Chinese/Taiwan 4” Dual Cone Speakers

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For the ferrite one we used the standard Fostex box that we built for the FE103E months ago but we changed the reflex port lenght to 50X17,5mm. As the deepth of the box was less longer, we used a curved pvc tube. A quite bigger volume (some 2-3 litres more) in simulations could give a more extended and linear bass freqs but with those boxes the sound is very good too!
 
For the ferrite one we used the standard Fostex box that we built for the FE103E months ago but we changed the reflex port lenght to 50X17,5mm. As the deepth of the box was less longer, we used a curved pvc tube. A quite bigger volume (some 2-3 litres more) in simulations could give a more extended and linear bass freqs but with those boxes the sound is very good too!

Thank you Peppennino, it would be great to collect people's experience and projects for these speakers, IMHO they are really nice!

It would be also nice to report experience about Scottmoose's project, AFAIK the only custom project for neo version!

Ciao
 
Why not

hi
i want to use this speaker for open baffle. what do you think?
there is new version for 5":
2pcs pair DAVIDLOUIS AUDIO HiEND 5 inch full range fullrange speaker PK lowther & fostex-in Consumer Electronics on Aliexpress.com
thanks
This would be okay for an open baffle; be prepared to augment the bass somehow.
Specs are similar to the 4" version I've got (4).
Mine work well as open baffle, sealed in 0.25 ft. cabinet. I even tried them as a tweeter- alright but not the best.
These aren't as smooth as a tang band, but are very enjoyable, and much less costly in Canada after the shipping burn.
 
4" whiz

That's a bit more like it. I can see the point of a 5in driver with a whizzer cone. More than a 4in anyway, and it's a pretty enough thing (for a drive unit -Rachel Weisz still has a considerable edge on that score ;) ). Probably OK for what it is.

I owns pair of 4" Tang Band magnesium cone full rangers,(15,000 hz) as well as the neodymium titanium 4" (20,000 hz rated, but the top seems to have a lot of resonance in it). Neither of these disperse as well off axis as the whizzer coned Taiwan 4"er.
I'm assuming it's the whizzer that's responsible.
And Rachel Weiz is stunning.
 
Actually, once again the pioneers figured it out ~ from the get-go:

GM
 

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Yeah, having available the 'deep pockets' of Bell Labs/W.E., RCA and later the movie industry allowed for the 'best of the best' of everything.

Some of it has, but nothing's changed, custom hand-made products of this type are only available to the wealthy. The couple of salaries for the best engineers I've seen published would be handsome even by today standards, so movie star paychecks once inflation adjusted.

GM
 
Last question about power before i order this 4".
i have the F5 25W class A amplifier for this speaker.
now i have bose acostimas full range speakers (they say 50W rms) and the power is fine.
this 15W looks very low. i"m wrong?
thanks

I'm driving mine with either a 6 watt 300B or 10 watt EL34 amp, depending on what mood I'm in.
Since I'm not asking them to do bass, it's been plenty of power.
You should be fine.
 
moving forward slowly

Looks very cool. I think you may have built yourself and accidental mass loaded transmission line (AMLTL). The port looks a little on the small side and that may be what is limiting your bass. Put some pillow stuffing in the upper third to half to reduce resonances.

What is the port dia and length you are using? A good rule of thumb is the port cross sectional area should be about 1/3 the area of the cone. Then set the length based on tuning. It appears to have quite a low fs which is good. Set the tuning freq just at of little below fs - say 60 Hz. What is the length of the pipe from driver face to bottom at base?

One thing you may be getting is a loss of bass due to baffle step loss as the area around the driver is small. You will need a baffle step compensation circuit to reduce the highs to balance with the bass. Probably a 0.8mH + 4 ohm resistor in parallel to start with and see if that helps.

thats what im all about the accidental design, thanks very much for your response i have now upgraded the port to a 35mm internal tube witch i winISD ed to 37 mm long ?? and will stuff as you suggested when installing driver im interested in the relationship between the distance the driver is from the port ?? mine so far is 490mm from center port to center driver hole my baffel dia is 165mm ive purchased my baffle step stuff i got from my local JCAR .82mH and 3.9 ohm res just to check i wire these 2 components in parallel then insert into pos lead to driver once again thanks for the responce
any further tuning advice is much appreciated including modding pipe lengths ect as im going to prep them for paint soon once there painted that will be it


colors ???????
 

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