Infinity primus

[jj59]

What's up all,
I'm new to this site and I have a question about infinity primus 250s. I'm currently having an issue with the 5 1/4 mids. Currently there not putting out the mid level sound I'm used to hearing. I was wondering if you guys have had similar issues, and if not what type of troubleshooting advice would you guys recommend to fix the issue. Thanks in advance.

 

[everettT]

More info about your avr and eq, your room and furnishings. What midrange sound are you comparing it to? Most find the primus midwoofer to be somewhat neutral

What's up all,
I'm new to this site and I have a question about infinity primus 250s. I'm currently having an issue with the 5 1/4 mids. Currently there not putting out the mid level sound I'm used to hearing. I was wondering if you guys have had similar issues, and if not what type of troubleshooting advice would you guys recommend to fix the issue. Thanks in advance.

 

[shadyJ]

Are these speakers you have owned for awhile and this problem has recently cropped up? Or did you just buy them and you aren't liking how the mids sound?

 

[jj59]

Well the problem just started happening. One tower is working fine and you can clearly hear the sound coming from both mid range speaker. The other tower is not producing the same sound, I can hear sound from it but it's not the same. Its very faint no bass at all. Could it be the crossover inside the speaker tower

 

[shadyJ]

Is sound from both the woofers in the malfunctioning speaker faint? If so, that clearly seems like a crossover problem. If it is only one woofer, than obviously it is a driver issue. Time to give Infinity tech support a call. If something went wrong with the crossover, it will need to be replaced.

 

[jj59]

Yes....Both woofers are faint. Is that something I can fix?

 

[shadyJ]

If you can get a schematic of the crossover, you might be able to fix that yourself. I don't think that is likely. Or, if you are lucky, the faulty part is apparent and also labeled. I guess it doesn't hurt to take out the crossover and give it a look at this point, since the speaker is already messed up.

 

[TLS Guy]

The drivers are in parallel with both taking equal power. If you have damaged one speaker you have probably damaged both in that speaker. Driver failures are much more common than crossover failures.

If you have an ohm meter (and if you don't buy one) and measure the DC resistance of both speakers at the loudspeaker terminals.

I suspect they will be different.

Now remove the drivers from the bad speaker and one driver form the good speaker. Disconnect the wires. Now measure the DC resistance of all three drivers. If the drivers of the bad speaker are different form the DC resistance of the driver from the good speaker, then the voice coils of the drivers from the bad speaker have been damaged.

If that is so then those drivers need complete reconing, if you can get reconing kits. If not the drivers need replacing with new drivers.

If the DC resistance of all the mid/woofer drivers is the same then you need to troubleshoot the crossover which is electrical fourth order.

There are two inductors in series with the woofers. For loss of output there would have to be a bad solder joint or the inductors burnt out. However those speakers have substantial inductors and I don't think they would burn out without burning out the mid/woofers also.

Let us know how you get on.

 

[jj59]

Can I test the drivers this way, I found this on instructions.com i can use a AA battery instead of a 9volt. Here's the instructions:"This is just going to be a short instructable because of its simplicity. This only works with the speakers that have the positive and negative wires that hook into a stereo. To tell if the speaker is blown or not without taking it apart is really easy. All you have to do is take a 9 volt battery and touch it to the wires. If it makes scratching noises its good. If it makes no sound at all its blown."

 

[TLS Guy]

Can I test the drivers this way, I found this on instructions.com i can use a AA battery instead of a 9volt. Here's the instructions:"This is just going to be a short instructable because of its simplicity. This only works with the speakers that have the positive and negative wires that hook into a stereo. To tell if the speaker is blown or not without taking it apart is really easy. All you have to do is take a 9 volt battery and touch it to the wires. If it makes scratching noises its good. If it makes no sound at all its blown."

You can do that, but it will give you limited information. It also might give confusing information. For one thing it will only show you open circuit and not a damaged but not blown voice coil. Owning a multi meter is just part of the basic tool set everyone should own.

One last thing. I assume you have proved this is a speaker and not an amp problem. If not you need to do so.

You need to switch the speakers over, by swapping the left and right speakers. If the fault moves with the speaker it is the speaker, if it does not you have an amp problem.

 

[jj59]

Sweet....I do own a multi meter, but it's pretty basic. I removed the mids, and tweeter so I can test the crossover. after putting the meter to the pos. and neg. lugs of the crossover. It read OL. I also tested the speaker and got 7.8Ω on both....next I'll switch one mid to the working speaker. Any advice is welcome.

 

[TLS Guy]

Sweet....I do own a multi meter, but it's pretty basic. I removed the mids, and tweeter so I can test the crossover. after putting the meter to the pos. and neg. lugs of the crossover. It read OL. I also tested the speaker and got 7.8Ω on both....next I'll switch one mid to the working speaker. Any advice is welcome.

OK now measure the DC resistance of all four mid/woofers and see if they are all the same.

Now connect the +ve and -ve leads from the crossovers to the mid/woofers together on each speaker. Now check the DC resistance of each speaker at the loudspeaker terminals at the back. Both speakers should be the same and read less than half an ohm.

By the way are you absolutely certain this is a speaker problem and not an amp problem?

 

[jj59]

Ok so i checked both mids on the good tower and they both work the resistance was the same with both mids when I measured from the neg and pos on the back side of the tower. I guess the only thing to check is the crossover. Oh yeah I tested the amp and it's working on all channels. Again any advice is welcomed. Thanks

 

[TLS Guy]

Ok so i checked both mids on the good tower and they both work the resistance was the same with both mids when I measured from the neg and pos on the back side of the tower. I guess the only thing to check is the crossover. Oh yeah I tested the amp and it's working on all channels. Again any advice is welcomed. Thanks

In that case I bet there is a dry solder joint in the crossover. Your meter should easily track that down.

 

[jj59]

Going to pull one of the caps on the crossover to check leakage, and what not. The information on the cap seems pretty legiable, but I was wondering if it was an analytic cap, oppose to anything else....do you guys know by chance

 

[slipperybidness]

Going to pull one of the caps on the crossover to check leakage, and what not. The information on the cap seems pretty legiable, but I was wondering if it was an analytic cap, oppose to anything else....do you guys know by chance

"Electrolytic" not "analytic"

You shouldn't have to remove a cap from a board to see leakage or if the cap has bulged or not.

Cap construction is usually pretty easily identified by visual inspection--different types look differently. Without you posting a pic, it's difficult to know what cap you would be talking about.

 

[TLS Guy]

Going to pull one of the caps on the crossover to check leakage, and what not. The information on the cap seems pretty legiable, but I was wondering if it was an analytic cap, oppose to anything else....do you guys know by chance

A cap failure is very unlikely to cause the problem you are having. The reason is that all the caps will be shunting the driver. So the caps would have to increase in value rather then the usual decrease in value over time. The latter would make the speaker bright by causing excess HF to pass to the woofer. The only way the caps could cause this would be severe DC leakage causing leakage across the diaelectric.

From pictures it does look as if the caps are electrolytic. Therefore it would not hurt to replace them.

Your problem is going to be either a dry joint or burn out of the voice coils. Inductor damage should be obvious from inspection.

 

[jj59]

So I pulled the capacitor from the crossover....it was C2 that I pulled and it turns out it didn't pass the leakage test. The test said it was bad....so I decided to remove another cap and tested it, it passed reading good. I guess now I need to replace the capacitor but I like to replace it with the exact one but I'm having a hard time trying to find it on line.....it is made by sounder, it's a 40microfard 100vdc cap. Any idea were I can get some of these.

 

[slipperybidness]

So I pulled the capacitor from the crossover....it was C2 that I pulled and it turns out it didn't pass the leakage test. The test said it was bad....so I decided to remove another cap and tested it, it passed reading good. I guess now I need to replace the capacitor but I like to replace it with the exact one but I'm having a hard time trying to find it on line.....it is made by sounder, it's a 40microfard 100vdc cap. Any idea were I can get some of these.

There really isn't any need to replace it with an exact match, as long as it has the same capacitance and the same or better voltage and temp ratings.

But, my 2 favorite parts suppliers are:
http://www.mouser.com/
https://www.parts-express.com/

 

[TLS Guy]

So I pulled the capacitor from the crossover....it was C2 that I pulled and it turns out it didn't pass the leakage test. The test said it was bad....so I decided to remove another cap and tested it, it passed reading good. I guess now I need to replace the capacitor but I like to replace it with the exact one but I'm having a hard time trying to find it on line.....it is made by sounder, it's a 40microfard 100vdc cap. Any idea were I can get some of these.

Well done, you have found the problem.

I would replace those caps with non electrolytic ones. You won't have this problem again. Electrolytic caps I don't believe really belong in passive crossovers. I would replace all of them in both speakers.

If you do use electrolytic caps make sure it is NON polarizing. Most electrolytic caps are polarizing types. The reason being that in a passive crossover there is no DC voltage to polarize the caps.

Madisound carry the good quality high value Solen caps, which is what I generally use. Don't forget that you can put caps in parallel to get the correct value. The final capacity is the sum of the values of the caps connected in parallel.