted August 2, 2012 I have a ECM 8000 mike and attachment to use REW but have not set it up yet. Is it worth trying to get any readings before changing the other speaker? Also normally how far a value to need to go to hear a change? Yes. Measurements are essential here. It would be possible to miss a 0.5db change somewhere with your ears .... your measurements will pick this up. Value for a certain FR change? .... that will depend on the circuit the component is in, there is no universal answer. Link to comment Share on other sites More sharing options...
rocky500 Posted August 2, 2012 Author Share Posted August 2, 2012 (edited) Thanks Dave, I have not used REW (or anything else to measure) before and I thought it would be the case that I should set it up. At least give it a go. I was actually also thinking that changing the cheeper resistors for better quality ones in itself, would give me a slightly better sound in some way. Edited August 2, 2012 by rocky500 Link to comment Share on other sites More sharing options...
Once was an audiophile Posted August 2, 2012 Share Posted August 2, 2012 I was actually also thinking that changing the cheeper resistors for better quality ones in itself, would give me a slightly better sound in some way. Not always the case rocky enjoy your journey Link to comment Share on other sites More sharing options...
LogicprObe Posted August 2, 2012 Share Posted August 2, 2012 Changing caps is usually more noticeable than resistors. Depends if they're series or parallel also. Link to comment Share on other sites More sharing options...
Addicted to music Posted August 2, 2012 Share Posted August 2, 2012 Dont kmow the resistors you have changed, but there are 2 types of resistors that may effect SQ. Most crossover employ wirewound ceramic types that have a high paracitic inductive value, if these are used in series for with the tweeter it will effect the highs. Therefore you used low inductor metal plate ceramic that are thin and square in shape. If you are using typical wirewound it is better to use 2 X the value and parallel them to reduce the paracitic inductance. Parallel two identical resistors halves the total resistance and paracitic inductance. Link to comment Share on other sites More sharing options...
THOMO Posted August 2, 2012 Share Posted August 2, 2012 (edited) Rocky, If you want an improved sound by changing crossover components[brands not values] you need to BELIEVE. Making an A/B comparison is the last thing you want to do. Edited August 2, 2012 by THOMO 2 Link to comment Share on other sites More sharing options...
THOMO Posted August 2, 2012 Share Posted August 2, 2012 (edited) Rocky, If you want an improved sound by changing crossover components[brands not values] you need to BELIEVE. Making an A/B comparison is the last thing you want to do. Double post sorry. Edited August 2, 2012 by THOMO Link to comment Share on other sites More sharing options...
rocky500 Posted August 3, 2012 Author Share Posted August 3, 2012 (edited) I am sure the caps improved them, but I did them both at the same time, so no comparison. A couple of pics showing the orig square shaped white ones and a pic with the new ones. Not sure of the type. It is a bit of a mess but it is my first shot at a crossover and I am a newbie at soldering. I put the white ones in there to drop the tweeter a bit as it was dominating too much. It could be I need to do both to get a better idea with stereo sound too. Edited August 3, 2012 by rocky500 Link to comment Share on other sites More sharing options...
Addicted to music Posted August 3, 2012 Share Posted August 3, 2012 (edited) I am sure the caps improved them, but I did them both at the same time, so no comparison. A couple of pics showing the orig square shaped white ones and a pic with the new ones. Not sure of the type. It is a bit of a mess but it is my first shot at a crossover and I am a newbie at soldering. It could be I need to do both to get a better idea with stereo sound too. All those white ones are wire wound with max parasitic inductance. In a mosfet output stage these are not warranted. if they are in series with the bass I dont think you will be able to detect audiable difference between the old and the new! I could be wrong though! The ones I an talking about (metal plate low inductance type ) are white and are square to rectangular and are 1/2 the thickness! http://www.digikey.c.../MPRSeries.html The cap change to MKP in series with the tweeter guarantees SQ improvements Edited August 3, 2012 by pchan Link to comment Share on other sites More sharing options...
gainphile Posted August 3, 2012 Share Posted August 3, 2012 Hi Rocky, in the past I had done components swaps, and found out as you did. As you have measurement tools, I'd suggest to activate it. 0.5dB difference is easily visible on the graph and audible and the change of caps/resistors "might" do that. If it doesn't (let's say the cheap caps vs. expensive caps value are the same)... then they would of course sound exactly the same !! Link to comment Share on other sites More sharing options...
Arg Posted August 3, 2012 Share Posted August 3, 2012 If you want to measure, try measuring the voltage on the driver terminals where you have changed xo component values. Get a before and after FR plot of the voltage. Measuring SPL is of course valid and ultimately more useful, but the terminal voltage is more repeatable and accurate, so it is a good place to start. Link to comment Share on other sites More sharing options...
rocky500 Posted August 3, 2012 Author Share Posted August 3, 2012 I put a recorder between the 2 speakers and recorded one speaker then switched to the other. Can anyone hear a difference? I am swapping every so often between left and right. I know its not a great way but I was interested if anyone could hear a difference. Uploaded here: http://kiwi6.com/file/9gzic3r23j Link to comment Share on other sites More sharing options...
rocky500 Posted August 3, 2012 Author Share Posted August 3, 2012 (edited) Hi Pchan. It is a Fountek JP3.0 ribbon tweeter. Will the resistors be ok for them? Are the ones you mention better than say the mills/mundorf ones I used. There is one more Resistor that is the rectangle white one but it looks like it is for the bass drivers. Did not want to mess with that one. The crossover are a series crossover, so have been advised a change somewhere can have an effect on the whole crossover. When I get a chance I will try REW out. I am sure my room has a big effect on my sound, not in a good way. Edited August 3, 2012 by rocky500 Link to comment Share on other sites More sharing options...
davewantsmoore Posted August 3, 2012 Share Posted August 3, 2012 Attached thumbnails Ah, those crossovers look familiar ;-) Link to comment Share on other sites More sharing options...
rocky500 Posted August 3, 2012 Author Share Posted August 3, 2012 Ah, those crossovers look familiar ;-) Just a little more hacked up by me. ;-) Link to comment Share on other sites More sharing options...
Paul Spencer Posted August 3, 2012 Share Posted August 3, 2012 It's not a big suprise that you don't notice a difference with your resistors. Resistors are probably the most benign passive component. Seems a shame to take some nice Jantzen caps and straps them onto that tiny board! Even if it doesn't sound better, a nicely spaced out board does give the builder a sense of satisfaction. Let's call it a deliberate and beneficial placebo effect! Measuring - I'm not sure I see the point if you can't hear anything. If you hear something, you can then measure and try to find the reason. Link to comment Share on other sites More sharing options...
rocky500 Posted August 3, 2012 Author Share Posted August 3, 2012 I am pretty sure there was a good improvement with the Jantzen caps, but have been changing a lot of gear at the same time, so no real fallback. I had some wood lying around and it was the only way I could think of to have the larger caps fit in there and keep it a little bit away from the big coil.. It all slides through a round hole on the back of the speaker. I will try and setup REW later. With the recorded file, I think I can hear a slight difference once played back through another system. It is subtle. The right speaker in the file is the one with the new resistors. Link to comment Share on other sites More sharing options...
Addicted to music Posted August 3, 2012 Share Posted August 3, 2012 If you dont mind me asking what type of cap was in there previously? If it was a MKT and a MKP was used to replace it, I will definately confirm an improvement. For resistors I dont feel that you can do any better than using a higher wattage. There are numerous types of resistors and the ones I would be using are ones that are plated, metal film or wire wound. I have noticed that Mundorfs have a metal oxide range and have outlined the benetifs but what they didnt outlined was that metal oxides are noisy, whether you can pick that up in a cross over is debatable, but should never be used in low voltage/wattage appliucation. The metal plates are only in the range of 0.1 to max of 1-2 ohms. Nice tweeter, I have a soft spot for any ribbon base speaker, I have 6ft ribbons and a Behringer Truth 3031A and I love the sound of either Link to comment Share on other sites More sharing options...
rocky500 Posted August 3, 2012 Author Share Posted August 3, 2012 Nor sure of the original caps but here is a pic. Yes once I have had ribbon tweeters it is hard to listen to normal tweeters. Takes a good 20 minutes to get used to the sound. Almost like the dome tweeter speakers sound a little flat at first until I have listened to them for a while. Link to comment Share on other sites More sharing options...
Addicted to music Posted August 3, 2012 Share Posted August 3, 2012 I hate to give to you Rocky, you have gone from a MKP to MKP have a look at the this: http://www.bennic.com.tw/en/acocap/index.asp the letters PMT said it all! Unless you just wanted to experiment for the fun of it and have cash to burn give the resistors a change! Link to comment Share on other sites More sharing options...
rocky500 Posted August 3, 2012 Author Share Posted August 3, 2012 (edited) I actually replaced the 2 yellow PMT caps with much larger Jantzen Caps. (seemed to have good reviews without being super expensive) http://www.jantzen-a...rior-z-cap.html The pic I posted last was from the other side of the crossover. I seem to see a lot on the net about the white square resistors been very cheap and others are better in crossovers. The resistor change was just to finish off what I could do without having to know to much about crossovers. Was also for the fun in it too as its nice to get some practice with a soldering iron. Edited August 3, 2012 by rocky500 Link to comment Share on other sites More sharing options...
ehtcom Posted August 3, 2012 Share Posted August 3, 2012 Hi Rocky. The Vishay thick film resistors are a good option. Datasheet here. Cheers, Earle. Link to comment Share on other sites More sharing options...
Addicted to music Posted August 3, 2012 Share Posted August 3, 2012 I actually replaced the 2 yellow PMT caps with much larger Jantzen Caps. (seemed to have good reviews without being super expensive) http://www.jantzen-a...rior-z-cap.html I seem to see a lot on the net about the white square resistors been very cheap and others are better. The resistor change was just to finish off what I could do without having to know to much about crossovers. Was for the fun in it too as it nice to get some practice with a soldering iron. As long as you had fun!!! I do this stuff day out and day in! Link to comment Share on other sites More sharing options...
Addicted to music Posted August 3, 2012 Share Posted August 3, 2012 Hi Rocky. The Vishay thick film resistors are a good option. Datasheet here. Cheers, Earle. Great option Earle Link to comment Share on other sites More sharing options...
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