21" Full Marty Build - AVS Forum | Home Theater Discussions And Reviews
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post #1 of 14 Old 12-21-2019, 12:26 AM - Thread Starter
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21" Full Marty Build

Hey Gents!, After seeing people praising a lot about LaVoce I recently got two of the 21" inch LaVoce SAN214.50 imported to NZ from US and looking to build Full Marty Sub. But I am struggling to find out cutlist for the same.
If I was staying in US my easy route would have been to get GSG Audio flatpack. Another problem is we don't get 19mm mdf here in NZ, only 18mm. So it would be really helpful if someone can help me out with the cutlist.

Thanks a lot
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post #2 of 14 Old 12-21-2019, 01:48 PM
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So like a normal every-day 15hz ported box then?

Probably best to make a 15hz ported box that is designed for those woofers, rather than designed for different woofers.

The net volume, port length/size and port velocity might have different requirements.
The the width and height too, since this is a 21, not an 18...

You should start by using winISD to plug all the values in for the driver, the tuning, the power, and then optimize for excursion/spl.

Once you have a rough idea of the size, then you can use sketchup to mock up a box in 3 dimensions.
You can use the ruler-tool to figure out the cut-list.

This is what I did for the HzHorn, but using HornResp instead of winISD.
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post #3 of 14 Old 12-21-2019, 03:27 PM - Thread Starter
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Thanks @BassThatHz , yeah I like to tune it at @15hz. I have already got dual sealed um18, dual VBSS tune 31hz and SVS pc13 in a small room 14ft by 12 ft but so wanted to see how 21 pro will sound. I will model it myself to see what I can do and will post back. Having it tune at 15 will make sure they are in sync with Pc13 but I am sure they ll not match in SPL level.
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post #4 of 14 Old 12-22-2019, 01:44 PM - Thread Starter
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I have been modelling Lavoce 21 in a ported box tuned at 15hz and at 2m I see its performance equal to SVS PB13 ultra. Is there something wrong I am doing? Isn't it suppose to do better than a 13.5 inch driver?

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post #5 of 14 Old 12-22-2019, 02:10 PM - Thread Starter
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Also, I am comparing the Model I did in winISD with GSGAudio performance tabel and I see I am bit off in the SPL table.

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post #6 of 14 Old 12-22-2019, 03:37 PM
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Looks like apples and oranges to me.

Why do you show it in two different volume boxes (and two different tunes) for the comparisons? Why is the tune different than the GSG spec that you are comparing? What is the signal level, and at what distance? Is it driven to xMax? Is there a HP filter in place? Did you use the GSG PEQ recommendation?

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post #7 of 14 Old 12-22-2019, 04:05 PM - Thread Starter
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Please correct me if I am doing this wrong as I am newbiew with winISD. Does this makes sense?





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Originally Posted by Augerhandle View Post
Looks like apples and oranges to me.

Why do you show it in two different volume boxes (and two different tunes) for the comparisons? Why is the tune different than the GSG spec that you are comparing? What is the signal level, and at what distance? Is it driven to xMax? Is there a HP filter in place? Did you use the GSG PEQ recommendation?
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post #8 of 14 Old 12-23-2019, 08:12 AM
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You've changed the volume again. Isn't the GSG flatpack 9.0 cu. ft.? I think they also recommend a PEQ filter set to +9 dB at 25 Hz., and lowering the gain 9 dB to compensate.

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post #9 of 14 Old 12-23-2019, 05:57 PM - Thread Starter
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Quote:
Originally Posted by Augerhandle View Post
You've changed the volume again. Isn't the GSG flatpack 9.0 cu. ft.? I think they also recommend a PEQ filter set to +9 dB at 25 Hz., and lowering the gain 9 dB to compensate.
I have taken the dimensions from their page for 21" full marty: 28.25” wide, 23.50” deep, 42.00” tall

Maximum power : 1200 Watt

Tuning 17hz


If I put them in the excel it comes like this













Please correct me if I am doing anything wrong here.
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post #10 of 14 Old 12-24-2019, 02:21 AM
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You're using gross volume of 13.50 instead of the net volume of 10.86. GSG uses more bracing, so this number would be even lower.
You're adjusting Gain -5 dB instead of -9 dB.

You may need to adjust input power down from 1200 watts, until the Cone Excursion is at or below the red line.

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post #11 of 14 Old 12-24-2019, 04:45 PM - Thread Starter
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Quote:
Originally Posted by Augerhandle View Post
You're using gross volume of 13.50 instead of the net volume of 10.86. GSG uses more bracing, so this number would be even lower.
You're adjusting Gain -5 dB instead of -9 dB.
Yeah right. I used -5 to keep it below excursion

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Originally Posted by Augerhandle View Post
You may need to adjust input power down from 1200 watts, until the Cone Excursion is at or below the red line.
I keep it to around usable excursion. Isn't Lavoce okay with usable excursion till 22mm or its best to check keep it near Xmax

I still couldn't figure out how GSG performance table can suggest: 21-Full Marty SAN214.50 15 121 127 (132)

Is it including room gain?
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post #12 of 14 Old 12-28-2019, 08:09 PM
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lavoce specs xmax as (Hvc - Hg)/2+ Hg/4.

that's on the conservative side.

(Hvc - Hg)/2+ 2/3 * Hg is roughly the usable both in theory as well as measured by josh at databass for the lavoce san214.50.

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post #13 of 14 Old 01-14-2020, 03:01 AM - Thread Starter
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Quote:
Originally Posted by LTD02 View Post
lavoce specs xmax as (Hvc - Hg)/2+ Hg/4.

that's on the conservative side.

(Hvc - Hg)/2+ 2/3 * Hg is roughly the usable both in theory as well as measured by josh at databass for the lavoce san214.50.
Thanks @LTD02 , I went with your devastator design and build two of them. Your designs are helping people across the globe to experience bass nirvana.

They are nearfield, I just need to play with dsp now.
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post #14 of 14 Old 01-14-2020, 09:54 PM
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way to go!!


...and, thank you.

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