Member
Joined 2004
Infinite Baffle: Looking for advice re: Manufacturing an OEM 18" for IB Applications
Hello everybody,
I am working with a subwoofer driver manufacturer to build an OEM 18” driver for Infinite Baffle applications. This is not a full time endeavor for me nor am I in the ‘business’. I do have a day job and this is basically a side project for me. I’m not in it for the money, that’s why I expect to be able to offer the best $/liter displacement ratio in all of wooferdom. I’m doing it to prove to myself that I can do such a thing and in the process help the community use a driver that is specifically and exclusively designed for IB applications.
The main parameters we’re trying to hit by order of importance are:
Xmax > 20mm (more is obviously better but we’re also looking at linear, low distortion performance)
Fs < 20Hz
18” driver – Sd = 1400 – 1500cm^2. We feel that an 18” driver gives us the best chance of hitting our goals.
MAX SPL: >98dB at 10Hz, 110dB at 20Hz, 116dB at 30-80Hz unechoically per driver. Each doubling of driver number will add 6dB to this number. Room gain should add about 20dB more to the above numbers give or take, YMMV.
Pe = 500W single coil
Qts = 0.7- 0.8 (flat response for IB applications, not recommended for small enclosures sealed or ported).
Vas > 500 liters
Neodymium magnet
Foam surround (new and improved stuff not the foam from the 70’s and 80’s)
Our goal air displacement volume is >6 liters.
Our cost goal is <$50 per liter so as to have the most cost effective IB driver out there that is specifically designed for Infinite Baffle operations.
I do not care about aesthetics, bling factor etc. Every single cent will be dedicated towards PERFORMANCE! No fancy graphics/materials just to make a silly statement (i.e. this is NOT an automotive application focused driver
)
This driver is aimed to DIY audiences that have the education, knowledge and experience to do a simple IB install with 1 or multiple of these drivers for UNPARALLELED bass performance.
For those who know IBs, the advantages are numerous and overwhelming:
1) Far lower cost than any commercially available subwoofer of an topology
2) Very simple structure (no fancy, expensive boxes required)
3) Out of sight, out of mind – High WAF
4) Did I mention the bass ROCKS? The house shakes, creaks and groans. Little children and puppies whimper in the corner. Neighbors file police complaints. You get the idea…
5) Perfectly blended and natural bass to the rest of your system.
Why am I writing this? Since I’m not a manufacturer, I would like the input of experienced IB owners and enthusiasts that are excited at the possibility of installing an Infinite Baffle in their home theater for a low cost. I’m a huge bargain shopper and the next step for me is to actually MAKE the drivers I want to buy. My potential ‘customers’ are NOT audiofools who spend $17k on a coffin sized sub with an undersized set of ports. My ‘customers’ are regular working stiffs like me with ‘real’ salaries and ‘real’ constraints because they need to include diapers and formula in their budget…
I hope my post wasn’t toooo long.
I’m looking for advice, desirable features, do’s and don’ts, lessons learned etc. etc.
I appreciate and thank you in advance for your feedback.
Andreas
Hello everybody,
I am working with a subwoofer driver manufacturer to build an OEM 18” driver for Infinite Baffle applications. This is not a full time endeavor for me nor am I in the ‘business’. I do have a day job and this is basically a side project for me. I’m not in it for the money, that’s why I expect to be able to offer the best $/liter displacement ratio in all of wooferdom. I’m doing it to prove to myself that I can do such a thing and in the process help the community use a driver that is specifically and exclusively designed for IB applications.
The main parameters we’re trying to hit by order of importance are:
Xmax > 20mm (more is obviously better but we’re also looking at linear, low distortion performance)
Fs < 20Hz
18” driver – Sd = 1400 – 1500cm^2. We feel that an 18” driver gives us the best chance of hitting our goals.
MAX SPL: >98dB at 10Hz, 110dB at 20Hz, 116dB at 30-80Hz unechoically per driver. Each doubling of driver number will add 6dB to this number. Room gain should add about 20dB more to the above numbers give or take, YMMV.
Pe = 500W single coil
Qts = 0.7- 0.8 (flat response for IB applications, not recommended for small enclosures sealed or ported).
Vas > 500 liters
Neodymium magnet
Foam surround (new and improved stuff not the foam from the 70’s and 80’s)
Our goal air displacement volume is >6 liters.
Our cost goal is <$50 per liter so as to have the most cost effective IB driver out there that is specifically designed for Infinite Baffle operations.
I do not care about aesthetics, bling factor etc. Every single cent will be dedicated towards PERFORMANCE! No fancy graphics/materials just to make a silly statement (i.e. this is NOT an automotive application focused driver
)This driver is aimed to DIY audiences that have the education, knowledge and experience to do a simple IB install with 1 or multiple of these drivers for UNPARALLELED bass performance.
For those who know IBs, the advantages are numerous and overwhelming:
1) Far lower cost than any commercially available subwoofer of an topology
2) Very simple structure (no fancy, expensive boxes required)
3) Out of sight, out of mind – High WAF
4) Did I mention the bass ROCKS? The house shakes, creaks and groans. Little children and puppies whimper in the corner. Neighbors file police complaints. You get the idea…
5) Perfectly blended and natural bass to the rest of your system.
Why am I writing this? Since I’m not a manufacturer, I would like the input of experienced IB owners and enthusiasts that are excited at the possibility of installing an Infinite Baffle in their home theater for a low cost. I’m a huge bargain shopper and the next step for me is to actually MAKE the drivers I want to buy. My potential ‘customers’ are NOT audiofools who spend $17k on a coffin sized sub with an undersized set of ports. My ‘customers’ are regular working stiffs like me with ‘real’ salaries and ‘real’ constraints because they need to include diapers and formula in their budget…
I hope my post wasn’t toooo long.
I’m looking for advice, desirable features, do’s and don’ts, lessons learned etc. etc.
I appreciate and thank you in advance for your feedback.
Andreas
You might want to start here:
http://home.comcast.net/~infinitelybaffled/
http://ibsubwoofers.proboards51.com/
FYI, a driver with Sd 1400-1500cm^2 and a surround capable of over 20mm excursion, will be larger than 18".
anechoically speaking
AJ
http://home.comcast.net/~infinitelybaffled/
http://ibsubwoofers.proboards51.com/
FYI, a driver with Sd 1400-1500cm^2 and a surround capable of over 20mm excursion, will be larger than 18".
anechoically speaking
AJ
Member
Joined 2004
A pair of IB 15's will meet your performance requirements for only about $200. Also, Hawthorne Audio is coming out with an 18" cast frame driver built by Eminence specifically for IB. They're sticking with the pro heritage and going with the Definimax cloth surround, so Xmax is only 14mm, but over excursion shouldn't be a banging nightmare.
Member
Joined 2003
One suggestion... Before latching onto a Neo magnet spec, have your OEM supplier quote both Neo and ceramic, and then check freight costs. Ceramic might give more "bang for the buck" in driver cost but, considering shipping costs, maybe not the best overall business decision. Look for the best tradeoff before you leap.
Just personal preference, but I'd go with a little lower Qts.
Just personal preference, but I'd go with a little lower Qts.
How about 15" versions? It makes sense to build in multiples of 2 so they can be push pull and transfer less vibration to the structure. A single 18" requires a more solid structure to prevent vibration problems than a pair of 15" drivers mounted in this way. Perhaps some price incentives to buy a number of drivers ...
Member
Joined 2004
Member
Joined 2004
I have a strong feeling that the physics are going to get in your way. Extreme excursion, very low Fs, high Qts, and a smooth response down low are going to be goals that will contradict each other when designing this driver. Where you're going to have to give is on the Qts, because you need a strong enough motor to keep things under control. Otherwise the response is going to be lumpy in the lower octaves. My guess is that the Dayton IB15 already pushes some of these limits, so with their price of only $100 or so, your plan may be an exercise in futility. I like the idea, but be sure to fully discuss these matters with the engineer helping you with the design.
Member
Joined 2004
Awesome news!!!
I have FANTASTIC news from my OEM!!!
Here are the parameters of the prototype driver (plug them in to your favorite subwoofer simulation software and compare them with ANY driver on the market!)
Fs = 14.5Hz
Qts = 0.42
Qes = 0.52
Qms = 2.14
Vas = 926.7 liters
Mms = 232.7g
Re= 4.5ohms
Le = 1.56mH
SPL = 89.2dB
Res = 40.9ohms
Rp = 18.3ohms
Rms = 9.9Kg/s
Cms = 0.51mm/N
Cp = 1487.2uF
Saved the best for last…
Xmax = 35mm!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Sd = 1123.3 cm^2
Displaced volume = 7.864 LITERS OF AIR!!!!!!!!!!!!!
Keep in mind all these are preliminary and maybe I’m jumping the gun a bit as the parameters may change a bit. But this is the driver we’re working on. Amazing stuff!!
As soon as I get the prototypes, I’ll put them in a MONTH-long burn-in in a lab and a real world environment (club, disco, etc.).
Only after reliability of at least 10 samples has been proven, this will be offered for sale.
You have no idea how excited I am! This is absolutely amazing. My OEM have been working solid on this and have delivered BIG TIME!
This is it, ladies and gentlemen, I’m awaiting for your inputs, comments, criticisms, suggestions, etc. etc.
Thanks,
Andreas
I have FANTASTIC news from my OEM!!!
Here are the parameters of the prototype driver (plug them in to your favorite subwoofer simulation software and compare them with ANY driver on the market!
)Fs = 14.5Hz
Qts = 0.42
Qes = 0.52
Qms = 2.14
Vas = 926.7 liters
Mms = 232.7g
Re= 4.5ohms
Le = 1.56mH
SPL = 89.2dB
Res = 40.9ohms
Rp = 18.3ohms
Rms = 9.9Kg/s
Cms = 0.51mm/N
Cp = 1487.2uF
Saved the best for last…
Xmax = 35mm!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Sd = 1123.3 cm^2
Displaced volume = 7.864 LITERS OF AIR!!!!!!!!!!!!!
Keep in mind all these are preliminary and maybe I’m jumping the gun a bit as the parameters may change a bit. But this is the driver we’re working on. Amazing stuff!!
As soon as I get the prototypes, I’ll put them in a MONTH-long burn-in in a lab and a real world environment (club, disco, etc.).
Only after reliability of at least 10 samples has been proven, this will be offered for sale.
You have no idea how excited I am! This is absolutely amazing. My OEM have been working solid on this and have delivered BIG TIME!
This is it, ladies and gentlemen, I’m awaiting for your inputs, comments, criticisms, suggestions, etc. etc.
Thanks,
Andreas
I don't have the room for IB, nor the space in my room for dipole, but I could do multiples of these in isobaric...
If you can get specs similar to those listed above for a price close to what you quoted on the first page, not only would I be astonished, but I'd also buy a couple of them, no questions asked...
If you can get specs similar to those listed above for a price close to what you quoted on the first page, not only would I be astonished, but I'd also buy a couple of them, no questions asked...
Member
Joined 2004
Member
Joined 2004
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.