LMS-5400 buy-in

**Ricci** · **10-05-07, 03:21 PM**

Lookin good Illka! I think you should tune that sucka as low as is reasonable. Maybe you can try it with 2 tunings, one around 16 and the other one lower, if it will go without exceeding the PR's mass abilities?

**jmcomp124** · **10-05-07, 03:30 PM**

Quote:

Ilkka wrote:

I tested the tuning frequency with the ten weights (+nut) that came with the PRs: ~18.9 Hz. So I will need to add some weight.

Does ~16 Hz sound good to you all?

16Hz sounds good. What HP filter do you plan to use? Those crowns look great. Did you get a chance to mod the fans?

**Ilkka** · **10-05-07, 03:40 PM**

Quote:

Ricci wrote:

Lookin good Illka! I think you should tune that sucka as low as is reasonable. Maybe you can try it with 2 tunings, one around 16 and the other one lower, if it will go without exceeding the PR's mass abilities?

I don't think going lower than 15-16 Hz is a good idea. That means one has to use more than 2000 grams of additional weight per each PR...

**Ilkka** · **10-05-07, 03:41 PM**

Quote:

jmcomp124 wrote:

16Hz sounds good. What HP filter do you plan to use?

2nd order BW at 16 Hz.

Quote:

Those crowns look great. Did you get a chance to mod the fans?

Yes I did but I will use the stock fans during the measurements just in case.

**ISLAND1000** · **10-05-07, 03:52 PM**

Ilkka,
Are you waiting to test until you have both boxes completed? Will you perform tests in the parking lot? How long before some more test results?

**Klip** · **10-05-07, 06:42 PM**

Quote:

ISLAND1000 wrote:

Ilkka,
... Will you perform tests in the parking lot? How long before some more test results?

Easy does it, or Ilkka will end up - Ilkkarus - you know, from the 21st Century Finnish mythology...

Quote:

Ilkka wrote:

P.S. With 4 Crown CE4000 - it's enough poweh to clip anybodies wings!

**jmcomp124** · **10-05-07, 09:10 PM**

Quote:

Ilkka wrote:

2nd order BW at 16 Hz.

Yes I did but I will use the stock fans during the measurements just in case.

2nd order BW at 16Hz is too low and others will disagree with all their energy. My experience with this design is that it should go no lower than 20Hz. 4th order L-R, at 16Hz should be ok, not a second order. If you do decide to go with 16Hz 2nd order, approach limits with great caution. Your tests are very controlled, so you will find the limitations of your sub easily and my fear of your sub bottoming out maybe unfound. You don't want bottoming out in any case. Period. You know everything about my subs and you know what happened with lower settings. Approach 16Hz with caution. The last thing I want to see is a post here mentioning your sub bottomed out. Considering how long it would take for another driver to reach you (do you have 2 of these drivers?) I would be very sad

if your driver bottomed out.

**jmcomp124** · **10-05-07, 09:13 PM**

Quote:

Ilkka wrote:

I don't think going lower than 15-16 Hz is a good idea. That means one has to use more than 2000 grams of additional weight per each PR...

2000 grams is fine and they were designed to take up to 2500gms. Those PRs have very robust components. I would still keep it below 2000. So 16Hz is the sweet spot.

**jmcomp124** · **10-05-07, 09:18 PM**

Quote:

Klip wrote:

Easy does it, or Ilkka will end up - Ilkkarus - you know, from the 21st Century Finnish mythology...

P.S. With 4 Crown CE4000 - it's enough poweh to clip anybodies wings!

One more thing about these amps. The first time, I did not follow the instructions carefully. When you bridge them, the gain on one of the knobs should be zero. I don't know what difference it makes, but the instruction manual has a clear note on this. So pay attention to that. Better to follow what it says. Secondly, try playing with the sensitivity settings to see what a good sweet spot would be.
Man Ilkka, I simply cannot wait to see the results. You are getting me very anxious, happy and nervous and the best word to describe this is anticipation. So please make it happen soon

**WillyD** · **10-05-07, 10:59 PM**

Quote:

jmcomp124 wrote:

2nd order BW at 16Hz is too low and others will disagree with all their energy. My experience with this design is that it should go no lower than 20Hz. 4th order L-R, at 16Hz should be ok, not a second order. If you do decide to go with 16Hz 2nd order, approach limits with great caution. Your tests are very controlled, so you will find the limitations of your sub easily and my fear of your sub bottoming out maybe unfound. You don't want bottoming out in any case. Period. You know everything about my subs and you know what happened with lower settings. Approach 16Hz with caution. The last thing I want to see is a post here mentioning your sub bottomed out. Considering how long it would take for another driver to reach you (do you have 2 of these drivers?) I would be very sad

if your driver bottomed out.

Jai - 2nd order BW @ 16Hz isn't too low. Even when you had your Rane set at 15Hz (with your 5400s tuned to 15Hz) you admitted you were a-ok.

**jmcomp124** · **10-06-07, 12:08 AM**

Quote:

WillyD wrote:

Jai - 2nd order BW @ 16Hz isn't too low. Even when you had your Rane set at 15Hz (with your 5400s tuned to 15Hz) you admitted you were a-ok.

Willy,
I don't recall that. If so, maybe I didn't update on forums. But as my memory recalls, anything below 20Hz 2nd order was unsafe. Can you point me where I said that so I can go and update.

**WillyD** · **10-06-07, 12:11 AM**

Quote:

jmcomp124 wrote:

Willy,
I don't recall that. If so, maybe I didn't update on forums. But as my memory recalls, anything below 20Hz 2nd order was unsafe. Can you point me where I said that so I can go and update.

http://www.avsforum.com/avs-vb/showp...&postcount=216

I don't recall you ever having a problem with the SSF set to 15Hz. I just thought you were afraid of potential problems at that setting so you set it higher.

**jmcomp124** · **10-06-07, 11:11 AM**

Quote:

WillyD wrote:

http://www.avsforum.com/avs-vb/showp...&postcount=216

I don't recall you ever having a problem with the SSF set to 15Hz. I just thought you were afraid of potential problems at that setting so you set it higher.

Thanks for the link Willy. I haven't been frequenting those forums as much as I used to, and I am back here only to see Ilkka's mesurements. You are right, I didn't post about problems with a setting lower than 20Hz. Sometime during the long experimentation process, I managed to bottom out one of the subs again when I pushed to +6dB beyond reference. If it is just reference levels it was fine. WIth the amount of power that the CE4000s deliver, I could keep pushing and the sub gave up before the amp.
At one time while measuring the THX intro scene, it was about +6dB beyond reference and there was a mild bottom out and thankfully that did not damage anything. So I switched back to 20Hz and since, I have not experienced any bottoming out. My fear of the potential problem was true though. Post #310 in my thread on avs talks about this 20Hz setting when I registered 119dB at LP. But the fact is, it did bottom out when the HP filter was set to 16Hz for the THX exploding ball scene. I hope this clears up some confusion. I had revisited WinISD models at that time and 16Hz 2nd order BW did show some warning signs with the peak excursion of the main driver. Blame it on the crown

, it doesn't stop delivering

.

**SteveCallas** · **10-06-07, 04:49 PM**

What's with all this concern over bottoming the LMS 18 below 20hz.....especially in such a small enclosure? As LLT owners have been showing for some time now - most with only 15" drivers - you'd really have to be asking for trouble to get one to bottom. Keep a lowish tuning and make the enclosure smaller like Ilkka is doing, and you get even more protection. You loose low end sensitivity, but you can't have it all if staying so small. If the LMS is bottoming with a 16hz tune and 16hz highpass, then I'd look to the claimed xmax capabilities.

Ilkka, what will the final enclosure volume be? 16hz tuning with a 16hz highpass seems like a bit of a waste of potential with these drivers to me. I highly doubt you will be listening at 130db+ levels, so trade some headroom for extension.

**WillyD** · **10-06-07, 05:22 PM**

Quote:

Sometime during the long experimentation process, I managed to bottom out one of the subs again when I pushed to +6dB beyond reference. If it is just reference levels it was fine. WIth the amount of power than the CE4000s deliver, I could keep pushing and the sub gave up before the amp.

Lets be real though, you're talking about purposefully playing them +6dB hot and cranking them up. That isn't a real world scenario.

Quote:

If the LMS is bottoming with a 16hz tune and 16hz highpass, then I'd look to the claimed xmax capabilities.

Well there were some other things going with Jai's setup early on. We'll know the full story with Ilkka's setup...but you are probably underestimating these CE4000s, to be honest. They really are beasts. And you got it mixed up, one shouldn't question the claimed xmax spec. Remember Steve, its the xmech that determines the mechanical limit. And that would be the only problem with the 5400, it doesn't have as much throw past xmax as a lot of other drivers have.

**SteveCallas** · **10-06-07, 06:04 PM**

Even if we assume the Crown amp has infinite power capabilities, I still look back to the TC2k tested outdoors at 2m with 2000 watts on a 115db sweep down to 10hz with no highpass and no bottoming or other mechanical driver issues. I'd hope an 18" with higher rated excursion capabilities from the same company could at least do that at 6db louder at all frequencies.

**WillyD** · **10-06-07, 06:13 PM**

I definitely understand where you are coming from. But that scenario and Jai's situation really can't be compared directly.

But there is no need for speculation when Ilkka himself will be fully testing the 5400 in a very similar alignment using a practically identical power setup. His observations and findings will be be more conclusive, wouldn't you say?

**SteveCallas** · **10-06-07, 06:54 PM**

Absolutely.

But I still say he shouldn't have to tune at 16hz with a 16hz highpass - wasted potential.

**WillyD** · **10-06-07, 10:47 PM**

Quote:

But I still say he shouldn't have to tune at 16hz with a 16hz highpass - wasted potential.

And I never disagreed with you there.

I too think he should be able to use maybe a 13Hz 2nd order BW, at least judging from the simulations.

**jmcomp124** · **10-06-07, 11:30 PM**

Quote:

WillyD wrote:

Lets be real though, you're talking about purposefully playing them +6dB hot and cranking them up. That isn't a real world scenario.

Well there were some other things going with Jai's setup early on. We'll know the full story with Ilkka's setup...but you are probably underestimating these CE4000s, to be honest. They really are beasts. And you got it mixed up, one shouldn't question the claimed xmax spec. Remember Steve, its the xmech that determines the mechanical limit. And that would be the only problem with the 5400, it doesn't have as much throw past xmax as a lot of other drivers have.

Agreed, it is not everyday real world usage, but you will agree that some of us do crank it up at times, don't we. It doesn't take much power to bottom out this design below tuning. In terms of listening experience setting the HP at 20Hz vs setting at 16Hz, did not make any noticeable difference for the several movies I tried. Except for the fact that, with the 20Hz setting of the 2nd order BW, I could safely push beyond reference (on any material to date) without reaching the subs limitations. Now transformers is coming out shortly. Could be a WOTW killer. With more and more demanding LFE tracks, it is better to be conservative.

**jmcomp124** · **10-06-07, 11:34 PM**

Quote:

WillyD wrote:

And I never disagreed with you there.

I too think he should be able to use maybe a 13Hz 2nd order BW, at least judging from the simulations.

All that I am saying is, start with 20Hz and then go lower. Proceed with caution. I have seen it happen and it is not pretty. 13Hz 2nd order BW? no I don't think so. Not with this design and tuning. His tests will tell.

**jmcomp124** · **10-06-07, 11:40 PM**

Quote:

SteveCallas wrote:

Even if we assume the Crown amp has infinite power capabilities, I still look back to the TC2k tested outdoors at 2m with 2000 watts on a 115db sweep down to 10hz with no highpass and no bottoming or other mechanical driver issues. I'd hope an 18" with higher rated excursion capabilities from the same company could at least do that at 6db louder at all frequencies.

Something to keep in mind. A sweep is different from real world movies. Set the 2nd order HP filter to 13Hz, calibrate to 80dB reference at LP in a large room (6000 cu ft plus) and with a similar design as mine (which this sub is), this will bottom out. It did in my room. And I have tried different drivers. Now what I observed may not show up in sweeps. Maybe the input level was higher than 115dB, who knows, I didn't measure what the input level is.

**SteveCallas** · **10-07-07, 01:17 AM**

If you are absolutely certain, and other owners are as well, then there is something amiss with this driver. There are quite a few of us LLT owners out there, and we use larger enclosures with low tunes, no highpass filters, and drivers that are supposed to have less excursion capabilities than the LMS 18, and there hasn't been bottoming yet, not with real material. Now I really want to see this design tested.

Also, I agree that the difference between reproduction of material at 20hz and 16hz will be extremely hard to notice, however, being flat and solid to 10hz as compared to 20hz is a different story.

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