Polk Audio MM840 DVC

[timsm80 10+ year member]

I've read a ton of great reviews on this sub i believe im going to get one any final advise?

it will be ported in the trunk and 350W@2ohms....thanks for any feed back

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[kramer_212 10+ year member]

for a boat, be more specific.

 

[timsm80 10+ year member]

i didnt know a boat had a trunk! its going in a car

 

[scparrish 10+ year member]

if you abuse them they won't hold up for long. but they sound good with very little space requirements.

 

[timsm80 10+ year member]

i see u have the 10s well i wont abuse them im getting in my 30's now and want quality not quantity and im truck driver gone 95% of the year so they wont get used much but the xmax is rated high and the vids of the 10's look retarted i believe they will hit plenty hard enough with one 8 ported!!

 

[scparrish 10+ year member]

yeah my 10's are pretty good but I think their rms is over rated though.

 

[THATpurpleKUSH 5,000+ posts]

There is more to a "good" sub than just a high xmax figure.

 

[timsm80 10+ year member]

got any other ideas for a 8 around $100 for sound Quality...ive looked at all of them!!!

 

[THATpurpleKUSH 5,000+ posts]

Skar VVX 8 or DC LVL 2 but those are a little over $100. PM mylows10 for a price quote on the DC, he is a DC rep.

skar link: SSA Store - SKAR Audio VVX Sub woofer note the low inductance, this is important for transient response, or the ability to sound musical and not boomy.

The Infinity Reference series also comes in an 8 and sells for under $100. It has even less inductance than the Skar 8. The only downside is that it comes in svc 4 ohm only. Here's a link to it, the pdf downloads for the manuals arent working, but I have a pdf for the 8 on my pc, I'll see if I can dig it up. http://www.infinitysystems.com/car/products/product_detail.aspx?prod=REF860W&cat=SUB&ser=REF&Language=ENG&Country=US&Region=USA

copied and pasted from my pdf:

SPECIFICATIONS

DIAMETER: 8" (200MM)

SENSITIVITY (2.83V @ 1M): 91dB

POWER HANDLING: 250WR M S (1000WPEAK )

FREQUENCY RESPONSE: 30HZ ~ 400HZ

NOMINAL IMPEDANCE: 4 OHMS

VOICE COIL DIAMETER: 2.0" (51.0MM)

THIELE-SMALL PARAMETERS

VOICE COIL DC RESISTANCE: REVC (OHMS) . . . . . . 3.30

VOICE COIL INDUCTANCE @ 1 KHZ: LEVC (MH) . . . . . . . 2.31

DRIVER RADIATING AREA: SD (IN2) . . . . . . . . 33.17

SD (M2) . . . . . . . 214.00

MOTOR FORCE FACTOR: BL ™ . . . . . . . . 12.56

COMPLIANCE VOLUME: VAS (FT3) . . . . . . . . 0.54

VAS (LITERS) . . . . . 15.23

SUSPENSION COMPLIANCE: CMS (μM/N) . . . . 232.70

MOVING MASS, AIR LOAD: M MS(GRAMS). . . . 124.20

MOVING MASS, DIAPHRAGM: MMD (GRAMS) . . . 122.40

FREE-AIR RESONANCE: FS (HZ) . . . . . . . . 29.60

MECHANICAL Q: QMS . . . . . . . . . . . 6.10

ELECTRICAL Q: QES . . . . . . . . . . . 0.483

TOTAL Q: QTS . . . . . . . . . . . . 0.45

MAGNETIC-GAP HEIGHT: HAG (IN) . . . . . . . . .0.315

HAG (MM) . . . . . . . . 8.00

VOICE COIL HEIGHT: HVC (IN) .. . . . . . . . . 1.34

HVC (MM) . . . . . . . . . . . 34

MAXIMUM EXCURSION: XMAX (IN) . . . . . . . 0.513

XMAX (MM) . . . . . . 13.00

 

[timsm80 10+ year member]

yea i considered those but have u actually heard them???

 

[THATpurpleKUSH 5,000+ posts]

Skar and DC no, Infinity, yes but it was sealed.

 

[timsm80 10+ year member]

what did u think of the Infinity? i really thought about getting that one. is it the Infinity Reference 860W

 

[THATpurpleKUSH 5,000+ posts]

Yea, it did pretty good for an 8. Its the only 8 that I've heard in person. SQ was great and it got fairly low due to the low fs and 13mm of xmax. It didnt get that loud to me, probably due to the sealed box and I'm used to hearing bigger speakers so I think I had high expectations. And the amp was a 250w rms so it wasn't getting much power after box rise. I recommended that a friend get one, after they heard my Ref 1262w's and wanted something better than stock. If I would have known about ported boxes then like I do now, I would have built a box for it.

can't go wrong for $50 though. You could even get 2 and not go much over $100. In WinISD with .7cu/ft tuned to 30hz it yeilds an f3 in the mid 20s.

http://www.google.com/products/catalog?q=infinity+ref+860w&um=1&ie=UTF-8&tbm=shop&cid=2856062076805969443&sa=X&ei=P_wMT_DvF6W20QHt1sySDw&ved=0CDMQ8wIwAQ#scoring=tp

 

[timsm80 10+ year member]

yea the price and the freq. range is what really draws me to get these there r so many choices out there though, but i think im gonna go with the Infinity!