Monitor 7's, are there differences in bass between versions?

pkquat

I noticed the MW crossover is different between the M7 with the SL2000 tweeter and the Series 2 version with the SL2500. The peerless version uses a different driver and PR, and I think has different MW crossover as well. I think the cabinet size was the same for all. Are there any differences in bass response?

codycatalist

The Crossover differences could be due to the tweeter, I know with the SL3000 there needs to be cross over changes but I am not as familiar with the 2500 (Which I think came AFTER the 3000). If they use a different PR then it is most likely tuned to a different freq than the other set. PRs act as a port and the frequency it is tuned to depends on the mass of said PR.

Only way to really tell is an A/B comparison.

Queue in the vets that will say I am wrong...but that's how I learn!

BOL

littlewoodboats

I have not had the Peerless model but have had both SL-2000 and Series II M-7's. Both sets had the correct replacement tweeters from Polk. Crossovers refreshed with dayton caps and mills resistors.

I did not notice a difference in bass responce. Where I hear a difference is in the transition from the MW to the tweeters. The RD-0198-1 tweeter sounds like it does a better job at the bottom end of its operating range making for a smoother overall sound than the RD-0194-1. It has been alleged I suffer from CHS so it might all be in my head.

If earlier models exhibit better bass it could be due to better cabinet construction. Every joint in my series II cabinets leaked to some degree.

skrol

Sometimes the Daycron can fall down behind the PR and mess with the bass. Comparing the 5A and the 5B, I think the 5B had a little better bass or maybe just different. It uses the MW6502 vs the MW6500 in the 5A. I am not sure if the PRs are different.

For the highs, it was 5A with Peerless all the way over the 5B with the SL2000.

pkquat

@codycatalist The SL2500, SL3000, and RDO198 are interchangeable and have the same highpass crossover. I was interested if the differences in the lowpass MW crossover between the models had any effect. The MW is the same between the version with the SL2000 tweeter, and the Series 2 version with the SL2500, but the low pass crossover changed.

@littlewoodboats That is the information I was looking for. Maybe the lowpass was changed to account for the added tweeter too extension. Now this has me wondering about the TL mod that can be done to the SL2000 version to use the RDO-198 tweeter vs the 194. Does the mod only account for the difference in tweeter resistance and other parameters or does it also change the crossover point for the entire system. AFAIK high pass and low pass crossovers are independent of each other.

On a side note, I think they ran out of glue on the later models because they used so much on the A versions. My monitor 5A's were dripping with glue plus there was extra rattling around. I would guess between what was laying in the bottom and the stalactites and stalagmites I trimmed off, I had a solid two hand fulls of extra in each speaker.

@skrol The 5B's had a bigger cabinet and am pretty sure a different PR tune which I have heard improved the lower end. I think the 7's had the same size cabinet for the entire model range.