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Genelec 8351B Teardown (2nd Disassembled)

YSC

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I’m talking about getting it serviced, not getting it serviced under warranty. You mentioned concern about taking it in and them not having the parts to repair it. I’m just pointing out that you have to worry about that at all. Genelec goes to great lengths to make sure that doesn’t happen, and there are indeed reports online of people getting service for that long. Being a “pro” brand, they live and die by their reliability, much more so than consumer audiophile brands. Studios need a speaker that will survive 8 hours a day of near reference level use for many years. Reliability and serviceability is often king in the studio world.
And actually, I guess for speakers things are a lot easier, since you mostly don't test and replace a single IC if that is the failed part, but the whole amp board, Genelec can easily swarp a new generation amp inside a sent in legacy product and all they need to do is to not over driven the speaker, and do a post repair factory calibration. it's not like cars with different dimension parts where you can't fit a newer gearbox into a old car as easy
 

antennaguru

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Yes, I understand the rigors of studio work, and also the innate and very personal preferences of studio engineers. The 45 year old pair of passive studio monitors came to me from a rather accomplished studio engineer, who said he had heard that I might be able to help him get his favorite monitors working again for his studio. He said up front that cost wasn't an issue, but that they needed to sound like they did before the failure. Well, I first re-capped both of the crossover boards, and also measured the other passive components hoping to find a failure. This I had said up front was needed work based on 45 years of age, and optimistically "might" solve the issue IF it wasn't a bad driver. That work led to the conclusion that one woofer had a failed voice coil. I removed the voice coil from the woofer and inspected it as well as carefully measured it - diameter, former type/length, length of winding, layers of winding (thickness to fit the magnetic gap), gauge of wire, impedance. Repairing it and/or rewinding it were not a likely solution as the break was invisible under magnification. However, I located a suitable replacement with the same parameters from one of my suppliers and ordered two. I installed one on the failed monitor's woofer and then measured both monitors, very carefully. They were a close match within tolerance so installing the second voice coil on the "good" monitor's woofer, nor completely replacing both woofers in their entirety was not necessary (and avoided a larger risk of affecting the sound the engineer was used to). Customer was happy as he had back his favorite monitors fully operational, working as original, with original drivers, and re-capped crossovers for a reasonable price. He put them to use immediately and then paid my invoice with profuse thanks. I provided a 10 year warranty on the repair, but fully expect them to last another 45 years - when we'll both probably be gone.

Had they been active monitors I would have had to perform circuit board level troubleshooting, and if that proved unsuccessful converted them both to passive.

Now, the topic at hand here is these small $4K 8351B monitors, which replaced the 8351A that preceded it, so that clock to get spare boards must be already ticking for the purchasers of the 8351A monitors. If I were the one buying then I would most likely buy one spare complete monitor in addition to the pair to make absolutely sure I had access to space parts. The fellow that posted the picture of his home theatre system had 5 of these speakers, a $20K capital expenditure. Had it been me I would have added 2 spares making it a $28K capital expenditure. That's pretty pricey IMO for a home theatre system that doesn't generate revenue, but if it brings happiness I guess it's good. IMO it would also sound better and bring more happiness without the reflective "coffee tables" in front of the listening position (zero cost).
 

YSC

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Yes, I understand the rigors of studio work, and also the innate and very personal preferences of studio engineers. The 45 year old pair of passive studio monitors came to me from a rather accomplished studio engineer, who said he had heard that I might be able to help him get his favorite monitors working again for his studio. He said up front that cost wasn't an issue, but that they needed to sound like they did before the failure. Well, I first re-capped both of the crossover boards, and also measured the other passive components hoping to find a failure. This I had said up front was needed work based on 45 years of age, and optimistically "might" solve the issue IF it wasn't a bad driver. That work led to the conclusion that one woofer had a failed voice coil. I removed the voice coil from the woofer and inspected it as well as carefully measured it - diameter, former type/length, length of winding, layers of winding (thickness to fit the magnetic gap), gauge of wire, impedance. Repairing it and/or rewinding it were not a likely solution as the break was invisible under magnification. However, I located a suitable replacement with the same parameters from one of my suppliers and ordered two. I installed one on the failed monitor's woofer and then measured both monitors, very carefully. They were a close match within tolerance so installing the second voice coil on the "good" monitor's woofer, nor completely replacing both woofers in their entirety was not necessary (and avoided a larger risk of affecting the sound the engineer was used to). Customer was happy as he had back his favorite monitors fully operational, working as original, with original drivers, and re-capped crossovers for a reasonable price. He put them to use immediately and then paid my invoice with profuse thanks. I provided a 10 year warranty on the repair, but fully expect them to last another 45 years - when we'll both probably be gone.

Had they been active monitors I would have had to perform circuit board level troubleshooting, and if that proved unsuccessful converted them both to passive.

Now, the topic at hand here is these small $4K 8351B monitors, which replaced the 8351A that preceded it, so that clock to get spare boards must be already ticking for the purchasers of the 8351A monitors. If I were the one buying then I would most likely buy one spare complete monitor in addition to the pair to make absolutely sure I had access to space parts. The fellow that posted the picture of his home theatre system had 5 of these speakers, a $20K capital expenditure. Had it been me I would have added 2 spares making it a $28K capital expenditure. That's pretty pricey IMO for a home theatre system that doesn't generate revenue, but if it brings happiness I guess it's good. IMO it would also sound better and bring more happiness without the reflective "coffee tables" in front of the listening position (zero cost).
I might be wrong, but with the same housing and drivers, mostly being the active circuitry being changed from the A to B version, I expected it is as simple or even more simple to put a newer generation amp board into the old speaker and wire the connectors together and make it work, at the level of you to install a new voice coil on the old driver or even easier.

As long as power ratings of the amp boards are the same, and both are genelec DSP models I can't imagine that the GLM can't handle it for calibration, maybe not your neighbor tech shop, but Genelec should have full document records and knowhow to perform such a repair+updating when needed. At a cost of course
 

thewas

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Classic analogue electronics of active loudspeakers can be repaired easily but replacing the usually widely available defective parts actually easier than changing a voice coil, it all ends up on the availiablity on some dedicated ICs, especially on DSP models which were produced in smaller amounts.

Also paper membranes cones will under normal use (so not standing outside in the rain) longer outlive all of us and often have very good acoustic properties, Charles Spinkle (the designer of JBL M2 and some other famous loudspeakers) changed the IN-8v2 cone to pure paper from coated paper (there was somethere a interview of him about it, but cant find it right now).

I have several paper cone and active loudspeakers in my collection which are more than 40 years old and still work fine.
 

Scoox

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Hello,

Thanks for your eagle eyes! The highlighted part of the woofer diaphragm is a designed feature and should look exactly like that. So, nothing to be worried about!
I was considering this monitor but the tears in that bass driver really don't inspire a lot of confidence... You do say that it should look exactly like that, but I ask, look like what? Are the cracks and tears exactly identical in all units? I'll bet not! To me that just looks like some random cracked-ass paper. Are we referring to different things?

index.php
 

Pearljam5000

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I was considering this monitor but the tears in that bass driver really don't inspire a lot of confidence... You do say that it should look exactly like that, but I ask, look like what? Are the cracks and tears exactly identical in all units? I'll bet not! To me that just looks like some random cracked-ass paper. Are we referring to different things?

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Now you worry me as well
 

voodooless

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I’ve always thought those racetrack drivers were suspect. Looks like a tiny 1” voice coil. That won’t eat up a lot of power. The paper scuffing doesn’t look good either. It’s clearly a weak point on the straight part of the track.
 

Scoox

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I’ve always thought those racetrack drivers were suspect. Looks like a tiny 1” voice coil. That won’t eat up a lot of power. The paper scuffing doesn’t look good either. It’s clearly a weak point on the straight part of the track.
Dang it! This sucks so much because I have been saving up for a pair of 8351B for a whole year. I will contact Genelec tech guys about this next Monday and see what they say, and will report back here as soon as.

Just to give this some context, the 8351B was released in October 2019—two years ago, so that's how old the particular unit being reviewed by the OP is at most. Now, my Adam S1X two-way monitors look as good as new after exactly 12 years and 1 month of daily use, on average 10 hours a day. Unless Genelec have reviewed and improved those LF drivers, I'm not going to be able to buy this product.
Genelec's Warranty Terms

All Genelec products are supplied with a minimum of 2 years warranty (from the date of purchase) against manufacturing faults or defects that might impact on the product's performance. During that time Genelec and its distributors will cover the cost of warranty service labour and spare parts.

As part of Genelec's sustainability program, from the 1st of January 2015 we now provide an extended spare parts warranty period of 3 years, in addition to the normal 2 years warranty terms. This applies to all registered products, and proof of purchase is mandatory. During this extended period Genelec and its distributors will cover spare parts free of charge, but normal labour costs will be charged.
 
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Pearljam5000

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Dang it! This sucks so much because I have been saving up for a pair of 8351B for a whole year. I will contact Genelec tech guys about this next Monday and see what they say, and will report back here as soon as.

Just to give this some context, the 8351B was released in October 2019—two years ago, so that's how old the particular unit being reviewed by the OP is at most. Now, my Adam S1X two-way monitors look as good as new after exactly 12 years and 1 month of daily use, on average 10 hours a day. Unless Genelec have reviewed and improved those LF drivers, I'm not going to be able to buy this product.
@Ilkka Rissanen is the main guy at Genelec and he's on this forum, so I hope he'll comment
 

maverickronin

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Maybe you should just buy some Focal monitors if you want your drivers to be blinged out like a high end Scanspeak, Seas, Satori, et al.
 

G|force

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I’ve always thought those racetrack drivers were suspect. Looks like a tiny 1” voice coil. That won’t eat up a lot of power. The paper scuffing doesn’t look good either. It’s clearly a weak point on the straight part of the track.
I understand that a first glimpse of the VC diameter would give gear-minded folks like us recollection to the 70's and 80's 6x9 speakers (some of us) were using in our cars. I totally get it.
I've got a couple 14 cu/ft cabinets loaded with (2) JBL 2226 15" in each box- those drivers have 4" voice coils and are rated 600W RMS. So what?

I also have a pair of 8341. The mass of that 'tiny' VC is probably one of the parameters that makes the LF response so fast and effortless, in it's 'relative performance envelope.' :cool:
 

Sancus

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What do you mean? :)

An R&D employee from Genelec already looked at this and said it's fine. I'm not a material scientist, and neither is anyone else in this thread I imagine, so worrying about how it looks in a photo seems totally ridiculous to me. If there was a problem, they would definitely want to correct it, and it's very unlikely anything broken is leaving their factory(compared to most) considering they test, measure, and tune the responses of each monitor individually.

The 8351B is the 2nd revision of a monitor released almost 7 years ago, if there were common woofer material problems then Genelec would have corrected them with this revision. They also have a very strong reputation for reliability in working studio environments to uphold. Looking at photos and saying 'wow that looks weird I wonder if the speakers will break' just seems like self-reinforcing anxiety with no factual basis.
 

Scoox

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I understand that a first glimpse of the VC diameter would give gear-minded folks like us recollection to the 70's and 80's 6x9 speakers (some of us) were using in our cars. I totally get it.
I've got a couple 14 cu/ft cabinets loaded with (2) JBL 2226 15" in each box- those drivers have 4" voice coils and are rated 600W RMS. So what?

I also have a pair of 8341. The mass of that 'tiny' VC is probably one of the parameters that makes the LF response so fast and effortless, in it's 'relative performance envelope.' :cool:
The 8341A has a slightly different LF driver than the 8351B, if you get a chance, could you shine a light torch on the driver to check if the paper has deteriorated as shown earlier?
 
OP
Jason K

Jason K

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I was considering this monitor but the tears in that bass driver really don't inspire a lot of confidence... You do say that it should look exactly like that, but I ask, look like what? Are the cracks and tears exactly identical in all units? I'll bet not! To me that just looks like some random cracked-ass paper. Are we referring to different things?

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Though I’m not him. I want to reply too. But I checked that other One’s monitor has that cracked on the bass unit.
They had that too, and Actually I didn’t worry about it. I didn’t know everything about this drivers, But it seems to look the rounding part will bear the main force. I don't think Genelec would have designed this roughly and skipped over it. And the 8351B has the best bass performance among monitor speakers of this size.
 

Scoox

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An R&D employee from Genelec already looked at this and said it's fine. I'm not a material scientist, and neither is anyone else in this thread I imagine, so worrying about how it looks in a photo seems totally ridiculous to me. If there was a problem, they would definitely want to correct it, and it's very unlikely anything broken is leaving their factory(compared to most) considering they test, measure, and tune the responses of each monitor individually.

The 8351B is the 2nd revision of a monitor released almost 7 years ago, if there were common woofer material problems then Genelec would have corrected them with this revision. They also have a very strong reputation for reliability in working studio environments to uphold. Looking at photos and saying 'wow that looks weird I wonder if the speakers will break' just seems like self-reinforcing anxiety with no factual basis.
No disrespect but I, and I'm sure a lot of people, might disagree. What you see in that photo has happened over the course of perhaps one year. I'd like to see how that driver is holding after 5 years.
 

Sancus

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No disrespect but I, and I'm sure a lot of people, might disagree. What you see in that photo has happened over the course of perhaps one year. I'd like to see how that driver is holding after 5 years.

Ilkka specifically called it a designed feature. There is no reason to believe anything happened over the course of any time period, it's probably exactly like that when it comes out of the factory.
 
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