Monitor 7s do not sound good / RT 10 are they worthy

rockinrob

Hi guys glad to be back hanging out with you folks.I just picked up a set of monitor 7 speakers and they do not sound near as good as I expected them to not at all.A while back a few of you folks helped me with a set of monitor 5s, xo rebuild and the likes and the 5s will slam the sound quality of the 7s.I truly expected these 7s to sound much better right off the bat.I have checked the cabs and they seem to be tight,all of the speakers mid bass and tweeters are functional and the xos appear to be original.Do you guys think that it could just be the xos needing to be taken care of or am I missing something here.I was really hoping to pair the 5 and 7s with the Carver receiver I just got and at this point the 5s will have to do,and they are doing quite well I might ad.I have not figured out how to post pix yet but will get my computer genius cousin to help me with that.I owe a couple of guys some pix of the 5s anyway.Any assistance is always appreciated.The rt 10s are in very good condition and I got them for 40.00 for the pair,just need to know about weather or not to mod them as well or if they even need to be modded.Thanks for any help you guys have time to give,Have a good day folks.Rob

F1nut

What is it about the 7's that doesn't sound right?

rockinrob

Hi F1nut I'm glad to see you on here again,you are one of the folks that helped me out on my 5s.The 7s do not seem to have the tight bass that the 5s have and the tweeters are very abrupt sounding.I did a little looking over of the cabs and have found a likely issue,when I pulled the tweeters out to see what they are (sl1000) I found no gasket around the tweeters on both cabs this is a probable issue that I will correct.I am assuming that the tweets must go,correct?I also checked the mid bass drivers and found them to be mw6500 I'm pretty sure they are correct.The xo's are original.Do you know if Polk sells the gaskets or what is best to make them out of,also do you know yourself or of anyone that I might contact about gluing these magnets on the 6500s I think I need to see a pix of what they are doing.This is very new to me as I only found out about this when I got my 5s and I still need to glue those as well.Any info about the xo upgrade on the 7s would be appreciated to.So if I'm getting into to much of your time just reach through and slap me i'll be ok,but I love what you folks helped me do with my 5s and you all seem to know exactly what your talking about and if your willing to talk I'm certainly going to listen and learn.Thanks for your interest and have a good eve,Rob

F1nut

No gaskets is definitely a problem. Pick up some Armacell foam tape at the hardware store. The SL1000 is not a good sounding tweeter, consider replacing it with the RD0194-1. You may have to do a little body work to get the RD0 to fit.

Gluing the magnets is easy, use either JB Weld or Locite Power Grab. There are plenty of how to posts here for that and the crossover upgrades.

rockinrob

Thanks for the input,I'll get on the issues and let you know how things work out.

nspindel

This should definitely be a solvable problem. I've owned 5's and have demoed 7's. The 7's should definitely edge out the 5's. Clearly the original crossover components aren't helping matters.

+1 on the Armacell, I've used it many times.

cnh

Good advice above. But I must say that I have NEVER heard a pair of any Monitors (5 jr, 5, 7 or 10) sound "bad", even if they had problems--seal was leaking a little, caps were old, they had an SL2000 tweeter, etc. They NEVER sound bad, unless, maybe, the tweeter is blown or the mids are frozen. But I've never seen any like that.

cnh

nspindel

Well, any source/amp combo that's making 5's sound great should make 7's sound even better. So if the only difference is the speakers (5's versus 7's, everything else is the same) and the 7's don't sound good, then something is wrong with those 7's. And if the sound is consistently bad in both speakers, I'd have a hard time believing it's a bad driver or tweeter. Also hard to believe it's an issue with the cabs being airtight, again since it's in both speakers. If the crossover components have deteriorated, it's much easier to swallow that both speakers have the same issue.

rockinrob

Got to give F1nut a thumbs up on the armacell,went H.D.and picked up a roll made new gaskets and I do believe the 7s are on there way to recovery.Noticeable difference.When I upgraded the 5s xo's I had to use dayton caps (keep the wife from pulling out her 357)and after a good long while of run time the speakers sound better every time I turn them.Question is are sonicaps worth the investment or will daytons be ok for the 7s.I will also be ordering a new set of RDO-194-1 tweeters.I also noticed that the PRs did not have screws in all of the screw holes,is this normal or do I need to fix that as well?They do appear to be tight.I have one other question and I will go away,I modified a plate tube amp from an old Stromburge Carlson console to be a stand alone stereo amp and I believe it is 12 or 15 watts per channel need to check on that though,I use an NAD pre with it.Do you folks think any of the 3 sets of Polks I own would work well with this amp?I do appreciate all of your input and help with my new Polk habit,I think I'm a junkie.You guys have a wonderful eve.Rob from Jacksonville Fl.

westmassguy

Sonicaps are worth it, as are Claritys. An acceptable compromise, would be Sonicaps for the Hi-Pass, and Dayton or Solens for the Lo-Pass Shunt. The 6, 8 and 10" PRs had only four holes used. You can certainly mark, predrill them, and install additional screws. Hurricane Nuts and Machine Screws would be a better choice however.

F1nut

Hurricane Nuts and Machine Screws would be a better choice however.

Yep, should do that to the mids, PRs and tweeters.

I modified a plate tube amp from an old Stromburge Carlson console to be a stand alone stereo amp and I believe it is 12 or 15 watts per channel need to check on that though,I use an NAD pre with it.Do you folks think any of the 3 sets of Polks I own would work well with this amp?

It'll drive any of them, but not at concert levels.

rockinrob

I'll make the investment and get these speakers up to par.At the risk of sounding stupid I have a 12mfd@100v and a 34mfd@50v in this xo which is high?wessmassguy and F1nut both of you guys chimed in on the 5s rebuild and they worked out very well.When I did replace the caps I went way up in the voltage of both caps,when I was putting it together it seemed like overkill however the speakers sound fantastic,should I do the same again or stay close to spec?I do appreciate all of you folks input.

F1nut

At the risk of sounding stupid I have a 12mfd@100v and a 34mfd@50v in this xo which is high?

The 12uF is the high pass, the 34uF is the shunt.

I did replace the caps I went way up in the voltage of both caps,when I was putting it together it seemed like overkill however the speakers sound fantastic,should I do the same again or stay close to spec?

The voltage doesn't matter as long as it is equal to or greater than the original spec.

rockinrob

Thanks Bud I'll get it handled.Can you please tell me how to find the how to post to glue these mags,I'm having trouble running it down.Thanks again and have a good day.

GospelTruth

Here's a thread put out by Larry (Toolfan66)

http://www.polkaudio.com/forums/showthread.php?98202

It's kinda hard to see where the JB Weld is located in the last picture if you don't know what you are looking for. You'll see a gray shiny epoxy at the the top and bottom of the black magnet. Most folks put the epoxy on the bottom and top side of the magnet in four distinct points. You can do it all the way around, but when I did mine, I just did it at four points like Larry did.

Additionally, when searching for stuff on the Polk site, it's easier to just use google. In the search, put "site:www.polkaudio.com (search string)" and you'll get much better results.

westmassguy

Loctite Power Grab is a lot easier. Just put a bead around the top and bottom of the magnet, smooth it out with your finger, and let it dry for a few hours. Wipe of any excess with a damp sponge.

voltz

I pickup some loctite power grab on Amazon. it really is super easy to use on magnets & to seal the corners of the inside of you cabinets to make sure they are airtight. I learned all this from Dave ^^^^

westmassguy

voltz wrote: »

I pickup some loctite power grab on Amazon. it really is super easy to use on magnets & to seal the corners of the inside of you cabinets to make sure they are airtight. I learned all this from Dave ^^^^

I like to share

rockinrob

Thanks you all,the photos are very helpful.I will try the search the way You told me to.I think I shall feel better about my drivers in a day or so.Good eve to you all,Thanks again,Rob.

westmassguy

You can buy Loctite Power Grab at Home Depot, or any good hardware store. Come in 6 oz tubes.

stogie

I have used the Loctite Power Grab (as suggested by Dave- westmassguy) on all my magnets. Easy to work with, easy clean up and very clean looking finished product. Home Depot and Lowes sell it.

Joey Ward

I like my 5b sound over the 7c when i run bothe 5b with 5jr together