You're right of course!
I was going to suggest the 305 instead of the 330 to our Kingsley (
) here but having familiarised myself (yep, I finally read the thread!) a bit more with the situation at hand I would rather go for an 18 or twin 15s with the 10" mid and compression driver. I suspect the woofer is expected to cover up to 200-300Hz where it passes over to the 10 and if one wants to have roughly equal sensitivities 12s just don't go low enough as I think the 12S330 and the LAB12 are near the physical limits of 12s with an Fs in the 20s.
There were threads here dissecting the infamous Daniel Hertz speakers here. Might yield some useful info.
I have some of the neo version of the BMS 12S330 - the 12N630 to be exact. These are intended to be used for two topologies: A three-way WTMW with a 10" 18s midrange and a 1" Faital driver. The other one will be used as LF extension for a 8" Beyma coax. So I will be able to experience them first-hand. Someone here has built three way studio monitors using these and he seems to be very content. But they are definitley not intended for a two-way speaker.
Since I like 15" woofers I will also bild a WTMW with 2x15", 1x12" and a 1.5" HF driver. But the build will not start before the beginning of next year. In the meantime I just like to stare at all the nice drivers and listen to my MTM (2x15" and 1x 1.4") occasionally. Maybe I will get a beefier amp as well. The 2x700 W LF channel amp runs out of steam long before the woofers do !
Regards
Charles
Since I like 15" woofers I will also bild a WTMW with 2x15", 1x12" and a 1.5" HF driver. But the build will not start before the beginning of next year. In the meantime I just like to stare at all the nice drivers and listen to my MTM (2x15" and 1x 1.4") occasionally. Maybe I will get a beefier amp as well. The 2x700 W LF channel amp runs out of steam long before the woofers do !
Regards
Charles
That is good to know since I am planning on using it in a similar application but do let us know your own impressions when you get a chance!
So how many 15"ers would you suggest for a home listening Environment ?
Regards
Charles
Hi Charles,
One would be enough for the majority of people. What level at what frequency are you aiming for?
Cheers, Carl.
" provides room crushing bass down to 35 hz"
In a broom closet (maybe).
The BMS 12S330 has too low of a Qts to properly vent (for deep bass).
"So how many 15"ers would you suggest for a home listening Environment ?
"So how many 15"ers would you suggest for a home listening Environment ? "
Depends on room size and listening requirements (or course).
A couple of friends of mine use a dual 15's in largish rooms, both owning the LSR&D 101 (160W) amplifier. They like very dynamic music, and the speakers are -3dB around 27hz. One felt he needed more power (for two CD's he liked), so we tried a 2KW QSC (did not sound hi-fi). Most listening is done under 1W, with plenty of headroom (speakers are over 100dB/W).
In a broom closet (maybe).
The BMS 12S330 has too low of a Qts to properly vent (for deep bass).
"So how many 15"ers would you suggest for a home listening Environment ?
"So how many 15"ers would you suggest for a home listening Environment ? "
Depends on room size and listening requirements (or course).
A couple of friends of mine use a dual 15's in largish rooms, both owning the LSR&D 101 (160W) amplifier. They like very dynamic music, and the speakers are -3dB around 27hz. One felt he needed more power (for two CD's he liked), so we tried a 2KW QSC (did not sound hi-fi). Most listening is done under 1W, with plenty of headroom (speakers are over 100dB/W).
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I disagree but like any low Qts driver it needs an EBS alignment to reach Fs.
Which is not good for free space positioning but very useful when the speakers find themselves close to walls.
However they are easily eq'd to flat if need be with the bass pot of practically any (pre-)amp that has tone control.
"I disagree "
It's your right to be wrong.
The optimum Qts for efficiency, deep bass, and box size is 0.312
As the Qts drops, the box becomes smaller, and the bass goes away.
As the Qts rises, the box becomes larger, and the bass comes back.
Don Keele gives the equations at his site, and they intersect at Qts=0.321 (optimum Qts for efficiency, deep bass, and box size)
It's your right to be wrong.
The optimum Qts for efficiency, deep bass, and box size is 0.312
As the Qts drops, the box becomes smaller, and the bass goes away.
As the Qts rises, the box becomes larger, and the bass comes back.
Don Keele gives the equations at his site, and they intersect at Qts=0.321 (optimum Qts for efficiency, deep bass, and box size)
Anyone would say on first hearing that that sounds ridiculous since efficiency, deep bass, and box size do not have optimums. They have trade-offs.
Perhaps you mean that Keele kind of felt a magic ".321" is a reasonable compromise for his purposes, unless of course you wanted more efficiency, deep bass, box size, or even low distortion.
The ideal speaker doesn't resonate or it has a very small Q because otherwise the speaker has a sound of its own.
B.
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The size of the resonant peak is largely determined by the Qms, In an ideal world (for current drive at least) it would be 00.5 to 0.707.
dave
What makes you say that? Why should any resonance be considered beneficial - except to provide some uncalled-for bass by sneaking in uncontrolled movement.
BTW, I cited your nice website about phaseplugs in the motional feedback sub forum thread today.
B.
All drivers have a LF resonance. The lower the Qms the lower the resonance peak. If 0.5 to 0.707 you are in the desired Q range like that of a sealed box. The resonany peal is no longer a peak. The closest i have seen specified is 1.2.
dave
You are oversimplifying things possibly by only looking at what box calculators usually call 'optimum' alignment which is not adequate for low Qts drivers.
What you need to do with them is use a fairly large box (0.75-1x Vas) tuned to Fs to get an EBS alignment. The trick is to find a tuning that does not result in a hump in the shelf.
It works very well, Tannoy DCs (Qts around 0.2) have been producing deep bass like that since the 1940s.
Personally I find an EBS alignment to be very user-friendly in the real world, particularly when using big(gish) speakers in small(ish) rooms.
Hi Carl
I intend to reach at least 120 dB per box from 40Hz upwards. Theoretically this should be feasible with two of these drivers per box. The main reason for using two per box is not so much SPL per se but the intended usage of a crossover with minimal group delay distortion which does have a lobing behaviour that is less nice than LR4 for instance. With the WTMW topology I can achieve at least some symmetry. Room modes should be less pronounced as an added benefit (maybe).
The intended tuning is 32 Hz in a 120 liter box.
Regards
Charles
Faital pro's 15PR400 is a nice driver http://www.faitalpro.com/en/products/LF_Loudspeakers/product_details/datasheet.php?id=101060100 they sim well in winisd if memory serves.
How about 2 of them per side in push push opposed format
Their 18fh500 is nice in a single driver per side set up
How about 2 of them per side in push push opposed format
Their 18fh500 is nice in a single driver per side set up
Further info about the 18fh500 I've found.
http://www.pearl-hifi.com/06_Lit_Archive/15_Mfrs_Publications/40_Voice_Coil/2010/2010_11_Nov.pdf
Starts page 12. Pretty in depth testing and a really positive result. I'm tempted
http://www.pearl-hifi.com/06_Lit_Archive/15_Mfrs_Publications/40_Voice_Coil/2010/2010_11_Nov.pdf
Starts page 12. Pretty in depth testing and a really positive result. I'm tempted
Errata
Qts=0.312
There are equations for box size, in general the box size follows the square of the Qts.
There are equations for efficiency, in general they follow the cube of the Fs.
There are equations for Fc, in general they are a simple curve following the Fs.
When overlaying these three equations, there is an intercept at Qts=0.312
One may optimize for any parameter desired, but a design optimized for a Qts=0.312 will yield minimum box size, maximum efficiency, and maximum bass extension.
As they say in the auto industry: YMMV
Qts=0.312
There are equations for box size, in general the box size follows the square of the Qts.
There are equations for efficiency, in general they follow the cube of the Fs.
There are equations for Fc, in general they are a simple curve following the Fs.
When overlaying these three equations, there is an intercept at Qts=0.312
One may optimize for any parameter desired, but a design optimized for a Qts=0.312 will yield minimum box size, maximum efficiency, and maximum bass extension.
As they say in the auto industry: YMMV
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