LMS-5400 buy-in

[SteveCallas]

Bottoming a speaker is NOT hard to do and doesn't necessarily take lots of power

Ermm, again, TC2k, 2000 watts, 115db sweep down to 10hz outdoors 2m groundplane, no highpass filter, and no bottoming. That's just one design too.

No more need to speculate or extrapolate from software modeling programs.

I'm doing no such thing. You guys are telling me that you are bottoming your LMS 18" drivers if tuning below 20hz without an extremely aggressive highpass filter.


Ilkka, last I recall, you said you won't be testing this until next Spring - does that still hold true?

[Ilkka]

SteveCallas wrote:

Ermm, again, TC2k, 2000 watts, 115db sweep down to 10hz outdoors 2m groundplane, no highpass filter, and no bottoming. That's just one design too.

It was a 110 dB sweep.

Ilkka, last I recall, you said you won't be testing this until next Spring - does that still hold true?

Definitely not.

[SteveCallas]

Excellent. How's the weather by you lately? It's early October and everyday is still 80-90 degrees here....kinda weird.

[anidabi]

SteveCallas wrote:

Ermm, again, TC2k, 2000 watts, 115db sweep down to 10hz outdoors 2m groundplane, no highpass filter, and no bottoming. That's just one design too.

Wrong. At 115dB sweep 2kW wasn't enought because the amp clipped. Don't you remember, the 115dB sweep was incomplete.

[anidabi]

SteveCallas wrote:

Excellent. How's the weather by you lately? It's early October and everyday is still 80-90 degrees here....kinda weird.

http://en.allmetsat.com/metar-taf/no....php?icao=EFLP

[SteveCallas]

It was a 110 dB sweep

Don't you remember, the 115dB sweep was incomplete.

Yes yes, my mistake. 39 degrees, ouch.

[ISLAND1000]

My concern for Ilkka and the LMS is that he holds a now rare specimen and that he waited months for shipment across the ocean for this opportunity. He also is handling a driver who many of us helped pay for. We all want success whether or not the driver meets our expectations.
It would be a sad sad experience if something unnatural or unexpected happened to the driver while Ilkka was in the process of assembling or testing and since some of us have experienced what we think was "bottoming" during our own trials, we want Ilkka to be watchful as his tests proceed. That's all.

[Ilkka]

You don't have to worry any more. The testing is already done and both drivers are still live and kicking. And they did DELIVER.

[ISLAND1000]

Congratulations Illka! And thank you for your persistence and audiologic spirit of adventure! Not to mention having lived through endless comments from some of us who are worse naggers than a 65 year old woman on diet coke.

[jmcomp124]

Ilkka wrote:

You don't have to worry any more. The testing is already done and both drivers are still live and kicking. And they did DELIVER.

Ilkka,
This is awesome news!
While we wait for these much awaited results, I had some thoughts that I am sure you would have contemplated too. How about some measurement results with real world movies? Pick the most intense most demanding tracks (there are several) so to be realistic we should narrow down to 3 movie tracks on which you can do some indepth outdoor measurements. Again this is simply a request. No expectations. What you already do for us Ilkka, is plenty. But I want to tickle your interest in this kind of test.
So here goes (only an example),.......
First, Calibrate your pre-amp receiver to 80dB reference at listening position with Avia in your own theater room. Next, let's say, we pick the "pod emergers/ground implodes scene in WOTW". Now you measure the input level to the amplifier to your sub/s at the most intense timestamps at reference level. This gives you a "reference point" for what one can expect in real world (any room similar to Ilkka's theater room). Now take the same setup outdoors and repeat the tests so that this time, you start from -6dB from "reference point", measure input level (should be -6dB from reference point as a double check) and measure Max output and other interesting parameters (the usual ones). Now you start increasing the input level to reference and as far beyond reference as you can safely go (maybe +6dB).
This will give us another dimension into a subwoofers performance that sweeps/mls tones cannot give.
The example test that I indicate here is pretty crude and not formalized, but it conveys the idea.
What do you think Ilkka? Is this something that you would be interested to do? Folks, what do you think?
Any suggestions? If there is enough interest.
My vote for the top 3 movies are,
1. WOTW (ground implodes/tripod emerges)
2. Flight of the Phoenix (plane crash)
3. Darla (tapping the fish tank).

-Jai

[funky_waves]

jmcomp124 wrote:

Ilkka,
This is awesome news!
While we wait for these much awaited results, I had some thoughts that I am sure you would have contemplated too. How about some measurement results with real world movies? Pick the most intense most demanding tracks (there are several) so to be realistic we should narrow down to 3 movie tracks on which you can do some indepth outdoor measurements. Again this is simply a request. No expectations. What you already do for us Ilkka, is plenty. But I want to tickle your interest in this kind of test.
So here goes (only an example),.......
First, Calibrate your pre-amp receiver to 80dB reference at listening position with Avia in your own theater room. Next, let's say, we pick the "pod emergers/ground implodes scene in WOTW". Now you measure the input level to the amplifier to your sub/s at the most intense timestamps at reference level. This gives you a "reference point" for what one can expect in real world (any room similar to Ilkka's theater room). Now take the same setup outdoors and repeat the tests so that this time, you start from -6dB from "reference point", measure input level (should be -6dB from reference point as a double check) and measure Max output and other interesting parameters (the usual ones). Now you start increasing the input level to reference and as far beyond reference as you can safely go (maybe +6dB).
This will give us another dimension into a subwoofers performance that sweeps/mls tones cannot give.
The example test that I indicate here is pretty crude and not formalized, but it conveys the idea.
What do you think Ilkka? Is this something that you would be interested to do? Folks, what do you think?
Any suggestions? If there is enough interest.
My vote for the top 3 movies are,
1. WOTW (ground implodes/tripod emerges)
2. Flight of the Phoenix (plane crash)
3. Darla (tapping the fish tank).

-Jai

I like the idea but i think one movie should be Atlantis, yes I know its a cartoon but out of all the movies I have seen it is one of the best for testing, it is one of the movies I have been useing to test my subs since it came out. The opening scene is realy good overall test and the scene with the laviathan has incredible lows.

[jmcomp124]

funky_waves wrote:

I like the idea but i think one movie should be Atlantis, yes I know its a cartoon but out of all the movies I have seen it is one of the best for testing, it is one of the movies I have been useing to test my subs since it came out. The opening scene is realy good overall test and the scene with the laviathan has incredible lows.

Hi Funky waves,
Can you post the exact time stamp on this movie? Is it DTS or DD track that you like?
There is a whole bunch of other movies that are potential candidates, for example, Happy feet, LOTR, Eragon, IRobot, The Incredibles...etc etc, and if Ilkka agrees, we have to narrow down to 3 at the most, nothing more. Maybe we can start a new thread for this and get votes, for Ilkka to consider. Ilkka, what are your thoughts along these lines?

[funky_waves]

jmcomp124 wrote:

Hi Funky waves,
Can you post the exact time stamp on this movie? Is it DTS or DD track that you like?
There is a whole bunch of other movies that are potential candidates, for example, Happy feet, LOTR, Eragon, IRobot, The Incredibles...etc etc, and if Ilkka agrees, we have to narrow down to 3 at the most, nothing more. Maybe we can start a new thread for this and get votes, for Ilkka to consider. Ilkka, what are your thoughts along these lines?

I will have to look when I get home, might be a few days. I don't have the test capabilities Ilkka has but I can do some, I will useing my 18"5400 in 300L with dual 6" ports tuned to about 17hz with a QSC PLX3602. after some sweeps and BFD tuneing I will be testing in room(28'x35' 8-12'ceiling) mostly with Atlantis,Iron Giant, Hitchhickers giude(new one), skycaptain and the world of tomorrow. Then I will probably want to watch every action/scifi movie ever made! lol

[jmcomp124]

funky_waves wrote:

I will have to look when I get home, might be a few days. I don't have the test capabilities Ilkka has but I can do some, I will useing my 18"5400 in 300L with dual 6" ports tuned to about 17hz with a QSC PLX3602. after some sweeps and BFD tuneing I will be testing in room(28'x35' 8-12'ceiling) mostly with Atlantis,Iron Giant, Hitchhickers giude(new one), skycaptain and the world of tomorrow. Then I will probably want to watch every action/scifi movie ever made! lol

Neither do I. Do you have a HP filter? If so, to what is it calibrated to? If not, has your sub ever bottomed out and how hard have you pushed it?

[funky_waves]

jmcomp124 wrote:

Neither do I. Do you have a HP filter? If so, to what is it calibrated to? If not, has your sub ever bottomed out and how hard have you pushed it?

I havnt finshed my box yet I will have an adjustable HP avialable I may test with and without(carfully) I have only tested it free air. a few times, its fun

[Ricci]

jmcomp124 wrote:

Neither do I. Do you have a HP filter? If so, to what is it calibrated to? If not, has your sub ever bottomed out and how hard have you pushed it?

This might be a dumb question, but are you sure that it was the driver and not the PR's that were out of gas? I wouldn't seem to be too hard to over excursion those PR's with a 5400 and CE4000.

[jmcomp124]

Ricci wrote:

This might be a dumb question, but are you sure that it was the driver and not the PR's that were out of gas? I wouldn't seem to be too hard to over excursion those PR's with a 5400 and CE4000.

Not a dumb question, since the PR was the first suspect. I video taped the excursions and it was the driver. I have never heard a PR bottom out and I think if it did, it would sound pretty different (there may not be a sound at all ?). The driver has a typical clank/snap sound when it bottoms out and it can be frighteningly loud on a hard bottom.

[Ilkka]

Hopefully you all have noticed this thread.

http://www.hometheatershack.com/foru...ll-2007-a.html

[Ricci]

jmcomp124 wrote:

Not a dumb question, since the PR was the first suspect. I video taped the excursions and it was the driver. I have never heard a PR bottom out and I think if it did, it would sound pretty different (there may not be a sound at all ?). The driver has a typical clank/snap sound when it bottoms out and it can be frighteningly loud on a hard bottom.

I assumed that you had ruled that out, but just didn't remember you mentioning it...



Illka,
Great job on getting the testing done and making us think it would be weeks still. I'm really glad that you included the Fathom as well. It will be a nice yardstick for the other subwoofers.

Can you give us a clue as to how you felt about the way the LMS systems performed? Perhaps with a single smilie, like this... or this...?

[Ilkka]

Ricci wrote:

Can you give us a clue as to how you felt about the way the LMS systems performed? Perhaps with a single smilie, like this... or this...?

How about :raped: ?

And those same smilies go as well for the Crown CE4000.

[jmcomp124]

Ilkka wrote:

How about :raped: ?

And those same smilies go as well for the Crown CE4000.

Man I am so happy to hear this . My ears and skin didn't lie . Did you notice I said skin. Because these subs make you feel. Ilkka,
Thyl would sure be happy to hear this as he was the first one to recommend the CE4000 to me.

[Ilkka]

jmcomp124 wrote:

Man I am so happy to hear this . My ears and skin didn't lie . Did you notice I said skin. Because these subs make you feel. Ilkka,
Thyl would sure be happy to hear this as he was the first one to recommend the CE4000 to me.

Oh but wait. Good performance on objective measurements doesn't mean anything because they can not tell anything how the subwoofer sounds and feels subjectively. It can sound absolute even though measures great, and vice versa.

And a single number (or max two) is all you need to define how good a subwoofer is.

Ilkka,

When you post the results of your tests, could you also please post the specs on your boxes. I'm currently running two 4.6 ft.^3 sealed boxes with LMS5400's but am interested in possibly building a couple of PR boxes to replace them. I'm looking for a little more subsonic slam and having followed jmcomp's AVS thread I think that is the way to go.

[Ilkka]

Weasel wrote:

Ilkka,

When you post the results of your tests, could you also please post the specs on your boxes. I'm currently running two 4.6 ft.^3 sealed boxes with LMS5400's but am interested in possibly building a couple of PR boxes to replace them. I'm looking for a little more subsonic slam and having followed jmcomp's AVS thread I think that is the way to go.

I can post them right now.

Sealed: ~3.88 ft^3 net, 15 ply BB all around, double baffle, four internal braces, ~1 lbs of lamb's wool as damping.

Reflex (PR): ~7.42 ft^3 net, 15 ply BB all around, double baffle, eight internal braces, ~1 lbs of lamb's wool as damping, ~16 Hz tuning frequency, 1443g of additional weight per each passive radiator (opposing firing).

[Ilkka]

jmcomp124 wrote:

How many points do you give this sub? LOL

-I'll give it 1 MILLION points!
-Sir, strictly speaking, a million points will not go very far these days. Basic rug alone gives away over 9 billion points a year.
-Really? Okay then... I'll give it 1... hundred... BILLION points!

Coming back to topic. What are your thoughts on real movie tracks I suggested?

It is an interesting topic of discussion, but the method you described isn't (IMHO) very good nor give accurate and consistent/comparable results. I will promise to ponder this issue a little bit further when I have finished with these current results. One thing is certain though: I will not take any new measurements until next spring/summer. Basically the weather just doesn't allow it.