I am planning to use 10" woofers in "open baffle" boxes for logistical reasons: they need to fit under a pair of electrostatic speakers and Madisound offers a really nice open back box for 10" drivers for the Lx mini. I'm using a First Watt B5 crossover, so equalization won't be a problem. What are the trade offs of going to a smaller woofer like this compared to the 15" woofers often used in open baffles? They seem to be inefficient and expensive for one thing. The drivers out there have large motors and stiff cones; do they have lower distortion? I'm kinda committed to the small woofer route, but I'd like to understand what I'm getting myself in to all the same.
Next, which one? The obvious choice seems to be the Seas L26RO4Y designed for the Lx mini+2. They're spendy. I'm wondering about some of the cheaper options: ae speakers dipole 10, css sdx 10, and the Dayton UM10-22. At $180 a driver, the Dayton is a lot less than the others.
Next, which one? The obvious choice seems to be the Seas L26RO4Y designed for the Lx mini+2. They're spendy. I'm wondering about some of the cheaper options: ae speakers dipole 10, css sdx 10, and the Dayton UM10-22. At $180 a driver, the Dayton is a lot less than the others.
Hmm, based on this info, the Seas's box loading BW (Fhm = 2*Fs/Qts') is limited to ~119 - 136 Hz, so assuming your XO point is low enough, distortion is moot if driven < ~14 mm on 'fast' transients to keep thermal power distortion low (inductance/Le spec distortion).
If XOing higher, then the driver ideally needs a higher Fhm to compensate and vice versa, so recommend using as an initial guide to choosing a suitable 'sub'.
(Qts'): (Qts) + any added series resistance (Rs)
If XOing higher, then the driver ideally needs a higher Fhm to compensate and vice versa, so recommend using as an initial guide to choosing a suitable 'sub'.
(Qts'): (Qts) + any added series resistance (Rs)
I'll probably cross over at around 125 herz. The Quads will got down to about 50 hz without much fall off, but they sound more compressed (and they need a stiff amplifier) if you want to run them full range. The other side of it is that Quads can have wonderful, tight, bass, and it would be nice not to lose that.
Hmm... how much eq does the B5 provide? Those low qt drivers will require a fair amount plus some juice. If the B5 is capable I would be inclined to try the Dayton Ref HE 10" driver, it should be better than the ultimax up high and at least it's equal down low. Sb also has a 12" ob woofer, but no 10".
According to the B5 manual, "This filter follows the low pass filter. You see that it provides a 6 dB bump at 20 Hz and filters
out subsonics. I've had this circuit around for 40 years, and it really works". Hooked up to the Eminence Betas, the bottom octave feels almost pronounced.
out subsonics. I've had this circuit around for 40 years, and it really works". Hooked up to the Eminence Betas, the bottom octave feels almost pronounced.
That's probably not enough boost and not flexible enough for just any woofer, gonna need some help with high qt and low fs.
Does that apply to any of the choices for 10" driver? The Qts for the Seas driver is .27. The equalization is more than enough for a 15" driver. The Acoustic Elegance website goes out of its way to state that their driver works well in open baffles - not sure what that means about equalization though.
The free speaker design software VituixCAD2 can show you very accurately what the performance will be for an open baffle build before you buy or build anything. There are youTube videos showing how to use it. You can throw numbers around with people and buy some parts and get a really random result. WIth an open baffle the distance from the driver to the baffle edge determines the frequency of that additional 6dB/octave low frequency roll off as well as that mid base bump. Mounting the driver close to the floor can help as there is a mirror image effect. As these things basically throw away most of the low bass, so you need very large displacement to get substantial bass at 30 Hz, so that leads people to large cone area and/ or very large excursion drivers. If software modeling is out side of your interest, go look at established designs that have published the frequency response and max SPL and copy or riff on something that has a known good result. If you have lots of time and money and like to experiment, cut and try can work eventually if you methodically track the results.
If you use an active system anyway, any woofer will do with enough xmax and power.
The rest can be compensated accordingly.
That's even what quite some high-end brands do these days.
That being said, 10 inch is rather small for a dipole system.
I don't really understand why not just go for a closed system?
The trade-offs compared to a 15 inch are less SPL and/or higher f3.
Depending on the type of baffle you're gonna make you don't only lose difference because of the smaller Sd of the woofer, but also a smaller front-to-back path since the diameter is (much) smaller, which is important in dipole systems.
So smaller woofers always have a sort of double penalty when it comes down to dipole systems.
I don't know what levels you're listening, but for just a single 10 inch in dipole (two in total), don't expect much lower than 40-45Hz if you wanna keep enough dynamic range on proper listening levels.
The rest can be compensated accordingly.
That's even what quite some high-end brands do these days.
That being said, 10 inch is rather small for a dipole system.
I don't really understand why not just go for a closed system?
The trade-offs compared to a 15 inch are less SPL and/or higher f3.
Depending on the type of baffle you're gonna make you don't only lose difference because of the smaller Sd of the woofer, but also a smaller front-to-back path since the diameter is (much) smaller, which is important in dipole systems.
So smaller woofers always have a sort of double penalty when it comes down to dipole systems.
I don't know what levels you're listening, but for just a single 10 inch in dipole (two in total), don't expect much lower than 40-45Hz if you wanna keep enough dynamic range on proper listening levels.
I wouldn’t start with expensive drivers, you wouldn’t be using half of the power capacity of the beefy subs in an ib arrangement.
Also that qts of .27 is just a bit low, would be looking towards something like .5 as a minimum.
A 5 sided box with a membrane across the back would help isolate the rear wave, since you probably don’t want huge cabinets. Or maybe a horn would provide a similar response with more output, getting larger with that however.
I am in the midst of an ob build now using a single GRS 10SW-4 in a car. That driver has a good response for that and is very low priced.
Also that qts of .27 is just a bit low, would be looking towards something like .5 as a minimum.
A 5 sided box with a membrane across the back would help isolate the rear wave, since you probably don’t want huge cabinets. Or maybe a horn would provide a similar response with more output, getting larger with that however.
I am in the midst of an ob build now using a single GRS 10SW-4 in a car. That driver has a good response for that and is very low priced.
I'm definitely running up against the limits of my knowledge here. Without understanding the principles of speaker design better, this may be a bad project for me. At any rate, her are some of my assumptions: The LX mini + 1 is a vetted design, although I don't know what sort of equalization was prescribed for it. Dipole woofers seems to gel with electrostatic speakers - that was my experience with the 15" drivers. Again, the choice of a small driver was really due to my desire not to jack the Quads way up in the air on tall stands. Time to take a step back I suppose.
A ripole is basically the same, just the path length is a little longer.
It wouldn't make any super significant differences.
If anything I would do double 10 inch per side.
Still, I am confused why a dipole sub is so necessary in this use case?
Great, but at lower frequencies there is none, it's mostly just pesky room modes.
A dipole is gonna help with that a little bit, but just a addition small closed subwoofer somewhere in the room is gonna do million miles more.
I've been doing some sound deadening on the front wall now that you mention it. Measurably fixes some issues with the current dipole speaker. There's this stubborn dip around 40 hz remaining that I suspect is the sound bouncing off the back wall and heading back my way.
Quad ESL57 on top of its 15" woofer base in the stereo dungeon. Having the electrostat coupled to the woofer isn't supposed to be ideal, although Gradient used to make woofers for the Quads in this configuration. The Gradients used small woofers and weren't supposed to generate a lot of bass. I hope Peter Walker isn't spinning in his grave.
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Under 200Hz any "sound deadening" or other acoustic materials don't work anymore.
What you are describing is something called standing waves, aka room modes.
There is nothing "heading your way" but it's a physical property of a room.
What you are describing is something called standing waves, aka room modes.
There is nothing "heading your way" but it's a physical property of a room.
"Quad ESL57 on top of its 15" woofer base " It is my understanding that Quad ESL speakers often fail due to the glue letting go of the diaphragms. Putting a woofer directly below the Quad panel like that will subject the Quad diaphragms to the full bass pressure wave with a differential pressure on the panel front and back. If those were my speakers and I wanted a subwoofer under them I would build a sealed box and play the woofers such that the pressure from the sub is directed equally to the front and back side of the Quad. So a sealed box woofer with top , bottom or side firing woofer would be what I would do.