I got some free speaker drivers last week on Craigslist:
- four 10-inch Cerwin Vega VSW-10
- two 8-inch Cerwin Vega VSW-8
All have manufacturer date stamps that vary from the early to mid 90's.
Now, anyone that knows vintage Cerwin Vega stuff, you probably have an idea why I got these speakers for free - rotten foam surrounds (very common for older CV speakers). Actually, the foam surrounds on the 8" drivers is still good and strong. But on the 10" drivers, it's all falling apart and even completely gone on two of the drivers.
Only question I have here: does anyone know the power rating of these speaker drivers or any other specs? Again, model numbers are VSW-10 and VSW-8. I can't find anything in particular on the net. All I can tell you about them is both the 8" and 10" drivers have the same size motor (same size magnets and same size 1.25" voice coil), and same impedance (3.3-3.6 Ohms when measured with multimeter, so I am guessing they are 4-Ohm drivers).
Already tested the 8" drivers, and they work great. Made a test paper foam surround for one of the 10" drivers as well, and that works too. Now I just need to think of a project where I can use them... after finding some specs about them, of course.
The 10" (VS-10 cab model)
Specs:
3 way floor standing
Response: 37 Hz to 20,000 Hz
Power Handling: 5/125 Watts RMS (minimum/maximum)
Woofer: 10” VSW10 w die cast frame Midrange: 4” cone ATM5 Tweeter: 1” Dome VS-T1
Crossover points: 650 Hz and 6000 Hz
Height: 25.5 “ Width: 12.9” Depth: 11.5”
Weight: 40 lbs each
8 Ohm Efficiency: 95 db
Overload protection on tweeter
If the 8" is from the VS-80 cab:
Peak Power Handling 100 W. Nominal Power 100 watt
Frequency Responses 38 Hz - 20 kHz
Impedance 8 ohm
Sensitivity 94 dB
Dimensions: Width 10.9 in. x Depth 11.5 in. x Height 20 in.
Woofer Size 8 in.
I haven't tested them yet, but it actually has two, the clear one and a black one just opposite it - they both have a 3 position switch, the p.o. must really believe in fans.
The 10" (VS-10 cab model)
Specs:
3 way floor standing
Response: 37 Hz to 20,000 Hz
Power Handling: 5/125 Watts RMS (minimum/maximum)
Woofer: 10” VSW10 w die cast frame Midrange: 4” cone ATM5 Tweeter: 1” Dome VS-T1
Crossover points: 650 Hz and 6000 Hz
Height: 25.5 “ Width: 12.9” Depth: 11.5”
Weight: 40 lbs each
8 Ohm Efficiency: 95 db
Overload protection on tweeter
If the 8" is from the VS-80 cab:
Peak Power Handling 100 W. Nominal Power 100 watt
Frequency Responses 38 Hz - 20 kHz
Impedance 8 ohm
Sensitivity 94 dB
Dimensions: Width 10.9 in. x Depth 11.5 in. x Height 20 in.
Woofer Size 8 in.
Hope that's helpful.
Thank you, Steve!
That is some very useful information (especially the cabinet size), because I'm actually considering to make cabinets for these speakers... and if I do, I probably will try to make them as close as possible to the originals.
Just not sure why they rated the drivers at 8 Ohms, since my drivers appear to be closer to 4 Ohms (3.4 Ohms measured with multimeter). I'm glad to see they gave them a min/max RMS power rating, though - a sign that the drivers are actually of decent quality, as I thought. (Then again, the aluminum basket is another indicator of quality, IMO.)
Granted that was from 2007 but since then the fundamental design of HDDs hasn't changed much. Keep in mind that the AL casing to HDDs acts as a nice heat sink, mainly due to the mass, although WD raptors and velociraptor 3.5" adapters do have fins for extra cooling.
The 2.5" bare velociraptors do probably need some form of air flow; then again, most purpose-built servers/workstations using such have heavily vented drive bays often with some provision for a fan (midplane, etc.) right behind (such as my two supermicro cases).
But for your run of the mill desktop drives (and SSDs for that matter), HDD cooling is not a high priority. They get warm but that's factored into the design.
the function of a heatsink is to transfer the heat to the air(or water etc)
if the air is static, the heatsink simply saturates and cant disipate any more heat.
most pc's draw some air over the harddrives because of case extraction or the psu fan, but it's not as good as it could be.
i pity people with fanless cases and fanless psu's - they wont be getting 5-10years 24/7 harddrive life like i *always* do.
Air is hardly ever actually static, but I agree, the more air that is moved the more cooling there is. I always run a case fan or two in my desktops and hard drives get too damn hot period. I don't care who makes them, they ALL do. Some are much worse than others but it's an issue for them all, that's why they are made with heat sensors
putting a fan to blow across the harddrives is essential if you want them to last.
The setup for the drive bay seems designed with cooling in mind, It'll take up to 4 drives
and there'll be approx. 3/4 inch between each drive, even with a couple of the thicker hdds. Since the mb has a couple unused chassis fan headers I think I'll sub a 100mm fan for the black one so it can be used in a more 'cooling-challenged' case.
putting a fan to blow across the harddrives is essential if you want them to last.
That's too much of a blank statement.
Some HDDs do not need cooling, because they simply do no produce enough heat to run hot. And quite a few HDDs simply don't care about the heat. Anything up to 45C is usually normal.
Not all HDDs are made equal at the factory. Many will pass the factory QC tests and get shipped out to customers. But latent failures and small defects rarely show up right away. Therefore, it's probably a better bet to say that if an HDD lasts 2 to 3 years of use, chances are it will make it to the 10-year mark as well. And this has very little to do with temperature or how you run the HDD.
I've seen HDDs get cycled ON-OFF multiple times a day and still last 10+ years (though, not 10 years in terms of power-ON hours... or not yet, at least - I'm counting still ). Even have a few like that myself. Also seen HDDs run at high temperatures and again last 10+ years.
And as some proof of concept: the 2.5" Hitachi Travelstar DK23EA-20 in my laptop will typically hang around the 42-50C temperature range. And sometimes, it will even peak up to 60C on a hot summer day. I usually shut down / standby my laptop so as to not let it run past 55C. But either way, it's never caused a problem if I didn't. And it's not like I was the first owner, anyways. That HDD probably got abused much more before me. Yet, my laptop is close to 15 years old now. HDD has only a little more than 9500 power-ON hours, but also 2930 power ON-OFF cycles and over 1 billion head parks! Also, this is not the only hot-running HDD I have that is this old.
Lastly, I have experience with a few HDDs that actually hate being cold. Namely, the Maxtor Atlas III/IV/V series in my HP NetServer. If the room temperature is 64F / 18C or lower, I disconnect the HDD fans so that the HDDs run between 30 and 40C. Otherwise, I get tons of read/write ECC errors when they are cold. Not to mention they make all sorts of weird noises and even sound like the heads are grinding against the platters when the HDDs are cold booted.
So to conclude all of this: HDDs usually have an optimal running temperature range (typically 30-40C), which will be usually achieved without any active cooling.
Thank you, Steve!
That is some very useful information (especially the cabinet size), because I'm actually considering to make cabinets for these speakers... and if I do, I probably will try to make them as close as possible to the originals.
Just not sure why they rated the drivers at 8 Ohms, since my drivers appear to be closer to 4 Ohms (3.4 Ohms measured with multimeter). I'm glad to see they gave them a min/max RMS power rating, though - a sign that the drivers are actually of decent quality, as I thought. (Then again, the aluminum basket is another indicator of quality, IMO.)
While I was looking around for the info I noticed some sources for cone and foam repair kits and also there were a couple of motors (coil and magnet assy) available. I suppose it's possible there are 4 and 8 ohm versions of those. Also those published ratings might be for the cab as a whole, not necessarily the individual speakers. It's hard to tell when it's 3rd hand knowledge. I'd trust your meter, that voice coil is 4 ohms to me.
flash chip retention and bearing life is temp dependent.
i will admit the second isnt soo bad if you dont mind a drive sounding like it's grinding coffee - i had a few scsi drives like that, but losing the firmware is a bit more critical
While I was looking around for the info I noticed some sources for cone and foam repair kits and also there were a couple of motors (coil and magnet assy) available. I suppose it's possible there are 4 and 8 ohm versions of those. Also those published ratings might be for the cab as a whole, not necessarily the individual speakers. It's hard to tell when it's 3rd hand knowledge. I'd trust your meter, that voice coil is 4 ohms to me.
there are places that do rebuilds, but i wouldnt try to do one myself - how the hell do you center the coil so it wont rub on the magnet?
@xelectech do read those backblaze blog posts while keeping in mind that the hard drives they buy (consumer) aren't really suited / "optimized" to be used in custom cases like the ones Backblaze uses.
They have custom built cases and insert more than 20-40 drives in the case, very close to each other so there's plenty of vibrations and probably also more heat than normal (their cases have fans but still)
NAS and Enterprise drives have tweaks to handle vibrations better (or a higher level of vibrations).
-
If you really want to see what drives fail you can check these articles at hardware.fr
The numbers are still not quite representative for several reasons.
* They use a database from a large French seller of computer components and they go through all the hard drives returned for RMA to them, but obviously they can't know of how many drives customers returned directly to manufacturers.
* In addition, in an attempt to be as impartial as possible, they only count the drives that fail after 6 months of purchase but in reality a lot of drives fail in the first 2-3 months of use as can be seen in the Google study guide, and a few drives are probably returned by users in the first few days as DOA (dead on arrival) or with problems due to shipping or user stupidity.
* And then, they only count the drives failed in a six month interval from that point.
* And then, they list only models that were sold in at least 500 pcs or 200 pcs
So for example, in the link above you have drives bought between 1st of October 2014 and 1st of April 2015, that were returned to them as faulty before October 2015 (6 months to 1 year of operation).
Still, you can go through the older articles (they publish one of them every 6 months or 1 year or something like that) so in theory you could build yourself an idea about how hard drive manufacturers improved in time, or what models have an increased failure rate or not.
While I was looking around for the info I noticed some sources for cone and foam repair kits and also there were a couple of motors (coil and magnet assy) available. I suppose it's possible there are 4 and 8 ohm versions of those. Also those published ratings might be for the cab as a whole, not necessarily the individual speakers. It's hard to tell when it's 3rd hand knowledge. I'd trust your meter, that voice coil is 4 ohms to me.
3rd hand knowledge is still better than none, I suppose.
Yes, I'm pretty sure the specs are for the whole cabinet and not the woofer alone. But in a speaker system, the woofer tends to eat most of the power anyways. Given that there isn't much difference between 100 Watts and 125 Watts and considering that the motor (magnet and voicecoil) for the 10" and 8" appears to be the same, I am pretty sure the woofers are rated for around 100 Watts then. Note the similar low-end frequency response too - another giveaway that the woofers perform similarly.
I can also see why you found cone and foam repair kits. The foam rots a lot on CV speakers, apparently. I'm pretty sure many unsuspecting people run these until the voicecoil is shorted out from all of the rubbing after the foam rots. Mine appear healthy, though.
Originally posted by stj
there are places that do rebuilds, but i wouldnt try to do one myself - how the hell do you center the coil so it wont rub on the magnet?
Shims, as SteveNielsen noted. It's easier than you think.
If you have the patience, you can even rewind the old voicecoil rather than buying a new one, provided you were able to remove the speaker cone and spider without damage. I already tried that with a crappy pair of disposable 4" speakers. Repaired one of them already and it works fine. I just need to replace the hot glue I used to hold down the foam surround to the basket - it makes annoying sticky noises. Might try silicone or wood glue. I know there are proper glues out there for that, but again, these were really crappy 4" speakers. I won't be doing that with the CV drivers, of course.
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