Re: Re: Re: A point of clarification
Harder or impossible to get really deep bass extension even with 15 and 18 inch drivers. Cabinets are often larger. The resultant much improved efficiency and reduced distortion however is the reward.
Also a `disadvantage` for those that plan to keep their quality speakers for a lifetime, the surrounds are not cheap, stupid foam and will last forever in home use and then still be entirely fine to those who inherit them 50 years from now. Oh what, that is actually another `advantage`.
jnb said:
Harder or impossible to get really deep bass extension even with 15 and 18 inch drivers. Cabinets are often larger. The resultant much improved efficiency and reduced distortion however is the reward.
Also a `disadvantage` for those that plan to keep their quality speakers for a lifetime, the surrounds are not cheap, stupid foam and will last forever in home use and then still be entirely fine to those who inherit them 50 years from now. Oh what, that is actually another `advantage`.
Just a thought- yesterday I was servicing several stacks of Turbosound Floodlight PA gear. One lowmid 12" driver was producing very low volume and distorting, so I pulled it out and put it on the bench. On further inspection, the magnet had shifted, (due to being dropped I assume), and the cone was virtually solid - even putting all my weight on the cone it wasn't moving perceptibly, just flexing around my fingers.
Could this be your problem?
Could this be your problem?
Re: Re: Re: Re: A point of clarification
@ Anonymous1: No need to be sorry, I knew you meant that type of driver specifically. The reason I posted was for the benefit of those like jnb.
Agreed re: efficiency and distortion (though i don't have measurements, more conjecture, to back me up)
I'm not quite sure I follow your meaning in the bottom paragraph, do you mind rephrasing? Pro surrounds usually are tougher than nails, and I think this is what you mean, but want to be sure.
@ Anonymous1: No need to be sorry, I knew you meant that type of driver specifically. The reason I posted was for the benefit of those like jnb.
rcavictim said:
Harder or impossible to get really deep bass extension even with 15 and 18 inch drivers. Cabinets are often larger. The resultant much improved efficiency and reduced distortion however is the reward.
Also a `disadvantage` for those that plan to keep their quality speakers for a lifetime, the surrounds are not cheap, stupid foam and will last forever in home use and then still be entirely fine to those who inherit them 50 years from now. Oh what, that is actually another `advantage`.
Agreed re: efficiency and distortion (though i don't have measurements, more conjecture, to back me up)
I'm not quite sure I follow your meaning in the bottom paragraph, do you mind rephrasing? Pro surrounds usually are tougher than nails, and I think this is what you mean, but want to be sure.
Re: Re: Re: Re: Re: A point of clarification
Huh? I mean FOAM BAD. It rots. Bye bye speaker investment. While it is rotting the speaker characteristic is changing. Pro drivers with their corrugated treated cloth or otherwise corrugated surrounds last virtually forever. I absolutely REFUSE to pay hard earned money for any driver that has a foam surround. IMO the entire DIY audio community should boycott that garbage. If one needs the higher excursion that is the only benefit of foam you can get it with a long lifetime in a modern synthetic rubber roll surround (neoprene, santoprene, etc.). If the market refused to buy this carp these holeasses would stop making it! Hello!
There does that help clarify my stand? You were just edging me on weren`t you?!
badman said:
Huh? I mean FOAM BAD. It rots. Bye bye speaker investment. While it is rotting the speaker characteristic is changing. Pro drivers with their corrugated treated cloth or otherwise corrugated surrounds last virtually forever. I absolutely REFUSE to pay hard earned money for any driver that has a foam surround. IMO the entire DIY audio community should boycott that garbage. If one needs the higher excursion that is the only benefit of foam you can get it with a long lifetime in a modern synthetic rubber roll surround (neoprene, santoprene, etc.). If the market refused to buy this carp these holeasses would stop making it! Hello!
There does that help clarify my stand? You were just edging me on weren`t you?!
Re: Re: Re: Re: Re: Re: A point of clarification
Well, maybe a little bit
However, modern foam surrounds aren't quite so bad as you make out, they often have treatments applied to keep them working properly as they age (within reason). Sometimes foam is chosen for reasons other than excursion and affordability. The surround plays a major role in a driver's behavior. Audax PR17OMO has a foam surround, the flat ring surround probably wouldn't work as well with other materials.... it's about as well-regarded a driver as there is.
Badman- rebelling against absolutism since.... whenever.
rcavictim said:
Huh? I mean FOAM BAD. It rots. Bye bye speaker investment. While it is rotting the speaker characteristic is changing. Pro drivers with their corrugated treated cloth or otherwise corrugated surrounds last virtually forever. I absolutely REFUSE to pay hard earned money for any driver that has a foam surround. IMO the entire DIY audio community should boycott that garbage. If one needs the higher excursion that is the only benefit of foam you can get it with a long lifetime in a modern synthetic rubber roll surround (neoprene, santoprene, etc.). If the market refused to buy this carp these holeasses would stop making it! Hello!
There does that help clarify my stand? You were just edging me on weren`t you?!
Well, maybe a little bit
However, modern foam surrounds aren't quite so bad as you make out, they often have treatments applied to keep them working properly as they age (within reason). Sometimes foam is chosen for reasons other than excursion and affordability. The surround plays a major role in a driver's behavior. Audax PR17OMO has a foam surround, the flat ring surround probably wouldn't work as well with other materials.... it's about as well-regarded a driver as there is.
Badman- rebelling against absolutism since.... whenever.
Re: Re: Re: Re: Re: Re: A point of clarification
1. Most foam-based surrounds are now treated. Not perfection, but a reasonable approach.
2. Foam is more compliant.
3. Foam is less expensive.
4. Foam is less prone to changes in compliance over time, though all mechanical systems are at least a little prone to these problems.
There is nothing about a foam surround that makes it inherently awful to use for a speaker and to suggest otherwise is rather asinine in my opinion.
rcavictim said:
Huh? I mean FOAM BAD. It rots. Bye bye speaker investment. While it is rotting the speaker characteristic is changing. Pro drivers with their corrugated treated cloth or otherwise corrugated surrounds last virtually forever. I absolutely REFUSE to pay hard earned money for any driver that has a foam surround. IMO the entire DIY audio community should boycott that garbage. If one needs the higher excursion that is the only benefit of foam you can get it with a long lifetime in a modern synthetic rubber roll surround (neoprene, santoprene, etc.). If the market refused to buy this carp these holeasses would stop making it! Hello!
There does that help clarify my stand? You were just edging me on weren`t you?!
1. Most foam-based surrounds are now treated. Not perfection, but a reasonable approach.
2. Foam is more compliant.
3. Foam is less expensive.
4. Foam is less prone to changes in compliance over time, though all mechanical systems are at least a little prone to these problems.
There is nothing about a foam surround that makes it inherently awful to use for a speaker and to suggest otherwise is rather asinine in my opinion.
Re: Re: Re: Re: Re: Re: Re: A point of clarification
Neil,
Your comment #3.
If you have to pay the same price as the driver cost initially to get the surround replaced after 15 years how is foam less expensive?
I see many home speakers at the local landfill site with rotted out foam surrounds. If they had not been made of foam they would likely still be in use and the owners better off financially and the planet a bit better off too.
As far as you thinking my comments being assenine. Well you are welcome to them and my opinion of foam surrounds stands.
DevilDriver said:
Neil,
Your comment #3.
If you have to pay the same price as the driver cost initially to get the surround replaced after 15 years how is foam less expensive?
I see many home speakers at the local landfill site with rotted out foam surrounds. If they had not been made of foam they would likely still be in use and the owners better off financially and the planet a bit better off too.
As far as you thinking my comments being assenine. Well you are welcome to them and my opinion of foam surrounds stands.
*Power handling: 500 watts RMS/700 watts max *VCdia: 3" *Le: 1.35 mH *Znom: 8 ohms *Re: 3.4 ohms *Frequency range: 35-150 Hz *Fs: 34 Hz *SPL: 84 dB 2.83V/1m *Vas: .60 cu. ft. *Qms: 4.83 *Qes: .65 *Qts: .57 *Xmax: 15.5 mm *Dimensions: A: 10-1/4", B: 9-1/4", C: 5-11/16".
That has to be a defective driver or a mistake.
That has to be a defective driver or a mistake.
How about using it as a driver in a big pro-style bass horn? It seems like the stiff suspension would enable it to withstand a ton of punishment, while that incredibly strong motor would work well for driving the horn itself. In fact, from what you described, this would be a perfect driver for a bass horn, with the exception of that crazy-high Qts.
Lampshade
I used to have a 12", where I could unbolt the magnet. It had no dust cover and never made a sound. Everyone who saw it said how they admired my lampshade . I glued the coils support ring, which was metal, to the cone and hung it on my ceiling rose. I was young and single back then. Wouldn't have one now!
Mike
I used to have a 12", where I could unbolt the magnet. It had no dust cover and never made a sound. Everyone who saw it said how they admired my lampshade
. I glued the coils support ring, which was metal, to the cone and hung it on my ceiling rose. I was young and single back then. Wouldn't have one now! Mike
Speaker or electro-piston?
Barring any defects in this driver, what you have is the pinnacle of the Car-audio gang.
The drivers used are nothing more than an electric powered gong,....one note response, grossly ineffecient & not really truely designed for MUSIC.
My RS 12" dual coil sub-woofer is rated for 60WPC (Each coil), at that power level she'll run some half inch or so of travel...moving plenty of air & accurate as well.
Get something else if you want to play music thru it.
If you want to hear good low clean bass, listen to the last thirty seconds of U2s' "Its' a wonderful day"
________________________________________Rick...........
Barring any defects in this driver, what you have is the pinnacle of the Car-audio gang.
The drivers used are nothing more than an electric powered gong,....one note response, grossly ineffecient & not really truely designed for MUSIC.
My RS 12" dual coil sub-woofer is rated for 60WPC (Each coil), at that power level she'll run some half inch or so of travel...moving plenty of air & accurate as well.
Get something else if you want to play music thru it.
If you want to hear good low clean bass, listen to the last thirty seconds of U2s' "Its' a wonderful day"
________________________________________Rick...........
Attachments
That's an inductance meter, as you correctly inferred. It tests the impedance of a coil at 1kHz to develop an inductance value. I'd suspect your delta-mass parameter measurement, because the mass needs to be very rigidly affixed to the cone, not just placed on it. You essentially need to sacrifice one and glue a weight onto the cone.
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