Hi-Eff 3-way speakers choice help


2011-12-31 11:47 pm
I'm going to do Hi-Eff loudspeakers system inspired by this one.
Hi freq will be paled by TRACTRIX-600 horn with BMS 4550.
I'd like build the loudspeaker with better low bas and good midrange so I want 2,5 or 3-way.
I mean woofer 15" or 18" working up to 100-150Hz and 10" or 12" for 100/150Hz up to 1KHz. High effective needed.
What driver do you suggest. Budget is up to 100-200(max) Euro for each driver (bas and midrange).
I preffer bass-reflex for woofer (maybe a bit smaller onken - but I find there is hard to calculate this type enclosure)

My choice is so far BEYMA SM115/K (or cheaper SM115/N) and BEYMA 10Mi100 or BEYMA 12G125 or 10G40 or Eminence Beta 10 A.
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If 18Sound products are fair priced in Poland, the 12MB420 12" midbass used in a sealed 0.8cuft with F3=140Hz has been discussed for similar projects. At least one 18" woofer in ported box alignments is required for acceptable SPL/watt efficiency if you plan to use passive crossovers with a single low power amplifier.

FOR PORTED BASS, what are your goals for low frequency vs. efficiency? For one 18" woofer vs. two? What speaker brands are fair priced in your city? Search for Qtc~0.37, modest Mms~160g, Le~0.8mH, and low Fs~30Hz.

Music woofers like the Peavey LoRider18 560400 are sometimes lower priced than audiophile products.
The Faital 18FH500 offers good ported performance, plus light weight.


2011-12-31 11:47 pm
Thanks for propositions :)
I think that I will not go into less than 10" midbas.
Good 10" midbas has Mms around 30g that is pretty good up to 1KHz.
The FAITAL PRO with Neodymium magnet looks very cool and I prefer lighter drivers :)
The Faital 18FH500 I can buy locally for 250Euro (a bit expensive but... maybe worth it)
The Faital 15FH500 is about 215Euro
The Faital 10PR300 is 150Euro

I don't know what speaker brands are fair priced in Poland but I can buy in European Union :)
I want Hi Efficiency speakers because I like quick dynamic sound, less eff speakers are lazy and plays good at narrow volume range only.
For a start it will be passive crossover - some day active with DSP :)
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I would suggest 6" midrange faitalpro 6fe200

Or any HE 6" driver
But...since Yotomeczek has this BMS 4550 driver which goes "low"
He may like 10 " and so the woofer to mate > it follows a decadic division
in the audio band of 250 to 2k5 Hz :confused::confused:

I want Hi Efficiency speakers because I like quick dynamic sound, less eff speakers are lazy and plays good at narrow volume range only

Say you only like it loud
Faital Pro drivers are an excellent choice. Faital 18FH500 marries well with the 12FH520 .
-Faital 18FH500 has good reviews for "good bass with good tone"
-Faital 10PR300 would be a good polar match to your horn if you decide to increase the tweeter crossover frequency above 1200Hz.

-Faital 12FH520 and 12FH530 both gets high recommendations for >95db/w efficiency designs. They both have demodulation rings for low inductance plus low Mms. If you keep your horn crossover below 1250Hz, you will probably favor these 12" midbass over the 10PR300. A 12" midbass is often a better choice with an 18" woofer, since the difference in surface area is closer for the bass-mid crossover transfer. I would use the 12FH520 with the 18FH500.

==== Sd ====
18" 1220 cm2
15" 855 cm2
12" 530 cm2
10" 345 cm2
8" 225 cm2
7" 180 cm2
6" 125 cm2
5" 85 cm2

PASSIVE CROSSOVER: Since you are using the midbass near their linear high frequency limits, you will need to explore steep slope crossovers like LR4/LR6 and 6th order Bessel. Midbass -to- Horn_Tweeter time alignment is very important, and it is worth some research to study "quasi-optimal" crossovers, like the LeCleach work, which use 2-different slopes to improve phase and time alignment with long horns.

"Quasi-optimal" crossover for high-efficiency loudspeaker system

ACCORDING TO MARCO: Here's a list of "approved" “quasi-optimal” crossovers in order of increasing offset:

3rd order Butterworth Low Pass, -3dB @ Fx*0.87 (+)
3rd order Butterworth High Pass, -3dB @ Fx*1.15 (-)
Offset = 0.22*c/Fx

4th order L-R Low Pass, -6dB @ Fx (+)
3rd order Bessel High Pass, -3dB @ Fx*1.4 (-)
Offset = 0.29*c/Fx

4th ordrer Butt Low Pass, -3dB @ Fx* 0,93 (+)
4th order L-R High Pass, -6dB @ Fx (-)
Offset = 0.31*c/Fx

6th order Bessel Low Pass, -6dB @ Fx*1.25 (+)
2nd order Butterworth High Pass, -3dB @ Fx*1.3 (-)
Offset = 0.40*c/Fx

6th order L-R Low Pass, -6dB @ Fx * 1.06 (+)
3rd order Butterworth High Pass, -3dB @ Fx* 1,13 (-)
Offset = 0.445 c/Fx

6th order L-R Low Pass, -6dB @ Fx * 1.07 (+)
4th order L-R High Pass, -6dB @ Fx * 0.92 (-)
Offset = 0.465 c/Fx
A quick sim of Faital 18FH500 in 8cuft ported box tuned to 35Hz, along with 12FH520 in sealed 0.42cuft volume illustrates the close match of SPL sensitivity, and also suitability for a crossover near the typical 150-200Hz baffle step frequency(just one SPL bump to solve instead of two). Tuning the woofer bass-reflex port length can provide some room integration help...wall placement etc...

When you sketch cabinet construction options you can explore: single large cabinet; OR woofer cabinet plus (midbass+horn) cabinet; OR (woofer + midbass) cabinet plus separate horn cabinet. Measurement data shows the value of large radius quater-round edges for horn, or horn+midbass cabinet.

Passive crossover components are expensive, diyAudio experts can help you setup correct simulations which will lead to both best sound and modest cost. "Quasi-optimal" crossovers are worth some study to solve Horn-Mid time delay difference.


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2011-12-31 11:47 pm
I did similar simulations :)
12FH520 F3 122Hz in optimal 13 dm3 (plus driver 2.4 dm3) - about 0.55 cuft
I think that for 12FH520 will be no need to HPF - only LPF
1 cuft = 28.32 dm3
18FH500 in optimal cabinet 235 dm3 (8.3 cuft) shows excellence f3 36 Hz
18FH500 in smaller 150 dm3 (5.3 cuft) is f3 44 Hz not bad but...
I was looking for some onken formula but I don't understand them :)
I'm going to do one cabinet for 18" and 12" and TRACTRIX-600 on top
Cabinet size 100cm/60cm/50cm ( 40"/24"/20") so about 200 dm3 (7 cuft) - maybe a bit taller or wider. I like design like this:
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Great progress! Spring is coming with extra daylight hours. Vivaldi

Because you will get excellent transient response from your sealed box 12" midbass, I am sure that you have made the best choice with this bass reflex woofer cabinet. The Onken design is optimized for a smooth room interface when one woofer is required to cover an extra-wide bandwidth range.

Your current design makes it easy to change horns in the future.

LeCleach horns have gained favor partially because of their large edge round-overs.
Dr. Geddes puts his OS-waveguide in a cabinet with large radius edges.
What do they know that we are skipping over?

You could get 8.3cuft for the 35Hz F3 woofer if you "artistically" increase your cabinet height in a manner that loosely surrounds your tweeter horn -- like a square slot with open top drop-in. Maybe a top with beveled edges like your side detail? 1200Hz =11" wavelength. No physical gaps around the crossover frequency "should" produce smoother midrange-to-tweeter SPL curves.

1)When your Faital speakers arrive, measuring time delay difference between the horn_with_tweeter and midbass is important for initial passive crossover design.
2) Next diyExperts can simulate a couple different crossover options using Faital datasheet frequency and impedance graphs.
3) After selecting the best paper-design crossover, you can feel save to construct your cabinets and purchase a microphone + free software to make REAL measurements.
4) Now diyExperts can simulate and tune a "high confidence" crossover before you purchase expensive crossover components.


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2011-12-31 11:47 pm
Well :)
I think that I leave horn on top without baffle - I want to make them a jewel :)
I'm scared of dimension required for this 8 cuft.
My Klipsch Tangent 400 are 100cm/38cm/36cm ( 40"/15"/14") and there was a little fight with my women when they arrived. To be honest I did 12cm (4,7") stand and still tweeter is a bit too low.
When I'm sitting on couch my ears are about 100-102cm (40-41") above floor.
To hide "fat" dimensions maybe I make the cabinet a bit taller (110cm or 43-44").
Other problem is time alignment.

When I make frot baffle angled that give me two positive - good time alignment and slimmer look, but less inside volume too.
I'm going use flexi playwood for rounded parts.
I choose BR over Onken because I read some negative opinions about them and there is hard to calculate for me (I founded some calc but not trust them 100%). Onken make the cabinet even wider. Classic BR with big vent area (min 25% od sd) is good enough I hope.
Need to find soft for modeling 3d cabinets :)
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You will want to wait until you receive the real Faital 18" & 12" speakers and accurately measure time delays, along with the Tractrix horn with BMS compression driver. A good solution for the time alignment between the midbass and horn tweeter is important because of the short-wavelength at 1000-1300Hz crossover frequency. You can decide between physical time adjustment by sliding the horn tweeter, or you can use a crossover circuit which rotates phase to compensate for time alignment, or you could combine the two technologies. I wonder if a felt doughnut time spacer behind the round horn might offer style and absorption from the midbass below.

Crossover circuits can be started after a horn time-alignment stragegy (physical / phase shift) has been selected.

Many designers do not find it important/necessary to time align the midrange to the woofer because of the long wavelengths(~80") of the ~150Hz crossover frequency.

A cabinet using flat sides is easier to construct than a rounded-rear bended-ply cabinet design. A few artistic cuts can provide some baffle edge diffraction reduction while creating "style" which can complement the living room.


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