Here's a better shot to show how tall the unit is in relation to the recliners.
Though it may seem that I'm arguing with you more than usually, I wanted to grab on this when I noticed that you brought it up again in Rodny's thread. :R :kiss::devil: :bigsmile: Compression, the silent killer. There's a lot of people out there who just don't know what they are missing - I think today you just found out :R
Running just the pair of SVS subs? I can probably test this Friday since I'm taking off to fiddle with the room some.It can be easily tested by running the same scene at rising output level (for example -10RL, -5RL, RL and so on) with an RTA running (peak hold on).
Yes, just SVS subs. When you find their limits, you can add the DIY sub and see how much higher it can take you. Though it's not healthy to push SVS' into more than ~5 dB of compression.Running just the pair of SVS subs? I can probably test this Friday since I'm taking off to fiddle with the room some.
Yup.Steve, I can also test that tuning frequency... I'll just use my CM-140 with the ECM8000 cal file. It will tell us what we wanna know anyway.
Again, no worries, it's not arguing, it's discussing :wave: :rant:Ilkka said:Though it may seem that I'm arguing with you more than usually
No, I don't have TrueRTA... I though you meant using an SPL meter... :huh:Yes, just SVS subs. When you find their limits, you can add the DIY sub and see how much higher it can take you. Though it's not healthy to push SVS' into more than ~5 dB of compression.
I assume you also have TrueRTA since it can't be done with REW.
Yes.... both subs running. Both subs were level matched and left the same. All we did was hold up the SPL meter during the same ~30 second scene and played just the SVS subs to start with, got the max reading and then turned on the LLT with the SVS subs and got another max reading.Sonnie, was the ~123db achieved with the SVS AND LLT running, or just the LLT? I was under the impression it was from just the LLT. And if both, was the sub level knocked down 6db before replaying the scene or lef as is?
Agree! You guys create some very healthy discussions IMO... if others followed your style in other forums, we'd have quite a few very fine forums. Unfortunately for some... and fortunately for the Shack... that will probably never happen elsewhere. :bigsmile:Again, no worries, it's not arguing, it's discussing
Okay. It can be done with an SPL too, of course then you won't be able to see where it starts to compress because SPL meter grabs only the peak SPL (total power), not the frequency response. Just monitor the master volume vs. SPL relationship. When the SPL doesn't rise by 5 dB or what ever you are adding, that's the point where your subs are starting to compress.No, I don't have TrueRTA... I though you meant using an SPL meter... :huh:
This was the exact scenario I was thinking about.Yes.... both subs running. Both subs were level matched and left the same. All we did was hold up the SPL meter during the same ~30 second scene and played just the SVS subs to start with, got the max reading and then turned on the LLT with the SVS subs and got another max reading.
I would be most interested if you could measure them separately. Though it would require that their frequency responses should be EQ'd as similar as possible.I can do each separately if it will help to determine something useful.
Yeah, going from -10 to -5 will get me a 5 dB measured increase on my SPL meter. If your receiver is showing dB, you will probably have the same thing going on, but measuring will let you know for sure.I -10 to -5 supposed to be 5db... or does that depend on the receiver? I guess I can measure it and see... :duh:
That part is going to be a challenge.Though it would require that their frequency responses should be EQ'd as similar as possible.
Unfortunately you can't really. You have to merge a driver close mic and port clos emic like Sonnie did. You'd have to test it outside from a good distance (considering how large the sub is) to allow the port and driver output to merge completely.brucek said:So with a ported design, where does someone correctly take a nearfield measurement to ensure optimum assist from the port effect while eliminating as much effect as possible from the room?
Yep, a close mic of the driver should look almost exactly like the box were sealed until you get around tuning. Above that point, the driver is moving too fast to effectively couple with the air in the port.brucek said:Right at the cone, we see the pure speaker output without the port effect (more like sealed I suppose).
Then right at the port output, we see the port assist.
Not sure what you are asking - do you mean what is the lowest frequency in which only the driver is still providing nearly all the output? At about an octave above tuning, the simulation shows the port output to be about 12db down and the difference in group delay when comparing to a similarly sized sealed sub is only about 0.001 second, so for all intents and purposes, I use one octave above tuning as the point where port output isn't significant anymore. Ilkka can correct, clarify, or expand upon that better. This is a main reason why I set one of the requirements for a LLT to have a simulated tuning <16hz. By doing this, the port won't be playing much of a role anymore at 30hz, and the majority of music doesn't dip below 30hz. I try to retain all the benefits a port can yield while eliminating or stifling the drawbacks :Tbrucek said:Where do they combine to produce the pure speakers total output before the room wrecks it?