Help integrating LMS Ultra 5400, Sanway FP14000 and miniDSP 4x10 HD - AVS Forum
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post #1 of 65 Old 05-26-2014, 11:14 PM - Thread Starter
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Hi,

First off, this has been and still is my first DIY project so please be gentle :) I've been reading a lot in this and other forums but I still have some basic questions. Let me first outline what I have done, and then what I aim for.

 

What's been done

Ordered LMS Ultra 5400, Sanway FP 14000 and miniDSP 4x10 HD. After playing around in WinISD and Sketchup I wanted to try a sealed enclosure with internal volume of around 4.2 ft^3 (not accounting for the driver) and built it in 2x22mm (= ~1.73") cheap fiberboard type material with a natural resonance which is far to low for a subwoofer enclosure as I've understood it. I've wired the Ultra for 4 Ohms.

 

I've played around with the system and set the high pass filter to 11 Hz to avoid the danger of bottoming out the driver. I've not done any EQ'ing, but I'm still impressed with the performance and low distortion it yields.

 

Also, I'm mostly using it for music and it is still burning in. xover is set to 175Hz and after some moving around it plays quite well with JBL 4343B which has a 15" 2235h driver that goes to 300 Hz (using miniDSP as active xover). Low pass filter on the 2235h's is 35 Hz.

 

Well, suffice to say I was so impressed with what the LMS Ultra 5400 could do that I opted to order another driver. :D The driver won't be here in Norway for a while, since it's being shipped over by sea, so there is a lot of time to plan ahead.

 

What I'd like to do

I'd like to build two new enclosures in either double or triple 19mm (~0.78") MDF and brace them into oblivion, maybe by using the so called matrix method. As for the internal volume of the new boxes, I'm thinking 4.2ft^3 sealed again, unless there are good reasons to go for bigger or smaller ones.

 

Furthermore, I would like to EQ the low end without risking damaging the drivers (they're not cheap as we know, haha). I've got a UMIK-1 from miniDSP and I'm wanting to do a Linkwitz Transformation, like described on miniDSP's website.

 

My hurdles and questions

  1. Headroom for EQ with miniDSP 4x10 HD
    As I've understood it, I have to lower the input, so I don't max at 0dBFS, if I max at -15dBFS that means I've got 15dB of headroom, right? Ie, there is no hidden headroom?

    Since the miniDSP 4x10 HD does not have a peak meter, could I disconnect all speakers and send pink noise to the unit to see how much headroom I've got? If not pink noise, can I use a sine wave?
  2. DIP Switches on Sanways's Labgruppen FP14000 clone
    First, in Norway we have around 230V. the amp is on a 16A breaker.

    As can be seen in the manual, the miniDSP 4x10 HD outputs 8Vrms through its balanced outputs as default.

    Currently I've got FP14k set to the minimum gain, but I'm not sure how to set the clip voltage meter and soft or hard operation. In the FP14k manual they say I should use hard for subwoofer applications, but I'm still not sure after seeing people on here have it at soft.

    My questions are:
    At which gain setting would I set the FP14k, the VCL and the opteration mode, given I'm on 230V. I'm afraid of overpowering the woofers obviously.

    Also, since miniDSP 4x10 HD has a 8Vrms output through balanced, I'm thinking that it can be dangerous with voltage peaks from the miniDSP. Would a 11Hz high pass filter protect me against failures? As such peaks are short by logic, I assume that heat building up won't be a problem?

  3. How many dB of equalizing in the low end is safe?

  4. Will 10AWG speaker wire be enough for the LMS Ultra 5400? (I'm planning 40-50A rated Neutrik SpeakON connections between FP14k and the woofers).

 

 

I realize that I'm asking a lot of questions and that there is a lot of information here. I'll be using this thread as a project thread, so any other poor old noob like me can follow it and hopefully get the same results I'm after. :)


DAC/Preamp: miniDSP 4x10 HD and Mytek 192 Stereo DSD DAC
Speakers: JBL 4343B, JBL 4430 and JBL 120Ti
Amplifiers: Emotiva XPR-1, Denon POA 1500, QSC GX5 and Sanway's LabGruppen FP14000 clone
Sub: DIY LMS Ultra 5400
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post #2 of 65 Old 05-27-2014, 07:31 AM
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that's about what josh measured his in:

http://www.data-bass.com/data?page=system&id=3&mset=35

he ran his up to what looks like 130 volts as the final sweep. that is roughly 4500 watts. at that point it was compressing on both the low and the high end, so you probably don't want to go any more than that.
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post #3 of 65 Old 05-27-2014, 12:22 PM - Thread Starter
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Thanks LTD02. :) So, the VPL is basically just an indicator of when one pushes a set limit, right? It won't limit the output, only let you know you're close to the specified value by a blinking led?

 

Been looking into the input sensitivity specification sheet for LabGruppen FP14k original.

 

 

If this is applicable to Sanway's clone FP14k then it seems like setting gain at 23dB and setting it to something like 100V will give 2500 watt output with peaks at 140V when pushing 7V in, ie almost the 8V the miniDSP is capable of.

 

Am I correct here, please?


DAC/Preamp: miniDSP 4x10 HD and Mytek 192 Stereo DSD DAC
Speakers: JBL 4343B, JBL 4430 and JBL 120Ti
Amplifiers: Emotiva XPR-1, Denon POA 1500, QSC GX5 and Sanway's LabGruppen FP14000 clone
Sub: DIY LMS Ultra 5400
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post #4 of 65 Old 05-27-2014, 02:46 PM
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i wouldn't trust the voltage limiter in that amp without measuring. too much at risk.

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post #5 of 65 Old 05-27-2014, 05:20 PM
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Here is what 65volts RMS does @ 20hz (it's almost bottoming out).
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post #6 of 65 Old 05-30-2014, 08:40 PM - Thread Starter
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How many dB of gain would you guys think it is safe to EQ an enclosure like this (~4.2 ft^3) in the low end? Going to be careful with the volume knob even though it's hard not to turn it up due to the low distortion, hehe.

 

Quote:

Originally Posted by LTD02 View Post

i wouldn't trust the voltage limiter in that amp without measuring. too much at risk.

 

Thank you, Will measure it and try to learn the system's limits.

 

Quote:
Originally Posted by BassThatHz View Post

Here is what 65volts RMS does @ 20hz (it's almost bottoming out).
 

Yikes, good to know, thanks!

 

Got some green laser pointers myself, I'll try to set up a contraption to see how much I'm pushing it. It's not only bottoming out I'm afraid of, but also overheating it, as a guy I know fried his LMS after a good hour of extreme usage. :D

 

I've thought about putting in place active water cooling on the motor and a sensor to measure the temperature inside of the enclosure, haha. That'll probably never happen though, at least not the water cooling.


DAC/Preamp: miniDSP 4x10 HD and Mytek 192 Stereo DSD DAC
Speakers: JBL 4343B, JBL 4430 and JBL 120Ti
Amplifiers: Emotiva XPR-1, Denon POA 1500, QSC GX5 and Sanway's LabGruppen FP14000 clone
Sub: DIY LMS Ultra 5400
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post #7 of 65 Old 05-31-2014, 01:55 AM - Thread Starter
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Another thing, in WinISD's overview it says that the volume used to estimate is the working volume, which I assume is the net volume. That begs the question of what the volume of the driver is, does anyone know, please?


DAC/Preamp: miniDSP 4x10 HD and Mytek 192 Stereo DSD DAC
Speakers: JBL 4343B, JBL 4430 and JBL 120Ti
Amplifiers: Emotiva XPR-1, Denon POA 1500, QSC GX5 and Sanway's LabGruppen FP14000 clone
Sub: DIY LMS Ultra 5400
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post #8 of 65 Old 05-31-2014, 12:21 PM
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if you use 0.5 cu. ft. and are off by 0.1, it won't make a difference. just take a best guess.
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post #9 of 65 Old 06-01-2014, 06:38 AM - Thread Starter
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Thank you again LTD02. I appreciate all the help! Hoped more people would chime in with some advice, but my way of asking is obviously not enticing vast enthusiasm amongst the forum members, haha.

 

Would very much like to EQ the bottom end and are currently using a shelf filter from around 30 Hz to boost 3dB with high pass filter at 11 Hz for protection. This is as far as I dare to go without any expert advice on the matter.

 

Made some new measurements, and the internal volume of the current (sealed) enclosure is 4.28 ft^3 less driver at ~0.5 ft^3, so about 3.8 ft^3 (107 litres) net internal volume. Estimating in WinISD that should yield around 110dB @ 20 Hz max SPL and a Qtc of 0.608 (which I don't understand what means yet).

 

 

Looking at the next picture of the transfer function there's a 13 dB loss of SPL from around 60 Hz where I aim to set the xover point.

 

 

If I were to use the suggested Likwitz transform in WinISD using biquad in miniDSP we can see that the boost is far more than 3dB.

 

 

With both high pass filter at 11 Hz and the Likkwitz, we see the following

 

 

Is this really safe?! :D


DAC/Preamp: miniDSP 4x10 HD and Mytek 192 Stereo DSD DAC
Speakers: JBL 4343B, JBL 4430 and JBL 120Ti
Amplifiers: Emotiva XPR-1, Denon POA 1500, QSC GX5 and Sanway's LabGruppen FP14000 clone
Sub: DIY LMS Ultra 5400
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post #10 of 65 Old 06-01-2014, 09:55 AM
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I used .59 for the displacement.....if you go to parts express and click in the 5400......at the bottom after the reviews there are some questions. The second one is the displacement.

My dual sealed LMS 5400 Ultra build
http://www.avsforum.com/forum/155-di...0-build-4.html
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post #11 of 65 Old 06-01-2014, 10:22 AM - Thread Starter
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Hahahaha, your avatar is hilarious! Is that your kid on the left? Yes, left!! :D

 

Thank you! I'll read through all of the Q&A there again.

 

Weird that nobody wants to chime in about how many dB I can safely boost the low end with. Was under the impression that most DIY'ers use EQ for their sealed subs. I won't hold anybody liable when I bottom out the driver or the voice coil goes up in smoke!! :D

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DAC/Preamp: miniDSP 4x10 HD and Mytek 192 Stereo DSD DAC
Speakers: JBL 4343B, JBL 4430 and JBL 120Ti
Amplifiers: Emotiva XPR-1, Denon POA 1500, QSC GX5 and Sanway's LabGruppen FP14000 clone
Sub: DIY LMS Ultra 5400
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post #12 of 65 Old 06-01-2014, 02:30 PM
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Quote:
Originally Posted by GizzeGutten View Post

Hahahaha, your avatar is hilarious! Is that your kid on the left? Yes, left!! biggrin.gif

nice kid... who's the baby next to it ? 😁😁
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post #13 of 65 Old 06-01-2014, 04:31 PM
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Quote:
Originally Posted by GizzeGutten View Post

Thank you again LTD02. I appreciate all the help! Hoped more people would chime in with some advice, but my way of asking is obviously not enticing vast enthusiasm amongst the forum members, haha.

Would very much like to EQ the bottom end and are currently using a shelf filter from around 30 Hz to boost 3dB with high pass filter at 11 Hz for protection. This is as far as I dare to go without any expert advice on the matter.

Made some new measurements, and the internal volume of the current (sealed) enclosure is 4.28 ft^3 less driver at ~0.5 ft^3, so about 3.8 ft^3 (107 litres) net internal volume. Estimating in WinISD that should yield around 110dB @ 20 Hz max SPL and a Qtc of 0.608 (which I don't understand what means yet).




Looking at the next picture of the transfer function there's a 13 dB loss of SPL from around 60 Hz where I aim to set the xover point.




If I were to use the suggested Likwitz transform in WinISD using biquad in miniDSP we can see that the boost is far more than 3dB.




With both high pass filter at 11 Hz and the Likkwitz, we see the following




Is this really safe?! biggrin.gif

I would double check that displacement spec. I don't think it is .5 ^3.

You seem to be good with winisd... to see if you're at safe levels why not just look at the excursion chart?
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boosting the low end is the same as playing at higher level with no boost on low end.

requires the same power. requires the same excursion.

each 3db of boost is about a double of power.

so long as you have enough power and enough excursion, you can boost as much as you want.

some boost small sealed subs by 12db on the lower end to try to achieve flat response.

where folks get into trouble is thinking that eq doesn't require any additional power or excursion...i.e. thinking that eq is "free". if that were true, everybody would run their subs at 1w with 40db of low end boost! :-)
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post #15 of 65 Old 06-01-2014, 05:28 PM - Thread Starter
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Quote:
Originally Posted by pdxrealtor View Post


I would double check that displacement spec. I don't think it is .5 ^3.

You seem to be good with winisd... to see if you're at safe levels why not just look at the excursion chart?

 

Thanks, I'll do that. I don't have a mental concept of how much a cubic feet is as I'm European, but try to use them because many of you are American. I'll adjust the displacement for the driver a little later, but assume that it is correct right now, as I want to understand the excursion chart a little better first (because I see that it is related to the net volume of the enclosure).

 

No, I'm not good with winisd, not at all. My knowledge on the matter of subwoofers is like a Swiss cheese – full of holes, so please consider me a noob at all times, haha! With my detailed posts, I try to convey what I understand and what I don't understand. It's simple to show people what I understand, but difficult to know what I don't know. Hope that makes sense, haha.

 

So, your question about the excursion chart is very welcome, and together with the reply from LTD02 below, I think I understand how this relates to one another! :) Fantastic!!

 

Quote:
Originally Posted by LTD02 View Post

boosting the low end is the same as playing at higher level with no boost on low end.

requires the same power. requires the same excursion.

each 3db of boost is about a double of power.

so long as you have enough power and enough excursion, you can boost as much as you want.

some boost small sealed subs by 12db on the lower end to try to achieve flat response.

where folks get into trouble is thinking that eq doesn't require any additional power or excursion...i.e. thinking that eq is "free". if that were true, everybody would run their subs at 1w with 40db of low end boost! :-)

 

Great! This seems to make a lot of sense! :)

 

I still have a couple of questions though, the maximum SPL chart will show me how many dB I can get at max even with EQ, whereas the transfer function is in relative terms. Ie, because the maximum SPL says I can get 110 dB @ 20 Hz, I can not get more than that even with EQ?

 

So here's the excursion chart, which looks to be peaking at 14.06 Hz @ 2.055mm. How much excursion do I have with this driver? What is the name of the spec I should look at. Parts Express has listed a lot of different ones, where xmax says 33.55 mm, but that is peak-to-peak as I've understood it. So from bottom to top, basically?

 

 

I said I was a noob, haha. I don't need spoon feeding, just some friendly pointers, and I will research things myself! :D


DAC/Preamp: miniDSP 4x10 HD and Mytek 192 Stereo DSD DAC
Speakers: JBL 4343B, JBL 4430 and JBL 120Ti
Amplifiers: Emotiva XPR-1, Denon POA 1500, QSC GX5 and Sanway's LabGruppen FP14000 clone
Sub: DIY LMS Ultra 5400
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post #16 of 65 Old 06-01-2014, 05:34 PM
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^^ something is wrong with that excursion chart. It looks like you don't have the xmax entered for the driver your modeling.

I have winisd open now, give me your numbers and I'll plug them in and show you the graphs.

Figure 0.25 ^3 for the driver displacement. It's probably a bit more, but not much.
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post #17 of 65 Old 06-01-2014, 05:46 PM - Thread Starter
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I downloaded the driver database from somewhere a while ago, can't remember where, but maybe here or another forum. However, here is the data I'm using. Sorry I'm using liters, but 107 liters = 3.77866934 cubic feet according to Mr Google.

 

Could it be that I had the "System input power" to the default of 1W? When I changed it to 2kW (which I assume to be the maximum for the Ultra), the excursion literally went off the charts! I guess that I'm all out of excursion looking at this chart, haha!

 

 

 

 


DAC/Preamp: miniDSP 4x10 HD and Mytek 192 Stereo DSD DAC
Speakers: JBL 4343B, JBL 4430 and JBL 120Ti
Amplifiers: Emotiva XPR-1, Denon POA 1500, QSC GX5 and Sanway's LabGruppen FP14000 clone
Sub: DIY LMS Ultra 5400
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post #18 of 65 Old 06-01-2014, 06:14 PM
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Your Z and xmax are incorrect. Assuming your wiring in series (which is how the t/s specs were taken) you need to enter 4 in the Z box. The xmax is 33.7.

Here are some charts based on your box size of 3.78 ^3 and 2000 watts of power. Depending on how far the Ultra can go past the rated xmax of 33.7, you should be safe in the excursion department giving it 1000 more watts, via raw power or boost.


Excursion- 2kw



SPL -



Excursion 3kw -

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post #19 of 65 Old 06-01-2014, 06:24 PM - Thread Starter
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Thank you very much!! I'll plot right the numbers and continue trying to tweak things to estimate my current vs future enclosures and read some more tutorials on winisd! :)

 

Really appreciate you guys taking the time to help me out! :D


DAC/Preamp: miniDSP 4x10 HD and Mytek 192 Stereo DSD DAC
Speakers: JBL 4343B, JBL 4430 and JBL 120Ti
Amplifiers: Emotiva XPR-1, Denon POA 1500, QSC GX5 and Sanway's LabGruppen FP14000 clone
Sub: DIY LMS Ultra 5400
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post #20 of 65 Old 06-01-2014, 07:05 PM
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You're welcome..... I'm no win-isd expert and FWIW I didn't mean to imply you weren't trying your best. smile.gif

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post #21 of 65 Old 06-01-2014, 08:34 PM
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fwiw, I think Z is just informational. re is used in the calcs.

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post #22 of 65 Old 06-02-2014, 06:41 PM - Thread Starter
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Have been downloading some new database files for the LMS Ultra 5400, but their specs differ a little bit, even if the database file says it's the 2010 version of the driver. However, I have been able to replicate the results of pdxrealtor in post #18 above, and assume that's correct.

 

After adjusting for driver displacement (which someone in the Q&A section at PE says is 0.59 ft3 [16.71 L]) the current enclosure comes in at a net volume of 3.69 ft3 [104.43 L].

 

Based on the current figures I've been experimenting with Linkwitz Transform using WinISD and miniDSP's spreadsheet to calculate the biquad coefficients. What I find, is that the current sub runs out of excursion fast, so there is not much flexibility with EQ in the current setup.

 

Theoretical questions

Please correct me if I'm wrong, but based on your help and input, there are three interrelated concepts that determine the limits of EQ on a sealed enclosure; power, excursion and implicitly the net internal volume.

 

  • The bigger the enclosure, the more excursion you get, (holding everything else constant)
  • The more power, the more excursion you get, (holding everything else constant)
  • The bigger the enclosure, the lesser the power required to get the same excursion, (again, holding everything else constant)

 

Why does excursion go up when we have a large enclosure? Is it because the air pressure inside the cabinet is less than that of a smaller one, hence the power required to move the cone/push air less?

 

Estimations on the current enclosure

Cone excursion @ 2kW before any filters are added

 

SPL @ 2kW before any filters are added

So without any EQ and 2kW raw power we get 109.8 dB @ 20 Hz.

 

3kW raw power, no EQ estimates 111.5 dB @ 20 Hz, and I still have some excursion left at 20 Hz, as can be seen below.

 

Does this mean I can boost about 1.5dB @ 20 Hz without running out of excursion? 1.5dB does not seem a lot when using Linkwitz-Transform. Also, the low distortion of the Ultra makes it seem like I'm not playing that loud (but I can feel that it is loud, haha).

 

It's slowly starting to dawn on me why some of you guys have all those woofers, hahaha. :D


DAC/Preamp: miniDSP 4x10 HD and Mytek 192 Stereo DSD DAC
Speakers: JBL 4343B, JBL 4430 and JBL 120Ti
Amplifiers: Emotiva XPR-1, Denon POA 1500, QSC GX5 and Sanway's LabGruppen FP14000 clone
Sub: DIY LMS Ultra 5400
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post #23 of 65 Old 06-02-2014, 07:06 PM
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Originally Posted by GizzeGutten View Post

Hahahaha, your avatar is hilarious! Is that your kid on the left? Yes, left!! biggrin.gif
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Originally Posted by Bombelman View Post

nice kid... who's the baby next to it ? 😁😁

I HAD TWINS!!

Blurry a$$ pic but you get the idea....
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post #24 of 65 Old 06-02-2014, 07:40 PM
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Quote:
Originally Posted by GizzeGutten View Post

Have been downloading some new database files for the LMS Ultra 5400, but their specs differ a little bit, even if the database file says it's the 2010 version of the driver. However, I have been able to replicate the results of pdxrealtor in post #18 above, and assume that's correct.

One thing you might want to check out is a thread by FoLLgoTT, mentioned below, in which he checks actual measured cone displacement with a laser and compares it with WinISD prediction.

Very low frequencies (WinISD vs. laser measurement)

It turns out that WinISD is very pessimistic regarding its estimate of box leakage Q, called QL. This in turn gives pessimistic predictions of excursion at very low frequencies. Try the simulation with the modified QL value of 50 instead of its default value of 10.
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post #25 of 65 Old 06-02-2014, 08:38 PM - Thread Starter
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^ Thanks, that was very helpful! After adjusting for (no) leaks (Ql=50) and (no) dampening (Qa=120), the excursion actually went up, leaving even less room for EQ @ 20 Hz.

 

Using LT this seems to be as good as it gets (assuming that the only variables I can adjust given the enclosure setting up LT are fp and Qp).

 

 

With a HPF @ 11 Hz, this is what excursion and SPL gives with input of 2kW

 

Excursion

 

SPL

 

So a little better with 112.5 dB @ 20 Hz. Do you guys think this looks right?


DAC/Preamp: miniDSP 4x10 HD and Mytek 192 Stereo DSD DAC
Speakers: JBL 4343B, JBL 4430 and JBL 120Ti
Amplifiers: Emotiva XPR-1, Denon POA 1500, QSC GX5 and Sanway's LabGruppen FP14000 clone
Sub: DIY LMS Ultra 5400
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post #26 of 65 Old 06-02-2014, 09:15 PM
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"•The bigger the enclosure, the more excursion you get, (holding everything else constant)
•The more power, the more excursion you get, (holding everything else constant)
•The bigger the enclosure, the lesser the power required to get the same excursion, (again, holding everything else constant)
Why does excursion go up when we have a large enclosure? Is it because the air pressure inside the cabinet is less than that of a smaller one, hence the power required to move the cone/push air less?"

yes.
yes.
yes.
yes.

:-)
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post #27 of 65 Old 06-02-2014, 09:15 PM
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"It turns out that WinISD is very pessimistic regarding its estimate of box leakage Q, called QL. This in turn gives pessimistic predictions of excursion at very low frequencies. Try the simulation with the modified QL value of 50 instead of its default value of 10."

yes.
:-)

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post #28 of 65 Old 06-03-2014, 09:02 AM
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I am thoroughly following this thread......I am still building the enclosures for my two babys, (having a real kid makes it take longer then usual 😐) and you have just about the same set up as me. My enclosures are 3.5 with the driver, which comes out to a QTC of .611, and I will be feeding them 4k each.

I downloaded WINSLD, but have not really played with it. Any free time I have I spend tinkering on my enclosures. Plus a lot of it is over my head. I've been hanging out in the DIY area for a while, and I'm still trying to wrap my head around some things. EQ being one of them.

So I'm really glad you have this thread going, and hope you get everything figured out. There are some smart people in this forum, and posting in this thread that should get you to where you want to be. For now I'll follow along and hopefully be able to copy what you are doing since we have almost identical sub systems.

👍

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post #29 of 65 Old 06-03-2014, 12:04 PM
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Everything your modeling is for one driver, and you said you have another on the way....right?

This what I do know....double power = 3db, double cone area = 3db, thats 6db of gain. Also the more drivers you add excursion goes down. I'm not sure how the 6db in spl equates to excursion reduction at a given spl and frequency, but I would think by having 2 would let you be able to boost the low end more?

Just a thought
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post #30 of 65 Old 06-03-2014, 12:37 PM - Thread Starter
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LTD02: Thanks for validating!

 

Quote:

Originally Posted by SeekingNirvana View Post

I am thoroughly following this thread......I am still building the enclosures for my two babys, (having a real kid makes it take longer then usual 😐) and you have just about the same set up as me. My enclosures are 3.5 with the driver, which comes out to a QTC of .611, and I will be feeding them 4k each.

I downloaded WINSLD, but have not really played with it. Any free time I have I spend tinkering on my enclosures. Plus a lot of it is over my head. I've been hanging out in the DIY area for a while, and I'm still trying to wrap my head around some things. EQ being one of them.

So I'm really glad you have this thread going, and hope you get everything figured out. There are some smart people in this forum, and posting in this thread that should get you to where you want to be. For now I'll follow along and hopefully be able to copy what you are doing since we have almost identical sub systems.

👍

 

Glad to hear I'm not alone, and a lot of this goes way above my head too! Happy to hear that more people than me are benefiting from the thread. :) Do you have a thread for your project (link)? If not, please feel free to hijack this one :) We've taken the plunge and put down the money, now we only need to beg for and acquire the knowledge to get the results!

 

So 4kW of dynamic power then? Thought the driver was rated at 2kW continually? This leads me to a question: Given that we have enough excursion, can we boost our way up, up, up until the peak power limitation (leaving some left for safety)? It sounds dangerous, as I have no idea what defines "continually" and "peak". For instance, would a hardcore dubstep tune drive a sub at low frequencies continually? ... So many questions, ... :)

 

WinISD is a great learning tool, imo. Don't know how things will work out with the final enclosures, but they will be sealed but maybe with a little different internal volume dependent on what comes of this thread. I see that TC Sounds recommend 4ft3 for large sealed. Idk if that's net or gross, but probably net, as that seems to be the convention.

 

Quote:
Originally Posted by SeekingNirvana View Post

Everything your modeling is for one driver, and you said you have another on the way....right?

This what I do know....double power = 3db, double cone area = 3db, thats 6db of gain. Also the more drivers you add excursion goes down. I'm not sure how the 6db in spl equates to excursion reduction at a given spl and frequency, but I would think by having 2 would let you be able to boost the low end more?

Just a thought

 

Yup, the second driver is coming by sea freight, so it'll be about a month until it arrives, at least that's how long it took with the first one. Can't wait to build a pair of beautiful matte black enclosures for the babies to play in, I'll enjoy hours on end, just sitting there just watching them go!! ;D What kind of finish are you aiming for?

 

Yes, I'm modeling for one driver. Didn't even know that adding another one would affect the both of the subs' excursion, only that the total SPL would theoretically increase. Basically thought they were to isolated systems, and don't even know if it's possible to model two separate enclosures simultaneously with WinISD.


DAC/Preamp: miniDSP 4x10 HD and Mytek 192 Stereo DSD DAC
Speakers: JBL 4343B, JBL 4430 and JBL 120Ti
Amplifiers: Emotiva XPR-1, Denon POA 1500, QSC GX5 and Sanway's LabGruppen FP14000 clone
Sub: DIY LMS Ultra 5400
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