|
Posted by Romy the Cat on
01-30-2025
|
|
|
|
|
|
Posted by Paul S on
01-31-2025
|
Plenty to chew on in your LF video, Romy. It almost
sounds like you just, finally, came to the conclusion that LF takes “serious
power”. An early audio guru of mine knew several people involved with changing
out theater and “venue” sound systems in greater LA at that time. Altec/JBL
were the go-to systems there, and even way back then they knew they needed more
power to keep up with changing film sound tracks, and they moved continuously
in that direction for many years. I have read in Heritage forums that JBL
wanted to stick with tube amps, X/O’s, etc., for “better sound”, but it
appeared to me at the time that they couldn’t go to SS quickly enough. As for
the speaker drivers, I have said around here for a long time now that they were
redesigned repeatedly to handle more power without distorting or blowing up.
Were sonics compromised by beefing up the drivers and going to SS? Sure, of
course, some aspects of sound took a few steps backward. To say it as a
non-sequitur, in keeping with one’s sense of this conundrum, “Compromise is de
rigueur” with audio. We as home hi-fi people will probably make different
compromises than theater or reinforcement systems, depending on what we prioritize.
However, if we are planning for Big Music from frequencies below 50 Hz, then we
need to take a look at actual response curves of LF drivers under consideration.
There is no substitute for appropriate listening, but why not narrow ones
search to plausible contenders, in the first place? Again, a given driver’s
“efficiency” is only relevant in the context of its physical and electrical
environment. In practical terms, there are no “106 dB efficient (direct
radiator) woofers”, because those drivers are nowhere near that efficient in
the actual pass band, not to mention in-circuit effects of reactive X/Os. Also,
older, better-sounding drivers “compress” and distort quickly as one tries to
push them down in frequency and up in volume. It sucks, but there you are. Like
I have said for years, please, someone, tell me about an SET-driven 15” woofer
in a sealed box that can put out Big Music 40 Hz (with no support below it…). A
15” in a sealed box is the sure-fire route to good-sounding 50 Hz, although
even that will take some power, if the driver can take it. Romy, you have said
you have not tried at all to work with ported LF, and this is fine. But you
sound like I used to when I panned horns for “horn sound” based on my time
spent listening to A7s and similar “pushed” installations. It has been a long
time since you talked about your own horns, but one look at them tells a story
to anyone who has spent time with horns. They are not chosen from or run like
the stock PA line-up. Back to LF, I heard the part about injecting processed
sound, but by the end of your talk it sounded to me like you are back to a
5-way system? I agree that a 4-way system involves compromise for FR. I have
detailed my own compromises while discussing my system. I very much envy your
access to per-driver amp loading (what a boon to system development!), but that
really requires the big horns, as well, and I doubt I will ever take that long,
long road.
Best regards,
Paul S
|
|
|
|
Posted by Romy the Cat on
01-31-2025
|
|
I think you missed, or not express not strongly enough, the main point of my message. And the main point of my message was that a low frequency section not necessarily need to be powered by just a plan signal that cannot be reproduced by main speakers. As I custom dial-in harmonics envelope for my individual channel by loading output stages, in a very same way low frequency section should have your own custom requirements for different type of harmonics. What good for 500 HZ is not good for 50 hertz or for 30 hearts. Could you please intentional do not give instructions what to do but from what I observe and experience it's need to be a custom tuned signal fat to low frequency sections.
|
|
|
|
Posted by Paul S on
01-31-2025
|
It seems like brewing up some special kind of soup to feed MF and HF to "sound how we like" requires a topology that supports that process. Using Big Music as an example, is it really possible to brew up something for LF that has less actual LF as "a substitute for real LF"? Well, I am certainly doing something like this now, in the sense that no one would mistake my LF for a live symphony orchestra. I will stay tuned.
Paul S
|
|
|
|
Posted by Edgar= on
02-04-2025
|
...over in the Reverb Injection thread, that my favourite thing about RI is what it does in the bass.
What I was referring to was the ability to add low frequency pressure to your room without it affecting the integration of your front main playback.
I did experiments at the time with huge speakers for RI and added lots of low end to the room and yeah, it never reduced the main systems coherence.It's a very powerful and under-utilised audio tool.
I'm interested to see how you are adapting this specifically for ULF.
Ed
|
|
|
|
Posted by Romy the Cat on
02-04-2025
|
Yep, the Reverb
Injection is a very cool thing. I insisted in the past that it is practically
impossible to get good sound under 40-45 Hz in a listening room less than 600
sq feet. If you do have a very large room, then it is very hard to properly
reinforce the room with LF, and it hit a whole other set of problems. So, the
best result is to have a moderate size of rooms, let's say 500-600 sq feet with
Reverb Injection. We need a reverberation time of 60hz to fade to the
background level (or let sat -60db) to be somewhere around 1.5 -2.5 seconds which
would be over 2k-3k sq feet with sealing of 14 feet. It is VERY hard to get
good sound in this room size.
I usually laugh
at the “big-name reviewers” who report a “stunning” bass from a new turntable, cartridge,
or new loudspeaker of the month while they are sitting in a listening room with
0.5-second reverberation. It is like discussing a “great bass” with my local
guy who does car audio. He uses a 10” hard-rubber suspended, long throw drivers
in ultra-small enclosures and drives them with 3-5kW of power, and he is
listening to it in a car with reverberation time under .01 second. The “big-name
reviewers” also idiotically staff the rooms with ridiculous sound absorbing
room treatments that eats the reverberation time even further. The sad part is the
speaker makers very intentionally make their product work in exactly this type
of environment, and the “big-name audio opinion makers” do not even understand how
far they are from any sensible bass on audio. I assure you that practically no “big-name
reviewers” understand what bass tone is, and the only thing they know is what is
bass sound pressure. Proper audio bass is a very difficult subject, and it could
not be approached by the morons whose objectives in audio are just to move UPS
boxes at warehouses.
|
|
|
|
Posted by Romy the Cat on
02-07-2025
|
I very much do not subscribe to his views on single drivers, but his commentary on bass is not far from being accurate. He looks like, did not experiment with reverberation injection then he would change his mind.
My comment:
I do not care about the subject of single drivers and low extension, as I do
not feel that single drivers have any advantages at all. Still, at the end of
your video, you advocate the notion that LF gup under the bottom should not be
filled in audio, and I perfectly understand where you are coming from. In my
view, you are right and wrong at the same time. You are right in stating that
filing the room with measurable LF to satisfy the amplitude gap is not a good
idea. However, if you fill the room at LF with a very specific constructed LF,
with proper enrichment of necessary reverberations/harmonics, then you do have
huge listening benefits. Ironically, the amplitude of that “proper LF
injection” is irrelevant to what your main speakers do.
|
|