New is not always better – Polk Monitor 7B and 5B

Polk Monitor 7B rear panel. Early Polks had fuses to the tweeters, replaced by polyswitches in later models.

Polk Monitor 7B rear panel. Early Polks had fuses to the tweeters, replaced by polyswitches in later models.

It was the Polk Monitor 7 speaker that really opened my eyes to what good sound was, or could be. And ever since that first beat-up pair I’d been a Polk convert, quickly finding a clean set of Monitor 7Cs, 4, then a modded set of 10s. The more I bought the more I liked them.

But every set had its idiosyncrasies. The 4s were little and sounded congested. The 7s were open and terrific with a wide soundstage, but the bass was punchy but not full in the lowest reaches, and the tweeter could be harsh and fatiguing. The 10s were softer but the imagine was blurrier, though the bass with much fuller.

Polk Monitor 5B in rosewood veneer on original Polk stand

Polk Monitor 5B in rosewood veneer on original Polk stand

The 10s made me realize that the additional bass wasn’t worth trade-offs in accuracy or imaging. And in the end the 7s could deliver just fine in the bass department if you really cranked them. Or you could get a subwoofer.

What I really needed then was a 7 that was smoother on top with a subwoofer. Finding a subwoofer was easy. Where would I find a Polk Monitor 7 that was smoother and nicer on the top end?

Good thing Polk made one – the original Polk Monitor speaker with the Peerless tweeter.

Polk devotees know that the Monitor line came with a number of different tweeters over the years. First up were tweeters designed by the Swedish Peerless company and made by them or under license by Polk. They are a silk dome tweeter with a small hole in the middle of the dome and the wire contacts exiting on both sides at a downward angle. The entire construction was black. All models of the Polk line (5,7,10 and JR) in the early years got these Peerless tweeters. Their sound is described as clean but smoother, perhaps a bit rolled-back. Later on, Polk substituted these with its own tweeters, the SL1000, 1500, and 2000 tweeters, depending on application. In particular the SL1000 and SL2000 Silver Dome tweeters were known for harshness and fatigue in the upper registers due to a bump in output around 10-12khz. Later series II Monitors got the upgraded SL2500 tweeter, an improvement. You can substitute any tweeter in the line with replacements from Polk, the RDO-194, which are better than them all.

Polk Monitor 5B Peerless Tweeter

Polk Monitor 5B Peerless Tweeter

But barring a wholesale replacement, the general consensus is that the original Peerless tweeters are the ones to have. And Monitors with them command a price premium.

I was luck enough to meet another Polk aficionado in my neck of the woods with multiple pairs of early Monitor 7s and 5s, which he was nice enough to bring over to my house to demo on my system. What a treat! We listened to a very early pair of Monitor 7As, and a pair of 7Bs and 5Bs, all with the Peerless tweeters. The verdict? The famous Polk Monitor accuracy and full sound was there, as was the great imaging, true to form. The highs were just right in my mind – not laid back at all, but definitely not fatiguing or harsh like my 7Cs could be. Surprisingly, there wasn’t a huge difference between the sound of the 7s and 5s, at least in my mind – right through the mid-lower bass regions they sounded the same and just as pleasing.

My luck continued as I negotiated a deal for a pair of the 5s and 7s in trade for my modded Polk 10s and some cash. In one morning I had acquired an entire Peerless Polk Monitor home theater system! I paired it with a Polk subwoofer and a Polk Monitor 5JR Series II as a center channel. All 5 speakers were timbre-matched and sounded amazing. And with the subwoofer hooked in, the Monitors were not responsible for hitting the lowest notes, allowing them to do what they did best – everything else.

Polk Monitor 5JR Series II with SL2500 tweeter. ALso recapped - sounds great as my HT center channel

Polk Monitor 5JR Series II with SL2500 tweeter. Also recapped – sounds great as my HT center channel

I really really enjoy this setup. In fact I haven’t been able to best the sound it produces with any other speaker/amp combo I’ve set up in my theater area yet, bar one – the Boston A200s are in another league, and they took the front spots in my HT setup. Right now I have the 7Bs in storage as I enjoy the Bostons, and I may take the 5Bs out of my rear-surround setup and put a pair of Boston A200s in there for a while.

When I do that I won’t need to have both the 5Bs and the 7Bs around – I’m thinking of selling one pair and doing a full restoration on the other – nice recap, remove the vinyl veneer and put on real wood, re-cover the grilles, etc. I’m debating right now to keep the 7s or the 5s. Value-wise the 7s are nicer but the 5s give up almost nothing in sound quality and take up much less space. And with a subwoofer added, they are a wash.

Oh, the possibilities!


~ by silverfacestereo on January 31, 2013.

11 Responses to “New is not always better – Polk Monitor 7B and 5B”

  1. any chance that you got those tweeters opened up? John


  2. Oh. No, I don’t have the old tweeters from my Monitor 10s – when I got them they already
    had the RDO-194s.


    • okay sorry to bother you. I thought you said stated that you were going to try to open up the tweeters to repair them. maybe I got my threads confused thank you


  3. Thanks for the article! I just bought a pair of Polk 7Bs (recognized them thanks to your details). And one of the speakers sounds just fine. No kidding, the other one has a muddy output.. Maybe some inside cleaning is needed? I don’t know a bit fixing a speaker, so I was wondering what this might take. Externally, woofer et al are MINT.


    • One of the woofers may have a shifted magnet and seized, a common problem on these as some of them are approaching 40 and the glue is deteriorating. My monitor 7b’s had this happen. the MW6503 is the current production replacement woofer for the original MW6500 but you can often find the 6500 on ebay. the way to prevent this from hapening is to place a bead of glue around the magnet seem to keep it from shifting.


    • Also be sure to check the fuses


      • Little follow up some months ago I took the speaker to the tech and they did fix it (they told me what it was but can’t remember though.. a lot of cleaning up and some problem with the crossover i think). They sound fine now but I’m just about to test them more thoroughly today in A/B, cross fingers 😀


  4. Curious what make/model subwoofer you paired with the 7s?


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