It's awfully easy to complain that an enclosure should be built when you aren't the one who actually has to do that for every in wall speaker review...
Where did you get that from? Maybe it is going in a 6 inch stud wall. Or a false front wall with 2 feet behind it. How about the total volume or leakage into the rest of the back space? You think of that?On what page do we find the data for the 3.5 inch deep stud space the speaker mounts in?
All of our regular speaker measurements are anechoic. Surely that is not how they get used.I think that the in-wall speaker should be tested in a enclosure similar in properties and volume to where it will actually be used.
Where did you get that from? Maybe it is going in a 6 inch stud wall. Or a false front wall with 2 feet behind it. How about the total volume or leakage into the rest of the back space? You think of that?
All of our regular speaker measurements are anechoic. Surely that is not how they get used.
Since there are no walls that are representative -- just as no room is representative -- the only thing we can do is to pick anechoic infinite baffle as the reference.
I think that can be too much a request to Amirm, he's just a hobbyist doing good to the community for his geekiness. since from what I saw the NFS isn't something light and easy to move around as a PC, and it's placed inside a room in his house, it's unreasonable to ask him to take bricks to build a wall to compromise room space just for the testing of in wall speakers, which isn't easy to demolish when one day he felt that's it, no more testing (that day will eventually come sadly).Hello,
Sure.
The wall could be built with 5 1/2” studs or a furred out 2 foot deep space. As always the exception is not the rule. The typical wall is framed with 3 1/2” studs. Leaving the typical infinite enclosure that speaker is installed in as a 15” width between the studs and 3 1/2” deep and sort of sealed front and back with drywall or something similar. The stud space may leak sum, that is what we have to work with and perhaps should be included in the software model.
If the only thing to do is select anechoic infinite baffle then do just that. Your instrumentation is set up with time windowing to remove the reflections, there you have anechoic. If your software is modeling an infinite baffle on the backside of that speaker build one. Take a half sheet of drywall, screw on a couple of 3 ½” studs and close up the back side with a smaller piece of drywall and your mockup is much closer to the software model that you are using.
If you want anechoic infinite baffle there you go. What you did may be good enough. I won’t bother you about it again.
Thanks DT
Hello,
Sure.
The wall could be built with 5 1/2” studs or a furred out 2 foot deep space. As always the exception is not the rule. The typical wall is framed with 3 1/2” studs. Leaving the typical infinite enclosure that speaker is installed in as a 15” width between the studs and 3 1/2” deep and sort of sealed front and back with drywall or something similar. The stud space may leak sum, that is what we have to work with and perhaps should be included in the software model.
If the only thing to do is select anechoic infinite baffle then do just that. Your instrumentation is set up with time windowing to remove the reflections, there you have anechoic. If your software is modeling an infinite baffle on the backside of that speaker build one. Take a half sheet of drywall, screw on a couple of 3 ½” studs and close up the back side with a smaller piece of drywall and your mockup is much closer to the software model that you are using.
If you want anechoic infinite baffle there you go. What you did may be good enough. I won’t bother you about it again.
Thanks DT
Or is this really just an indirect indictment of Revels strange choice not to include sealed enclosures even though several competitors do, who seem to get more predictable results perhaps because of that?
I've been thinking, dreaming, about a full surround system with in walls for a while. I keep dithering back and forth between a sealed box as part of the designed package being a must have. Your note spurs another thought. Other than a few* rare, and usually very expensive to purchase and more difficult and costly to install, sealed boxes are going to be quite small. So there's the tradeoff, which always happens, is either sealed box that can retrofit with a really small volume, or variable volume of an open back retrofit style.
*I've seen a few subs and in wall speakers that basically take the whole stud space for their sealed enclosure. But those will need to be installed and then drywall installed over them. This will clearly be a more difficult and costly install than a retrofit. And from my memory they are usually prohibitively expensive.
What does it got to do with the Klippel NFS? So if the test is done in a 2π anechoic chamber, your "stud issue" goes away?On what page do we find the data for the 3.5 inch deep stud space the speaker mounts in? I believe that you will have better luck modeling with the woofer TS/P and the dimensions of the stud cavity in the wall.
If I was to hazard a guess that is where the speaker manufacturer started.
This information is not in the Kippel patent.
Speaker doesn't care about the size of the studs. it cares about the volume behind it which you can't possibly control. This will always be a variable that you need to deal with using equalization as I explained.The wall could be built with 5 1/2” studs or a furred out 2 foot deep space. As always the exception is not the rule. The typical wall is framed with 3 1/2” studs. Leaving the typical infinite enclosure that speaker is installed in as a 15” width between the studs and 3 1/2” deep and sort of sealed front and back with drywall or so
You are wrong. You don't need a Klippel scanner if all you want to do is gate the measurements. Klippel only uses that for high frequencies as indicated in the graph I already showed you:Your instrumentation is set up with time windowing to remove the reflections, there you have anechoic.
I am not sure there is much science behind any of those recommendations. Half the time they are boilerplate writing anyway. They want to show us reality, give us measurements and why they recommend what they recommend. Not that some designer in his ad-hoc testing thought it sounded better one way or the other.Some (not many) manufacturers issue detailed placement instructions, which should be mandatory IMHO.
The reference axis ("on-axis") for these speakers should be 30 degrees horizontal.
Since these are wall mounted speakers there is no toe-in possible.
Btw, I feel this should be standard practice with regular free standing speakers too to find the optimal horizontal axis.
Some speakers are designed for full toe-in while other speakers are designed to point straight forward and should be measured under 30 degrees horizontal.
For what it's worth I'm all for designing speakers that are not meant to be toed-in. You get a better power response and more natural reflections in the room that way which results in better sound quality.
Some (not many) manufacturers issue detailed placement instructions, which should be mandatory IMHO.
Most rooms will "play" more than the speakers, especially if the speakers are placed "at random".
For testing and measuring (speakers) there are very precise conditions (as for the setup used by ASR) - what I mean is getting the most of the speakers potential in my listening room, and this response can be measured, too, however in a different way (and will always be more or less different than "anechoic" because of the room response).
With wrong or unprecise positioning of speakers in any listening room, the SQ will more or less suffer.