Tech advances and makes ELR very attractive....
I have been experimenting with ELF for a few years and have come to the following conclusions:
(1) Its best suited to low Qts / low Qes Pro drivers with large voice coils, low Mms (low moving mass) and cotton / linen surrounds.
(2) Must be used with DSP crossover / Eq.
(3) Requires powerful amplifier(s)
(4) Requires 24mm Birch Ply solid cabinets.
If you can live with the above the rewards are:
(1) You have control over over cabinet volume / system sensitivity / Q can pick your ideal Q.
(2) Super accurate low distortion bass / low mid-range which is time domain accurate ie no out of phase ports / passive radiators / back loaded horns or transmission lines.
(3) Small non resonant cabinets which save money on materials and are easier to fit into real world rooms.
I have been experimenting with ELF for a few years and have come to the following conclusions:
(1) Its best suited to low Qts / low Qes Pro drivers with large voice coils, low Mms (low moving mass) and cotton / linen surrounds.
(2) Must be used with DSP crossover / Eq.
(3) Requires powerful amplifier(s)
(4) Requires 24mm Birch Ply solid cabinets.
If you can live with the above the rewards are:
(1) You have control over over cabinet volume / system sensitivity / Q can pick your ideal Q.
(2) Super accurate low distortion bass / low mid-range which is time domain accurate ie no out of phase ports / passive radiators / back loaded horns or transmission lines.
(3) Small non resonant cabinets which save money on materials and are easier to fit into real world rooms.
So do you think that I could get away with one of these ST255-8 with the right ELF electronics and get some lower end out of it? Or is this driver not suitable.
I just want to make sure that before I start cutting additional or larger holes in this cabinet that I am going the right direction. I do have a 15 inch woofer here
but the only things I know about it is it has 40 oz magnet and it says Olson Big Rock on the back.
budzos
I just want to make sure that before I start cutting additional or larger holes in this cabinet that I am going the right direction. I do have a 15 inch woofer here
but the only things I know about it is it has 40 oz magnet and it says Olson Big Rock on the back.
budzos
Generally most good low Qts / Qes drivers will work well. I will run a sim and get back to you.
Here is the link to download the free sim software AJ Design Software - Math Science Engineering Finance Physics Health Calculators Apps
I really like this as its so simple to understand and it gives both the output response and Power response.
For me power response mode is great as I only use DSP / Eq active crossovers so I can model in great detail the low end.... Ie By varying the Q, max power and / or Xmax you can see exactly how the driver performs under all conditions.
Every driver is different so you have to juggle the variables until you get an overall compromise that suits your needs.
Sorry if the above is a bit vague.... I will try to show examples when I run your ST255 driver sim.
Cheers
Alex.
Here is the link to download the free sim software AJ Design Software - Math Science Engineering Finance Physics Health Calculators Apps
I really like this as its so simple to understand and it gives both the output response and Power response.
For me power response mode is great as I only use DSP / Eq active crossovers so I can model in great detail the low end.... Ie By varying the Q, max power and / or Xmax you can see exactly how the driver performs under all conditions.
Every driver is different so you have to juggle the variables until you get an overall compromise that suits your needs.
Sorry if the above is a bit vague.... I will try to show examples when I run your ST255 driver sim.
Cheers
Alex.
Dayton 10 inch sim
This driver has a high Qts / Qes so it forces the system Q a bit too high (0.85) for my liking.
I cant really show a good spread of options with this driver so I will dig out some other driver sims and make up an example PDF.
This driver has a high Qts / Qes so it forces the system Q a bit too high (0.85) for my liking.
I cant really show a good spread of options with this driver so I will dig out some other driver sims and make up an example PDF.
Thanks for all the help Hydrogen Alex. A lot of this stuff is a bit over my head. I was a big audio nut back in the 80's but things have changed quite a bit since then.
budzos
budzos
@budzos
I use computer calculations since the early 90`, this has saved me a lot of wood. Simulations are really good if the input is right, you can take the results as granted.
The problem with input is, drivers change over the first time in use. If the data sheet shows a factory fresh driver, the data are not usefull. Serious manufacturer put a remark in the fine printed, how it was measured. To precondition a driver, you usualy let it run in free air, driven at it´s resonace frequency and serious load, about 1/2 rms, over night or better, 24 hours. After a few hours cooling down (for hifi driver, PA might be measured warm) you will have final TSP parameters.
With these Data and correct housing, the simulation will fit the finished box.
But ! You allways have to be aware of the influence of the listening room, just like it is with commercial subs. Wrong placement, bad room dimensions...
Retrofitting a driver to a used cabinet is much more promising if simulated in advance. Very often the results are way better than the sub was with the factory driver, is my experience.
So putting some time into lerning a simulation programm pays really off!
I use computer calculations since the early 90`, this has saved me a lot of wood. Simulations are really good if the input is right, you can take the results as granted.
The problem with input is, drivers change over the first time in use. If the data sheet shows a factory fresh driver, the data are not usefull. Serious manufacturer put a remark in the fine printed, how it was measured. To precondition a driver, you usualy let it run in free air, driven at it´s resonace frequency and serious load, about 1/2 rms, over night or better, 24 hours. After a few hours cooling down (for hifi driver, PA might be measured warm) you will have final TSP parameters.
With these Data and correct housing, the simulation will fit the finished box.
But ! You allways have to be aware of the influence of the listening room, just like it is with commercial subs. Wrong placement, bad room dimensions...
Retrofitting a driver to a used cabinet is much more promising if simulated in advance. Very often the results are way better than the sub was with the factory driver, is my experience.
So putting some time into lerning a simulation programm pays really off!
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Thanks Turbowatch2, I have a lot of things to consider. At first I thought I could just plop in a driver and be done with it. Now I am carefully reading specs and narrowing down my choice of drivers. I have actually started looking at some car audio related subs that may work well in this size enclosure which gives me even more options. Some time in the future I
will post a pic of the box so you can see what I am working with.
budzos
When you consider "car subs", be carefull, because the recommended volume of the cabinet is usualy too small for a normal room. Inside a car there are different pressure conditions, which influence the resulting frequency response. So in the car it will sound mighty, but in a home cinema lack deep response.
On the other hand, there are no special car sub´s any more, maybe they are (hopefully) a little more corrosion resistant and have usualy 4 Ohm or less. That´s all.
At the end it is only the TSP that count, car, PA or living room.
So if you find a nice driver in the car audio section, there is no objection to using it at home. In the USA I would sure find something in the broad Dayton range, they are much cheaper where you live and sure have more than one that will fit your box.
On the other hand, there are no special car sub´s any more, maybe they are (hopefully) a little more corrosion resistant and have usualy 4 Ohm or less. That´s all.
At the end it is only the TSP that count, car, PA or living room.
So if you find a nice driver in the car audio section, there is no objection to using it at home. In the USA I would sure find something in the broad Dayton range, they are much cheaper where you live and sure have more than one that will fit your box.
Yeah, the better ones work well in small TH/TTL whereas the cheap ones are best suited to fairly large sealed, though small [Vb = Vas + EQ] works too, just keep the XO pretty low as > ~120 Hz they sound horrible IME.
I'm familiar with these + EQ and BestBuy, Fry's use to regularly put them on sale for $35-40, so could use as a shopping guide:
Pioneer TS-W309D4 Champion Series 12" subwoofer with dual 4-ohm voice coils at Crutchfield.com
https://www.pioneerelectronics.com/StaticFiles/Manuals/Car/TS-W309S4_InstructionManual052011.pdf
GM
I'm familiar with these + EQ and BestBuy, Fry's use to regularly put them on sale for $35-40, so could use as a shopping guide:
Pioneer TS-W309D4 Champion Series 12" subwoofer with dual 4-ohm voice coils at Crutchfield.com
https://www.pioneerelectronics.com/StaticFiles/Manuals/Car/TS-W309S4_InstructionManual052011.pdf
GM
Thanks for the tips and links. I am going to take my time with this so I don't regret it later.
So many variables. Kinda hoping there is an unbeatable deal that comes up that will make
my decision easier. That usually doesn't happen till after I purchase something and install it.
budzos
So many variables. Kinda hoping there is an unbeatable deal that comes up that will make
my decision easier. That usually doesn't happen till after I purchase something and install it.
budzos
I apologize for jumping in this thread at a very late date. Does anyone know where to find the Sub-Woofer Controller article that is referenced above. When I click on the phrase above I go to a dead link. Any help would be appreciated
another old guy trying to learn proper woofer cab building
Bubba
