Building a pair of Polk Monitor 10's

heiney9

No difference for volume and coupling, but big difference on imaging, lobing, etc. One shouldn't just place drivers willy nilly in the front baffle.

A car still rolls down the street w/ 1 wheel in front and 3 in back. But probably better to have 2 in front and 2 in back........a poor analogy, but you get what I'm saying.

willwilly

heiney9 wrote: »

No difference for volume and coupling, but big difference on imaging, lobing, etc. One shouldn't just place drivers willy nilly in the front baffle.

That's what I'm thinking? But since M10's have issues with that anyway, does it get worse if I set the drivers vertically over the PR like a 7?

heiney9

I would imagine so, you'd have to design a new crossover. How tall are you making the cabinets so that all those drivers can fit vertically? As soon as you increase the size of the cabinet then you have to use your speaker software to compensate. You are using speaker software?

It's nothing like a Monitor 7 if you do that. M7's us a single driver, not two.

Yes, it will be much worse.

H9

heiney9

I think you're focusing too much on the side by side drivers in the M10. All the comments are compared to the M5 and M7. In and of itself, it's not ideal, but it's still pretty damn good.

Don't overthink, build the M10 clones and enjoy them.

H9

willwilly

willwilly

heiney9 wrote: »

Don't overthink, build the M10 clones and enjoy them.

H9

That's what I'm doing. I like hearing you say M10's are "pretty damn good" finally. They are damn good for what they are. Just playing around with ideas.

willwilly

So I had a little bit of time this evening to start the crossovers. I started by stripping one of the boards including the inductor since it came loose from the old hot glue. I reinstalled the inductor with new hot glue and a tie strap.
So my first question. Isn't the red post positive and the black post negative? If so, than my eBay crossovers had them reversed according to the schematic.
Also, the schematic I'm following is slightly different than my eBay crossovers which I believe someone has mentioned these crossovers are for the old peerless tweeters and I'm using RD0-194's.
I have seen other M10 updated crossovers with the same components I'm using. Some are far neater installations than others so I need to do a little searching of this forum to find a the best. One I remember seeing had a two tier approach.

willwilly

The buisness side.

willwilly

Inductor installed.

westmassguy

willwilly wrote: »

So I had a little bit of time this evening to start the crossovers. I started by stripping one of the boards including the inductor since it came loose from the old hot glue. I reinstalled the inductor with new hot glue and a tie strap.
So my first question. Isn't the red post positive and the black post negative? If so, than my eBay crossovers had them reversed according to the schematic.
Also, the schematic I'm following is slightly different than my eBay crossovers which I believe someone has mentioned these crossovers are for the old peerless tweeters and I'm using RD0-194's.
I have seen other M10 updated crossovers with the same components I'm using. Some are far neater installations than others so I need to do a little searching of this forum to find a the best. One I remember seeing had a two tier approach.

I believe this is what you're referring to:




The Red Binding Post is +/Positive, Black Post -/Negative. The internal wiring, is Black +/Positive, White -/Negative. The wiring under the circuit board could be different. I've seen them use all white, with tape marking the black leads. Just trace the circuit.

heiney9

Have you figured a way around the x-overs you have since they are from an earlier pair of M10's that used the peerless tweeter. You will have to address that issue. I'm pretty sure there is a simple solution, I just don't recall.

H9

willwilly

That is exactly what I want. That is the cleanest update I have seen. Thank you very much. I'm ordering new stand-offs today.

willwilly

heiney9 wrote: »

Have you figured a way around the x-overs you have since they are from an earlier pair of M10's that used the peerless tweeter. You will have to address that issue. I'm pretty sure there is a simple solution, I just don't recall.

H9

I'm using this schematic.

RD0-194 Tweeters
MW6503's
10" Polk PR
Sonicap and Mills Caps and Resistors...



I'm using fuse rather than the switch...

willwilly

Do I recess the tweeter in the front panel?

heiney9

I'd jumper the fuse, unless you think you will overdrive your amp. I jumpered the fuse on my 5B's and didn't look back.

Toolfan66

I agree, the fuse, and or poly switch= crap IMO.. Just power them with a good amp, watch the volume, don't look back...

willwilly

I'm powering with a Deno AVR5700 so I think I'll keep the fuse for now. 140 W

willwilly

Well my MDF doesn't come in until Wed so I played around with the PR'S this evening. I cut out 50 mil sound deadening material to cover the cages.

willwilly

rmpolk wrote: »

If it helps I took some measurements of my 10a's with the speakers ...BTW the outside dimensions of the finished box are- [ 40.4x71.1x11cm deep ] the cabinet board thickness is 1,5cm

11 cm deep. That doesn't sound right. Should be near 12.5 inches?

Toolfan66

Impressive layout...

willwilly

Original spec state 28x16x11.5. This depth includes the grill which is 1/2" MDF. Perfict.

Thanks again for measuring. I'm adding 1/2" since I'm using 1" MDF front and back to keep the same volume.

I haven't decided if I'm going to compensate for the decreased volume by rounding all the interior corners.

I also haven't decided if I'm rounding the corners or use a 45 degree gusset? Round takes a router/shaper bit that I don't own.

willwilly

Gottcha, I may skip the filling of the corners. That gets off the original plan of making a clone and adding gusseting just creates another question. Then the solution to the volume change sets up another question, which axis do you add the volume, or is it all three?

Arrrg!

willwilly

I'm pre-fitting the components in my crossovers. I'm planning on using 3M foam tape to secure the caps, both top and bottom on the first tier.

Instead of using a disc of press board, I'm going to use scrap polk driver boards and 1 1/4" steel risers that will fit in the originals.

I also re-purposed some clear sticky tape from polk drivers to wrap the large inductors. My old eBay drivers only had a dab of hot glue to secure the coils. I didn't do the job.

What's next?

willwilly

Mess with them how?

willwilly

Most importantly, how much?

willwilly

By the way Love your profile picture!!

willwilly

nbrowser wrote: »

The profile picture is from the day I acquired my SDA 2 speakers which are standing proud in my listening area...and can shock and amaze people with the imaging, especially when friends learn the whole HT was off but for those two bad boys.

I have never heard a pair but always keep my open for a pair of SDA'S fixer-uppers... Very sweet!

willwilly

Looks like you have your work cut out for you. Would love to hear them.

Here is a layman's article on the effect of steel near the inductors. I think I would be far more concerned with the driver/tweeter magnets in the vicinity of the inductors. It looks like the crossover is placed very close to the magnets in the original M10 design. Something to keep in mind.

Effect of magnetic fields are inversely proportional to distance cubed, so you don't have to get too far away to make the effects inconsequential. It would be an interesting test to compare inductance with nylon risers or with steel risers, including the screws. And with the driver in speaker then out. The steel in the cap leads could also be considered.

May make a good case to relocate the inductors someplace else.

I wonder if polk tested speakers in real world application or just followed the theoretical.

Far more than what I want to get into.

https://rennieash.wordpress.com/2013/02/08/the-effect-of-iron-on-inductance-value/

willwilly

Received my MW6503's

willwilly

rmpolk wrote: »

If it helps I took some measurements of my 10a's with the speakers still installed,They're in [cm] for easier reading- The BLACK face board is 36.4x67cm, giving a vertical center line of 18,2 for the tweeter and PR [Note: the measurements are taken from the face board edges [not the outside cabinet edges]-the [tweeter] -from board top edge down is 9.3 to top of tweeter and to the bottom of tweeter edge is 17 -from the board [side] edge is 12.3// The [spk mids] are 1.5 from board [side] edge to the outside spk edge and 18.1 to the inside. Then again measured from the board [top] edge down are 17.4 to top of spk and 34 to spk's bottom edge [26 from board [top] down to the spk horizontal center line]// The PR is 5.6 measured from the board bottom up to the PR's bottom and 31.1 to the top and 5.5 to the board [side] and with a horizontal center of about 18.5. The tweeter used is a peerless and the measurements should be within 1.5 mm accurate,Maybe you can lay it out on some graph paper to check and make a template with your drivers altering the measurements to adjust for their flange edges,,,BTW the outside dimensions of the finished box are- [ 40.4x71.1x11cm deep ] the cabinet board thickness is 1,5cm

rmpolk took some time and posted measurements he took from his pair of M10's.
Below are two drawings, the first in cm and the second in inches. These may not be exact but it gets me very close to the original placement of the components.

Thank rmpolk for posting. I will be using your measurements as the basis of my clones.