|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
206.255.208.188
In Reply to: RE: a basic speaker question.. posted by cloudwalker on July 30, 2016 at 12:40:16
Lets say a driver is busy with a certain sound (or frequency) and along comes another sound in its "range of duty". How do those multiple "sounds" affect each other?
So long as the driver exhibits consistent directivity with both sets of frequencies and is driven in its linear range, you simply hear the added content. Other times, however, an instrument generates overtones or another instrument's output is added outside the driver's optimum directivity pattern. Then the image's width clamps down like a fun house mirror effect. Listen to most any 70's JBL monitor like a 4310/4311 to hear what I'm referring to.
My friend once told me that almost any speaker is better off with a subwoofer.
Only those that are inherently bass challenged at the intended output level. It does reduce overdriving a driver that cannot handle the higher excursion requirements of the bottom octaves and reduces doubling distortion.
Follow Ups:
wasn't the 4310f and 4311 designed as actual studio monitors. Predating our idea of "monitor" speaker. But to be using in a studio and not called a studio monitor.
Floyd Toole would be appalled at the excess of bandwidth attempted by the 5" midrange. Fortunately, you don't find that overt fkup with current designs like the LSR6332 . It cuts off the same size driver a full octave lower.
The 4310/4311 series imaging is comic book - wide at the bottom and top and decidedly pinched in the upper midrange where the piston diameter is significantly larger than the wavelength it attempts to reproduce.
The kind of distortion you are describing is the kind Bob Carver specifically designed to diminish with his new Amazing Loudspeakers. Read the review in TAS by Robert E. Green to an excellent description.
Which is one reason why I've favored and used full range electrostats for nearly forty years. And confess that I've never been fan of hybrid monopole woofer / dipolar planar or electrostatic based systems to avoid discontinuity experienced elsewhere.
One pebble in the pond. :)
nt
The driver's piston diameter (typically about 1" less than driver size) should never be used for frequencies smaller than the wavelength or else the imaging will be compromised.
Huh? Start with a wavelength calculator as found here .
First example: New Advent with 9" piston crossed over at 1500 hz.
Wavelength is 9.04 inches. Ok.
Second example: Polk LSi9 with 4" piston crossed over at 2500 hz.
Wavelength is 5.4 inches. Ok.
JBL 4311 with 4" piston crossed over at 6000 hz.
Wavelength is 2.25 inches. Fail!
So that would indicate that pretty much all full range drivers cannot image properly?
I don't have any experience using FR speakers but a lot of experienced audiophiles seem to like them.
Directivity varies greatly by frequency. What I find less disturbing is those designs start exhibiting a gradual narrowing of dispersion as frequency goes up. There's no drastic contrast.
With the JBL's I mentioned, however, the 5" midrange is driven beyond its ideal range - so far ok - but then is transitioned immediately to a wide dispersion dome tweeter sitting right in the middle of its sweet spot.
Huge contrast!
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: