mw6503 drivers

zagamon

Hi

I recently obtained a pair of these fantastic mid bass drivers that were used in the monitor 10s. Im looking to build a pair of bookshelf speakers with them, and was wondering if anyone out there had any parameters (TS) or frequency response curves so that I could design some crossovers and match a tweeter with them. Any info would be appreciated and may be in an old handbook that came with any of the models they were used in.

ben62670

I talked to Ken in customer service, and the only info I could get is that you can cross them up to 2500hz. Welcome to Club Polk.

zagamon

Thx for all your help guys. Sensitivity would also be great.... I may have to set up a rig... or find somewhere that could measure them for me. Certainly the 2500 cross is a starting point for experimentation.

The items on ebay look good. I have emailed the seller to see if they are prepared to ship to Australia...which is where I am from!!

thanks for the welcome!

jakelm

Just buy a M10 series 2 crossover. I'm sure you can find a few on ebay. Thats what I did when building my center channel with 2 mw6503's and a Peerless tweeter. I accually picked up a 10a crossover that works great.

http://cgi.ebay.com/Polk-Audio-Monitor-10-Crossover-Input-Panel_W0QQitemZ170081374326QQihZ007QQcategoryZ71571QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

That should work for you. Takes the "guessing" out of it.

zagamon

jakelm wrote:

Just buy a M10 series 2 crossover. I'm sure you can find a few on ebay. Thats what I did when building my center channel with 2 mw6503's and a Peerless tweeter. I accually picked up a 10a crossover that works great.

http://cgi.ebay.com/Polk-Audio-Monitor-10-Crossover-Input-Panel_W0QQitemZ170081374326QQihZ007QQcategoryZ71571QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

That should work for you. Takes the "guessing" out of it.

I am not sure at this stage if he will send to aussie land...I have asked him, but no reply as yet.....

I also need some parameters to determine the box volume.. things like Fs, Vas, Qts, Qes and an impedance curve would be nice....

zagamon

oh well..back to the beginning...the guy wont post to australia. does anyone have any contacts in the company that might be helpful.. that I could email??

thx

Polk65

Welcome to the club, it sounds like a fun project.

The parameters are proprietary information but some people have used equipment to get the needed info. Try searching our forum (the search link in the blue line above) for certain words like thiel, curve, parameters etc. Click contact in the top right corner for the customer service info.

As others have mentioned, finding a crossover on ebay that used mw6503 mid-woofers would be a good starting point. The Monitor 10b is one example but ebay sellers often don't know what they are selling and are not able to describe it.

The only problem with mw6503's is they were used in the larger models. As far as I remember the Monitor 10's were the smallest speaker to use them.

Here's a list of which drivers were used. Check the SDA, RTA and Monitor series.
http://clubpolk.polkaudio.com/service/models/

Schematics are here:
http://www.polkaudio.com/forums/showthread.php?t=38755

http://www.polksda.com has vintage brochures which you can read through.

ben62670

They like .9 cubic feet. I have studied the dimensions of many speakers that use the mw6503, and they all are right at .9 cubic feet. One thing to keep in mind is that they all also use passive radiators.
The model 10 crossover will not work if you are using a single driver per cabinet. They are wired parallel for 4ohms.

ben62670

use a 1.82mh inductor, and a 27uf cap to get a 2nd order crossover frequency of 2500hz. I have made some custom polks and you can either get the Polk rdo silk tweeter for $48 a piece, and I have also used the seas textile domes with great success.

zagamon

ben62670 wrote:

use a 1.82mh inductor, and a 27uf cap to get a 2nd order crossover frequency of 2500hz. I have made some custom polks and you can either get the Polk rdo silk tweeter for $48 a piece, and I have also used the seas textile domes with great success.

thanks for the info...btw what type of second order is this? LR, Butterworth, Bessel, Chebychev? The values are very similar to what Polk have used in their monitor 10s schematics(1.75mH and 27uF) (thx to polk65) with the drivers in parallel @4ohm.

My calculations using these have substantially lower values ie Linkwitz/Riley yields a 1.02mH inductor and a 3.98uf cap for 2nd order for single 8 ohm driver and 0.51mH and 7.96uF into 4 ohm (2 drivers in parallel) @2500Hz

zagamon

zagamon wrote:

thanks for the info...btw what type of second order is this? LR, Butterworth, Bessel, Chebychev? The values are very similar to what Polk have used in their monitor 10s schematics(1.75mH and 27uF) (thx to polk65) with the drivers in parallel @4ohm.

My calculations using these have substantially lower values ie Linkwitz/Riley yields a 1.02mH inductor and a 3.98uf cap for 2nd order for single 8 ohm driver and 0.51mH and 7.96uF into 4 ohm (2 drivers in parallel) @2500Hz

so I am a bit confused..if anyone can help...

jakelm

http://www.partsexpress.com/pe/pshowdetl.cfm?&PartNumber=302-750&DID=7

Thats the box.

Here is my finished project.

http://www.polkaudio.com/forums/showthread.php?t=45852&page=2

Post #39

jakelm

Follow this design

http://www.polkaudio.com/forums/attachment.php?attachmentid=18778&d=1155784729

ben62670

zagamon wrote:

thanks for the info...btw what type of second order is this? LR, Butterworth, Bessel, Chebychev? The values are very similar to what Polk have used in their monitor 10s schematics(1.75mH and 27uF) (thx to polk65) with the drivers in parallel @4ohm.

My calculations using these have substantially lower values ie Linkwitz/Riley yields a 1.02mH inductor and a 3.98uf cap for 2nd order for single 8 ohm driver and 0.51mH and 7.96uF into 4 ohm (2 drivers in parallel) @2500Hz

The monitor 10's have 2000hz crossover, and for what type XO it is I have no Idea except that Polk designed it.

zagamon

Thanks everybody for your help. i think what I will do is reproduce a crossover from the schematics Polk provide and adjust them to suit the tweeter I match it with. I am thinkin at this stage I would like to try a Hiquphon OW1 because of its amazing soundstage. i will need to build my own box and may try a couple of different sizes as per ter Monitor 5jr, 4a, 10b and 7c and VS19 where single 6.5in drivers were used and see how it goes. i will keep you updated on progress.

who knows if I find great success I will post all the details and thinking...maybe someone over younder USA may have a couple of spare MW6503's they may want to experiment with and could reproduce what Ive done over here.

best wishes