Goal: 40Hz, 92-94dB, 2 cu.ft

Hello guys.

I would need an advice for the woofers in a 3-ways system.
I was hoping to go down to 40 Hz (around 35 Hz in room), in an enclosure around 1.5-2 cu.ft, with an sensitivity of 92-94 dB (close to 90dB including the baffle step). Also, to keep the price under 100/speaker for the woofer(s)...
Also, I was hoping to do that with paper-cone drivers (I'll use paper midrange and soft dome tweeters). The best solution I could find was a pair of Visaton W 200 S 8 Ohm speakers...

I know I'm asking for a lot... but... any advice, please? :)
 
Visaton, and that driver, are a good idea - and they do excellent customer service. They might help you with complete plans for box, crossover and everything.
Even better, if the exchange rate is a horror (or does Romania have the €?):
If available, have a look at Monacor. Cheaper and really really good, and the plans they offer for free will make you smile.

Greetings,

Pit
 
I have a great tip monacor spa30a, meets perfect your requirements.
MONACOR INTERNATIONAL:product detail page

Here with simulation and reflex port dimensions. 75L so that means a box of 60liter with stuffing.

Great alu frame and bottom price super price performance.

images


Mid frequency. 93dB.
Dayton RS 52
images


or morel EM1308
[IMGHTTPDEAD]http://www.hasaudio.co.nz/images/morelEM1308.jpg[/IMGHTTPDEAD]

tweeter morel et448
[IMGHTTPDEAD]http://www.europe-audio.nl/img/Data/HQ/ET448.gif[/IMGHTTPDEAD]

monacor dt28
mon_dt28n.jpg


monacor dt-25ti
mon_dt25ti.jpg



succes
 

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Thank you Chris, I already played a bit with the BoxSim, and it really seems a very good and powerful program. It also simulates the difraction and several other stuff...
The only thing that worries me a bit about Visaton drivers is that they look... I don't know, cheaper and more fragile than, let's say, Silver Flute or several Vifa or Peerless drivers, not to mention SB Acoustics. I'm talking about the stamped chassis (vs cast chassis for the others) and the aluminium VC. I know that cooper in the speaker's motor helps a lot with the distortions...
Helmuth... an impresive amount of suggestions! I must say I love the idea of a 1st order series crossover, I was also thinking about it, or a 1st order series everywhere, and second or third order for the tweeter only, if I have to cross it low...
The problem is that I really don't know anything about Monacor, I haven't heard of them or of any great project with their drivers...
Also, the monacor spa30a is a PA high sensitivity driver, with great efficiency over 100-150 Hz, but like any other pro driver, poor efficiency down to 40-50 Hz. I'm looking for home drivers, with good efficiency from 40 Hz up to 350-500 Hz.
 
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Most PA drivers have indeed the highest efficiency in the mid/bass band. But, if you want a driver that doesn't need a large cabinet, has good efficiency and can take some power then you should also take a look at this one 10B200

Oberton makes great loudspeakers for a reasonable price. I have two 10b200's at home and they have a stunning bass performance down to 40hz in a 35 liter bassreflex enclosure (tuning between 40 and 50hz).
 
it does not matter - home or pro. high sensitivity (read - low Q) driver have (in the limit) 6db\oct slope at LF :)

Precise it doesn't matter I simulated a lot of drivers. And when the same volume spl and frequency response come together. In simulation they all become the same.

I began with visaton drivers 20 years ago last project I used monacor woofer real good result nice tone dynamic bas and good subbas.
I have to say I am fully satisfied although there is one point they have problems with manufacturing consistency IMO.
If you do not won't a pro driver(they have often better thd figures).

I know a other nice driver from monacor polypropylene cone.
sph-300ct only connect one coil to have 8ohm.

[IMGDEAD]http://www.hifisound.de/oxid/out/oxbaseshop/html/0/dyn_images/1/MON-1101489.jpg[/IMGDEAD]
Heimkino$2BWohnzimmer$2B12.jpg



Good suggestion that oberton chassis. Amazing price for such a cool chassis.
 

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Again the sph300ct port tuned to 30hz.

And the port gain in the second picture.with the port near the floor it is possible to stretch the response down to 30Hz and that with 93dB/1wmtr. it doesn't get better then this.

German hobby hifi magazines use often monacor in their design. I think that visaton promote it self better world wide.
 

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Good suggestion that oberton chassis. Amazing price for such a cool chassis.
In simulation it shows that the oberton driver doesn't support 40Hz 93dB. it is 90 dB

Like some posts before when you want 93dB and cut off at 40Hz you will end op with the same group delay and port tuning and volume. Doesn't matter witch brand driver you find.

I did try it over and over again.
40Hz and 93 dB is a border when you go lower with the -3db point the efficiency will drop. The same as you increase the cut off upwards the efficiency increases.
 

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The oberton 10b200 is pretty efficient for a 10" chassis. You will not get sub-bass out of it (below 40hz) but above 40hz it can get very loud and produces very little distortion. The bass "quality" is outstanding due to the stiff fiberglass cone and fiberglass voicecoil former which keeps the mechanical losses low.
 
I think I'll go with 2 x SB ACOUSTICS SB17NRXC35-8 in parallel for each speaker. They seem to work great and go really low in 45-50 liters. Decent sensitivity, and I love the aluminium cast chassis, the low distortions due to a lot of cooper in the motor, and it has a paper cone. I'll mate it with an SB ACOUSTICS SB15 as a mid and a SB ACOUSTICS SB29RDC for a tweeter. I can't cross them first order, but I'm sure they will sound great!
 
I think I'll go with 2 x SB ACOUSTICS SB17NRXC35-8 in parallel for each speaker. They seem to work great and go really low in 45-50 liters. Decent sensitivity, and I love the aluminium cast chassis, the low distortions due to a lot of cooper in the motor, and it has a paper cone. I'll mate it with an SB ACOUSTICS SB15 as a mid and a SB ACOUSTICS SB29RDC for a tweeter. I can't cross them first order, but I'm sure they will sound great!

SB ACOUSTICS looks like great drivers for the money. Are they available in Romania?

simulation calculates 91dB 1wmtr. SB-acoustics claim 89dB one driver that shout make 92dB for two drivers.

You can cross them 1st order why not maybe adding a notch filter, RC-RL impedance compensation.

And tweeter tip vifa XT25TG-30/04 is cheaper and looks hightec.
[IMGDEAD]http://www.europe-audio.nl/img/Data/HQ/xt25tg-30-04.gif[/IMGDEAD]
 

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Yeah, they should be pretty efficient. Specially if you consider that with placing them in parallel, the impedance will go down to half... I loved the SB23NRX woofer (twice the cone area!), but 2 of those require about 80 liters or more to go lower than two SB17NRX.

There is no "official" SB Acoustics dealer in Romania, but I can get the drivers here from a very small company.

I wouldn't cross them via a first order crossover due to the relatively low breakup points. And I would rather avoid any complications in the crossover, since this will be the first crossover I'll build on my own. :)

About the tweeter, yes, I have heard a lot of good things about most of the Vifa XT25 tweeters, but I really don't like their "nipple". It's a personal thing, nothing wrong with the drivers. The SB29RDC is another approach to the ring radiator: the "dimple". I love the way it looks, I love how flat the freq plot is, and I only heard good things about it!
SB Acoustics :: SB29RDC-C000-4

Now, I only have to decide upon the design, get some more money, and order the drivers. I saw a crazy, but very original, impressive and beautiful build thread on this forum, thread started by trusound:
http://www.diyaudio.com/forums/multi-way/169849-lowther-dipole-2way.html

I just love the bass cabinets and the arm holding the dipole in his project!
Also, I read a lot about the diffraction lately, and the fact that a spherical enclosure will cancel the diffraction better than anything else is stuck somewhere in my mind. So I was thinking about combining the 2 ideas, by building something like in the attachment (please excuse the crappy scheme, it's made quickly in paint). If not, I'll settle with a "classical" TransLam 3 ways tower, with a rounded cabinet, something like the "Sonus Faber Cremona M" speakers.
 

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