LSi 15 crossover burned

Face

I was kidding before, alll volume controls aren't linear.

You should be able to listen at 90-95db without a problem. Since they are used, it's possible that they were abused before. It could also be that your amp is passing DC and is in need of service. If it happens again, have the amp checked out.

vmaxer

Face wrote: »

I was kidding before, alll volume controls aren't linear.

You should be able to listen at 90-95db without a problem. Since they are used, it's possible that they were abused before. It could also be that your amp is passing DC and is in need of service. If it happens again, have the amp checked out.

Face,

Thanks a lot, I am very new at this and have a lot to learn. Is there an easy way to check to see if the amp is passing DC??

Face

Possibly with a DMM, I honestly have no idea though.

vmaxer

I have an electronic genius friend I will ask tomorrow...most likely will know more than I want to afterward:eek:

This place is great, I really appreciate all the advise and information!!:D

Vette C6.r

Same thing happen to my XO's on the 15's and the LSic. For me it was caused by an all night party and loud levels.

Luckly the store that I got them from is super friendly and took care of both of them and even replaced the tweeters for free.

I did learn my lesson though.

McLoki

vmaxer wrote: »

Isn't clipping from not enough power?? I think I have the opposite problem.. The Sunfire Signature is rated at 810 watts at 4 ohms. Ken Swager also said it can be caused by too much power. As I understand the tweeters usually get fried first from clipping. I use to have that issue until I upgraded to the amps I have now.....

My pre doesn't have a marked knob, it turns a long way also, so the 12 o'clock don't work either.

I have a pair of crossovers coming from Polk and will be back up.

There are three signals that could be clipping.

Source to pre
Pre to amp
amp to speakers.

I think your amp to speakers is covered pretty well and that is what you are running the 810 watts to cover....

Source to pre is mainly if your source is recorded overly hot or you have a variable output turned up to far.

Pre to amp is the individual channel adjustments that you can make in your avr. If these are turned up to far, they can clip the output signal to your amp.

The first two adjustments (source to pre and pre to amp) can cause clipping even at fairly low volumes as they often occure before the volume control in the signal path.

Good luck on your search,

Michael

vmaxer

McLoki wrote: »

There are three signals that could be clipping.

Source to pre
Pre to amp
amp to speakers.

I think your amp to speakers is covered pretty well and that is what you are running the 810 watts to cover....

Source to pre is mainly if your source is recorded overly hot or you have a variable output turned up to far.

Pre to amp is the individual channel adjustments that you can make in your avr. If these are turned up to far, they can clip the output signal to your amp.

The first two adjustments (source to pre and pre to amp) can cause clipping even at fairly low volumes as they often occure before the volume control in the signal path.

Good luck on your search,

Michael

First, Thanks for the tip..I hadn't thought of that.

I can check the levels in the pre, is there a level that is best ...better to keep them on the lower side, maybe 0 or below??

I have no idea of the source to the pre, unless you are talking about the levels in the DVD/SACD player. I think they are all on 0 and the system is balanced in the pre. Is this what you are meaning or am I missing the point??

Thanks again to everyone!!

F1nut

vmaxer wrote: »

Isn't clipping from not enough power?? I think I have the opposite problem.. The Sunfire Signature is rated at 810 watts at 4 ohms. Ken Swager also said it can be caused by too much power. As I understand the tweeters usually get fried first from clipping. I use to have that issue until I upgraded to the amps I have now.....

No, clipping results from overdriving the amp be it 10 wpc or 800 wpc. In that vein, watts don't mean all that much. Current (amps) and headroom, resulting from beefy power supplies, are what makes an amp "powerful."

Kex

vmaxer wrote: »

... I put a SACD in and played it there with the one speaker and get around 78 db on the SPL meter. ...

That is high enough for some people, but I usually listen between 75dB and 85dB on my system (all RT55 and a CS400, soon to be forsaken, I fear, a NAD receiver, currently no amplifier whatsoever) with A-weighting. Levels of 80-85dBA for movies are typical, but for music I tend to listen at about 75dBA ... sometimes less, sometimes more.

I might be doing this wrong, so don't laugh at my ignorance, but I calibrate each channel with the recommended C-weighting to 75dB with the volume control set to -10dB, and then measure actual listening levels with the conrol set at the 0dB position and verify that it is indeed "reference", or 85dB, using A-weighting (since A-weighting is typically used to measure ambient listening levels, or "the human ear's most sensitive range"). In my estimation, 85dBA for music is "party level", but still considered "safe", and 95dB (A-weighted) is where hearing damage may occur in less than one hour, even if concerts are typically amplified well beyond that. At reference level on my system, it is basically impossible to carry on a conversation without shouting, even though it doesn't seem to be that loud until you actually try to talk!

Permissible levels seem to vary, but there is a table on this page that matches what I have read elsewhere: http://brneurosci.org/noise.html

I can't imagine you cannot drive your LSi system, with your quality amplification equipment, to those loud levels without fear of damage. Only Ben listens regularly beyond 100dB, and even he admits to having calmed down recently (if we can believe him), and besides, he likes to flip lawnmowers in his spare time, so I wouldn't trust him if I were you.

vmaxer

Kex wrote: »

Only Ben listens regularly beyond 100dB, and even he admits to having calmed down recently (if we can believe him), and besides, he likes to flip lawnmowers in his spare time, so I wouldn't trust him if I were you.

:eek:Flipping lawn mowers...I did that once and that was enough for me....Sounds like an adventurous type of person!!

I will admit that I sometimes like to listen to 2 channel a bit loud......

It really would be nice to have a method to know the limits.

ben62670

Hey bud I have only gone completely over once in my whole life. I even had a lawn mower I named Herbie(the love bug) that we used to do wheelies with(1982-), and I never flipped it. My neighbor did, but I never did:)

OK back to audio. You really should get an SPL meter. Good speakers/gear can go a lot louder than you think while being clean. It is real easy to figure out how much power your speakers are using. LSi's are mostly 88db for 1 watt at 1 meter.
1w=88db
2w=91db
4w=94db
8w=97db
16w=100db
32w=103db
64w=106db
128w=109db
256w=112db
512w=115db
This table can be adjusted for other speakers. You need to double your power to gain 3db. Adjust your SPL meter to C weighting, and slow to get your measurements. Please note that receivers, and lesser amps can not sustain the currant necessary to maintain high db listening with out damage. A good 60wpc amp is much better than nearly all 150wpc receivers;) Also the 5w resistor used in the LSi's should have been specked at 10-12 watts for the application. The tweeters are 4ohms and place too much current load on the 5 watt pieces when listening to the speakers cranked for extended periods of time. Also please do not turn up the treble on your pre, or receiver. This places an unnecessary load on the speakers.
Ben

vmaxer

ben62670 wrote: »

Hey bud I have only gone completely over once in my whole life. I even had a lawn mower I named Herbie(the love bug) that we used to do wheelies with(1982-), and I never flipped it. My neighbor did, but I never did:)

OK back to audio. You really should get an SPL meter. Good speakers/gear can go a lot louder than you think while being clean. It is real easy to figure out how much power your speakers are using. LSi's are mostly 88db for 1 watt at 1 meter.
1w=88db
2w=91db
4w=94db
8w=97db
16w=100db
32w=103db
64w=106db
128w=109db
256w=112db
512w=115db
This table can be adjusted for other speakers. You need to double your power to gain 3db. Adjust your SPL meter to C weighting, and slow to get your measurements. Please note that receivers, and lesser amps can not sustain the currant necessary to maintain high db listening with out damage. A good 60wpc amp is much better than nearly all 150wpc receivers;) Also the 5w resistor used in the LSi's should have been specked at 10-12 watts for the application. The tweeters are 4ohms and place too much current load on the 5 watt pieces when listening to the speakers cranked for extended periods of time. Also please do not turn up the treble on your pre, or receiver. This places an unnecessary load on the speakers.
Ben

Ben,

I appreciate your response. I do have a analog SPL meter from Radio Shack and will use it to find my "safe zones" per your chart.

Another question, earlier in this thread I have been advised to check the tweeters....how is this done?? I checked with a multimeter and get about 2.8-3.0 ohms?? Is it this simple??

I don't usually use the trebile or bass controls, I leave them on 0.

ben62670

The readings on your tweeters are in order. Sometimes the voice coils will heat up and drag making some distortion. You should be good. If you are running a receiver figure max volume to about half the "rated" watts. IE a receiver rated at 125w "4ohm capable" you should only drive your speakers to around 106db peaks.
Ben

McLoki

vmaxer wrote: »

Ben,

I appreciate your response. I do have a analog SPL meter from Radio Shack and will use it to find my "safe zones" per your chart.

Another question, earlier in this thread I have been advised to check the tweeters....how is this done?? I checked with a multimeter and get about 2.8-3.0 ohms?? Is it this simple??

I don't usually use the trebile or bass controls, I leave them on 0.

A few other things to keep in mind - how far are you from the speakers when you listen, and how many speakers are you listening to? Both of those questions can move that chart up and down....

for example - if you're listening position is 12 feet away from a stereo pair - you need to drop two lines from bens chart. (essentially your would start with 82db efficient not 88db meaning you are at 512 watts with only 109db, not 115.

ben62670

McLoki wrote: »

A few other things to keep in mind - how far are you from the speakers when you listen, and how many speakers are you listening to? Both of those questions can move that chart up and down....

for example - if you're listening position is 12 feet away from a stereo pair - you need to drop two lines from bens chart. (essentially your would start with 82db efficient not 88db meaning you are at 512 watts with only 109db, not 115.

Thanks for clearing that up. Measurements for power handling need to be taken at one meter:o

vmaxer

ben62670 wrote: »

The readings on your tweeters are in order. Sometimes the voice coils will heat up and drag making some distortion. You should be good. If you are running a receiver figure max volume to about half the "rated" watts. IE a receiver rated at 125w "4ohm capable" you should only drive your speakers to around 106db peaks.
Ben

See my list below,,,I am using a Sunfire Signature 405 watt at 8 ohm and 810 watt at 4 ohm.

Thanks a lot to everyone for the continuing education. I am learning and the more I learn the more I find I need to learn:eek:

vmaxer

trying again the signature line skipped out on me!!!

McLoki

ben62670 wrote: »

Thanks for clearing that up. Measurements for power handling need to be taken at one meter:o

and with one speaker playing....

The math works like this:

Every time you double the distance from the speaker, SPL drops by 6db. (12 feet - about a 12db drop (6db from 3-6' another 6db from 6-12'))

Every time you double the number of speakers (very close to each other compared to your listening distance - (more technical than that - but for our purposes close enough)) you increase the SPL by 6db.

When playing a stereo pair - your chart is accurate (or close anyway) with a listening position about 2 meters (6.5 feet) away from the speakers.....

Michael

ben62670

vmaxer wrote: »

...Thanks a lot to everyone for the continuing education. I am learning and the more I learn the more I find I need to learn:eek:

It is a vicious cycle:eek: I feel much dumberer than the day I signed up here at CP:p

F1nut

If you are running a receiver figure max volume to about half the "rated" watts. IE a receiver rated at 125w "4ohm capable" you should only drive your speakers to around 106db peaks.

You're being generous.

Hawkeye

vmaxer wrote: »

Does anyone here know if there is such a thing as a "wattmeter" that you can check and see how much power you are sending to your speakers?? I know some amps have them?? I sure would like to know where my limits are...

I don't think that is what caused this failure as I wasn't playing them that loud..

I'm not aware of an outboard wattmeter you could in line with your speakers. I do know that my amps are true watt meters and are accurate to within 95%

It sounds like your XO was lame to begin with. If it wasn't, then maybe an available 800 watts for an extended period at high spl levels is too much for your speaks although pretty much doubtful.

Gordon

vmaxer

Update...

I received a pair of new crossovers from Polk and have replaced the one that fried.

Polk customer service is the best I have ever dealt with.:D Absolutely Awesome!!!

:cool:And it seems like that type of attitude is carried over here by most everyone, a great bunch of people. I really appreciate all the advise and information provided here. A lot of you spend a lot of time here helping others. I hope some day I can return the favors and give something back!!:cool:

ben62670

Yes Polk CS rocks. I have never dealt with none better:)
Enjoy.
Ben