Just received a pair of Peerless 830874 on my doorstep.
https://www.google.com/url?q=https:...0QFnoECAQQAg&usg=AOvVaw1zJ_P1_ueAc2StgwnlBHEJ
One of them has a magnet assembly off center. Not purchase from parts express. Above is just for reference.
This is all I could find in a quick search of Google addressing this ..
https://audiokarma.org/forums/index.php?threads/speaker-magnet-off-center-klipsch-woofer.841026/
Realizing that the polepiece/ backingplate alignment is much more important than the magnet itself, I would still have thought that axial alignment of all parts of a speaker would be more critical than this. It's not really a 'cheap' driver either at 53usd.
Sorry for the bad cell phone pic. The edge to edge of the backing plate and magnet is 5mm on one side and 10mm opposite it. Is this a concern? The glue on the inside between the cone and the half roll in this one, compared to the other, is REALLY sloppy as well. Did I just get a factory second here?
https://www.google.com/url?q=https:...0QFnoECAQQAg&usg=AOvVaw1zJ_P1_ueAc2StgwnlBHEJ
One of them has a magnet assembly off center. Not purchase from parts express. Above is just for reference.
This is all I could find in a quick search of Google addressing this ..
https://audiokarma.org/forums/index.php?threads/speaker-magnet-off-center-klipsch-woofer.841026/
Realizing that the polepiece/ backingplate alignment is much more important than the magnet itself, I would still have thought that axial alignment of all parts of a speaker would be more critical than this. It's not really a 'cheap' driver either at 53usd.
Sorry for the bad cell phone pic. The edge to edge of the backing plate and magnet is 5mm on one side and 10mm opposite it. Is this a concern? The glue on the inside between the cone and the half roll in this one, compared to the other, is REALLY sloppy as well. Did I just get a factory second here?
Last edited:
Ah....overthinking. The bane of DIY perhaps.😣
Last edited:
I commercially make speakers from the ground up.
What you have is not that bad, because that magnet is quite oversized respect to iron plates, usual is to have even 3 to 6mm all around, ferrite further away from plates is somewhat wasted because plate iron does not "catch" magnetism well, so the effective magnet diameter you are using is plate diameter + 3 to 6 mm, and you are still within that, only it looks sloppy.
It did not slide after assembly, Epoxy is very rigid and if cracked, speaker would be dead, because polepiece would be pinching the voice coil; that displacement is somewhat common (don´t ask) when magnet system is being cured in an oven, hot epoxy is "liquid" and behaves "greasy" so ferrite ring easily displaces sideways under the slightest pressure and after curing stays there forever.
1-2mm deviations are acceptable, 5-6 mm or more turn speaker into "B stock".
I set mine aside, do NOT magnetize them which complicates things, and when I reach 8 or 10 duds I unglue and clean them, recenter and reglue.
In principle they "should" do the same, but sometimes speakers are not sold on their own but inside cabinets, invisible to average user, so they risk it.
What you have is not that bad, because that magnet is quite oversized respect to iron plates, usual is to have even 3 to 6mm all around, ferrite further away from plates is somewhat wasted because plate iron does not "catch" magnetism well, so the effective magnet diameter you are using is plate diameter + 3 to 6 mm, and you are still within that, only it looks sloppy.
It did not slide after assembly, Epoxy is very rigid and if cracked, speaker would be dead, because polepiece would be pinching the voice coil; that displacement is somewhat common (don´t ask) when magnet system is being cured in an oven, hot epoxy is "liquid" and behaves "greasy" so ferrite ring easily displaces sideways under the slightest pressure and after curing stays there forever.
1-2mm deviations are acceptable, 5-6 mm or more turn speaker into "B stock".
I set mine aside, do NOT magnetize them which complicates things, and when I reach 8 or 10 duds I unglue and clean them, recenter and reglue.
In principle they "should" do the same, but sometimes speakers are not sold on their own but inside cabinets, invisible to average user, so they risk it.
"a cheap fix.....".
What are you describing?
I'm likely to just answer my own question here...but here goes
I'm really not OCD about this stuff. And I try to act responsibly, within limits. I would never return a dish of food in a restaurant, to be wastefully tossed in the garbage, simply for a hair in it. That's life. Stuff happens.
If both of these woofers we're identically, or nearly enough, matched in their flaws, I might feel confident with my finished project. The possible differences in published specs, in an acceptable range, would mirror and cancel each other out. But for one driver to be so flawed and mated with one that is apparently not...it would always bother me while listening. There is a very large difference in the mass of glue at the cone's edge from one driver to the next.
i own no measurement tools. I'm using these to build the Cardinal TA project described at ampslab.com.
I have until July 1 to return/exchange this driver postage paid, so I guess I ought to just clear my mind of such doubts and do it. It won't go to waste. Another buyer may not be as nervous about it as I am.
What are you describing?
I'm likely to just answer my own question here...but here goes
I'm really not OCD about this stuff. And I try to act responsibly, within limits. I would never return a dish of food in a restaurant, to be wastefully tossed in the garbage, simply for a hair in it. That's life. Stuff happens.
If both of these woofers we're identically, or nearly enough, matched in their flaws, I might feel confident with my finished project. The possible differences in published specs, in an acceptable range, would mirror and cancel each other out. But for one driver to be so flawed and mated with one that is apparently not...it would always bother me while listening. There is a very large difference in the mass of glue at the cone's edge from one driver to the next.
i own no measurement tools. I'm using these to build the Cardinal TA project described at ampslab.com.
I have until July 1 to return/exchange this driver postage paid, so I guess I ought to just clear my mind of such doubts and do it. It won't go to waste. Another buyer may not be as nervous about it as I am.
Last edited:
Rebuilding a speaker is not for most people, it is a special skill to take apart a speaker, remove the glued magnet, center it, then put back voice coil, cone, glue the cone and so on.
So if done by a specialist, not a cheap fix.
And the workmanship looks terrible, as if a trainee tried his hand with a glue gun or silicon gun.
Like Galu says, so much glue, and badly applied.
You can return it, do not overthink it, it is going to be at the back of your mind otherwise.
Look closely at the other speaker, and if that also looks less than good, send both back and opt for another brand.
This is sloppy work, and says a lot about the supervision and management of the factory.
So if done by a specialist, not a cheap fix.
And the workmanship looks terrible, as if a trainee tried his hand with a glue gun or silicon gun.
Like Galu says, so much glue, and badly applied.
You can return it, do not overthink it, it is going to be at the back of your mind otherwise.
Look closely at the other speaker, and if that also looks less than good, send both back and opt for another brand.
This is sloppy work, and says a lot about the supervision and management of the factory.
Wish I had a better camera for this.
That's definitely better, the other one is a klutz work, and who knows if the VC is centered, I have never seen so bad work even on crap-cheap drivers, I would return it as it is at least a brand name driver, not some no-name.
I also noticed in one of the first pictures the baffle seal seems to also have excess glue in comparison with the better looking driver.
ps. If you are taking pictures with mobile phone, consider installing Open Camera (available also on Google Play), much better for macro photo, and don't forget to wipe the lens/lens-cover as the pictures look hazy from greasy paws.
I also noticed in one of the first pictures the baffle seal seems to also have excess glue in comparison with the better looking driver.
ps. If you are taking pictures with mobile phone, consider installing Open Camera (available also on Google Play), much better for macro photo, and don't forget to wipe the lens/lens-cover as the pictures look hazy from greasy paws.
:)
Last edited:
+1 on returning the sloppy one or the pair, up to asking for a refund and buying elsewhere, your choice.
Not sure about "official" origin but those are Chinese made, or at least Oriental (Malaysia, Indonesia, best case Korea), those are not made in Europe.
Not sure about "official" origin but those are Chinese made, or at least Oriental (Malaysia, Indonesia, best case Korea), those are not made in Europe.
What's not made in China at this price point anymore? It's Peerless/Tymphany. The pair of 830874 and pair of SEAS 27TDFC for this project come in at under 180usd. There is not another project I could find with this (purported) level of raw drivers for close to that price. The overnight sensations? The c-notes?
What a shame.
What a shame.
Use window / glass cleaner spray on your camera lens, remove with soft tissue.
You seem to have a film of oily stuff on it.
In the old days, photographers used to smear Vaseline on the lenses to get a hazy effect, very good to dull out details.
Very suited to get dreamy landscapes, and make aged film stars look younger, their wrinkles would be obscured...
As for the drivers, it does look like the seller has become a trader, getting it made outside at a contract factory, and buying finished goods, without any supervision on the shop floor.
The good driver is also suspect, bearing this in mind.
Check out other brands, prices in regions vary, see about that also. Items sold in Asia may have a different price and quality compared to those sold in Europe by the same manufacturer.
You seem to have a film of oily stuff on it.
In the old days, photographers used to smear Vaseline on the lenses to get a hazy effect, very good to dull out details.
Very suited to get dreamy landscapes, and make aged film stars look younger, their wrinkles would be obscured...
As for the drivers, it does look like the seller has become a trader, getting it made outside at a contract factory, and buying finished goods, without any supervision on the shop floor.
The good driver is also suspect, bearing this in mind.
Check out other brands, prices in regions vary, see about that also. Items sold in Asia may have a different price and quality compared to those sold in Europe by the same manufacturer.
I have never seen a mass produced driver like most Tymphany branded units look that sloppy, specifically the first one posted.
Thats one thing I like about the heavily automated assembly processes Asian companies favor. I tend to be very picky about my drivers and don't hesitate to send one 2back it it doesn't pass my scrutiny. If it isn't a visible defect on the outside of the driver, I tend to dismiss most cosmetic issues as long as the drivers measure reasonably close. Having a closely matched pair of drivers is the most important factor for me.
That much extra glue on the first pictured driver will affect TS parameters for sure (ie Fs, efficiency along with Qts. I dont think there's much wrong with expecting a certain level of craftsmanship even if the driver is inexpensive.
Thats one thing I like about the heavily automated assembly processes Asian companies favor. I tend to be very picky about my drivers and don't hesitate to send one 2back it it doesn't pass my scrutiny. If it isn't a visible defect on the outside of the driver, I tend to dismiss most cosmetic issues as long as the drivers measure reasonably close. Having a closely matched pair of drivers is the most important factor for me.
That much extra glue on the first pictured driver will affect TS parameters for sure (ie Fs, efficiency along with Qts. I dont think there's much wrong with expecting a certain level of craftsmanship even if the driver is inexpensive.
Please post a photo of the label.
Possibly a reworked plant reject, we used to have that here, clock movements would be scrapped if they did not work after assembly.
They used a hot soldering iron to damage the logo, so no dealer would honor factory warranty.
Almost all the wall clocks in India are made in a small town called Morbi, and a parallel industry developed, repairing and selling scrap movements cheaply, or using them in cheap no name clocks.
Volumes? 100k daily in season, for all clocks.
Some factories make alarm clocks too, volumes are going down as people use smart phones a lot.
The seller may be cranky about returns, bear that in mind.
Possibly a reworked plant reject, we used to have that here, clock movements would be scrapped if they did not work after assembly.
They used a hot soldering iron to damage the logo, so no dealer would honor factory warranty.
Almost all the wall clocks in India are made in a small town called Morbi, and a parallel industry developed, repairing and selling scrap movements cheaply, or using them in cheap no name clocks.
Volumes? 100k daily in season, for all clocks.
Some factories make alarm clocks too, volumes are going down as people use smart phones a lot.
The seller may be cranky about returns, bear that in mind.