6,5" to 7" midwoofer for sealed enclosure

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#62
Deon, problem with these drivers is not limited excursion but that when they have to move more, the voice coil partialy leaves the optimal magnetic field which causes less damping of the cone and this introduces tons of intermodulation distortion. Correct me but Mark audio uses soft suspensions on their drivers which indicated that driving them hard is not best. As I sent a PM to Alspe ( we shared some thoughts on this topic and also about the bulgarian summer resorts, a very nice person 😀 ) - I see fullranges as the ideal driver to fill in the role of the classical midrange unit - their ability to operatre fullrange quite well alows the use of low order crossovers ( 1st 😀 ) and to move the crossover out of ear`s most sensitive range while they will still not crap on the sound before and after the xover regions. But to obtain bass, you need either a 15" or bigger woofer or at least 3 10" ( 3 will limit the need for longer voice coil travel for a constant volume of air ) used 20-80Hz, a big fullrange and a very well designed one, possibly a 8" or bigger and 4 tweeters, 2 front - 2 back for greater Sd and 360 frad radiation patern over 10Khz. Again, this is not the topic but which is the best 6.5-7" for a sealed box.
 
#63
Have to agree with Mario. And thanks for nice words.😀

Seems that development of fullrange drivers has gone "forward" lately but I think they should live with their limitations. They are not good speakers for all situations and all genres + high level listening. Development of those drivers has gone in wrong direction with some manufacturers as they smaller cones while gaining XMAX. If speaker should play highs, cone should not move much, even if its dust cup is playing highs.

Those 3-4" "fullrange" drivers are very much all but fullrange. How can you describe driver as fullrange if it cann't play 3 lowest octaves out of ten so that human could hear or feel it?😀 I think they are big tweeters or midranges that play highs quite good what comes to driver size. 😉

They are quite nicely tried to develop for fullrange, but they became nice mid drivers. 🙂 Lacking cone break up and usefull to lower mids. Very useful outside their band pass, as mid driver 🙂
 
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#64
rob g said:
Hi Navin,
Side mounted force cancelling bipole bass drivers and coax mid.
Would this be something of a poor mans Kef blade?
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Sort of. The idea came to be before I saw the Blade or the SEAS coax. The NHT 3.3 was probably the first well received fullrange system that used a side firing woofers but even in the early 80s I had ready articles in Speaker Builder of peoplke using side firing wofers. I remember one design in '86 or '87 that used 4 7" woofers mated to a Gold Ribbon wide range (the Gold Ribbon operated from about 200Hz+).

There are 2 issues I am grappling with and would love help on.

1. A Coax that is easy to use. Others on the forum have warned me that the C/16 SEAS Excel coax is not an easy driver to crossover using passive components.

2. How high can I crossover to side firing woofers? 200Hz? 300Hz? The higher I can crossover, the smaller the coax I can use. For example it has been recomended that I use the T18RE coax but I do not need a sheilded driver so I was wondering if I could use the L12RE instead but since that is a small driverr i will have cross it over quite high. Hence the question "how high?".
 
#65
alspe said:
Those 3-4" "fullrange" drivers are very much all but fullrange. How can you describe driver as fullrange if it cann't play 3 lowest octaves out of ten so that human could hear or feel it?
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I have some 4s here that do close to 40 to over 20k. That is almost 9 octaves. But i do feel that adding helper woofers and releiving the small FR of the bottom 2-3 octaves brings a very good compromise between th epurity of a FR and the evils of XOs.

And certainly when you talk about frugal,FRs dominate similar cost multiways.

dave
 
#66
planet10 said:
I have some 4s here that do close to 40 to over 20k. That is almost 9 octaves. But i do feel that adding helper woofers and releiving the small FR of the bottom 2-3 octaves brings a very good compromise between th epurity of a FR and the evils of XOs.
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The only 4" I have heard that can be considered a wide range is the JX92. I feel it needs help in the HF too. It's own HF is very ragged and not comparable to a good dome tweeter. No wonfer Jim Griffin added a tweeter to it.

Are there any fullrange drivers that have a HF that could be compared to a dome tweeter like the Morel ET448, Seas T25, ScanSpeak D2004 or a ribbon like the Neo3, G2Si, Fountek CD3 etc...

If not then does it not make sense to get a dedicated 4-5" woofer instead? There are quite a few good small woofers from Seas W15 (LY/CY), Morel ECW (Elite), etc but the one that peaks my interest is the Vifa NE149.

alspe said:
They are quite nicely tried to develop for fullrange, but they became nice mid drivers. 🙂 Lacking cone break up and usefull to lower mids. Very useful outside their band pass, as mid driver 🙂
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Eventually for the common speaker we seem to to be getting back to a 3 way with a wide range, midrange or mid-woofer covering the 'central' 5 octaves (say 150-4kHz or 100-3kHz) and a woofer and tweeter helping this mid-woofer.

Fullrange drivers like the Lowther etc... do have their place and can produce good music but seem to have limitations.
 
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#67
planet10 said:
I have some 4s here that do close to 40 to over 20k. That is almost 9 octaves. But i do feel that adding helper woofers and releiving the small FR of the bottom 2-3 octaves brings a very good compromise between th epurity of a FR and the evils of XOs.
Click to expand...

Yes it "does". But does it do authority like 15" woofer and sparkling like very good dome tweeter? I'd like to see power response of 4-6" fullrange.
 
#68
navin said:
Eventually for the common speaker we seem to to be getting back to a 3 way with a wide range, midrange or mid-woofer covering the 'central' 5 octaves (say 150-4kHz or 100-3kHz) and a woofer and tweeter helping this mid-woofer.

Fullrange drivers like the Lowther etc... do have their place and can produce good music but seem to have limitations.
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So it seems. If you want your speaker to reproduce physical vibrations and lifelike sparking in treble, I do not think that very lonely 4" fullrange could do that.
 
#69
martinbls said:
Most available drivers in the 6,5" to 7" range have ts-parameters optimized for the use in vented enclosures. Somehow I think for a really nice sounding low frequency range sealed enclosures might (theoretically) be better!

There is the low-efficiency-problem with such a design, though.

That's why I would like to construct a 2,5 way with 6,5" drivers that work really good in sealed enclosures around 20 l. Until now, I wasn't able to find such a driver. Btw., it has to be good in the midrange, too! A smooth response that allows simple crossovers is what I'm looking for.

Any suggestions or experiences?
Thanks a lot!
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hi. ur from Germany. you must be knowing Visaton. i am using following woofer in my Visaton Clou project. check it out. xover is damn simple too!
Visaton - Lautsprecher und Zubehör, Loudspeakers and Accessories
 
#72
Visaton has using these paper cones with black paint on them coupled to tiny magnets since at least the mid nineties, which is when I tried to work with some of them. Easy to cook the VC, never worked with them again. TS measured even below the already disappointing manufacturers specs as well.

vac
 
#74
vacuphile said:
Visaton has using these paper cones with black paint on them coupled to tiny magnets since at least the mid nineties, which is when I tried to work with some of them. Easy to cook the VC, never worked with them again. TS measured even below the already disappointing manufacturers specs as well.

vac
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I think it's intended as a replacement for speakers in radios, etc.
 
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