Just considering woofer choices for my OB project. I have seen my fair share of Alpha 15 H frames but no Beta 15 H frames. I know the Alpha is preferred for the high Qts, but have heard comments on the Beta as going a bit lower and sounding a bit more defined with eQ (I've pieced together a few comments there 😛). The magnet size I'm sure has some influence. Using eq to boost Q, is it logical to think we can get similar performance to an Alpha from a Beta 15? Has anyone tried this? Assuming one can get it to do so, I agree with another's logic that to cheap out over $10 or so dollars may not be worth it if the SQ is better.
I am torn between the Beta, Alpha and Goldwood 1858 in an H Frame (possibly for fun, ive considered a slot load the Beta ala Pass Burning Amp 2012).
I am torn between the Beta, Alpha and Goldwood 1858 in an H Frame (possibly for fun, ive considered a slot load the Beta ala Pass Burning Amp 2012).
actually, a few members have 'recommended' to use the Beta instead
evenso, somehow the Alpha still seems to 'stick'
as does the Eminence for OB, in general
but also Fane could have a good 'contender' among the Sovereign woofers
evenso, somehow the Alpha still seems to 'stick'
as does the Eminence for OB, in general
but also Fane could have a good 'contender' among the Sovereign woofers
With eq the Beta's will be fine. Personal preferences prevail when it comes to high-med-low q drivers for dipole bass. Try both 😉
I use the Eminence Delta 15 LFAs in u-frames, and with eq I'm quite happy with the bass. I've used high Q drivers in the past and I prefer the Deltas. I have to use about 14db of boost on the low end, and I shelf from 100hz up -8 to get flat response down to 40hz.
How loud and how low do you plan to run these? Excursion can be an issue with the kind of eq you're going to need and high spl.
I use the Eminence Delta 15 LFAs in u-frames, and with eq I'm quite happy with the bass. I've used high Q drivers in the past and I prefer the Deltas. I have to use about 14db of boost on the low end, and I shelf from 100hz up -8 to get flat response down to 40hz.
How loud and how low do you plan to run these? Excursion can be an issue with the kind of eq you're going to need and high spl.
I have a 15x12x9 lwh room. I listen to everything from jazz to metal.
I am more interested getting a woofer that is defined than a few extra Hz... a dozen extra Hz, I can be persuaded 🙂
Likely, a single driver h frame per side is my best option in my current rented location.
I am more interested getting a woofer that is defined than a few extra Hz... a dozen extra Hz, I can be persuaded 🙂
Likely, a single driver h frame per side is my best option in my current rented location.
or could be a matter of a little bass, or no bass at all, more than just a few hz 😉
anyway, defined bass will have close relation to crossover phase with other drivers in your speaker
If you add a 6.8Ohm power resistor in series with the Beta Driver then the Qts= 0.585 moves up to Qts= 1.126 but at an expense of a large power loss as a undesired consequence...
b🙂
I've heard Beta 15s on an OB (flat baffle) - there's sufficient bass, but IMHO sounds better than I've heard an Alpha 15 (which has a tiny motor trying to drive a huge cone).
Chris
So added resistance increases the load to ~14.8ohm? Me just needs more power? Will the woofer suffer any other shortcomings?
How does changing the dimensions from the 16x16" cavity to say 20x20" change sound and response??
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That would improve the design,Yes more power but you cannot arrive at an higher SPL than I showed in the picture. No short commings..
b🙂
or do the 'unthinkable', wire multiple small inductors with thin wire in series 
just ad more until you get the desired result 😀
just ad more until you get the desired result 😀
So in this case I lose much ability in hitting higher SPL? Do I get more SPL if I use active EQ to change response instead? Or do you mean the SPL is my max sensitivity at 1watt?
In this case, wouldn't it be preferable to lower Qm of the alphas with a bat of fibreglass insulation stapled over the back of the driver? Some efficiency might be lost but I believe this is preferable to heating a series resistor.
Of course,by showing:
1. First the two drivers in the plot are (Repeating the context in the picture )at 1 W input power,but when making the Beta driver having a similar response to the Alpha:
2. You have to EQ or passively add an resistor that as a consequence will affect max SPL(SPL at xmax), as shown in the picture.
Both ways works in a similar way when it comes to SPL loss (i.e. at mid-band SPL): Using an EQ will not improve max.available SPL compared with when adding a
passive resistor.
b 🙂
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I am still confused with the graph... In the blue line, this is Beta at xmax... The driver cannot play louder than that level at any volume? In that case, the Alpha can go higher in max SPL than the blue line Beta?
What does running two woofers per channel do to the scenario? Simply a 3db increase in efficiency?
What does running two woofers per channel do to the scenario? Simply a 3db increase in efficiency?
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