Difference between a pro 18" and a hifi 18" woofer?

[crazybastard]

I'm looking to buy some 18" woofer to cover the range below 200hz. Could some one explain what the difference between say a B&C18" pro woofer and a soundsplinter 18"? Not talking about t&s parameters, but from a practical standpoint. Why would one choose one over the other?

[kingpin]

I don't think the pro woofers are designed to go down to the lower frequencies like say an SS would.
A pro driver would maybe see active duty in the 30-45hz(club music) range while that doesn't really cut it these days for a ht sub. A lot of movies now and in the future have a frequency range down in the low teens and even single digits.
This is where a ht sub come be made to excel when used properly.

Then again I could be totally wrong. I am sure one of the more experienced guys will speak up in the morning.

Good Luck
Mike

[servicetech]

A pro sub is designed primarily for SPL, a HT sub is designed for Sound Quality.

[Kevin Haskins]

Really the differences are mainly T/S related. They are different markets and the design s typically focus on the different requirements of those markets. Sometimes those are technical requirements, sometimes they are "market" requirements. "Market" requirements may have nothing to do with better/worse but what is "sellable".

Pro drivers are made to operate in venues where the cabinets are often moved. There is a focus on lighter rather that heavier drivers. They are also aimed at large venue type playback. They have to be efficient and put out a lot of SPL. They have to take a lot of power because those guys pump a couple KW into a driver on a regular basis. What they don't do.... is reach very low. In pro-sound 30Hz is considered deep. If you look at pro-sound drivers you will notice they don't have much excursion (x-max) and their efficiency is higher on average. They don't need the excursion, because they are not designed to play deep, just loud.

Efficiency at its root is a function of just two physical parameters of the driver, BL (motor strength) & mms (moving mass of the driver parts). Pro-audio drivers typically have high motor strength (larger VC & stronger magnetic flux) and lighter cones. The consequence of that property also makes them not play as deep, and they need larger boxes for a given low frequency cutoff.

[joetama]

A pro sub is designed primarily for SPL, a HT sub is designed for Sound Quality.

I would say that this is a false assumption. Beause of the pro drivers design they are very efficent so they can generate SPL easily and it is true that a lot of pro drivers sound like butt. But, some pro drives actually sound very nice. Meyer Sound, Adamson, and L-Acoustics are some examples of Pro-PA speakers that sound amazing IMO. Anyway, as said above the big difference is what they are designed to do. A pro driver is made to work in large venues, in BIG boxes, with a lot of other drivers. They also do not reproduce the lowest of the lows by themselves easily because of their application and design. Several pro drivers together will play low, but you are trading off excursion and displacement for number of cones when compaired to a Home Audio or Car Audio driver.

[crazybastard]

Thanks for all the great replies. A friend of mine gave me a pair of 12" Radian coaxial driver that he couldn't use. Since I can't build boxes worth anything, I was going to experiment with it on an open baffle. I tested it on a flat baffle 20" wide, sounds pretty good, but definitely light on the bass. I thought about getting a pair of 18" woofers on each side. Since I've got subs already I'm probably OK with the woofers going down to only arounnd 35hz. I looked at the ficaraudio.com 18" woofers which has around 30mm xmax, vs a b&c 18" which has around 9mm xmax. Both has qts of around .55. I'm leaning towards the b&c since they are a bit cheaper and the efficiency is a better match for the radians (~100db/watt?). Any thought as to which one would be better for this application?

[ThomasW]

I looked at the ficaraudio.com 18" woofers which has around 30mm xmax, vs a b&c 18" which has around 9mm xmax. Both has qts of around .55. I'm leaning towards the b&c since they are a bit cheaper and the efficiency is a better match for the radians (~100db/watt?). Any thought as to which one would be better for this application?

This is an apples vs oranges comparison. The Fi is a very high output subwoofer, the B&C is a woofer.

[Kevin Haskins]

This is an apples vs oranges comparison. The Fi is a very high output subwoofer, the B&C is a woofer.

Its an expensive one too. They sell of bunch of them though. A reliable source gave me the sales numbers for those suckers in Europe and I was stunned into silence.

[crazybastard]

Its an expensive one too. They sell of bunch of them though. A reliable source gave me the sales numbers for those suckers in Europe and I was stunned into silence.

They're reasonably priced in the US. The q18 on their website is only $310 shipped each.

I guess I have t figure out if I need the subs or just woofers on the baffle as Thomas suggested. The 12" coaxials should play down to 200hz on a 20" wide baffle, so may be subs would work better? Sorry about all the newbie questions. I read that on an open baffle, bass rolls off real quick. I've read reviews on the jamo r909. The jamos have a pair of 15" woofer and compensate for the roll off by shear displacement. I've never heard them, but the reviews are great. I figure if 2x15" works, then 2x18" works better by the above reasoning. I think I'll pick up 4 of the FIs next week. Any major flaws in this decision? Educate me please

[Kevin Haskins]

They're reasonably priced in the US. The q18 on their website is only $310 shipped each.

I guess I have t figure out if I need the subs or just woofers on the baffle as john suggested. The 12" coaxials should play down to 200hz on a 20" wide baffle, so may be subs would work better? Sorry about all the newbie questions. I read that on an open baffle, bass rolls off real quick. I've read reviews on the jamo r909. The jamos have a pair of 15" woofer and compensate for the roll off by shear displacement. I've never heard them, but the reviews are great. I figure if 2x15" works, then 2x18" works better by the above reasoning. I think I'll pick up 4 of the FIs next week. Any major flaws in this decision? Educate me please

Ok... here is your education:

If you don't have measurement gear, and know how to use it, your throwing your money to the wind.

Class over!

I'll stop being a smartass though and just say, if your a newbie you don't stand a chance in hell of designing a OB loudspeaker from scratch. Your better off following someone else's design, who has the skill, equipment and knowledge to do the design.

Jon has plenty of loudspeaker kit designs. I'm sure they are well executed and your money would be better spent building a couple of those, getting started on a learning curve before trying your own design.

Just my 0.02. Ignore me if you are already fully emotionally involved in the project.

[ThomasW]

The 12" coaxials should play down to 200hz on a 20" wide baffle, so may be subs would work better?...... I think I'll pick up 4 of the FIs next week. Any major flaws in this decision? Educate me please

No you don't want to run high Le subs like the Fi's much above 80Hz. If you need something to run that high cleanly, look at the 12" AuraSound or the Hawthorne Audio 15" woofers (they're made by Eminence)

[crazybastard]

Thanks Kevin:
I'm just trying to make use of the radian coaxials right now. I really just want to build something that is in the ballpark of a decent sounding speakers, rather than something technically correct. You're right, no way to build a good open baffle without prior experience. I do have access to some measurement equipments. Basically a berhinger calibrated mic and basic rta software. I tried looking at the loudspeaker builder's book, but at my age, learning a new language is too much. I heard the radians run around $1200/pair, so I just want to do it some justice by pairing it with something to bring up the bottom end. I've read the Hawthorn audio forum, seems like lot of people just screw their drivers to a board and rave about their speakers. Makes it seem too simple. But I hear you.

Thanks Thomas. Maybe I'll try a pair of 15" augies. Is this the aura sound driver?:

http://www.madisound.com/catalog/product_info.php?cPath=45_338_381&products_id=1730

BTW Thomas, I don't live far away from 5280'. Are you a speaker consultant? I'll be glad to pay you for specific advise.

[ThomasW]

Thanks Thomas. Maybe I'll try a pair of 15" augies. Is this the aura sound driver?:

http://www.madisound.com/catalog/product_info.php?cPath=45_338_381&products_id=1730

BTW Thomas, I don't live far away from 5280'. Are you a speaker consultant? I'll be glad to pay you for specific advise.

Yes that's the driver.

Sorry not for hire, but I work for free on occasion...

With a Quest IP addy I imagine you live fairly close... :T

Are you going to the RMAF? If so I live 2 miles from the venue. Sunday after 3:00PM Jon and I will be showing off some speakers at my place. If you stop by you could talk to both of us, for free.... 8O

[Kevin Haskins]

Thanks Kevin:
I'm just trying to make use of the radian coaxials right now. I really just want to build something that is in the ballpark of a decent sounding speakers, rather than something technically correct. You're right, no way to build a good open baffle without prior experience. I do have access to some measurement equipments. Basically a berhinger calibrated mic and basic rta software. I tried looking at the loudspeaker builder's book, but at my age, learning a new language is too much. I heard the radians run around $1200/pair, so I just want to do it some justice by pairing it with something to bring up the bottom end. I've read the Hawthorn audio forum, seems like lot of people just screw their drivers to a board and rave about their speakers. Makes it seem too simple. But I hear you.
.

I like your handle.... No problem though.... drive on. The only way to learn is to experience.

[crazybastard]

Yes that's the driver.

Sorry not for hire, but I work for free on occasion...

With a Quest IP addy I imagine you live fairly close... :T

Are you going to the RMAF? If so I live 2 miles from the venue. Sunday after 3:00PM Jon and I will be showing off some speakers at my place. If you stop by you could talk to both of us, for free.... 8O

Thanks Thomas. I may take you up on the offer. I'll bring the beer :P