Polk L800 speakers - SPL below 100 Hz dropped about 6db.
Comments
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Gardenstater wrote: »I think it would help if Polk technical support would tell you what the resistance measurement should be across the binding posts; positive to negative. Easy measurement to do when they are cold and then when they are "hot" after playing bass heavy material for a while.
Just pick up an inexpensive DVOM, assuming you don't want a real fancy one, and read the instructions on resistance measurement.
If you detect an anomalous reading, perhaps Polk could give you a shipping label to the nearest authorized repair center, or authorize you to remove the crossovers and drivers and test further, or ship the crossover to them. Various possibilities but you will be making progress towards a solution.
Thanks for the advice, I haven't heard anything back from Polk NZ, let's see how it goes. -
nooshinjohn wrote: »My L800 carries 10 years full warranty so I can't pull the bass drivers out and measure them by myself, that should be done by Polk NZ.
Do you expect them to send a tech to the house? Or do you want to pay the freight to a Warranty center? Polk does not want the two-way freight bill, and there is no field support. Therefore they have no problem whatsoever having their customers swap drivers and other parts on their own. Pull the drivers and put an Ohm meter on them and record the readings. Inspect the crossovers and report back.Thanks for the advice, I also tested with Rotel RA-1592 MK2, same result. My job is software tester, I guess I know how to do a test under controlled conditions.
I am not saying at all that your problem is with the Rotel. What I am saying is there is a bilateral internal problem with your speakers and that problem is either a pre-existing condition from their time as demos or caused by some mis-match between the Rotel and the speakers. Further, the problem is now confined to the speakers themselves and no amount of further testing is going to solve that. The time has come to open them up and start inspecting the individual crossover components for damage and test the drivers for resistance to a load. That is the only way to learn what is truly going on here.
I do not mean to come across as an asshat, but the time has come to stop testing and getting the same results and start investigating for the cause.
Thank you. I don't know what Polk NZ will do.
Polk NZ distributor's head office is about 10 minites drive from my home. So in the worst case I will drop off the speakers to their office.
The testing results I post here is for Polk NZ's referrence. -
You need to stop testing and open up them up because right now you are going in circles.
BTW, being a software tester means nothing when it comes to solving stuff like this.Political Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk -
You need to stop testing and open up them up because right now you are going in circles.
BTW, being a software tester means nothing when it comes to solving stuff like this.
Thanks.
All the test results are for troubleshooting purpose. I guess it's useful for Polk Tech support.
I won't open the speakers, that's Polk NZ's job, that's how things work here. -
Thanks for the advice, I haven't heard anything back from Polk NZ, let's see how it goes.
By the looks of the last graph, you have one driver in each cabinet dropping out... is that correct?
Are the drivers in the same position in each cabinet? I would be pulling those drivers and putting a meter on them.
The Gear... Carver "Statement" Mono-blocks, Mcintosh C2300 Arcam AVR20, Oppo UDP-203 4K Blu-ray player, Sony XBR70x850B 4k, Polk Audio Legend L800 with height modules, L400 Center Channel Polk audio AB800 "in-wall" surrounds. Marantz MM7025 stereo amp. Simaudio Moon 680d DSD
“When once a Republic is corrupted, there is no possibility of remedying any of the growing evils but by removing the corruption and restoring its lost principles; every other correction is either useless or a new evil.”— Thomas Jefferson -
nooshinjohn wrote: »
Thanks for the advice, I haven't heard anything back from Polk NZ, let's see how it goes.
By the looks of the last graph, you have one driver in each cabinet dropping out... is that correct?
Are the drivers in the same position in each cabinet? I would be pulling those drivers and putting a meter on them.
Thanks. No driver dropping out.
The graph shows that all four woofers' SPL at 30Hz is too low. -
You burnt something in the crossovers .
Either it happened when they were demos or when you were using that amp that is not compatible. -
On my L800, which I run bi-wired from a pair of Carver Raven mono's, I get readings of 3.1 ohms at each input. That means each of the 4 speaker inputs is 3.1 ohms at rest and no signal from the amplifiers going to the speakers.
I am curious to know what your reads. Without that knowledge, there is little more we can do to assist.The Gear... Carver "Statement" Mono-blocks, Mcintosh C2300 Arcam AVR20, Oppo UDP-203 4K Blu-ray player, Sony XBR70x850B 4k, Polk Audio Legend L800 with height modules, L400 Center Channel Polk audio AB800 "in-wall" surrounds. Marantz MM7025 stereo amp. Simaudio Moon 680d DSD
“When once a Republic is corrupted, there is no possibility of remedying any of the growing evils but by removing the corruption and restoring its lost principles; every other correction is either useless or a new evil.”— Thomas Jefferson -
You burnt something in the crossovers .
Either it happened when they were demos or when you were using that amp that is not compatible.You burnt something in the crossovers .
Either it happened when they were demos or when you were using that amp that is not compatible.
Thanks, I also guess it's a crossover issue.
But according to Scott Orth, woofer crossover is compatible to all type of amplifiers:
7. Amplifier type should have no bearing on the woofer performance like they would for the dimensional array. -
Thanks, I also guess it's a crossover issue.
But according to Scott Orth, woofer crossover is compatible to all type of amplifiers:
7. Amplifier type should have no bearing on the woofer performance like they would for the dimensional array.
The woofers and the dimensional arrays are fed by the same amplification. If they were fed different signals then amplifier type would not matter.
Personally, Scott's statement there is misleading from a practical standpoint in your scenario. You are using an integrated amp to drive your speakers, so you are amplifying the entire cabinet of each with the same
signal. In that case, your amplifier is feeding the arrays and the woofers, thus making woofer performance dependent on the same signal. I could see a crossover failing at the woofer section due to a problem with improper amplification moreso than the arrays failing for the same reasons.The Gear... Carver "Statement" Mono-blocks, Mcintosh C2300 Arcam AVR20, Oppo UDP-203 4K Blu-ray player, Sony XBR70x850B 4k, Polk Audio Legend L800 with height modules, L400 Center Channel Polk audio AB800 "in-wall" surrounds. Marantz MM7025 stereo amp. Simaudio Moon 680d DSD
“When once a Republic is corrupted, there is no possibility of remedying any of the growing evils but by removing the corruption and restoring its lost principles; every other correction is either useless or a new evil.”— Thomas Jefferson -
One more thing to note is that low end frequency cut for these speakers is 32hz...
The Gear... Carver "Statement" Mono-blocks, Mcintosh C2300 Arcam AVR20, Oppo UDP-203 4K Blu-ray player, Sony XBR70x850B 4k, Polk Audio Legend L800 with height modules, L400 Center Channel Polk audio AB800 "in-wall" surrounds. Marantz MM7025 stereo amp. Simaudio Moon 680d DSD
“When once a Republic is corrupted, there is no possibility of remedying any of the growing evils but by removing the corruption and restoring its lost principles; every other correction is either useless or a new evil.”— Thomas Jefferson -
More information for troubleshooting:
Today after warm up the speakers, I tested again from 30cm (Right speaker), the bass is weaker than yesterday.
1os7dxzco1ul.jpg
Being a retired Lineman I have to ask this....
Have you checked voltage at your house?
Do you have any power issues?
Power issues at different times of any given day? -
So other than testing the sound using software what is your next step to troubleshoot and get issue repaired?2-channel: Modwright KWI-200 Integrated, Dynaudio C1-II Signatures
Desktop rig: LSi7, Polk 110sub, Dayens Ampino amp, W4S DAC/pre, Sonos, JRiver
Gear on standby: Melody 101 tube pre, Unison Research Simply Italy Integrated
Gone to new homes: (Matt Polk's)Threshold Stasis SA12e monoblocks, Pass XA30.5 amp, Usher MD2 speakers, Dynaudio C4 platinum speakers, Modwright LS100 (voltz), Simaudio 780D DAC
erat interfectorem cesar et **** dictatorem dicere a -
"analysis paralysis"
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Almost seems like some sort of elaborate troll.
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Next step send speakers back and get replacements or open them up and check the crossovers ,wire and woofers Period!
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Are the DCR measurement values and locations for the L800 proprietary information? I'm thinking along the lines of the tests that are in the vintage SDA Handbook. I'm sort of surprised that Polk didn't provide that.
I'm pitying the OP to wake up and have a cup of coffee and open this thread and find out he might be a troll
George / NJ
Polk 7B main speakers, std. mods+ (1979, orig owner)
Martin Logan Dynamo sub w/6ft 14awg Power Cord
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iFi Mercury 0.5m OFHC continuous cast copper USB cable
Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
Custom Vibration Isolation Speaker Stands and Sub Platform -
txcoastal1 wrote: »So other than testing the sound using software what is your next step to troubleshoot and get issue repaired?
Polk will send someone here to test the spearkers next week. Thanks.
The L800 speakers are covered by warranty. -
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skipshot12 wrote: »More information for troubleshooting:
Today after warm up the speakers, I tested again from 30cm (Right speaker), the bass is weaker than yesterday.
1os7dxzco1ul.jpg
Being a retired Lineman I have to ask this....
Have you checked voltage at your house?
Do you have any power issues?
Power issues at different times of any given day?
No power issues. Thanks.
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txcoastal1 wrote: »So other than testing the sound using software what is your next step to troubleshoot and get issue repaired?
Polk will send someone here to test the spearkers next week. Thanks.
The L800 speakers are covered by warranty.
I would be very interested in knowing what they find, and shocked they are sending a live human to do the work. Is it law where you live that makes them do this?The Gear... Carver "Statement" Mono-blocks, Mcintosh C2300 Arcam AVR20, Oppo UDP-203 4K Blu-ray player, Sony XBR70x850B 4k, Polk Audio Legend L800 with height modules, L400 Center Channel Polk audio AB800 "in-wall" surrounds. Marantz MM7025 stereo amp. Simaudio Moon 680d DSD
“When once a Republic is corrupted, there is no possibility of remedying any of the growing evils but by removing the corruption and restoring its lost principles; every other correction is either useless or a new evil.”— Thomas Jefferson -
Gardenstater wrote: »Are the DCR measurement values and locations for the L800 proprietary information? I'm thinking along the lines of the tests that are in the vintage SDA Handbook. I'm sort of surprised that Polk didn't provide that.
I'm pitying the OP to wake up and have a cup of coffee and open this thread and find out he might be a troll
Thanks. I thought here is the right place to submit the issues I found to Polk Audio Team. Because this forum is Polk Audio official forum and my post is in "CUSTOMER SERVICE" category.
Shocked to see some strange guy call my post "elaborate troll". -
Why do you care what some strange guy thinks anyway?
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Also, I said "almost" seems like. Try to relax.
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nooshinjohn wrote: »txcoastal1 wrote: »So other than testing the sound using software what is your next step to troubleshoot and get issue repaired?
Polk will send someone here to test the spearkers next week. Thanks.
The L800 speakers are covered by warranty.
I would be very interested in knowing what they find, and shocked they are sending a live human to do the work. Is it law where you live that makes them do this?
That's how warranty works here in New Zealand, I was extremely shocked when someone suggested me to repair the speakers by myself.
In New Zealand, we simply get a replacement or full refund. We never repair anything under warranty by ourselves.
I post my issues here to seek tech support from Polk US directly to see if I can resolve this issue in another way.
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Great job, team! I knew we'd reach resolution putting all heads together!
I disabled signatures. -
nooshinjohn wrote: »txcoastal1 wrote: »So other than testing the sound using software what is your next step to troubleshoot and get issue repaired?
Polk will send someone here to test the spearkers next week. Thanks.
The L800 speakers are covered by warranty.
I would be very interested in knowing what they find, and shocked they are sending a live human to do the work. Is it law where you live that makes them do this?
That's how warranty works here in New Zealand, I was extremely shocked when someone suggested me to repair the speakers by myself.
In New Zealand, we simply get a replacement or full refund. We never repair anything under warranty by ourselves.
I post my issues here to seek tech support from Polk US directly to see if I can resolve this issue in another way.
It was me that made the suggestion. In the U.S. Polk sends us the failed parts and we put them back together.The Gear... Carver "Statement" Mono-blocks, Mcintosh C2300 Arcam AVR20, Oppo UDP-203 4K Blu-ray player, Sony XBR70x850B 4k, Polk Audio Legend L800 with height modules, L400 Center Channel Polk audio AB800 "in-wall" surrounds. Marantz MM7025 stereo amp. Simaudio Moon 680d DSD
“When once a Republic is corrupted, there is no possibility of remedying any of the growing evils but by removing the corruption and restoring its lost principles; every other correction is either useless or a new evil.”— Thomas Jefferson -
Why do you care what some strange guy thinks anyway?
I don't really care what you said, unless you work for Polk Audio, do you work for Polk Audio?
Thanks. -
Where in this thread was it suggested that you perform the repair by yourself? All that was suggested is troubleshooting methods in order to obtain additional data.
https://www.youtube.com/watch?v=Twb9AvdCnpE