I think the foam surrounds are often chosen for home and studio applications for several good reasons. It is the lightest and help the cone to fractionate at higher frequencies. It produce a minimum of self noise and distortion (good damping few vibrating nodes). it is economical and serviceable. In fact, it last 15/20 years, and, during the same time, the loudspeaker magnet lose 20% of his magnetization. Time to change the surround AND to remagnetise the magnet. or change the speaker, don't you think ?TI never could figure out why AR started using foam surrounds... But maybe that decision was based on economics i.e. AR's managers wanted their customers to come back after @10 years for a new set of speakers.
I just changed the surround of my loudspeakers yesterday, it is so easy. I have now to tune my filter, because the efficiency of my bass driver had decreased more that, the treble motor, and to tweak the tune of my vents, because the QT had changed too. Not because the new foam, but because of the magnet after 20 years.
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So what T/S parameters for bass drivers that are suitable for a.s. enclosure? Fs has to be low if low bass is wanted likewise Qts has to be around .5. Vas should be ?? I don't why it has to be high like someone said. High Vas makes large box. Low Fs usually means heavy cone or lossy surround so low efficiency. Hmm...
Suitable 8" drivers for closed design?
Suitable 8" drivers for closed design?
I too am a fan of some of the visaton drivers......im particular the AL130 and G20SC im using currently.
I DO not agree with helmuth's recommendations though, the TIW200 doesnt sim NEARLY well enough in either sealed OR sealed box for my liking. The cone is way too heavy for my liking too, and I found my inital interest in these 'woofers' quickly waned. I would take the W200, or my favourite, the AL200 woofer instead, even though this is also perhaps not the best for sealed.
from a quick look on the links he posted, I would prefer to use ANY of the Seas drivers, if only due to the lower quoted resonance in combination with lower cone mass. The same applies for the tympany, with the extra Qt the box would be larger, but this one may be the best of the lot. If a higher Qt is needed the the twin coil visaton GF200 may be worth a look, and could allow the user to dial in the Qt to match requirements....
In my very humble opinion.
I DO not agree with helmuth's recommendations though, the TIW200 doesnt sim NEARLY well enough in either sealed OR sealed box for my liking. The cone is way too heavy for my liking too, and I found my inital interest in these 'woofers' quickly waned. I would take the W200, or my favourite, the AL200 woofer instead, even though this is also perhaps not the best for sealed.
from a quick look on the links he posted, I would prefer to use ANY of the Seas drivers, if only due to the lower quoted resonance in combination with lower cone mass. The same applies for the tympany, with the extra Qt the box would be larger, but this one may be the best of the lot. If a higher Qt is needed the the twin coil visaton GF200 may be worth a look, and could allow the user to dial in the Qt to match requirements....
In my very humble opinion.
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Seas Drivers that Helmut linked are smaller than others. I think 6,5"-7" is way too small for closed box, being the only bass radiator in the system. Maybe 8" is too small also, though I have smallish room with bass gain (like most peolpe do, I think). (better look for 10", but my ~35 l box sets some limits...)
TIW 200 seems to be subwoofer (84 dB and heavy cone).
W 200 has Qts quite large and has not response as good as for example Seas CA22RNX in 35 l enclosure, though it has 2 dB more efficiency in upper bass.
What do you think of Davis MC208A?
TIW 200 seems to be subwoofer (84 dB and heavy cone).
W 200 has Qts quite large and has not response as good as for example Seas CA22RNX in 35 l enclosure, though it has 2 dB more efficiency in upper bass.
What do you think of Davis MC208A?
Is 84 DB/W/M a LOUDspeaker ?
Is 1Khz a reasonable frequency to fractionate for a 8" ?
This look like junk to me. An expensive junk.
I had tried to find a model for alspe at Monacor or Beyma.
Now, i remeber why i never use closed boxes anymore: it is nearly impossible to build a efficient 2 way system with that kind of enclosure and low frequencies enough.
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Yes, that's exactly what it'll be. A half wave length at 800Hz is ~ 8.5 inches.
How long foam lasts depends on your local climate. In northern parts of New Zealand where I'm from, the humidity is high a lot of the time, especially summer, where 25+ deg c and 80%+ humidity together is not uncommon, along with salt air from the coastline, and foam surrounds on speakers there will last AT MOST 10 years before they are totally destroyed. (In tropical regions they last even less than this)
You can touch one with your finger and it will crumble away to nothing. I've seen many speakers in otherwise perfect condition suffer this fate. On the other hand here in the UK the humidity is very low year round (at least indoors) so I can see that foam surrounds would last much longer here, maybe 20-30 years.
Is it acceptable for a speaker to be destroyed in 10 years through no fault of the owner ? I don't think so. My dad still has speakers he built in the mid 70's, and they are still going strong and still sound great, despite ~35 years of exposure to high humidity. No foam surrounds on any of those drivers...(rubber on the woofer, fabric on the mids)
Any speakers I built myself I'd expect to last at least 20+ years and still be in good condition, so I wouldn't be using any materials known to have a short life span despite any benefits they might have.
Agree, i was furious too. But, as i said, it is only a half day work to replace the surrounds. And now, i suppose i will be dead before those new foams
Is-it acceptable for a man to be destroyed in 75/80 years ?
I used on a enclosure loudspeakers with rubber surrounds. They are still here after 30 years, yes. But the enclosure is in the cellar : i was tired with this "wow wow" sound. I would definitively go for that kind of speakers, and surrounds, today:
MONACOR INTERNATIONAL : Page Détails du produit
Despite the accident you can see around 490hz witch is, for sure due to the paper surrounds.
It is curious to see how the oldest way to build a speaker remains, at the end, as the best ones ! And i have no idea how those neodymium magnets will remain magnetized with time
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I think it is suitable for small car subwoofer.
I believe efficiency-bass-matter depends much of room gain what is awailable, bsc and box size. If you have "enough" big enclosure i believe you can have bass down to 30 Hz in room but you have to use large midbass and cross it low with some 4" fullrange. Bass can be 10" 93 dB and fullrange couple of dBs lower. Different thing if you want use small dome and cross higher.
if you can stand the garish surround, and 4 Ohm impedance...also foam it would appear...then maybe this:
MONACOR INTERNATIONAL : Product Detail Page
or if you hate purple with a passion then:
MONACOR INTERNATIONAL : Product Detail Page
MONACOR INTERNATIONAL : Product Detail Page
or if you hate purple with a passion then:
MONACOR INTERNATIONAL : Product Detail Page
This one would be fantastic in a quarter wave line column around 100 liters !!!
Will works in a closed enclosure of 50 litters, with a cutoff around 46hz.
The first one in 4 ohms has a dome witch produce an accident as horrible than the surround color ;-).
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That looks as a very nice one. Big box I think.
That monacor is very cool but 10" than I know another 10" one -3dB 45Hz.http://www.monacor.de/en/products/speaker-technology/product-listing/product-detail-page/?artikelid=2075
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Seems that almost all bass drivers fullfils the first reserve.
I think low Fs that is not achieved by heavy cone (low SPL) must the first rule to fulfill. Fs around below 30 Hz (better below 25 Hz), SPL over 90 dB and Qts around 0,45-0,5 would be nice.
Yep. One good bigger one here : KLIK low Fs, highish SPL, highish Qts and low Le.
I think low inductance is always good?
Question for anyone: I'm not exactly sure how an aperiodic design (like the Dynaco A-25) would be classified, but would the modern version* of its woofer SEAS sells now be a good candidate for an acoustic suspension enclosure?
Seas Prestige A26RE4 (H1411) 10" Paper Cone ($138 bucks....yikes)
The driver's rubber surround looks like something a subwoofer driver would use! And cone excursion - 8mm peak to peak - seems good.
* SEAS says this newest version of the new version will no longer fit in an A-25 because the frame is now larger by 1cm - I wonder why they did that?
Seas Prestige A26RE4 (H1411) 10" Paper Cone ($138 bucks....yikes)
The driver's rubber surround looks like something a subwoofer driver would use! And cone excursion - 8mm peak to peak - seems good.
* SEAS says this newest version of the new version will no longer fit in an A-25 because the frame is now larger by 1cm - I wonder why they did that?
yep i like the 10incher i last linked as my favourite. There doesnt seem to be an equal in 8inchers so far. Either leant toward vented with low qts or a sub with very heavy cone. Neither are ideal. I may have a look at audax 8s, something puts me off morel...
The visaton W20 is interesting if only the qts wasnt so high...
The visaton W20 is interesting if only the qts wasnt so high...
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