Replacement for MTL2

[Arnau Pro Audio]

Hi there!
Just new at forum with the aim of colaborate and share as much as i can.
However i'm just entering today for asking a question about a subwoofer drivers replacement.

A friend have two ElectroVoice MTL2 which, originally, had the following drivers: DT18M http://www.electrovoice.com/downloadfile.php?i=969957
Which is a 400W AES power 96dBspl@1w1m

And we are looking if we can replace them for the following model:
BEYMA 18P1000Fe http://profesional.beyma.com/pdf/18P1000FeE.pdf
Which is a 1000W AES power 98dBspl@1w1m

So the diference in power wats will be from 800W to 2000W AES! Seems a big increasement.

In order to calculate the sound pressure i developed this excel which shows that SPL in the box for the beyma drivers will be 6dB spl higher! Seems much more!

An externally hosted image should be here but it was not working when we last tested it.

Few years later Electrovoice released the MTL2-B model which, with the same box design they upgraded the power to 1200W AES (instead of the 800W from the first MTL2 model)

Then comparing other specs of the 3 drivers are:

EVX180 and DT18M are much similar than my Beyma replacements...

DT18M
XMAX 1: ...................................................................... 5.59 mm (0.22 in.)
Volume Displacement (SD x XMAX): ................................................ 0.725 liters (0.0256 ft3)


EVX180 PE(max): .................................................................................. 600 watts
fS : .............................................................................................. 29 Hz
VAS: ......................................................................... 416 liters (14.7 ft3)
SD: .......................................................................... 0.122 m2 (189 in.2)
XMAX 1: ........................................................................ 6.4 mm (0.25 in.)
Volume Displacement (SD x XMAX): 0.781 liters


While the Beyma have:
Resonant frequency, fs .................. 40 Hz
Equivalent Air Volume to Cms, Vas ....... 163.2 l
Effective Surface Area, Sd (m2).......... 0.1250 m2
Maximum Displacement, Xmax*** .......... 8 mm
Volume Displacement (SD x XMAX): .............. 1000 cm3 = 1 liters

So its 25% more volume displacement!
Then, look at the Vas. I dont know what it is exactly but does it matter the high diference?
And what about the high resonant frequency fs? its higher than where i cut the subs (above 35 hz)

So i know that maybe is too much information at one shot but, after all, do you think we could have problems of resonances or too much air volum displacement for the box using as replacement the Beyma 18P1000?

 

[djk]

Will it even fit?

Many drivers will not fit the MTL boxes.

 

[sine143]

sensitivity means little to nothing in regards to max output of a sub box.

 

[djk]

Based on No=2.5% it's actually 96dB, same as the EV. The Qts is too high and the Vas too high to work properly in an MTL box (even if it did fit).

 

[djk]

At 8" deep, it will fit, but the Qts is too high for it to work properly in that small of a box.

If you fill in what country you are in, we might be able to find a driver you can actually get.

 

[epa]

18sound 18lw2400 is 21.5 cm deep ,and you have 22cm (if i'm correct)
vas 230ltrs and qts .31
beyma 18 sw1600 wil fit vas 206 qts .33
beyma 18pw1400fe wil fit vas 228 qts.27
beyma 18p1200 nd wil fit vas 198 qts .34

spain?

 

[Arnau Pro Audio]

Hi guys! thanks a lot for the responses.

@ Epa: Actually the beyma 18p1000 is 21mm
vas 163 liters and qts 0.39.

This seems much more similar with the cone you have mentioned: 18sound18lw2400.

Do you mean the MTL2 boxes works ok with the driver you said? (18sound18lw2400)

However seems that DJK user said the diference in Vas and Qts is much more than the boxes suits

 

[Arnau Pro Audio]

Yes i'm from barcelona, spain,
so you mean the drivers you mentioned can suit the MTL2 box?

Seems that beyma 18p1200 nd wil fit vas 198 qts .34 does not differ too much from the drivers that I already have. Beyma 18p1000fe

18p1200 nd wil fit vas 198 qts .34
18p1000fe vas 163 qts .39

However, djk said before that this specs above does not match ok with the small box of an MTL.

The Qts is too high and the Vas too high to work properly in an MTL box (even if it did fit).

What you think about epa? And other opinions are welcome

 

[Arnau Pro Audio]

I have two 700W drivers inside this VIETA BOXES four Beyma with the following specs.
400W AES
Qts 0.49
Vas 300l
Xmax 5.5
Vdisplacement 0.630 liters
Beyma

And it suits the MTL boxes.

What about puting there the 18P1000fe from beyma.
http://www.vietapro.com/site/files/usuario/890212-Fa-218BP ESP.pdf
This is a trichamber bandpass model of cosntruction.

And move the original drivers to the MTL2?

 

[Djim]

Hi Arneau,

Keep the Qts below 0.28
Too high Xmax and the ports will start to compress.

 

[Arnau Pro Audio]

Thanks for the response Djim.
I understand that at higher Qts, more space
So neither the 18P1000fe nor the SM-118/N will suit the MTL2... as Qts are 0.39 and 0.49 respectively.

Beyma Qts 0.39
Beyma Qts 0.49

Since the volume in MTL is not enuff for any of this drivers which one of them would you recomend me to put in the MTL in order to have it working for some days waiting for the originals to be repared.

 

[Arnau Pro Audio]

We should say the air volume displacement also depends on the voltage aplied to the driver. So could it be that: ?
Qts 0.49 with 400W AES might be lower air displacement than Qts0.39 with 1000W AES?

 

[Djim]

Hi Arnau,

Looks like the Precision Devices PD188 is a good candidate.

(some old G-series from Beyma work also)

 

[Arnau Pro Audio]

Hi Djim and company,
finally we had inside the Vieta 18sound 18LW1400 Qts 0.29 Vas 297liters Xmax 9mm BL 24.7
http://www.eighteensound.it/renderPdf.aspx?pid=197

Seems that the 18LW1400 can suits better in the Electrovoice MTL? for the low Qts, lower Fs and higer Vas. Do you think it can suits the MTL2?

And put the 18P1000 in the Vieta VD218BP?
As the Qts from the 18P1000 is 0.39 which suits better in a bandpass box than low Qts 0.29 of the 18sound 18LW1400,

 

[Djim]

Hi Arnau,

Both should work, 18LW1400 in MTL2(b) and 18P1000 in the Vieta bandpass.