HiVi LK8A

jr@mac

If the advertised specs are accurate, this is a killer sealed box and vented box woofer. Long throw, etc. 

I did some modeling using the provided TS, and using some various settings in WBCD and 0.5 - 1.0ohm series resistance, I was able to see low to mid-30's in 30L vented, and mid-40's sealed. Outstanding. There are some wrinkles and a rise in the impedance not congruent with modern advanced motor design - but that may simply mean it is limited to 3-way use for a high end build. However, it is my belief that the impedance curve receives too much attention when it comes to judging distortion, so I will wait for 3rd party feedback. 

My greater concern is the history of HiVi being, shall we say, less than reliable on their provided specs. I have measured enough of them at this point not to trust a damn thing they claim. Le sigh, looks like a killer woofer on paper. 

https://www.parts-express.com/hivi-lk8a-8--sandwich-cone-woofer--297-712

dcibel

Sensitivity is low for an 8" driver, an obvious compromise for cabinet size and excursion.

Wolf

I think it looks great too!

PWRRYD

Wolf said:

I think it looks great too!

I agree

Nicholas_23

I wonder what the creamy center is made of ? Looks like styrofoam maybe 

Wolf

It's likely a composite that isn't Rohacell but made to approximate it. They really put a lot of good design principles into this woofer.

Gowa

It needs a larger dust cap.

dcibel

It needs a larger voice coil to justify the size of the dust cap

Ed_Perkins

Looks interesting, but for $20 more you could get an equivalent Wavecor.  You certainly can't fault Wavecor's data sheets - on & off axis, impedance, distortion and CSD .

https://www.parts-express.com/wavecor-wf223bd02-8-3-4-balanced-drive-paper-glass-fiber-cone-mid-woofer-8-ohm--298-1214

dcibel

The current "sale price" is a pretty good price on that Wavecor. The Hivi would be a lot more attractive if they actually sold the trim rings that they use with that frame in the Swan commercial speakers. The lip of the surround isn't super attractive to me, even the L6-4R with a similar frame edge has a flush surround so it looks cleaner.

Ed_Perkins

Was looking at this driver again and noticed PE has the Sd listed as 324 cm2.  That can't be right for an 8" woofer, maybe it should be 234?

Tom_S

I think you're right - just a data entry error at PE. The cutout diameter is 7.5", about the same as the Peerless HDS 8" - that woofer has an SD of 227 cm2.

Ed_Perkins

I calculated 213 cm2 using the other published T/S parameters, so we're definitely in the ballpark.

DaveFred

Anyone ever pull the trigger on this one?

jr@mac

On sale today for $90.

DaveFred

$90 today, what was it before?

I find PE's prices hard to follow. "List"=MSRP that no one has ever sold it for, "Sale"=Street price.

DaveFred

Actually PE has them for $89.99 on Amazon.com, so I don't really know how they can be considered on sale at PE...

jr@mac

It was a "flash sale", one day only. They are back to $130 now.

DaveFred

Opps, my bad.

DaveFred

Here are the specs,

72 litre box
F3 = 35.41Hz
F6 = 26.84Hz
F10 = 20.35Hz

42 litre box
F3 = 37.08Hz
F6 = 29.44Hz
F10 = 22.95Hz

30 litre box
F3 = 39.55Hz
F6 = 32.29Hz
F10 = 25.4Hz

Wolf

For me- 4Hz loss in less than half the volume is a no-brainer.

Ed_Perkins

Looks very enticing. Your measured T/S parameters are pretty close to the HiVi spec.s which is nice. How did you arrive at Xmax = 5.3 mm? I see HiVi lists it as 8 mm.