Kenford HW-1206 (Rockwood HW-1206) measured TS parameters

[erikjan]

Hi,

Ik recently purchased 4 Kenford HW-1206 woofers from the German webshop A&D Audio for 45 euro's each. Perfect service, quick delivery. When I received the drivers I found them labeled not Kenford but Rockwoord HW-1206. Ik had noticed speculation on the internet that these drivers are identical, and that seems to be the case.
The drivers are well made, heavy, and come with a rather big sized magnet. They feature large (rubber?) surrounds, capable of large excursions. There is however no specification of the max lineair excursion form the manufacturer. 5-6mm seems about right, as a guess.

Well ventilated:

First thing I did was running all drivers for about 24 hrs on 18Hz with about 4mm excursion. I tried larger excursions and did not notice umwanted mechanical noises. Then I measured the impedance and TS parameters. Driver 2 was clearly an outlier so I did a second run in with this driver for about an extra 18 hrs. That fixed the problem. Be aware that the image showing the 4 driver impedance graphs is with the first measurement of driver 2 (to be replaced later on).

White = driver 1
Red = driver 2
green = driver 3
yellow = driver 4

I repeated the impedance and TS measurements 17-11-2024.

driver 1 = Red
driver 2 = White
driver 3 = Green
driver 4 = Yellow

TS parameters (with the correct measurent of driver 2) measured with the Clio Pocket. The first column for a driver shows the first measurement, the columns indicated (2) show the second measurement performed after an additional 24hrs of burn in at about 5mm excursion, 18Hz. Essentially with Fs ~40Hz and Qts ~1,0 this is a good driver for a OB project.

Parameter	Driver 1	Driver 1 (2)	Driver 2	driver 2 (2)	Driver 3	driver 3 (2)	Driver 4	driver 4 (2)
Fs	39,55	39,55	40,28	41,02	37,35	37,35	37,35	37,35
Re	7,0	7,0	7.1	7,1	7,1	7,0	6,9	7,0
Sd	520	520	520	520	520	520	520	520
Qms	9,99	12,5	9,3	10,51	10,69	11,05	11,77	11,69
Qes	1,17	1,14	1,06	1,18	1,22	1,17	1,08	1,09
Qts	1,04	1,04	0,95	1,06	1,09	1,06	0,99	1,0
Cms	0,2375	0,2375	0,2235	0,2415	0,3312	0,2871	0,2871	0,2461
Mms	68,18	68,15	69,84	62,24	54,82	63.23	63,22	73,76
Rms	1,7	1,36	1,9	1,53	1,2	1,34	1,26	1,48
BI	10,08	10,22	10,86	9,81	8,66	9,42	9,72	10,52
dBspl	88,8	88,91	89,17	89,29	89,3	88,86	89,29	88,48
Vas	89,67	89,67	84,4	91,35	125,05	108,42	108,42	92,93
Zmin	7,28	7,22	7,36	7,35	7,31	7,29	7,24	7,24
L 1kHz	0,96	0,96	1,01	1,01	1,03	1,03	0,98	0,98
L 10kHz	0,52	0,52	0,53	0,53	0,53	0,53	0,52	0,52

(2) Second measurement

 

[hurrication]

In the US, Kenford and Rockwood are the cheapest flea market brands.

 

[wg_ski]

No they are not. Q Power is by far worse. AudioPipe isn’t far behind (or above, depending on how you look at it). A 1.0 Q and 89 dB/W isn’t all that bad for a cheap China driver.

 

[erikjan]

It is obvious that these are budget drivers. However, I think for the price you get a lot of driver. For hifi the use cases are limited, even a closed box gets really big (~ 200 liters and more). But, for a compact OB subwoofer, for small to medium sized rooms, crossed over at 150Hz or lower, these drivers are quite good. I did some rough simulations, and a H-frame with two drivers will give you a Fs of about 35-36Hz, and a sensitivity in the 85-86dBspl range. And if you build the H-frame as a M-frame it is really compact (about 45x40x40cm (HxWxD). Not bad. And as far as I am concerned, a nice little project to combine with the pair of Celestion SL6s monitors that I recently purchased for 80 euros (cabinets need work, but technically perfect).

And the budget driver market in Europe does not offer the kind of choices the Us market offers. Most brands available in the US are not available in Europe, and even when a brand is imported it is usually only a limited part of the offerings in the US.

 

[hurrication]

No they are not. Q Power is by far worse. AudioPipe isn’t far behind (or above, depending on how you look at it). A 1.0 Q and 89 dB/W isn’t all that bad for a cheap China driver.

They literally are, I used to see them with my own eyes at flea markets right along Q power and Pyramid/Legacy, and those big traveling speaker sales held at convention centers. Their names are meant to knock off Kenwood and Rockford.

https://www.facebook.com/share/p/1EC9Z63yNU/

https://www.facebook.com/photo.php?fbid=1513890555355515&id=315302638547652&set=a.442711215806793

https://www.reddit.com/r/subwoofer/comments/1fu5d4r/can_someone_help_me_identify_what_sub_this_is

 

[wg_ski]

Well, the specs he provided on that particular one sure beat most of the flea market stuff I’ve seen. And just a basic driver, no bling bling bling. More like a Goldwood. Although you can get those with a stronger motor if you pay enough.

 

[GM]

It is obvious that these are budget drivers. However, I think for the price you get a lot of driver. For hifi the use cases are limited, even a closed box gets really big (~ 200 liters and more). But, for a compact OB subwoofer, for small to medium sized rooms, crossed over at 150Hz or lower, these drivers are quite good.

Yeah, I learned PDQ that as long as limited to its mass loading/acceleration BW (Fhm = 2*Fs/Qts') even a RadioShack 8" 'FR' driver with a 3.86 Qt (highest I've measured) works in free space!

(Qts'): (Qts) + any added series resistance (Rs)

 

[Brian Steele]

They literally are, I used to see them with my own eyes at flea markets right along Q power and Pyramid/Legacy, and those big traveling speaker sales held at convention centers. Their names are meant to knock off Kenwood and Rockford.

Agreed. They are the worst. Well, the worst since you can't get Funky Pup drivers anymore. Or can you ...

 

[hurrication]

🤣 Oh god, I don't think this site is ready for the pups!!!