Woofer cost is primarily application driven. High end auto subs can be over $1,000 each. You are paying for volume of displacement 10 times the amount needed in a residential application. Beautiful drivers, but near worthless for most applications, professional or otherwise.
Defining application is the key to getting the most out of your investment.
Defining application is the key to getting the most out of your investment.
Mr John Busch,
Thank you very much for your very logical answer to my question regarding what 15" woofer to use.
I fully know that i throw myself backwards into the diy speaker world by asking this question, it it is because i always loved these BIG JBL 80's studio monitor sound and design....cannot say why
I heard a pair of K2 S9800, this is my dream speaker, fantastis sound, and i will say that the sound that this speaker provide is my reference.
I can see it uses a huge 15" driver, guess there is nothing on the marked that can match that driver....or?......does this driver have parameters that no other 15" driver can match.....and if i wanted the sound like the K2 S9800, would you know of any diy projects that would sound like this speaker?
Thank you very much for your very logical answer to my question regarding what 15" woofer to use.
I fully know that i throw myself backwards into the diy speaker world by asking this question, it it is because i always loved these BIG JBL 80's studio monitor sound and design....cannot say why
I heard a pair of K2 S9800, this is my dream speaker, fantastis sound, and i will say that the sound that this speaker provide is my reference.
I can see it uses a huge 15" driver, guess there is nothing on the marked that can match that driver....or?......does this driver have parameters that no other 15" driver can match.....and if i wanted the sound like the K2 S9800, would you know of any diy projects that would sound like this speaker?
Other than the 2 units I linked to from PE, were are all these other choices ?
Mtolesen
Yes the K2 is what a lot of engineering, time and money can do... and even with that, it has some major compromises. Don't get me wrong... a very good speaker. But as with all speakers, there were quite a few compromises made in the over all design.
Given this speakers size, the operating efficiency is not all that high, and bass extension not all that deep. It's real positive is tonal balance and very low traditional distortions at practical listening volumes. Actually surprised Just Big & Loud built it. Suspect a demo of their design abilities, particularly in the woofer department. But, not practical to make.
With that said, you have a lofty design goal. I think the cost of the K2 is around $40 to $50 grand U.S. Dollars a pair. Don't even know if they are currently available. Would have to do some research.
Will be interested to see your design goals... Money and time usually have a lot to do with were one ends up. Assuming enclosure size, with in reason, is not a problem for you.
Yes the K2 is what a lot of engineering, time and money can do... and even with that, it has some major compromises. Don't get me wrong... a very good speaker. But as with all speakers, there were quite a few compromises made in the over all design.
Given this speakers size, the operating efficiency is not all that high, and bass extension not all that deep. It's real positive is tonal balance and very low traditional distortions at practical listening volumes. Actually surprised Just Big & Loud built it. Suspect a demo of their design abilities, particularly in the woofer department. But, not practical to make.
With that said, you have a lofty design goal. I think the cost of the K2 is around $40 to $50 grand U.S. Dollars a pair. Don't even know if they are currently available. Would have to do some research.
Will be interested to see your design goals... Money and time usually have a lot to do with were one ends up. Assuming enclosure size, with in reason, is not a problem for you.
sorry, typo on my part...were is supposed to be "where", as in where are they ?
Thiele-Small Parameters (295-325)
Resonant Frequency (Fs)18.8 HzDC Resistance (Re)6.4 ohms
Voice Coil Inductance (Le)3.09 mHMechanical Q (Qms)2.87
Electromagnetic Q (Qes)0.34Total Q (Qts)0.30
Compliance Equivalent Volume (Vas)13.82 ft.³Mechanical Compliance of Suspension (Cms)0.39 mm/N
BL Product (BL)20.4 TmDiaphragm Mass Inc. Airload (Mms)182.9g
Maximum Linear Excursion (Xmax)4.35 mmSurface Area of Cone (Sd)834.7 cm²
You are, ofcourse, right. Sorry, I was drifting off.
Aside from the pure cost of material, it's a question of production capacity and development costs. For PA, low level performance isn't sought after and for hifi almost all properties, qualities and dynamic can be reproduced also by smaller drivers and much, much smaller enclosures. But the hifi-drivers got no room in the PA field except maybe some large studio-monitors (but even that becomes less and less popular). That makes them not profitable in quantities, that means the price goes up. And the freaks who DO want them are willing to pay almost anything. And that makes them even more expensive. There are some cheap alternatives though, depending on where you live and what you're expecting in enclosure size and upper and lower range reproduction (cut off).
There is probably a sea of drivers that would have topped or still be in the same league as your JBL 15" unit of the past, which is btw a really beautifully executed piece of a product.
I know what I would have started building with to get me in the zone, a loudspeaker comprised of GRS units, GRS 15PF-8; GRS 6PR-8, GRS Phenolic Ring Tweeter; total of 120 $/stereo. No measurements available so not for everyone's taste. A very light and rigid cabinet of thinner particle boards, really large one stuffed well to supress the Qtc in the comfort zone and prevent Fb from rising too much.
Ha ha! That would be a funny speaker, probably a lot of bang for the buck. Crossover might cost you as much as the drivers. I use GRS drivers and like them OK, but I'm not sure I'd be willing to go there.
Scott... I know I may sound (no pun intended) like a broken record, but what are your performance goals? I happen to have 4 each of the PE 15" you reference in your post. Left over from a previous design project.
For a low cost, sealed enclosure of reasonable size (for a 15" driver) the PE 295-325 is a good value in a residential application.
Actually surprised I don't see many DIY designs using it.
Get back to issues, need to know what you want to do...and what kind of money you can justify.
For a low cost, sealed enclosure of reasonable size (for a 15" driver) the PE 295-325 is a good value in a residential application.
Actually surprised I don't see many DIY designs using it.
Get back to issues, need to know what you want to do...and what kind of money you can justify.
Most pro type 15 inch woofers will not work well for domestic speakers.If they are around 100db/watt sensitivity you are probably only going to run about half a watt into them at home for normal listening and they need more power than that to produce their full bass response.
I have used the RCF L15/554K which is a fantastic sounding woofer but needed equalisation in home speakers to produce much bass below about 100Hz.
I have used the RCF L15/554K which is a fantastic sounding woofer but needed equalisation in home speakers to produce much bass below about 100Hz.
OK... Lets engineer this woofer for a Hi Fi application. Balancing the good with the not so good. A lot of potential here... we just need to apply good design principals...
This driver is ideal for a Thiel / small design application... Using likely crossover QT as a basis for tuning, box size and low end cut off.
So... using the math and assuming the driver is remotely close to spec...
For a residential Hi fi application working a balance between lowest practical FS and highest efficiency.....
The very high efficiency of the driver limits it to a low frequency cut of in the mid 50's. You can do an extended bass frequency design, but the box gets very large for the extension realized. As a small PA high output monitor monitor this is an excellent driver... which is exactly what it is designed to do.
This driver is ideal for a Thiel / small design application... Using likely crossover QT as a basis for tuning, box size and low end cut off.
So... using the math and assuming the driver is remotely close to spec...
For a residential Hi fi application working a balance between lowest practical FS and highest efficiency.....
The very high efficiency of the driver limits it to a low frequency cut of in the mid 50's. You can do an extended bass frequency design, but the box gets very large for the extension realized. As a small PA high output monitor monitor this is an excellent driver... which is exactly what it is designed to do.
I use GRS drivers and like them OK, but I'm not sure I'd be willing to go there.
The crossover could be as low as 60$ (solid core inductors dayton, NPE all the way, some resistors), finished in speaker carpet ( front, rear, sides) and top/bottom solid pine, including everything but boards, 260$. All prices off PE except the poly stuffing, best sourced from upholstery supplies. This speaker would have been a dynamite surprise, ideal starter kit for a newbie builder.
Hi John, I am not looking to purchase any units right now. I do design and sell speakers from time-to-time, and was just recently looking for 12 inch hi-fi woofers. The search led me to conclude that there are very few choices these days, as compared to maybe 20 years ago. Going back in time even further than that, back in 1990 I built a pair of very large woofer towers, using 2x15's in each enclosure, of some units Madisound offered. I have since discovered that way indeed the way to go for very, very deep bass, but above the 60-80 Hz range, pro style mid bass units gave me the sound quality I wanted. Back then I adopted a 60Hz crossover frequency, and still use this approach today, 28 years later.
Appears to be a clone of Altec's 411-8A, a '70s era true woofer optimized for 6 ft^3 sealed studio monitor and premium consumer furniture speaker apps. Inflation adjusted, just as expensive too. Regardless, if true, then it's well worth the expense if a relatively high XO point is desired [up to its 500 Hz/2nd order design limit].
GM
GM
Some rambling thoughts (who me, never!)
The SB Acoustics SB42 is an excellent example of a modern (off the shelf) 15” woofer. It offers a lot of potential! But, once again, we need to get back to the core issue, is it a good fit for what one wants to do?
With all its high value attributes, including, but not limited to high Volume of Displacement, combined low F/S - low QTS suitable for compact sealed designs, flat frequency response to 1,500 Hz, low / medium operating efficiency & pro level construction, it still may not be appropriate for certain Hi-Fi (residential) goals. As an active sub, OH YEAH! But as the woofer end of a residential two or three way, not so much.
Gets back to why choose a 15” in the first place? Again, assuming for use in a residential space.
Past commercial efforts from the likes of Tannoy, Altec, JBL, Klipsch and others using 15” woofers have mostly been 2 and 3-way designs. All with the focus on highest practical electrical-acoustical efficiency, maximum dynamics, smallest possible enclosure volume offering a reasonable low frequency cut off and as simple a crossover as is practical. Enclosures range from as simple as can be to very complicated. Complicated being the Klipsch corner horn. All, by necessity, are rather large by residential standards. 6-15 Cu. Ft. and larger. Altec A 500 VOTT comes to mind. Yikes!!
I tend to value the above priorities, particularly the dynamics. Small systems can do a lot of things, but just can’t match the dynamics of a large 2 or 3 way with the right 15” woofer. Walking down the street, doing a little bar hopping, (come on you have all done it at least once or twice!) you know immediately where the live music is. It is the dynamics that give it away. Drums leading the music. Only a large speaker system can approach that. That takes cone area, high operating efficiency and sufficient Volume of Displacement in the mid bass and throughout the mid-range.
So, if the above is the goal, we need a 15 that can play down (flat if possible) to around 42Hz in a practical sized enclosure. Practical being a bit of a misnomer. And have enough VD to deliver 105 – 110 dB out of a stereo pair at 42 Hz (half space) without exceeding Xmax.
This driver will have a true electrical efficiency in the 97-98 db/watt area, REALLY!! Not at break up, but down at 200 Hz or so. This is what it takes! Only need an Xmax in the 5-6 mm peak area. We also want it be naturally flat in the frequency domain within +/- 3 db out 3.5 Khz. Makes a two- way very practical. And if you want to, you can do the major extra work and expense and go 3 way. Assuming either passive or active crossover. Add a low Mms of below 75 grams and high BL. Light cone and a lot of linear magnetic force.
Such woofers do exist and for only around $160 U.S. No, I am NOT selling anything.
The SB Acoustics SB42 is an excellent example of a modern (off the shelf) 15” woofer. It offers a lot of potential! But, once again, we need to get back to the core issue, is it a good fit for what one wants to do?
With all its high value attributes, including, but not limited to high Volume of Displacement, combined low F/S - low QTS suitable for compact sealed designs, flat frequency response to 1,500 Hz, low / medium operating efficiency & pro level construction, it still may not be appropriate for certain Hi-Fi (residential) goals. As an active sub, OH YEAH! But as the woofer end of a residential two or three way, not so much.
Gets back to why choose a 15” in the first place? Again, assuming for use in a residential space.
Past commercial efforts from the likes of Tannoy, Altec, JBL, Klipsch and others using 15” woofers have mostly been 2 and 3-way designs. All with the focus on highest practical electrical-acoustical efficiency, maximum dynamics, smallest possible enclosure volume offering a reasonable low frequency cut off and as simple a crossover as is practical. Enclosures range from as simple as can be to very complicated. Complicated being the Klipsch corner horn. All, by necessity, are rather large by residential standards. 6-15 Cu. Ft. and larger. Altec A 500 VOTT comes to mind. Yikes!!
I tend to value the above priorities, particularly the dynamics. Small systems can do a lot of things, but just can’t match the dynamics of a large 2 or 3 way with the right 15” woofer. Walking down the street, doing a little bar hopping, (come on you have all done it at least once or twice!) you know immediately where the live music is. It is the dynamics that give it away. Drums leading the music. Only a large speaker system can approach that. That takes cone area, high operating efficiency and sufficient Volume of Displacement in the mid bass and throughout the mid-range.
So, if the above is the goal, we need a 15 that can play down (flat if possible) to around 42Hz in a practical sized enclosure. Practical being a bit of a misnomer. And have enough VD to deliver 105 – 110 dB out of a stereo pair at 42 Hz (half space) without exceeding Xmax.
This driver will have a true electrical efficiency in the 97-98 db/watt area, REALLY!! Not at break up, but down at 200 Hz or so. This is what it takes! Only need an Xmax in the 5-6 mm peak area. We also want it be naturally flat in the frequency domain within +/- 3 db out 3.5 Khz. Makes a two- way very practical. And if you want to, you can do the major extra work and expense and go 3 way. Assuming either passive or active crossover. Add a low Mms of below 75 grams and high BL. Light cone and a lot of linear magnetic force.
Such woofers do exist and for only around $160 U.S. No, I am NOT selling anything.
Such as? Once we know which series we can look at the woofer
Really, you can probably find all the info you need here and even maybe someone's already DIy'd a modern day 'clone' same as many have done with Altecs: INTRODUCTION
GM
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