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4" drivers

So in an attempt to make my hobby really fun again, I decided to take this year and just focus on a specific driver size. Strange as it sounds, I just want to do some experimenting and decided on the 4" size class due to: cost, size of finished product, and just to see if I can find a 4" driver that surprises me in the same fashion as the (in my opinion) best in class (based on performance/cost) 4" which is the poly cone HDS. I am unsure if I will find a similar driver at that price point, but that is no deterrent.

First up is the Dayton CX120 woofer module and a 4" driver from Aliexpress. They are both 120mm frames, but that is where the similarities end.

The Dayton uses a poly cone, the Aliexpress uses aluminum. The Dayton currently has a gaping hole where I removed the tweeter, the Aliexpress has a shiny gold phase plug. The Dayton is overall a driver with lower build quality. For example, the top and bottom plate on the Dayton is stamped - the Aliexpress is machined. The Aliexpress has gold plated terminals and uses the 6 hole mounting. The Dayton has the tinned terminals and uses a four hole mounting. The Aliexpress frame has additional supports in the gap under the spider. The Aliexpress has a notably larger motor and considerably more overhang excursion. The Dayton has (I think) 3mm of advertised Xmax. There is at least 2mm additional on the Aliexpress. The Aliexpress is one very nice looking and built driver. It likely does not have any kind of shorting rings in the motor, but neither does the Dayton. I plan on adding a poly dustcap to the Dayton. The Aliexpress phaseplug is well centered.

The Dayton measured more or less as advertised, the Aliexpress yielded this:

In my opinion, decently usable for a 4" driver. Reasonable sensitivity for a 4", but that is due in no small part to the 4 ohm impedance. Both drivers measured within a percentage point or so. I am generally impressed with this little guy. A pair will currently run about $100 shipped, so absolute value isn't really there - but maybe if it measures well enough in linear and non-linear distortion I will find out how much a much larger quantity would cost to import.

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ugly_wooferrjj456thplanet4thtry
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Comments

  • I have two more pair of different Aliexpress drivers still to arrive along with several different Vifa ring radiator knock-off tweeters just for fun.

    I have a pair of old HiVi M5A that I will use as a control. It is well-known, and Zaph did some measurements on it back in the day so it can serve as a control that we can easily use to compare the performance of the Chinese drivers. When the rest of the drivers get here, I will cut a 4' x 4' baffle and take some measurements.

    Hopefully I end up with three pair of small speakers each with a 4" Chinese woofer and a knock-off Vifa ring radiator tweeter. I am looking forward to this summer.

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  • Forgot to point out something kind of minor - the mounting holes on the Aliexpress are somewhat larger than the Dayton. Not sure if that is good, bad, or who gives a shit - just something interesting that I never gave thought to before.

    6thplanet
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  • PS, the Dayton I tore down was first generation with the unfortunate air leak problem. Figured it was a good one to sacrifice to do some experimenting with the driver as a dedicated midbass. I might plant a copper washer on top of the pole-piece before gluing a dustcap in place, just to see. I'm not worried too much about changing the gap geometry since it is already extremely limited Xmax - but if it does some good for the midrange and lower treble distortion it might make it a pretty good midrange. The tweeter module is just not very good on these things.

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  • I love the idea of multiple 4 inch builds.

  • Why all this fuss? Just build the Holy Grail of DIY 4" speakers... the awesome Nano Neo's. LOL

    Wolfjr@macScottSS7910
  • Multiple 4 inch drivers in a horn would be fun =)

     John H, thanks to JP I did get that email
  • The carbon fiber and black nipple showed up late this week:

    Carbon Fiber measured parameters:

    They are definitely both good looking drivers in my opinion.

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  • Curse you JR! Those look nice and I've done some searches on Aliexpress...its amazing how drivers can accumulate on a storage shelf and not build themselves into actual speakers.

    rjj45Steve_Lee
  • I like those CF drivers :)

  • My personal favorites are the 6 hole flanges. 8 would be better... The original HiVi D6.8 had 12 holes, which is probably why they sounded so good.

    jr@mac
    Keep an open mind, but don't let your brain fall out.

    Sehlin Sound Solutions
  • Imagine how good they would sound with 16 holes or better yet 24. =)

    jr@mac
  • While I personally do not care how many mounting holes are used - it is an indicator of where money was spent and where money was saved (it costs money to machine those out). Unless it is the Dayton DA/DS/DSA drivers than the odd number is ridiculous.

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  • @ugly_woofer said:
    Imagine how good they would sound with 16 holes or better yet 24. =)

    Spread the word and watch as impressionable audiophiles start drilling extra mounting holes in their woofers, mids & tweeters.

    rjj45
  • Sometimes I wonder if we overestimate the power of a bookshelf speaker at 87db.

  • @ugly_woofer said:
    Imagine how good they would sound with 16 holes or better yet 24. =)

    That ^ is the 'spice of life' to a screwdriver . . .

    6thplanet
  • @Tom_S said:

    @ugly_woofer said:
    Imagine how good they would sound with 16 holes or better yet 24. =)

    Spread the word and watch as impressionable audiophiles start drilling extra mounting holes in their woofers, mids & tweeters.

    Maybe I can start selling the service of adding extra holes to drivers, and magic power power cords. Lol

    4thtry
  • edited March 16

    So you could remove the metal from the framed then glue pieces to the cone for a "balanced" driver

    I remember the conformal(Enable?) coating guys who said the pattern of dots on the cone was important and changed the sound dramatically.

    https://www.enjoythemusic.com/diy/0310/modifying_ff85ken.htm

    4thtryrjj45
     John H, thanks to JP I did get that email
  • The LAT250 had 30 screws in it! I purposely used hex-head screws and used the 1/4" driver to install them. Much better than a handheld screwdriver...

  • edited March 17

    @jhollander said:
    So you could remove the metal from the framed then glue pieces to the cone for a "balanced" driver

    I remember the conformal(Enable?) coating guys who said the pattern of dots on the cone was important and changed the sound dramatically.

    https://www.enjoythemusic.com/diy/0310/modifying_ff85ken.htm

    I must have missed the trend of stuffing the frame openings with felt or batting. Blocks reflections from hitting the back of cone....OK. Yeah, I'll bet that driver sounds very different with all crap that in place! ;)

    4thtry
  • Is that ^ supposed to be an aperiodic sealed back driver?

    4thtry
  • edited March 17

    @Wolf said:
    The LAT250 had 30 screws in it! I purposely used hex-head screws and used the 1/4" driver to install them. Much better than a handheld screwdriver...

    Yup. 30 it is. Those things sounded amazing! (InDIYana 2015).

  • Looking at the photo again, I think they just wrapped the spokes with that stuff, not stuffed the openings. But they do mention "the restriction of airflow" due to the frame. Now that seems like poor engineering, but they don't show any examples.

    JR - sorry to have dragged this thread off course. Your woofers don't look like they will have any problems with airflow!

  • edited March 17

    George did a great job on his build of my NEHDs. Said his wrists hurt for a while after they were mounted.
    The great thing about them is the horizontal off-axis response, and that the Z offset is '0' top to bottom.
    It's still the weirdest 3-way I've done. McJerry told me, 'Thank you for being different!' when he heard them back in 2008.

  • One of the last pair of drivers showed up. Waiting for the other one to get here. The seller sent me a message that it would have cost 4x as much to ship if they were paired up.

    Hoping the last pair of nipple tweeters show up with it. These woofers/tweeters were ordered quite a bit before the other stuff and is the last to show up.

    Anyways, I am considering adding one more pair to the mix, even though they are obviously not targeted towards the same kind of application:

    https://www.aliexpress.com/item/1005003162082561.html?spm=a2g0o.cart.0.0.78773c00mGyWVu&mp=1

    The rubber boot looks like it is pulled back to get a better view of the top plate. The top plate looks a few mm thicker than the other 4" drivers, is machined, and it has a 30mm voice coil instead of the 25mm the others use.

    It only has four mounting holes, so performance definitely takes a hit.

    In all seriousness, I only brought that up originally to point out where costs are cut on different drivers. The frame with six holes also has the additional struts under the spider - the extra material and the extra machining adds cost. Not sure if either feature is really important on a 4" driver.

    Steve_Leejhollanderrjj45
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  • Looks to be worth every penny of the $45.

  • @ugly_woofer said:
    Looks to be worth every penny of the $45.

    That's what I'm thinking.

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  • Aiyima sells some pretty respectable little amps. I've looked at some of their drivers, but haven't pulled the trigger on any yet (I have to build a few more speakers before I'll let myself add anything more to the driver shelves - at least that's what I'm telling myself). Those definitely look interesting.

    Keep an open mind, but don't let your brain fall out.

    Sehlin Sound Solutions
  • @jhollander said:
    So you could remove the metal from the framed then glue pieces to the cone for a "balanced" driver

    I remember the conformal(Enable?) coating guys who said the pattern of dots on the cone was important and changed the sound dramatically.

    https://www.enjoythemusic.com/diy/0310/modifying_ff85ken.htm

    Yah, that was effing hilarious! Something like 1500 posts with "The light is shining now!"

    Don, Donno, or "Hey you" all work for me, But never "Mr Johnson"
  • Got six flat packs cut up yesterday. Will glue one pair a day today, tomorrow and Wednesday. Tomorrow, Wednesday, and Thursday I will machine the previous days glue-up. Still to come is the 4x4 test baffle - wanted to make some scraps first to build multiple inserts.

    jhollanderrjj45ugly_woofer4thtrysquamishdrocSilver1omo
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  • I also calibrated my fancy new metric Jasper jig, yesterday as well.

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