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Aiyima Audio Labs 6.5" 4 ohm woofer

Here is a well built, nicely thought out Chinese car audio driver. It has a nice frame with under spider venting and a vented back side. The machined trim might be a turn off for some people - but (imo) lends a nice contrast to the all black cone and surround. The cone is machined aluminum, concave dust cap, rubber surround and flat spider. Peeking through the under spider vents, it looks like around 5-6 mm of coil showing.

They are still warming up from being in the mailbox, when they are at room temp I will exercise them and take some sweeps. Out of the box, they exhibit high compliance with a semi-loosey goosey suspension and GOBS of mechanical throw, and I am talking at least 12mm one way of throw. The soft parts act as an arrest - I could not bottom things out so a bumped back plate is likely not necessary here. 

It is a true 165mm driver, meaning it will drop into stamped frame cutouts, although the lip is a few mm shallower than the typical gasketed 6-1/2" woofer so for flush mounting in existing enclosures a thick gasket may be required.

This is a damn fine looking driver, although at the imported price of ~$60/ea probably is not a good absolute value. The advertised specs do nto mention shorting rings etc, so... I have a specific purpose for this driver, I wanted something better than the stamped frame stuff out there but do not want to modify the enclosures to accept a cast frame driver. This fit the bill, had excellent T/S parameters, etc. 

Here it is from the front (pardon the potato quality of my cell phone):

...and here is the ass:

You can see the very long throw potential in the basket design. Note the top plate is machined, which is nice. This really is a nicely built driver. 

I'll get T/S in an hour or so, I'll set them on the furnace duct. 

I have a signature.



    You can see the rising inductance squashes the breakup, but also starts a mild roll-off starting at 1K, -6db around 2K. Should be easy enough to massage a 4th LR at 2K or so on this. 

    We will see what some further measurements show us.
    I have a signature.
  • Okie dokie, some warmups and some calisthenics later this is what I came up with.

    Here are both drivers overlaid:

    Close enough for me. 

    Here are the measured TS compared to advertised:

    Here is the text grab of those parameters:


    Fs  = 46.00 Hz
    Re  = 3.48 ohms[dc]
    Le  = 124.25 uH
    L2  = 326.36 uH
    R2  = 9.82 ohms
    Qt  = 0.37
    Qes = 0.43
    Qms = 2.61
    Mms = 15.94 grams
    Rms = 1.764817 kg/s
    Cms = 0.000751 m/N
    Vas = 18.58 liters
    Sd= 132.73 cm^2
    Bl  = 6.081322 Tm
    ETA = 0.40 %
    Lp(2.83V/1m) = 91.75 dB

    Added Mass Method:
    Added mass = 25.10 grams
    Diameter= 13.00 cm


    Fs  = 46.79 Hz
    Re  = 3.53 ohms[dc]
    Le  = 121.70 uH
    L2  = 356.43 uH
    R2  = 10.38 ohms
    Qt  = 0.38
    Qes = 0.44
    Qms = 2.75
    Mms = 16.18 grams
    Rms = 1.728956 kg/s
    Cms = 0.000715 m/N
    Vas = 17.69 liters
    Sd= 132.73 cm^2
    Bl  = 6.168274 Tm
    ETA = 0.39 %
    Lp(2.83V/1m) = 91.62 dB

    Added Mass Method:
    Added mass = 25.10 grams
    Diameter= 13.00 cm

    I really expected Le to measure higher, I'll take it. 

    Here is one of them overlaid with a 5" SB Acoustics driver, to demonstrate the inductance rise:

    Keep in mind, the price I paid for these Aiyima drivers is effectively the same as what the SB will cost you (the black aluminum 8 ohm 5" model). So, what I mentioned about absolute value is likely very true. Now, if someone were to import, say quantity 1000 of the Aiyima (and they came packaged like HiVi packages things, incidentally - two to a molded styrofoam enclosure) I imagine the retail price would drop considerable. 

    Here are a couple very quickie models I threw together to get an idea of how they will perform in their intended installation:

    These drivers make me very happy, cost notwithstanding. 

    I have a signature.
  • Nice find on these, JR. Looks like a really solid driver.
  • Yup, nice. Except the deep back side. Not shallow mount friendly.
  • Good looking driver! Makes me think I should dig out all the china crap I got and retest them.
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