|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
98.66.58.117
Don't need to get much below 50 hz as I plan to add a sub if needed. I would like to move a lot of air.
It is to mate with these (TAD 2001 LC horn, EV 10" Mid in old temporary subwoofer cabinets):
Follow Ups:
Yorkville ls608 hits hard between 50 and 100 Hz. Great speaker!
.... though personally, 30-40 Hz is what I consider the minimum for bass reproduction
I don't know the details, but I recall that there is a very large compression driver which is reportedly outstanding for midbass.
Retsel
At that frequency, the "room" has as much to do with response (or lack there of) as the equipment - if not more.
........I was a vegetarian for 15 minutes... until the main course.
Carefully read the "Explore the Lambda 001 Motor Design / Knowledge" section Chris.This bass driver would be lovely for a direct-radiating woofer application.
Jeff Medwin
Edits: 04/02/12 04/02/12 04/02/12
Slightly OT: I would have gone with a full-zoot (incl. wood horn) Pi Speakers 4Pi if they used this driver, just as they use an AE driver in their 3Pi. Wayne seems wedded to the JBL for the 4Pi, so I passed. Too many comments that the JBL sounds best loud and needs at least 5W, preferably 10W, to come alive - not my scene... well above my volume tolerance before it sounds alive.
Cheers.
Nice woofers for sure. Thier nitch is from 40hz to 1K.
A "modern power supply", non critical L1, no cap over 50 uF., no L over 2 HY, good internal wire, low DCR power transformer. Bass to die for !!
Jeff Medwin
mid/upper bass rather but agreed that speedy and very nice.
Driving a Bose wave radio speaker with a LESS DC Coupled 12AX7 to 2A3 amp would not quite make the sound I am looking for.;-)
Stacked multi-way horns are disjointed and passe. You should have just done a Synergy Horn where it will be a point source and phase coherent.But we will never get around the need for a good audio amp to make it go.
You can do all the name calling you want, but you won't beat the performance of a 7B4 DCed to a 2A3 when its done exactly as Serious Stereo currently does it.
Jeff Medwin
Edits: 04/01/12 04/01/12
"LESS" instead of LSES, acronym for "low stored energy supply".Study a AE TD15M Chris (and its motor design), IF a direct radiator woofer is in the cards.
Jeff
Edits: 04/02/12
To match your efficient pretty wood horn tweeter, I would put a single 18" or 21" woofer in a LARGE pretty wood cabinet with a very large port on the bottom similar to what B&W does for its 801. Efficiency = dynamics. You should be able to get 99db/watt at 50Hz before any baffle step compensation. This can be part of your 3-way with a 95-99 db/watt 10" midbass crossed LR4 at 1.1Khz to match the 90 degree polar response of your pretty wood horn tweeter.
Now you can start to put your walls and corners to work for you to smooth out the bass modes and gain efficiency. Instead of a separate subwoofer, you could build another pair of these woofers for a more uniform timbre.
Quick tight low end can be achieved with smaller drivers and more of them
Think big and slow
Think small and fast
I would think more about the characteristics and TS parameters of the drivers according to your needs. Usually 15 inch woofers dont go much below 35 hz by design, but you can get a bunch of 10" woofers with an Fs of 20 hz that put toghether can sound very good!
Also having a woofer from 50 to 150 hz its great for a clear sound, but adding a subwoofer under it can become a nightmare. Be sure to have high order slopes and perfect time alignment to avoid woofers fighting each other making a mess of sound!
I think I will shoot for 35-40hz and forget a sub. That is what I do not like about my current bass crossover at 75hz.
B&W Whitepaper on Bass
Advantages of Producing a Coherent Wavefront
One remarkable fact was consistently noticed during the development of the new 380mm bass unit for the Nautilus™801, and that was that a single large and stiff bass cone always sounded better than a number of smaller cones, even though they may well have had the same aggregated properties. One possible explanation for this is the concept of the production of a “coherent wave front”. This will be produced by a single large very stiff cone, which can couple with the air in a uniform manner over the whole of its surface area unaffected by differences in loading over that area. This behaviour is to be compared with that of several cones which, even though they may be closely spaced, will still leave gaps of “uncoupled air” between them. The very stiff cone material of the large single driver, which is a thick sandwich of Kevlar® reinforced paper fibres with a very stiff skin, makes it less responsive to local changes of acoustic impedance or unbalanced modal pressures either behind or in front of the cone.
A “coherent wavefront” simply means there is either a constant or a smoothly changing phase relationship between neighbouring parts of the wavefront. So even if two drivers are relatively close together compared to a wavelength. Also, even if their contributions are equivalent to a single large driver, their different acoustic environments will mean that their outputs are slightly different, in terms of both amplitude and phase.
Furthermore, the air between the drive units is not being driven at all and this will translate into a change in phase across the resulting wavefront as the air tries to “fill in” the lost contribution. One can postulate that, at low frequencies, air can “spill off the edges” of the
individual cones more easily in an array of small cones, which obviously have more edges for it to spill off, than from a single large one. For instance, two 12 inch drivers have a combined circumference of 1630mm whereas one 15 inch cone has a circumference of only 1037 mm. It is also interesting to note in this context that the radiation resistance and reactance at low frequencies of one 15 inch cone, is actually larger than that of two 12 inch cones, even though the area of the 15 inch cone is 0.02m2 smaller than two 12 inch cones. This is because the change from a steadily rising radiation resistance characteristic at low frequencies, to a horizontal one at high frequencies, occurs at a lower frequency with one large driver than with two smaller ones (Fig 15). Mutual radiation impedance effects will redress this imbalance to some extent, provided
that the two individual drivers are close enough together for one driver to acoustically load the other, though it will only be totally redressed if the array of small drivers produces a totally contiguous surface in all directions.
Probably the LaScala bottoms. I really never cared for them as 50Hz is about as low as they go and I prefer to reach at least into the solid 30's. One thing they do well is punch. They also do not require specific requirements such as corners as does the Klipschorns. If you could build a pair, be sure to damp them somewhat as the sidewalls can flex which cuts down on total output and causes more unmusical resonances. Some braces should do the deed.
/
Published SPL measurements of several LaScala speakers all show at least an 8db SPL drop between 150Hz and 50Hz. This is the range of interest in this thread.
IF ITS NOT ON THE RECORD,,YOUR FOOLING YOUR SELF..
Post a Followup:
FAQ |
Post a Message! |
Forgot Password? |
|
||||||||||||||
|
This post is made possible by the generous support of people like you and our sponsors: