gma952b

Responses from gma952b

Old Classic Receivers: A Mistake to Buy?
I retailed the gear mentioned in the 1970s and early `80s, and still own and respect much of it today. The praise for many of the units mentioned above is deserved, even though I presently also use current Edge, Presence Audio, Manley, Rowland, Au... 
Dynaudio 1.3SE question
Thanks Dennis! I hope you enjoy them.Call me if any questions arise. Also, yours may or may not have the upgraded crossover- need s/n's to know.Best regards,Roy JohnsonGreen Mountain Audio(719) 636-2500 
Time coherence - how important and what speakers?
Gmood1-I am glad to know you do not generalize based upon the design of the speakers. Ears should lead the way- So play an extremely wide variety of music and recordings (old/new/audiophile/distorted) until you hear what the speaker cannot do, as ... 
Time coherence - how important and what speakers?
And your point would be... not to discuss the many approachs to design, and the pros and cons THAT EACH MAN MADE DEVICE FACES?Or would it be that every speaker is good? Then why are you reading...Oh well,Roy 
Time coherence - how important and what speakers?
Hi Karls-Much of what you say I agree with. And to answer you, I need to qoute your statements below. However, there is a lot of peer-reviewed published research which disputes a couple of points you have taken as fact:You say, "(1)The commonly ba... 
Time coherence - how important and what speakers?
Bigtree,Vandersteen 2's and 3's have an unusual arrangement where the rear driver is both active AND passively driven. It is an active woofer below ~100HZ and is also a passive radiator reacting to the cubic air volume driven by the front woofer- ... 
Time coherence - how important and what speakers?
Karls, Phasecorrect, no speaker is without time delay in its lowest three octaves, because a moving mass on a spring has 90 degrees of wave-period time delay at its primary resonant frequency.Also, any port's output is time delayed, from the inter... 
Time coherence - how important and what speakers?
A ported or transmission line speaker can never be time coherent, nor dipole, bipole or omni, OR SEALED. See my 1/16/03 post, about why any moving system has a natural time delay down at its resonance. The ported or "transmission line" (which is a... 
Time coherence - how important and what speakers?
Just because it can do a square wave does not guarantee it will sound excellent on music. A nice square-wave response does not reveal many other problems that affect what we hear. However, it is a GIANT step in the right direction.Roy 
Time coherence - how important and what speakers?
Eldartford-Have a look at this link- let it load all its photos-http://melhuish.org/audio/response.htmYou'll see how bad many drivers are at impulse response. You'll see ringing- just count the time period for each "cycle"- the ring is 1/period. Y... 
Time coherence - how important and what speakers?
Phasecorrect-If you use pink noise or MLS or swept sine waves (common for testing dispersion), most of what we see on the printout does not explain what we hear. Dispersion, as heard on music, depends on some very definite factors:--the diameter o... 
Time coherence - how important and what speakers?
Yeah, the original Ohm had a lot going for it. Magazines replaced square-wave tests with the computerized MLS test, which can interpolate the phase response and any ringing from the MLS psuedo-noise (but not in great detail- as most of what you se... 
Time coherence - how important and what speakers?
The simplest electrical crossover on a speaker is an inductor placed in series to the woofer, and a capacitor to the tweeter. The amplifier drives into both simultaneously. If they are perfectly equal and opposite in "reactance", then they cancel ... 
High efficiency speakers vs Low, pros and cons
Thanks guys. I'm glad you learned from them and that my writing wasn't too confusing.Best regards,Roy 
Time coherence - how important and what speakers?
Cdc- Thiels use a complex crossover circuit to force first-order acoustic rolloff responses from the drivers, because of their driver choices and cabinetry. Dunlavy and to some extent, Vandersteen employ similar approaches.Your question about a si...