Do 45 rpm 12" LPs really sound better than 33 rpm?

Agree with Mike L...if all else is equal, the 45rpm will typically sound better. However, is all else is not equal, then all bets are off! As an example, i own several excellent Music Matters Blue Note reissues on the 45 and the 33 label. The 33 in many instances sounds better than the 45! The reason, is that Music Matters changed their studio/recording cabling when they did the 33 reissues, and to my ears, this made a significant and beneficial difference! Therefore, in this instance and with these particular pressings, the 33 sounds better than the 45 issue.

Now that I recall, the sound of the jukebox 45 was "always" superior to the 33 of the same record in the 60's; now we are comparing apples to apples, and not apples to oranges.

While there are two factors involved: the superiority of the jukebox rig, as opposed to the average home audio rig playing the 33, I am accounting for that; plus, keep in mind we are talking about only one cut off the 33 LP that was specifically pressed for the jukebox.

I'm positive there were cuts off "Kind of Blue" that were 45's made for the jukebox.

Perhaps there's a valid comparison to tape machines operating at different speeds. Higher tape speed means more 'headroom', as in more length of tape to enscribe the same signal. Likewise on vinyl  higher speed rotation and more space between the grooves means better dynamics. This usually results in more output, which subjectively sounds better if you don't compensate the volume setting. But I'm not entirely sure this really does translate to better sound quality at the exact same volume level.

To escape more inconclusive anecdotes, it might be interesting to compare the Music Matters Blue Note reissues. Their first series were on 2x45rpm, their recent issues are back to 33.3rpm. It seems reasonable to assume they initially made this choice in order to get as close as possible to the huge dynamics that the originals were famous for. It makes you wonder why they went back to 33.3rpm, but this may have been just a way to reduce cost.

I have a few titles, but not the same titles on both speeds. So I haven't been able to make a direct comparison myself. But with use of the same master tapes and mastering engineers on both these series, the comparison might yield more conclusive results.

For what it's worth, to my ears the 2x45rpm titles I own do NOT sound more dynamic than the ones I have on 33.3rpm. In this respect nothing compares to RVG's originals.

@edgewear  You posted what you did seconds after my post, which i think addresses why MM did what they did. I don't think MM went back to 33 to reduce cost, but I do think they did this to allow for more people to buy the titles ( not everyone can playback at 45) and because the original LP's were all done at 33. With their new cable loom, it would be interesting to see and hear what the same album would sound like at 45. I suspect it would be even better than their original release. Problem is that they apparently have ceased all releases at this time. BTW, owning several of the original Deep Groove RVG Blue Note pressings, I don't think they are actually superior to the MM's. In one way, they are VERY inferior ( at least mine are..and I would bet yours are too) that is...they are far noisier than the new vinyl.

@daveyf 
I was typing while you made your comments. So you did make the 2x45rpm versus 33.3rpm comparison of the MM reissues. Results are again inconclusive as they changed their hardware to master the 33.3 version. I didn't know this, so my suggested 'controlled comparison' was based on an illusion. My bad.