Best Enclosure Design for Faital Pro 18FH500

Yotomeczek

Member
2011-12-31 11:47 pm
I'm going to build loudspeaker like Dynamikks Monitor 12.18.
There are two Faital Pro 18FH500 in the boxes waiting :)
Crossover about 100Hz (passive).
First idea was bass-reflex (200dm3/8ft3) with bigger ports but maybe it is better enclosure for 18FH500? I want quick low bass. Loudspeaker must be placement near the wall.
I don't know if 18FH500 are compatible with Onken (can't find any easy to use calculator).
 
I'm going to build loudspeaker like Dynamikks Monitor 12.18.
There are two Faital Pro 18FH500 in the boxes waiting :)
Crossover about 100Hz (passive).
First idea was bass-reflex (200dm3/8ft3) with bigger ports but maybe it is better enclosure for 18FH500? I want quick low bass. Loudspeaker must be placement near the wall.
I don't know if 18FH500 are compatible with Onken (can't find any easy to use calculator).

100Hz PASSIVE crossover... Ouch, that sounds expensive.

Why choose so low a crossover frequency?
 
You could start with something like this: ZOUDIO AIO4CH – Z O U D I O If you add a 24 V SMPS, you have a stereo active filter and amplifier for the price of a just passive filter.

It beats having a passive filter anyway as you can experiment with the best crossover, before deciding on a permanent setting. Personally I don't like crossing an 18" higher then 80 - 100 Hz and with a decent 12" coax you won't have to.
 

Yotomeczek

Member
2011-12-31 11:47 pm
You could start with something like this: ZOUDIO AIO4CH – Z O U D I O If you add a 24 V SMPS, you have a stereo active filter and amplifier for the price of a just passive filter.

It beats having a passive filter anyway as you can experiment with the best crossover, before deciding on a permanent setting. Personally I don't like crossing an 18" higher then 80 - 100 Hz and with a decent 12" coax you won't have to.

Nice stuff - thx :)
 
Greets!

'Best' is what best meets your space, performance requirements, so based on what little has been posted and lacking any measured specs, this is the pioneer's [pre T/S] Classic alignment for best trade-off between size, bass output [Vb = Vas/1.44, Fb = Fs] and my preference of Vb = Vas, Fb = 0.81x Fs.

GM
 

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Yotomeczek

Member
2011-12-31 11:47 pm
From this calculator I've got:
Cabinet volume in litres: 227.3
Cut-off frequency f3 (-3dB) in Hz: 37
Cut-off frequency f8 (-8dB) in Hz: 29

This classic bass-reflex is quite big (but not 0.81 x Vas = 300 liters) - f3 is quite good :)
I think that 230 liters of cabinet volume is near the maximum for me.
Is the Classic alignment [Vb = Vas/1.44 = 260 lites, Fb = Fs] better than calculated in Volume Calculator For Vented Loudspeaker (this didn't show Fb even)?
I tried to use WinISD 0.50a7 but it just didn't work at all.
 
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?? I don't follow. I mean using the closed box: Volume Calculator For Closed Cabinets

------------------------------ Driver ------------------------------- -------- Loudspeaker ------
Resonance frequency
fs in Hz: Equivalent volume of
compliance Vas in litre: Total driver Q factor Qts: total Q factor Qtc:
Recommended: 0.71
30
374.08
0.38
0.71

Volume in litre:
122.9 (150)
1)
Cut-off frequency f3 (-3dB) in Hz:
66
Cut-off frequency f8 (-8dB) in Hz:
42
Efficiency in dB (1W/1m):
96

=========================

Qts correction calculator
(Qts-Correction) Q factors Qes, Qms to be entered with two decimals
Please enter decimal separators as "."
------------------------------ Driver ------------------------------- ----- Crossover, Cable -----
Electrical Q factor Qes: Mechanical Q factor Qms: DC resistance Re: Coil's DC resistance R ... in Ohm:
.36
12.5
5.1
.5
Qts old of driver only:
0.35
Qts new with cable, coil, ...:
0.38

GM
 
From this calculator I've got:
Cabinet volume in litres: 227.3
Cut-off frequency f3 (-3dB) in Hz: 37
Cut-off frequency f8 (-8dB) in Hz: 29

With this calculator I get this near 300 L alignment, so how did you get such a small cab? :

Bass Reflex Cabinet
(Vented Cabinet) according to Hoge Internal volume with one decimal
Please enter decimal separator as "."
------------------------------ Driver ------------------------------- -------- Bass Reflex Tube --------
Resonance Frequency
fs in Hz: Equivalent volume of compliance
Vas in litre: Driver's total Q factor Qts: Diameter
in cm: *) No of Tubes:*)
30
374.08
0.38
25.4
1

Cabinet volume in litres:
298.3
Cut-off frequency f3 (-3dB) in Hz:
33
Cut-off frequency f8 (-8dB) in Hz:
26
Efficiency in dB (1W/1m):
96
*) Please note:
The bass reflex tube should have at least 1/3 of the driver's diameter to prevent singing noise
(for two tubes ¼, for 3 tubes 1/5, for four 1/6). . Length of bass reflex tube(s) in cm
31.5
Diameter of bass reflex tube(s) in cm
25.4
No of bass reflex tubes
1
Total area of bass reflex tube(s) in cm2
507
Ql
7

================================


Qts Correction Calculator
(Qts-Correction) Q factor Qes, Qms to be entered with two decimals
Please enter decimal separators as "."
------------------------------ Driver ------------------------------- ----- Crossover, cable -----
Electrical Q factor Qes: Mechanical Q factor Qms: DC resistance Re: Coil's DC resistance R ... in Ohm:
.36
12.5
5.1
.5
Qts old of the driver only:
0.35
Qts new with cable, coil, ...:
0.38

GM
 

Yotomeczek

Member
2011-12-31 11:47 pm
Like this:
BR.jpg

You typed Qts=0.38 not 0.35 - and it give 298 liters
 
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Yotomeczek

Member
2011-12-31 11:47 pm
Here's an Onken Excel WS: http://www.audiodesignguide.com/HiEff/ONKEN_SP-15A-402PA.xls and online version of it: HiFi Loudspeaker Design

Note that the n = 5.7 is the classic [Vb = Vas/1.44].

Technically, better to use a single large vent and critically damp it using an impulse response test if using a computer program, otherwise: Click Test | GM210 | Flickr

GM

Thx a lot :)
I calculated 18FH500 and it's not driver for Onken - total port area is too small (about 1/2 of Sd) when Port length are acceptable. Vb total is about 430 liters :)
Is the Onken just type of overlarge Bass-Reflex or something else?
I think I should project B-R bigger than calculator says, with one big port (with area about 0,2-0,25 Sd of speaker). Right?
 
You're welcome! It was hypothesized as a type of TL, but it's just a multiple vent BR: Untitled Document

To get a low vent mach with a high Xmax driver you need at least a Av = Sd/2 vent with some needing Sd/1.33 or even Sd = Av. Use Hornresp or similar to most accurately confirm vent mach.

At this point, better to morph the volumes, lengths into a straight or folded inverse tapered TQWT.

GM
 
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freddi

Member
Paid Member
2005-08-16 4:21 pm
that driver and GM's input make a nice speaker - it would make a nice enough Karlson punch (36"x22.5"x18") box with no low end for bass guitar. I played some live stuff with a weak CTS 15" n a Traynor 30 watt push pull EL34 combo amp - the reflex chamber had less than 2 cubic foot volume - muddy,distorted - probably nothing under 80Hz - lol. An open E (41Hz but with harmonics stronger than the fundamental with round wound strings, was rarely played. Usually nothing below a "G" on a 4-sting bass E string.

https://i.imgur.com/20RECmW.png
 
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Yotomeczek

Member
2011-12-31 11:47 pm
that driver and GM's input make a nice speaker - it would make a nice enough Karlson punch (36"x22.5"x18") box with no low end for bass guitar. I played some live stuff with a weak CTS 15" n a Traynor 30 watt push pull EL34 combo amp - the reflex chamber had less than 2 cubic foot volume - muddy,distorted - probably nothing under 80Hz - lol. An open E (41Hz but with harmonics stronger than the fundamental with round wound strings, was rarely played. Usually nothing below a "G" on a 4-sting bass E string.

https://i.imgur.com/20RECmW.png

I think that I need low bass - I've got only one system fo music and TV/films - soo low freq are needed.