Chinese/Taiwan 4” Dual Cone Speakers

[mrneedle]

I think the speakers are rating 15W, so for safety sake you'd better stay way beyond clipping zone .
Volume knob position depends on your system (do you have an active preamp? what is the sensitivity of your amp? what is the output voltage of your sources? and so on...).

How did you find the design you use?

Ciao!

Yeah i know they are rated for 15 w, my amp is rated 13w. I use it with a noname solid state riaa pre. But seeing the cone come out this far with the volume at 50% I didnt dare to turn it up higher.

The design is a mixture of ideas. I used a friends TL as example, but folded it to keep it small. I tried some guessculating and came up with the length of around 100cm/110cm. Which is to heigh so i folded it. De lower part is filled with sand to give it more weight.

Still the blake record sounded awesome but the dark dark dark record sounded kind of dull

James Blake - Limit To Your Love - YouTube
Dark Dark Dark - Daydreaming (Official Video) - YouTube

 

[GM]

How hard can I drive the speaker? I did have my amp (iTube) volume knob 50% and didn't dare to turn it up higher...

the whole construction is filled with pillow stuffing. but how much should there be? do I stuff it lightly or completely full and tight?

another question I have is how big the hole on the backside should be?

Probably just a few watts down low.

Depends, though mostly it depends on how little is required to make them sound good to you.

Don't know which driver you used or the cab design specifics required to do a sim, so no clue.

GM

 

[peppennino]

Almost certainly a Guide Sound (the people who make the Audio Nirvana drivers) unit. Slightly different to the AN drivers, but based on the stated figures similar inasmuch as there are few quality reflex alignments available, and those that are, are large by current standards. If you want flat, about 19.5ft^3 tuned to 25Hz will get you ~'close enough.' Of course, a flat alignment is very rarely useable in-room, so you'd probably need to drop Fb to about 20Hz for something more practical. Sealed, TL or leaky sealed (what's often called aperiodic) would be preferable.

Thanks Scott!

 

[mrneedle]

Probably just a few watts down low.

Depends, though mostly it depends on how little is required to make them sound good to you.

Don't know which driver you used or the cab design specifics required to do a sim, so no clue.

GM

Ok well the driver specs are found in the first post but i'll attach them again since were at page 17.

the cab specs are attached, the wood I used is 12mm powerplex. the total size of the inside "tunnel" would be 120cm x 11cm x 8,8cm filled with pillow stuffing.

As I said before I'm a compleet newbie and trying to use all the combined information I find on the web.

I'd love to try a frugal horn but it's just a bit bigger and I need to take into account the WAF. I can put new speakers in the living room but they can't be bigger than the previous speakers...

the previous speakers being: 90cm x 12cm x 20cm

 

[birca1987]

Ok well the driver specs are found in the first post but i'll attach them again since were at page 17.

the cab specs are attached, the wood I used is 12mm powerplex. the total size of the inside "tunnel" would be 120cm x 11cm x 8,8cm filled with pillow stuffing.

As I said before I'm a compleet newbie and trying to use all the combined information I find on the web.

I'd love to try a frugal horn but it's just a bit bigger and I need to take into account the WAF. I can put new speakers in the living room but they can't be bigger than the previous speakers...

the previous speakers being: 90cm x 12cm x 20cm

Hi, I'm in the same situation as you, and I was watching the TABAQ thread and found the plans for building a TABAQ model. Your speakers look a bit identical to TABAQ and you can try the stuffing like in those drowings and you have to modify the back hole like in TABAQ design and let us know

 

[mrneedle]

Thanx birca! That looks promising, although this is a four inch driver I'll see what happens.

ok, I've removed the middle piece, filled it half with pillow stuffing and made the opening smaller at the back.

the bass has improved but the middle really sufferd...

 

[birca1987]

Thanx birca! That looks promising, although this is a four inch driver I'll see what happens.

ok, I've removed the middle piece, filled it half with pillow stuffing and made the opening smaller at the back.

the bass has improved but the middle really sufferd...

Try to remove some stuffing as they only use 100 gr per box and as well try to add a piece on the bottom like here

 

[mrneedle]

Ok I'll try that but won't have the time until Monday... I'll built a complete new one with the speaker also a bit lower.

 

[erez1012]

i speak with the seller and ask for the max power and the answer is 50 W

 

[GM]

Ok well the driver specs are found in the first post but i'll attach them again since were at page 17.

the cab specs are attached, the wood I used is 12mm powerplex. the total size of the inside "tunnel" would be 120cm x 11cm x 8,8cm filled with pillow stuffing.

As I said before I'm a compleet newbie and trying to use all the combined information I find on the web.

Ok, just wanted to make sure which version you’re using.

Hmm, your design has a ultra ‘fast’ expansion/contraction through the bend [its area is ~13.6% larger] that I’m not set up to sim, so can’t do as accurate a sim and never having experimented with different ‘choke’ points, no clue then how it might affect TL pipe action, if at all at this relatively low percentage.

I assume that the 10 cm vent is a circular hole and that it and the driver cutout is down 7.5 cm to their centerlines from the inside of the cab.

Two sets of default reflex cab alignments can be made with the published specs, 13.709 L/51.78 Hz [using BL, Mms] and 19.591 L/51.95 Hz [using T/S], so using T/S for your cab…………….

The 1st sim is with no stuffing and we see that it has a much too high an aspect ratio for its net volume [Vb], ~70 Hz pipe tuning, so adding any damping will just further reduce [mid] bass output and enough stuffing to damp the dip requires more than the software can sim!

Little wonder then that most recordings will sound dull if heavily damped enough to minimize its 3rd harmonic dip up around 280 Hz, so better off overall to remove most of it and seal up the vent.

To deal with the dip and tuning requires moving the driver down to ~41.86 cm and the vent down ~24 cm and reducing to a 2.4 cm diameter hole to lower tuning to ~52 Hz [2nd sim].

Now, a minimal amount of stuffing along its length [0.25 lbs/ft^3 of polyfil] smooths it right out with a nice amount of mid-bass baffle step compensation [BSC] and/or a bit of mid-bass ‘slam’ if near a wall or corner, though still not much bass as the driver’s Fs is too high and the cab is too small [3rd sim].

GM

 

[GM]

Ok I'll try that but won't have the time until Monday... I'll built a complete new one with the speaker also a bit lower.

Using your previous speaker dims and keeping the driver at 7.5 cm, a 2.4 cm diameter vent down ~70.1 cm yields an acceptable response with somewhat more bass at the expense of some mid-bass, but still a better overall alignment in general and especially if it can be near a wall or corner.

GM

 

[mrneedle]

Ok, just wanted to make sure which version you’re using...
GM

Wow! GM Thanx! So I guess loosing the sand and making the box bigger would be better. What software are you using?

 

[GM]

You're welcome! MJK's long time unavailable MathCad freeware and sadly, no longer available cheap software, which is much more powerful, flexible.

GM

 

[mrneedle]

Ok just to be thorough I've drawn the new cab plan, I'll be using your suggestion of [0.25 lbs/ft^3 of polyfil] can't wait to try this

(the speaker will be near the wall. another setting to play with...)

 

[Goodlagger]

sounds like your getting close

Ok just to be thorough I've drawn the new cab plan, I'll be using your suggestion of [0.25 lbs/ft^3 of polyfil] can't wait to try this

(the speaker will be near the wall. another setting to play with...)

hi i am to experimenting with this speaker different cab design though im not having much luck with have got a few more mods to try but might have a crack at yours one question to those involved helping with the design can the port be swung to the front with out any cabinet changes

 

[ttan98]

A variation to this 4" Driver

Hi,

I own a pair of this 4" driver which I bought about 2-3 years ago using neo magnet and I was very happy with its performance. Except for a spike at around 8Khz which I designed a notch to fix it I was totally happy with it.
The designer is following the same foot path of this drivers has manufactured a similar driver using the same technology but it is now 5" and spl is about 90dB at 8 ohms. See attachment for an image, it also costs more. You can buy them from Aliexpress or Ebay via anitaydavid shop or search for DavidLouis Audio Hiend at Ebay. I took the risk and bought a pair. If they are any good I will report back.
BTW I am not associated with the supplier. I actually pay full price for them.

 

[GM]

FWIW, even though 0.25 lbs/ft^3 isn’t much once distributed along the cab’s entire length, many folks wind up using less in reality, but if I don’t make the sim look smooth, folks tend to dismiss them as too ‘rough’/not good enough.

I see I forgot to mention that all my dims are inside [i.d.] and assumed it would be made from 1.2 cm thick material, but the minor differences between i.d. and o.d. are insignificant.

Just to be sure we’re on the same ‘page’, the dims are to the hole centerlines.

BTW, relatively small, lightweight [ML]TLs ideally need to be mass loaded to the floor due to its 1/4 WL pipe action, so heavy weights such as a potted plant perched on top is a good plan [one designer loaded them with stacks of old LP albums and another used old cookie tins full of pennies], ditto some sort of outrigger framework to stabilize them.

Anyway, looking forward to how these perform in room.

GM

 

[GM]

one question to those involved helping with the design can the port be swung to the front with out any cabinet changes

Yes, the sims assumes it's on the front, so with it on the rear there will be a minor change in response due to a slightly later arrival time plus reflections.

GM

 

[mrneedle]

So I built the plans today but found out the wood was cut wrong. some pieces were not rectangular. I decided to built the plans anyway and overal I'm amazed what this driver can do.

I didn't think the amount of bass would be possible from such a little driver. But then again it could be better.

I listened quickly to some bass heavy records and they sound ok.
some other more acoustic records sound very nice, (for instance Thomas Dybdahl, Patrick Watson)

but I'd still have to give them some more listening time....

Maybe it's because I have the port at the back, maybe the room is to big. probably the cab is to small... I also could play a bit more with the stuffing. and placing them near or further away from the wall.

I still like m for now, but they looked a little crooked and out of shape so I went back to the store and they were kind enough to do it over again...

so I have some more building to do, when they are finished I'll post a picture.

Also a friend of mine offered me to borrow a Denon mic. He got it with his new receiver. Together with an audio sweep cd record. It wil auto set the EQ settings. pretty cool gadget i think. I'd like to record the sweep cd to my computer and see what the speakers are doing.
Don't know if it will work but I like the experiment.

Just one more question GM, I looked into buying the MathCad software, but couldn't find a trial version. Is it worth buying if I like to design another cab, maybe 2?

 

[GM]

Yes, but I've been told MJK no longer will sell/license it. Bummer! By the time I found out it was too late! 'Snooze you lose'.

GM