Designing mid-high speakers to match SUB

**Spadez** · **10-20-09, 07:33 AM**

Aha, thank you, now we are on to something! This looks very promising, especially this bit:

Quote:

0.75 liter (46 cubic inches) sealed and stuffed for an F3 of 150Hz

1.5 liter vented (92 cubic inches), stuffing, 1" diameter vent x 3" long, F3 90Hz

If I was to go for the 0.75L enclosure, would the F3 of 150Hz mesh well with my subwoofer or is this cutoff too high?

**Spadez** · **10-20-09, 07:40 AM**

Ive also found this, it says it is good for 0.5 to 1 liter:

http://www.madisound.com/catalog/pro...oducts_id=8593

How about if I went with one of those and a very small tweeter in each 0.75L enclosure?

**Yad** · **10-20-09, 07:41 AM**

yes. good driver. But it is not necessary to use the tweeter here. Because you will not have a free volume inside the box to put the crossover. But if there is free to use extra volume 0.5-1L approx - you may try.

Frankly speaking, i would advise you to try it without tweeter. Then you will make your own decision about "2-way or not 2-way"

**Spadez** · **10-20-09, 07:43 AM**

Woo hoo!

**Spadez** · **10-20-09, 07:51 AM**

Will the lower frequency end of the mid range posted above mesh well with the upper range of the sub im designing, or will there be a frequency gap or over emphised freqency range? Ill look into the tweeter thing a little more now.

**Yad** · **10-20-09, 08:04 AM**

You should make crossover point as low as possible. 90Hz is much better than 150 There fore it's better to use larger volume that 've been recommended above

**Spadez** · **10-20-09, 08:15 AM**

I think ive got around the tweeter problem, I think Ill mount the crossover in an external box which will sit under the table and conntent to the speakers.

Im going to have a go at modeling my first speaker to see how low I can get that driver in that given volume.

**Yad** · **10-20-09, 08:21 AM**

ok. Try to find very small 20 mm-dome tweeter. Do you have the IKEA store nearby ?

**Spadez** · **10-20-09, 08:23 AM**

About an hour away, why is that?

**Yad** · **10-20-09, 08:30 AM**

http://www.ikea.com/ru/ru/catalog/products/20066660
This is IKEA in russia.

You may try to use this kitchen thing as acoustic lens for the tweeter (like B&O's)

**Yad** · **10-20-09, 08:35 AM**

http://www.ikea.com/us/en/catalog/products/20066660 in the USA

i mean to use a cone part of it )))))

**Spadez** · **10-20-09, 08:39 AM**

Haha I love the idea of using a spoon to reflect the sound! Ive modelled the speaker for my enclosure. I wasnt able to put in all of the values as I couldnt find them, but most are there. If anyone is free, can they have a look at this file.

**Yad** · **10-20-09, 08:42 AM**

oo-ops...

what program do you use ? I have a mistake while opening

**Spadez** · **10-20-09, 10:15 AM**

I used winisdalpha, is the file broken?

**Yad** · **10-20-09, 10:19 AM**

no, it is not....just my software does not understand it (LEAP & LSPcad)

**Spadez** · **10-20-09, 10:21 AM**

Oh. Well might you be able to model it in your program if I give you the spec?

Nominal impedance [ohm] 8
Voice coil resistance [ohm] 5.5
Nominal power [W] -
Short term max power [W] -
Long term max power [W] -
Operating power [W] -
Sensitivity [dB] 86
Frequency range [kHz] 0.1-15
Free air resonance [Hz] 81
Voice coil diameter [mm] 20
Voice coil height [mm] 5.1
Air gap height [mm] 3.8
Voice coil inductance [mH] 0.33
Eff. diaphragm Area [cm²] 38
Moving mass [g] 3.2
Magnet weight [g]/[oz] 210/7.4
Force factor [Bl] 3.8
VAS [l] 2.5
Qms 3.40
Qes 0.60
Qts 0.51

**Yad** · **10-20-09, 10:23 AM**

ok. Specify the driver please.

**Yad** · **10-20-09, 10:27 AM**

o, sorry. it's VIFA shown above ?

**Spadez** · **10-20-09, 10:38 AM**

Hi,

Yes the vifa one on this page I think, since you said it is a good choice.

For enclosure size im looking at around 60-90CI

**Yad** · **10-20-09, 10:39 AM**

**Spadez** · **10-20-09, 10:45 AM**

Super, I dont fully undserstand the units in that picture, but ill look into it. Is your program able to plot this info on a graph with Hz to see what range the box would give it?

EDIT: Also I beleive that speaker is a mid range and not full range.

**Yad** · **10-20-09, 10:54 AM**

this is model of "cubic" (LSP cad)
well... you can see strong difraction (black line). blue - is half space response.

It's better to make spherical box...

**Spadez** · **10-20-09, 10:57 AM**

I cant see the graph with the black and blu line, am I missing something?

A cube is a bad idea then I guess, Ill look into round ones. Is it important to have mid ranges pointing at you when you listen, can you point up at the ceiling for example?

**Yad** · **10-20-09, 11:02 AM**

this is model of "cubic" (LSP cad)
well... you can see strong difraction (black line). blue - is half space response.

It's better to make spherical box...

wow at least.... too much troubles while uploading ))))))))

**Yad** · **10-20-09, 11:05 AM**

diffraction - re-reflections from the facets of front panel (usually it's called baffle step)

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