Way back in college (early 1980s) a friend of mine had a pair of Polk Monitor 10s - they were by far the best speakers I'd ever heard, but alas I had no money to fund a purchase... Fast forward to today and I've had this possibly hair-brained idea to try building a pair myself, and have acquired all of the components to do so - I have a pair of crossovers that indicate Model 10/11T, a pair of Polk 10" PRs , four Goldwood 6028 drivers, and a pair of RDO198 tweeters.. Now that I have all the parts, I'm reconsidering trying to build a simple copy of a Monitor 10. Since I'd be building the cabinets myself, I figure with these parts I could build something like an RTA-11T copy (i.e. arrange the drivers vertically in a tower, but with single PR), or I could move the tweeter outside the cabinet and build something that looks like an RTA-12C (again using what amounts to M10 parts)... Any thoughts on whether there's a better way to utilize Polk M10 parts in a different configuration?
Should I build Polk Monitor 10s from scratch?
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Lavane
Lunatic Member
The right replacement tweeter for the 10's are the RDO-194's, unless your going to modify the crossovers for the 10's.
I have a pair of 10's in my main system right now that I recapped the crossovers in and replaced the SL-2000 tweeters with the RDO-194's, alao 7's with the Peerless tweeters, and a pair of 5jr's. In my garage I have a ratty pair of 10's in my garage system.
my main system is tube based and I don't have tone controls. So I like the 10's a little more than the 7's only because the 10's have better bass at lower volumes. But the 7's really are the the better speaker over all I think.
Good luck with your Monitor 10 build. I'm thinking of having new cabs built for the ratty pair I have in the garage. I'm soon getting a new table saw, so maybe I'll make them myself. I have several routers and plenty of other wood working tools.
I have a pair of 10's in my main system right now that I recapped the crossovers in and replaced the SL-2000 tweeters with the RDO-194's, alao 7's with the Peerless tweeters, and a pair of 5jr's. In my garage I have a ratty pair of 10's in my garage system.
my main system is tube based and I don't have tone controls. So I like the 10's a little more than the 7's only because the 10's have better bass at lower volumes. But the 7's really are the the better speaker over all I think.
Good luck with your Monitor 10 build. I'm thinking of having new cabs built for the ratty pair I have in the garage. I'm soon getting a new table saw, so maybe I'll make them myself. I have several routers and plenty of other wood working tools.
I guess I was thinking that Polk must have gotten the cabinet volume mostly right (given a pair of 6.5" drivers and 10" PR), so maybe keep the cabinet volume the same as M10 but arrange the pair of drivers vertically?
Lavane
Lunatic Member
Polk did a pretty good job with the design. The 11's are supposed to sound a little better due to the crossovers being tweeked to cancel the combing effect the 10's supposedly suffer a bit from.
The RTA-12's are what I would like to try.
Lavane
Lunatic Member
Mine came without grills, so I made my own using P.E.'s grill kits.
They are good sounding speakers.
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I'm thinking that the crossover I have (which is labeled "10/11T" and has the thermal fuse) would have been from Monitor 10 Series 2? I was thinking those had SL2500? I think I'll replace the caps in the crossover anyway, but hadn't planned to modify them - was trying to match the tweeter to the crossover... I do remember hearing a pair of Monitor 7s back then, thinking they sounded really nice, but with no side-by-side comparison figured the 10s must be better... seems like the consensus now is that 7s ARE better, but now I have the parts for 10s, so....
Sorry to burst your bubble, but four Goldwood drivers is not going to make you a pair of Monitor 10s. Either get EXACTLY all the same components that are in a pair of Monitor 10s (especially the Polk woofers), or just wait and find yourself a good pair of original 10s. Only then would I be considering making cabinets to different sizes and/or configurations.
Definitely a concern... A couple of reasons I wanted to try building these with the Goldwoods: 1) brand new drivers with no concerns regarding prior abuse, etc and 2) I'm curious how they'd stack up against actual Polks... I did look for the Goldwoods that appeared to have similar frequency response to the Polk drivers, so hoping that helps some. I'm also thinking that the Polk tweeters might be largely responsible for the 'Polk sound', with the woofers kinda just doing the heavy lifting, but we'll see... Worst case I can build them and if they sound like crap I can start looking for some original Polk woofers to retrofit.
I recently rebuilt my 1979 Kenwood LS-403A speakers (I'm the original owner, from my first 'stereo') - there was no foam surround left in the woofers, one of them had noticeable friction between the cone and magnet when I replaced the foam - and they'd just been sitting around for 30 years... I pictured having to worry about that sort of thing (X4) with a pair of M10s, so decided to maybe give the new drivers a try...
swechsler
Frog Whisperer
That's a refoam issue, no disrespect, but it sounds like they weren't refoamed properly. How did you align the voice coils?
Polk monitor series woofers didn't use foam, so no issues there. I have seen postings here where magnets get misaligned due to being dropped, but they can be epoxied in place before anything bad happens and you should be good.
Polk monitor series woofers didn't use foam, so no issues there. I have seen postings here where magnets get misaligned due to being dropped, but they can be epoxied in place before anything bad happens and you should be good.
Yep, there's a good chance that I didn't get the voice coil aligned when I refoamed it ( I was able to loosen and repair it), and as you say maybe these issues don't really translate directly to the Polk drivers - but the fact remains that these are now 40 year old mechanical devices - so I figured it would be worth the gamble on the new drivers. Agree that it doesn't seem reasonable to assume that a $45 Chinese-made driver is going to sound the same as an original Polk woofer - but that's part of the reason to try this... Looks like I can get the 6503 woofers for around $70 each if the Goldwoods don't work out. At that point I'd have maybe $500-600 in my homemade Monitor 10s LOL
swechsler
Frog Whisperer
If you have the time and inclination to experiment, sure, go ahead; however, the reason we have T/S parameters and speaker design software now is so we don't need to go through all the experimentation. Sure, speaker design is still somewhat of an art as well as a science, but in my opinion, you should start out with a design based on the parameters of what you've got, rather than trying to copy some other design using different hardware.
At any rate, good luck with whatever you decide and report back here with your results.
At any rate, good luck with whatever you decide and report back here with your results.
Thanks - I do appreciate the constructive criticism... Back to my original question - asking whether it is now known, given the 40+ years since their introduction, that there is a more optimal arrangement of the Monitor 10 drivers? I didn't necessarily want to design from scratch, given that I know the basic design of the M10 is good, but beginning to doubt simply copying the M10 if there is a better approach.
Lavane
Lunatic Member
Ok, let's get @F1nut in on this. With the drivers and crossovers you have he will be a great help here. It kind of sounds like you have components for
Monitor 11's maybe? Anyway in your next post list the tweeter, midbass driver and passive radiator part numbers. Also a few pictures of the crossovers with a list of capacitor and resistor values.
As for those poly switches that protect the tweeters, they drift in value over time. They were way out of spec in my pair of 10's. I replaced them with .5 ohm precision wire wound resistors I found at Partsexpress. As long as you don't crank the volume so high they distort, you don't need to worry about tweeter burn out. I replaced the other two resistors with precision wire wound resistors as well.
Monitor 11's maybe? Anyway in your next post list the tweeter, midbass driver and passive radiator part numbers. Also a few pictures of the crossovers with a list of capacitor and resistor values.
As for those poly switches that protect the tweeters, they drift in value over time. They were way out of spec in my pair of 10's. I replaced them with .5 ohm precision wire wound resistors I found at Partsexpress. As long as you don't crank the volume so high they distort, you don't need to worry about tweeter burn out. I replaced the other two resistors with precision wire wound resistors as well.
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Couple of things.
The 11T is a very different speaker than the Monitor 11.
The 11T is not a very good speaker. I wouldn't try to copy it.
The correct replacement tweeter for the Monitor 10 is the RD0194-1.
The Polk mid-drivers have very specific parameters. Those Goldwood 6028 drivers are not acceptable replacements.
The 11T is a very different speaker than the Monitor 11.
The 11T is not a very good speaker. I wouldn't try to copy it.
The correct replacement tweeter for the Monitor 10 is the RD0194-1.
The Polk mid-drivers have very specific parameters. Those Goldwood 6028 drivers are not acceptable replacements.
The crossovers in the Monitor 11 were not tweaked. Polk added a dividing wall between the two mid-drivers that went slightly below them. They then added acoustic foam below one of the mid-drivers to alter the frequency range thereby greatly reducing the comb filtering inherent to the Monitor 10.