MW 6500 vs. MW 6503

[b_dick]

My pair of 7b's is lacking one midwoofer, a MW6500. Polk cannot provide a new one. They offer the MW6503 as a suitable replacement (if I went that route I would get two, to have symmetry.) Does anyone have direct experience comparing these two drivers. Is the difference in sound subtle or not so subtle?

[Polksaladanni]

Kinda,

1 of my monitors fell off the speaker stand during a raging halloween party. they were 10yrs old at the time. Soooo, the epoxy that held the magnet on didn't hold the magnet on! The magnets aren't pinned either...

Mine were the 6502's and the replacement is the Mexican made 6503. Pretty much looks and sounds the same. The lead wires to the cone are different and the terminals are single male instead of double male.

Paul

[John30_30]

My pair of 7b's is lacking one midwoofer, a MW6500. Polk cannot provide a new one. They offer the MW6503 as a suitable replacement (if I went that route I would get two, to have symmetry.) Does anyone have direct experience comparing these two drivers. Is the difference in sound subtle or not so subtle?

I saw a couple of each on ebay. Here's a pair of 6500's, couple days to go.



http://cgi.ebay.com/POLK-AUDIO-6-1-2...d=p3286.c0.m14

[b_dick]

I saw a couple of each on ebay. Here's a pair of 6500's, couple days to go.



http://cgi.ebay.com/POLK-AUDIO-6-1-2...d=p3286.c0.m14

Thanks for the heads up.

[rocks911]

If you are still loooking:

http://www.diyaudio.com/forums/showt...hreadid=143152

[doctor r]

Personal experience to add on this subject. Two years ago when I rebuilt my Monitor 7Bs crossovers I also replaced the MW6500s with two new MW6503s. The sound initially seemed a little darker during the breakin period, but ultimately I think the detail and soundstage are as good if not better than before. Some of these changes were probably due to the crossover upgrades but the MW6503s performs as well or better in the 7s. I have no regrets in this change/upgrade.

[ausgeflippt]

I just purchased a pair of SDA CRS and discovered one MW 6503 (yr:1995) locked up with a wire broken at the cone solder point. Along with this pair I got a Polk mystery box, apparently some kind of subwoofer that has two 6500s (yr:1994) side-by-side and a 15 in. passive disc, a coffin-shaped rectangle 28x11x16, with two pair of binding posts and no identifying marks whatsoever, except "Polk Audio", in the exact dark wood finish as the CRS speakers, a matching set. There is a slight appearance as though a small rectangular paper was once glued to the back, possibly carrying the model# and other info.

Question 1: what model is the mystery box?
Question 2: how does it hook up? one speaker in and out? there are zero markings to show which is which.
Question 3: the real reason I write this post. I have searched everywhere for a definitive answer and everyone seems to be chasing their tails with the question of interchangeability between the 6500 and 6503. Clearly the 6500 is no longer manufactured. Most want to know if the 6503 is a good replacement for the 6500 WITHOUT also swapping out the crossover. My question is the inverse. Can I use the 6500 in the stead of the 6503, at least temporarily, since I have two of them that I don't know yet what to do with, without changing the crossover, without damaging anything and without any strangeness in sound, especially considering that the CRS are interconnected?
Question 4: Where is Polk Audio in all of this? Why doesn't someone monitor this forum to answer some of these questions, rather than let everyone just futz around with what could very well be very bad advice?

Yes, I'm new here.

[ausgeflippt]

I had to repost this to make corections, since my 20 minutes to make corrections expired. mostly a mental typo (1985, not 1995)

I just purchased a pair of SDA CRS and discovered one MW 6503 (yr:1985) locked up with a wire broken at the cone solder point. Along with this pair I got a Polk mystery box, apparently some kind of subwoofer that has two 6500s (yr:1984) side-by-side and a 15 in. passive disc, a coffin-shaped rectangle 28x11x16, with two pair of binding posts and no identifying marks whatsoever, except "Polk Audio", in the exact dark wood finish as the CRS speakers, a matching set. There is a slight appearance as though a small rectangular paper was once glued to the back, possibly carrying the model# and other info.

Question 1: what model is the mystery box?
Question 2: how does it hook up? one speaker in and out? there are zero markings to show which is which.
Question 3: the real reason I write this post. I have searched everywhere for a definitive answer and everyone seems to be chasing their tails with the question of interchangeability between the 6500 and 6503. Clearly the 6500 is no longer manufactured. Most want to know if the 6503 is a good replacement for the 6500 WITHOUT also swapping out the crossover. My question is the inverse. Can I use the 6500 in the stead of the 6503, at least temporarily, since I have two of them that I don't know yet what to do with, without changing the crossover, without damaging anything and without any strangeness in sound, especially considering that the CRS are interconnected?
Question 4: Where is Polk Audio in all of this? Why doesn't someone monitor this forum to answer some of these questions, rather than let everyone just futz around with what could very well be very bad advice?

Yes, I'm new here.

From the specs, it appears that the rated power, nominal impedance, DC resistance, linear cone excursion and piston area are all the same and the Fs (free air resonance) is almost the same. Otherwise, the Qts, Qms, Qes differ by about 30%, while the Vas differs by about 12%.

[skrol]

Welcome to Club Polk.

A pic would be helpful in ID'ing your subwoofer. I am guessing that it may be an LF14. Post #8 of this thread has the manual for the LF-14: http://www.polkaudio.com/forums/show...highlight=LF14


I believe if you call PolkAudio Customer Service they will tell you the MW6503 to replace the MW6500. Therefore, it should be safe.

I had found this a while back.

Driver: MW 6500 Driver's model #.
Brand: Polk Driver's brand name.
Fs: 31.0000 Hz (Free air resonance)
Vas: 2.6486 ft^3 (Compliance volume)
Qts: 0.2190 Total Q
Qms: 1.3000 Mechanical Q
Qes: 0.2640 Electrical Q
Sd: 0.0130 M^2 (Piston area)
Xmax: 3.1800 mm (Cone excursion, linear)
Revc: 6.5000 ohms (DC resistance)
Znom: 8.0000 ohms (Nominal impedance)
Pmax: 35.0000 watts maximum rated power


Driver: MW 6503 Driver's model #.
Brand: Polk Driver's brand name.
Fs: 29.8600 Hz (Free air resonance)
Vas: 3.0017 ft^3 (Compliance volume)
Qts: 0.3100 Total Q
Qms: 1.7680 Mechanical Q
Qes: 0.3760 Electrical Q
Sd: 0.0130 M^2 (Piston area)
Xmax: 3.1800 mm (Cone excursion, linear)
Revc: 6.5400 ohms (DC resistance)
Znom: 8.0000 ohms (Nominal impedance)
Pmax: 35.0000 watts maximum rated power


This information won't tell you how a driver sounds, only what to plug in for basic mathematical modeling. For example, these drivers all used a doped paper cone & rubber surround (Polk made these themselves for many years, using cone & surround from Kurt Mueller Co in Gemany, don't remember where the basket & magnet assemblies came from), but the specs don't describe everything -- including the breakup/resonant modes of the drivers which have a lot to do with the resulting sound.

So simply substituting a different driver brand or model with different construction but having identical specs will virtually guarantee it will sound different. Better or worse? No way to know without trying.