• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

Kali Audio IN-8 Round 2, How Should I Measure Hiss? Hiss Videos? (Anyone else notice less hiss in later purchased pairs?)

Neddy

Addicted to Fun and Learning
Joined
Mar 22, 2019
Messages
754
Likes
1,019
Location
Wisconsin
I have a pair of very early SN (but oddly different) IN8s, as well as REW/mic's, so could, in theory, measure as a comparison.
I'm only using them for TV audio at at the moment, and though I did hear more hiss from them up close when I got them, it isn't noticeable or objectionable for this use (at 10ft).
Maybe I should contact Kali and ask about the hiss....:)

@detlev24 your REW measurements of the M2 match very closely the measurements I've taken on my 2216ND-1 powered L200s.
They do go incredibly deep, and VERY cleanly.
I'd love to hear Genelecs or anything else that can compare to them, but not very likely to ever happen (and not going to change anyway).
PS. I do also have a JBL 4645C sub in the mix, but have not yet gotten around to measuring it vs. the NDs; it does have far more SLAM! than the NDs, but seems a bit less precise, and a bit deeper.
Definitely can move more timber (room modes), though. Keep wondering what a 2269 would do in that box, too.
;)
 

richard12511

Major Contributor
Forum Donor
Joined
Jan 23, 2020
Messages
4,335
Likes
6,700
Companies sometimes override what could be done with physics, and instead prioritize volume. EX: The Devialet Phantom Reactor with a pair of 4" speakers has significantly more bass extension than most studio monitors. (I honestly think it puts most of them to shame, and would love to see EDM makers focus on lower bass and monitor with an extremely flat version of the Phantom with regular inputs. Also, before someone brings up bass compression, if they like Dynaudio speakers, they might remember that some of them adapt the bass based on the volume level, because that's how the human ear hears. More bass is needed at lower volumes, with higher volumes needing less/flatter bass. On either speaker I'd consider it a feature, as it would help the device follow the fletcher munson curve.)

Here is the graph of the JBL M2 on the left, and the Genelec 8260 on the right. The 8260 starts rolling off around 30 hz. The M2 starts rolling off around 40hz.

The Genelec 8260 is down about 5hz, which the JBL M2 is down nearly 10hz. If you take the JBL M2 and cut the output from 123dB to 113dB, the same as the Genelec 8260, then it could be contoured to be better than the Genelec and get flat down to 20hz.

Both of these are anechoic. In room my Genelec monitors get down to 18hz.

View attachment 63697

Because of the measurements I've seen and the whitepapers I've read, I consider the M2 to be inferior when it comes to extension, price, use of physical volume, overall system noise from what I've heard from others and experienced on their 3 and 7 series, cabinet material choice, cabinet geometry, vertical response, and use, or rather omission, of DSP calibration.

I consider the M2 to be superior when it comes to peak volume, and maybe horizontal dispersion.

I think we have different ideas on what extension means. To me, extension has little to no meaning unless it's contextualized with spl. I could go in and apply a +20db boost at 15Hz to my JTR 110 surround speaker, but that doesn't mean my surround now has 15Hz extension. It can't play a 15Hz tone any louder than it could before.

Given that both of these are active speakers, they could simply be applying different levels of bass boost. I get that there are other properties to drivers other than size, but we're talking about a much larger driver in a much larger enclosure. Hoffman's law should apply here. Which speaker can play a 20Hz tone louder? A 15Hz tone? That would be a better test of true extension. I find it very unlikely that the 8260 would win that test, but I could be wrong.

I agree mostly with your assessment of the strengths and weaknesses of each, though I see it a little less one sided than you. I would say:

8260
+ Directivity smoothness
+ Size
+ Cost
+ Room EQ
+ Noise(quieter)

I don't list vertical response, as that is already baked into the first advantage I listed. Maybe worth noting that horizontal directivity is far more important than vertical directivity for overall sound quality.

Likewise, cabinet material and cabinet geometry aren't additional advantages, as again, they're already baked into the other advantages. No need to double dip just to make it look better.

M2
+ Output
+ Extension

You listed "horizontal response", but I'm not so sure of that. I couldn't find anything other than a basic spinorama for the M2. Without seeing separate vertical and horizontal graphs, I'm not sure how we can be sure of this. Have you seen those graphs for the M2?

I do think that in general, the 8260 is probably the better value, but I would say it heavily depends on one's situation and listening habits. The M2 might be the better choice if one likes to listen loud, or sits at 3.5+ meters.

For my main room(4m), I'm pretty sure I'd prefer the M2. For my office(2m and much smaller room), I'm pretty sure I'd prefer the 8260.

That's at least my assessment. I don't own either speaker, so I have no skin in the game, so to speak.
 

q3cpma

Major Contributor
Joined
May 22, 2019
Messages
3,060
Likes
4,416
Location
France
Likewise, cabinet material and cabinet geometry aren't additional advantages, as again, they're already baked into the other advantages. No need to double dip just to make it look better.
Well, it depends a bit. Genelec's aluminium allows for a high internal:external volume ratio, which helps sensitivity a little.
 

detlev24

Senior Member
Joined
Dec 3, 2019
Messages
305
Likes
291
[...] You listed "horizontal response", but I'm not so sure of that. I couldn't find anything other than a basic spinorama for the M2. Without seeing separate vertical and horizontal graphs, I'm not sure how we can be sure of this. Have you seen those graphs for the M2? [...]
On the previously by @thewas_ linked measurements you can find them both; although, in a quite bad image resolution...

I would expect that the same standard has been applied for the measurements, as they are published by the same magazine. However, the vertical axis is of different magnitude, which makes a direct comparison more challenging.

Genelec_8260A.png JBL_M2.png
 

richard12511

Major Contributor
Forum Donor
Joined
Jan 23, 2020
Messages
4,335
Likes
6,700
Well, it depends a bit. Genelec's aluminium allows for a high internal:external volume ratio, which helps sensitivity a little.

That's kinda my point. Genelec's superior cabinet is already baked into the other advantages I listed, so no reason to list it as a separate advantage. I do think the aluminium cabinet is a big part of what gives it a decent advantage over it's competitors(like JBL). It probably contributes to multiple advantages, like more even dispersion, better output, ect. Improved sensitivity would make the JBLs superior output less of a positive, but it's still not a positive for the Genelec.
 
Last edited:

richard12511

Major Contributor
Forum Donor
Joined
Jan 23, 2020
Messages
4,335
Likes
6,700
On the previously by @thewas_ linked measurements you can find them both; although, in a quite bad image resolution...

I would expect that the same standard has been applied for the measurements, as they are published by the same magazine. However, the vertical axis is of different magnitude, which makes a direct comparison more challenging.

View attachment 63884 View attachment 63885

Hmm, maybe I'm looking at it wrong, and it's definitely close, but I see an advantage for the 8260, if anything. I see close to +=40 for the higher ranges, but the Genelec seems to have better(wider) horizontal dispersion in the low end. Am I reading that wrong? I really don't see an advantage for the M2 there. The M2 doesn't go wider than 90 on the low end, while the Genelec does.
 

detlev24

Senior Member
Joined
Dec 3, 2019
Messages
305
Likes
291
[...] Am I reading that wrong? [...]
According to the descriptions in the magazine, the 8260A has a region of 109° x 107° [horizontally x vertically], in which sound level decreases by (-)6 dB [between 1 kHz - 10 kHz], vs. 113° x 93° on the M2; with a range of variation of x 9° [8260A] vs. 10° x 9° [M2]. A -6 dB difference to the centerline has been reached on transition from yellow to bright green.

Furthermore, they mention the narrowing around 800 Hz on the M2's vertical plot, which is at the crossover between LF and HF drivers. [No further information is given on the 8260A in these regards; but it seems a bit less evenly controlled.]

Neumann has some further explanation on their website regarding measurements, including this field of interest.

PS: The frequency range starts at 125 Hz on those directivity plots, as sound travels naturally to all directions at lower frequencies. // Also note, that the final result on your listening position(s) is highly influenced by room acoustics. It simply is wrong not to treat early reflections, as mentioned earlier.
 
Last edited:

richard12511

Major Contributor
Forum Donor
Joined
Jan 23, 2020
Messages
4,335
Likes
6,700
According to the descriptions in the magazine, the 8260A has a region of 109° x 107° [horizontally x vertically], in which sound level decreases by (-)6 dB [between 1 kHz - 10 kHz], vs. 113° x 93° on the M2; with a range of variation of x 9° [8260A] vs. 10° x 9° [M2]. A -6 dB difference to the centerline has been reached on transition from yellow to bright green.

Furthermore, they mention the narrowing around 800 Hz on the M2's vertical plot, which is at the crossover between LF and HF drivers. [No further information is given on the 8260A in these regards; but it seems a bit less evenly controlled.]

Neumann has some further explanation on their website regarding measurements, including this field of interest.

PS: The frequency range starts at 125 Hz on those directivity plots, as sound travels naturally to all directions at lower frequencies. // Also note, that the final result on your listening position(s) is highly influenced by room acoustics. It simply is wrong not to treat early reflections, as mentioned earlier.

Thanks for that. So perhaps the M2 does have better horizontal dispersion, while the 8260 has better vertical dispersion. Once again, I think it's important to point out that horizontal dispersion is more important than vertical dispersion.
 
OP
stevenswall

stevenswall

Major Contributor
Forum Donor
Joined
Dec 10, 2019
Messages
1,366
Likes
1,075
Location
Orem, UT
Thanks for that. So perhaps the M2 does have better horizontal dispersion, while the 8260 has better vertical dispersion. Once again, I think it's important to point out that horizontal dispersion is more important than vertical dispersion.

Horizontal dispersion to what point? For me, a speaker with lobing issues (the blobs you see on the JBL M2 at the crossover point,) indicate a problem. Moving left and right in front of many speakers, they generally sound okay. When I move vertically, many sound literally broken.

Yes, horizontal is more important, and it's been solved by many competent companies.

Vertical crossover blobs, not so much.

Concerning the loudness argument to extend the bass, JBL should have those settings recommended by default to play down to 20hz or so by default... But my guess is it would take the total SPL down, which I'm okay with, though many would complain.

In the end, I find it laughable that I could set up an IN-8 and an M2 pair in a living room, and if I had people over to listen to music and some liked sitting on the floor, some got up to get drinks, and some sat on the couch, the M2 would sound physically broken as they moved around, while the IN-8 and a couple of subs wouldn't have that obvious issue.

I'll concede that for some people, the lack of going to 120dB is an "obvious issue" on the Genelec and basically any speaker that is not a main monitor. Don't think that would show up in a blind or casual test in most anyone rooms but different people like different things I suppose, and I can see how some people need many JBL M2s to master movie soundtracks at theater volume levels.
 

richard12511

Major Contributor
Forum Donor
Joined
Jan 23, 2020
Messages
4,335
Likes
6,700
Horizontal dispersion to what point? For me, a speaker with lobing issues (the blobs you see on the JBL M2 at the crossover point,) indicate a problem. Moving left and right in front of many speakers, they generally sound okay. When I move vertically, many sound literally broken.

Yes, horizontal is more important, and it's been solved by many competent companies.

Vertical crossover blobs, not so much.

Concerning the loudness argument to extend the bass, JBL should have those settings recommended by default to play down to 20hz or so by default... But my guess is it would take the total SPL down, which I'm okay with, though many would complain.

In the end, I find it laughable that I could set up an IN-8 and an M2 pair in a living room, and if I had people over to listen to music and some liked sitting on the floor, some got up to get drinks, and some sat on the couch, the M2 would sound physically broken as they moved around, while the IN-8 and a couple of subs wouldn't have that obvious issue.

I'll concede that for some people, the lack of going to 120dB is an "obvious issue" on the Genelec and basically any speaker that is not a main monitor. Don't think that would show up in a blind or casual test in most anyone rooms but different people like different things I suppose, and I can see how some people need many JBL M2s to master movie soundtracks at theater volume levels.

If you're constantly standing up and sitting down while listening to music, than the Genelecs are definitely a better value. If you mostly listen to music while sitting down, then it's probably a toss up, or maybe a slight edge to the JBLs, due to the horizontal dispersion.
 
OP
stevenswall

stevenswall

Major Contributor
Forum Donor
Joined
Dec 10, 2019
Messages
1,366
Likes
1,075
Location
Orem, UT
If you're constantly standing up and sitting down while listening to music, than the Genelecs are definitely a better value. If you mostly listen to music while sitting down, then it's probably a toss up, or maybe a slight edge to the JBLs, due to the horizontal dispersion.

Ceiling and floor reflections seem like they would be more even and that would be beneficial in an interested room. Could be a tossup since it's narrower and might be quieter even if ragged.

The standing up and sitting down and multiple vertical positions is more for movie watching and casual listening, yes, but in that situation I'd be appalled if my TV changed colors as much as many speakers change the balance of frequencies.

Wish there were more blind test events people could buy tickets to, to finance more of them. I'd love to see an IN-8 and their woofer vs an M2. Apparently both have audible hiss. And maybe I'd find I liked the M2 more than all other speakers I've listened to.
 

detlev24

Senior Member
Joined
Dec 3, 2019
Messages
305
Likes
291
In the end, I find it laughable that I could set up an IN-8 and an M2 pair in a living room, and if I had people over to listen to music and some liked sitting on the floor, some got up to get drinks, and some sat on the couch, the M2 would sound physically broken as they moved around, while the IN-8 and a couple of subs wouldn't have that obvious issue.
Now I am a bit confused. Are you talking about these Kali Audio IN-8; or did I miss something?

Concerning the loudness argument to extend the bass, JBL should have those settings recommended by default to play down to 20hz or so by default... But my guess is it would take the total SPL down, which I'm okay with, though many would complain.
I am also not sure whether I understand this statement; in-room the M2 do play down to below 20 Hz 'by default' and this with exceptionally low distortion over a variety of realistic listening levels. "[...] For demanding dance music production, while providing exceptional accuracy required in cinema post production applications [...]" there is the SUB18 available, "[...] with in-room response below 18 Hz and 137 dB peak output [...]". - Different story...

Furthermore, I highly doubt Dr. Sean Olive and all other involved personnel stopped at a point and decided to release a "physically broken" sounding loudspeaker. There still seems to be some HUGE misconception about what to expect from an M2. But I agree, it is not a loudspeaker for everyone and it never was meant to be - probably like any other loudspeaker out there. The M2 is not just about loudness and far-field, as I said before, and it certainly does not directly compete against an 8260A.

And yes, it is not the best choice if you want to squat in front of it. ;)

--Pardon me, I'm out.
 
OP
stevenswall

stevenswall

Major Contributor
Forum Donor
Joined
Dec 10, 2019
Messages
1,366
Likes
1,075
Location
Orem, UT
Now I am a bit confused. Are you talking about these Kali Audio IN-8; or did I miss something?


I am also not sure whether I understand this statement; in-room the M2 do play down to below 20 Hz 'by default' and this with exceptionally low distortion over a variety of realistic listening levels. "[...] For demanding dance music production, while providing exceptional accuracy required in cinema post production applications [...]" there is the SUB18 available, "[...] with in-room response below 18 Hz and 137 dB peak output [...]". - Different story...

Furthermore, I highly doubt Dr. Sean Olive and all other involved personnel stopped at a point and decided to release a "physically broken" sounding loudspeaker. There still seems to be some HUGE misconception about what to expect from an M2. But I agree, it is not a loudspeaker for everyone and it never was meant to be - probably like any other loudspeaker out there. The M2 is not just about loudness and far-field, as I said before, and it certainly does not directly compete against an 8260A.

And yes, it is not the best choice if you want to squat in front of it. ;)

-- Pardon me, I'm out.

With user tuning and some room gain, absolutely, I'm sure they can go to 20hz. Without a user adjusting them, wouldn't they roll off around 40hz as designed?

Without user tuning, the 8260 seems like it would roll off 10hz lower, as designed.

I'd rather have the latter and consider that more accurate because it's more extended, though yes, if a speaker can play loud enough you can make it just as or more extended.
 

detlev24

Senior Member
Joined
Dec 3, 2019
Messages
305
Likes
291
Last edited:

Absolute

Major Contributor
Forum Donor
Joined
Feb 5, 2017
Messages
1,084
Likes
2,125
Like I said earlier, the M2 in standard tuning plays flat down to 17 hz in my room. I actually needed to remove one of the standard EQ points in the original settings to reduce output below 30hz because it was too much.

With any speaker that have drivers physically separated in space there will be driver interference somewhere. That's not a fault, it's a physics thing. The M2 is a large and tall speaker and in my experience it's a bigger problem sitting on the floor than standing up when it comes to driver integration.
 
OP
stevenswall

stevenswall

Major Contributor
Forum Donor
Joined
Dec 10, 2019
Messages
1,366
Likes
1,075
Location
Orem, UT
Like I said earlier, the M2 in standard tuning plays flat down to 17 hz in my room. I actually needed to remove one of the standard EQ points in the original settings to reduce output below 30hz because it was too much.

With any speaker that have drivers physically separated in space there will be driver interference somewhere. That's not a fault, it's a physics thing. The M2 is a large and tall speaker and in my experience it's a bigger problem sitting on the floor than standing up when it comes to driver integration.

Yeah, with room gain. Should have rephrased: without any room gain or user tuning, the M2 performs as the measurements show, correct?

I don't understand why the frequency response measures worse, why they would set it up and measure it that way and publish it, and why wouldn't JBL correct it so that it was as extended as a much cheaper, much, much smaller Genelec 8260?

It sounds like you're telling me the M2 in room can play 1hz lower than the Genelec with nearly 3x the physical volume and a 15" woofer?

Not much more to discuss. I just get more disgusted with JBL with every model I hear, each perspective it's examined from, and the only thing left to figure out is how much they hiss if there is a video that captures that.

Wish I had the ability to test both in home with a curtain installed. Wouldn't be surprised if I loved the sound of the M2. I'd probably burn my house down if the hiss was noticeable in my living room from 8 feet away. Also wouldn't be surprised if I had $30k to blow, if I picked the Genelecs because the return on doubling the price and tripling the physical volume was so vanishingly small.

Heck, even the 8260 I'd probably forgo if Devialet tweaked the Phantom a bit.
 

thewas

Master Contributor
Forum Donor
Joined
Jan 15, 2020
Messages
6,747
Likes
16,180
I don't understand why the frequency response measures worse, why they would set it up and measure it that way and publish it, and why wouldn't JBL correct it so that it was as extended as a much cheaper, much, much smaller Genelec 8260?
Because as said to you several times a linear very deep free field bass response is just something nice to look at in the brochure and impress your unexperienced friends, but in the room you need to EQ it down due to room gain and boundary reinforcement.
 

Absolute

Major Contributor
Forum Donor
Joined
Feb 5, 2017
Messages
1,084
Likes
2,125
Yeah, with room gain. Should have rephrased: without any room gain or user tuning, the M2 performs as the measurements show, correct?

I don't understand why the frequency response measures worse, why they would set it up and measure it that way and publish it, and why wouldn't JBL correct it so that it was as extended as a much cheaper, much, much smaller Genelec 8260?

It sounds like you're telling me the M2 in room can play 1hz lower than the Genelec with nearly 3x the physical volume and a 15" woofer?
In anechoic chamber the measurements as delivered from JBL and Genelec will be (mostly) correct. Amir and the Klippel machine is more accurate than anechoic chamber, so that gives the best answer.
What you don't get to see is the actual output they can deliver. Genelec have plenty small models that show nice extension on paper, but in reality they can only deliver that at whispering level - which is inaudible.

Physics is the key here, a small 6" driver producing 20 hz at 100dB would need to move 7,6 cm to make that kind of sound while a 15 inch needs 1,2 cm. If a 6 inch driver could produce the equivalent of JBL M2's ~ 110 dB output in the deep bass, it would need to be able to move 24,2 cm to do so. A 4 inch would need 54,5 cm.

All you need for calculation of available SPL is the xmax and size of a driver and this link; http://www.baudline.com/erik/bass/xmaxer.html

* Edit; I'm sorry, that calculator is only valid for sealed boxes so not accurate in regards to vented designs. The point still remains, though.

Not much more to discuss. I just get more disgusted with JBL with every model I hear, each perspective it's examined from, and the only thing left to figure out is how much they hiss if there is a video that captures that.

Wish I had the ability to test both in home with a curtain installed. Wouldn't be surprised if I loved the sound of the M2. I'd probably burn my house down if the hiss was noticeable in my living room from 8 feet away. Also wouldn't be surprised if I had $30k to blow, if I picked the Genelecs because the return on doubling the price and tripling the physical volume was so vanishingly small.

Heck, even the 8260 I'd probably forgo if Devialet tweaked the Phantom a bit.
Blaming JBL for your complete lack of understanding of technical issues and physics is strange, but if it makes you happy then by all means.
For listening at low volumes you don't need the M2's. You can calculate what spl capability you need by taking your desired average spl and allow for 30 dB headroom and that's it. If you like to listen at 75 dB you need speakers with 105 dB max output to avoid clipping transients.

Those little Genelecs can probably do that from 50 hz and above.
 
Last edited:
OP
stevenswall

stevenswall

Major Contributor
Forum Donor
Joined
Dec 10, 2019
Messages
1,366
Likes
1,075
Location
Orem, UT
If you like to listen at 75 dB you need speakers with 105 dB max output to avoid clipping transients.

Those little Genelecs can probably do that from 50 hz and above.

Thankfully these 'little' Genelecs play noticeably higher than 105dB peak, and if you have the data showing what you're insinuating with your last line I'd love to see it.

Also, do you know if they hiss and how much? Maybe it would be worth listening to a pair next time I'm in Denver or Los Angeles, but I can't find the self noise spec and hope the engineers paid attention to that or are going to when they release an improved version.

To be fair in my critiques, Genlec seems to be trading some accuracy and extension for loudness and directivity, and hopefully they have something technically and audibly better in every way compared to their 8260 at some point. (More accurate, smoother horizontal and vertical polar plots, more extended, and sure, louder.)

Concerning that bass response calculator above:
Here it looks like 4" drivers (25 square inches for a pair) can handle playing above 95dB at 30hz. (The M2 has 178 square inches to work with.)

https://www.audiosciencereview.com/...tor-900-measurements-now-with-spinorama.9963/

How would you convert the data in that post to this calculator? Sounds like the user is 9 feet away, and Devialet publishes 6.5mm, as the max excursion. Seems like I can't get an accurate representation of the Phantom's capabilities poking around with this calculator.

1589766010667.png
 

Attachments

  • 1589765794705.png
    1589765794705.png
    18.1 KB · Views: 69

Absolute

Major Contributor
Forum Donor
Joined
Feb 5, 2017
Messages
1,084
Likes
2,125
Thankfully these 'little' Genelecs play noticeably higher than 105dB peak, and if you have the data showing what you're insinuating with your last line I'd love to see it.
I don't know why I was thinking of the 8351, possibly because of that other thread I'm currently reading. The 8260 is equipped with a 10 inch woof and isn't very small. It seems like they'll play 113 dB A-weighted averaged from 100 hz - 3 khz long term, which doesn't really tell me much.

https://www.genelec.com/previous-models/8260a#section-technical-specifications


Also, do you know if they hiss and how much? Maybe it would be worth listening to a pair next time I'm in Denver or Los Angeles, but I can't find the self noise spec and hope the engineers paid attention to that or are going to when they release an improved version.

To be fair in my critiques, Genlec seems to be trading some accuracy and extension for loudness and directivity, and hopefully they have something technically and audibly better in every way compared to their 8260 at some point. (More accurate, smoother horizontal and vertical polar plots, more extended, and sure, louder.)
They hiss as all speakers do, but not much according to themselves. They claim below 5 dB at 1 m A-weighted, which is an absolutely useless metric. I wish there were adequate standards for this. In general Genelec is on the better side when it comes to this.

As for technical issues, yes they are trading off some things to gain in others. By using a small cabinet with deep extension, they are sacrificing sensitivity and extension of the controlled directivity in order to gain in usability and simpler construction/lower cost.
I don't mind that because they have good solutions for extending the bass and spl with add-ons such as a bunch of subwoofers.

I don't know how much smoother graphs would improve the subjective sound quality, but it would cost some dsp power and headroom or a complete redesign with different components. At some point good enough means just that, and who am I to argue that they haven't succeeded with that aim around that price point? I don't think our ears have the resolution of a microphone, so more pretty doesn't necessarily mean better sound. :p

Concerning that bass response calculator above:
Here it looks like 4" drivers (25 square inches for a pair) can handle playing above 95dB at 30hz. (The M2 has 178 square inches to work with.)

https://www.audiosciencereview.com/...tor-900-measurements-now-with-spinorama.9963/

How would you convert the data in that post to this calculator? Sounds like the user is 9 feet away, and Devialet publishes 6.5mm, as the max excursion. Seems like I can't get an accurate representation of the Phantom's capabilities poking around with this calculator.
I don't know how to convert that data to this calculator. What I do know is that the bigger Phantom Gold can produce around 75-80 dB at the rated 16 hz, which is below the audible threshold.

You add 3 dB for two speakers, and then you subtract 3 dB for each dobling of the distance and then you can add some room gain into the equation to guesstimate the spl you can achieve with a given design.

But the thing with small active speakers with deep extension is that they need heaps of power to get down there, and that means heaps of heat. So the excursion limit isn't the only concern, thermal compression is another which will end the party quite quickly at sustained high power outputs.
This measurement shows how fast you run into limiting factors;

Reactor Compression.png
 
Top Bottom