[Captain]

Has any body heard the scan-speak R2904/700000 ring radiator tweeter. I got my cross over's tweaked last week and dropped a pair of these drives in my speakers. The detail in the upper end is pretty stunning, and the sound stage is massive sort of extends right out to the walls of my living room, and give's the sound real height, also very smooth. The strangest thing that they do is increase the bass making it bigger with a lot more detail and control. This was one of the reasons to get them(as advised by Wilmslow Audio), as my speakers are very small with small bass drivers which were lacking a bit. Before having them the bass was very much confined to the living room you can now feel it through out the house, why would this happen?

 

[Polaris111688]

I think I can explain the improved control and tightness. Basically, the initial hit on a drum of any kind actually produces a high frequency and that quickly decays into lower frequencies.

 

[Garbz]

The other thing you've just done is basically replaced your upper end of the spectrum with something that works differently. Imagine you want more bass using an EQ. Do you take everything below 500 up? Or do you take everything above 500 down?

Lots of people tune their music (volume wise) to the mids and trebble. It could be that it's ever so slighlty quieter and you may inadvertently have just given it one extra click on the volume.

 

[Wodgy]

There are several things that could explain what you're hearing.

Before I get into that, you need to be realistic about what kind of bass you'll ultimately get out of those speakers. That's a fairly unusual driver combo; very high end ($400 each) tweeters combined with 4.75 inch midranges. The midranges are always going to be the limiting factor here. The Excels are good drivers, but even with aggressive porting, you won't get a large amount of deep bass out of 4.75 inch drivers. Also, judging from the sensitivity numbers and the other comments on the Wilmslow Audio website, your speakers have no baffle step compensation, which means they *must* be used against a wall or you'll get the impression of lacking bass. That also means that if you make minor changes to the positioning of the speakers, which you probably did when you made the changes to the tweeters and crossovers, you can make a significant impact on the amount of bass they generate in-room. Different positioning alone may explain your results.

The tweeter you moved from (S2905) is quite different from the tweeter you moved to (S2904/7000). The tweeter you had before is actually a little flatter in the top octave, but it cannot be crossed as low. It's possible that the new crossover is crossed slightly lower, moving the Excel driver out of an area where its distortion increases, causing the overall sound of the speaker to become subjectively more bassy, even if its on-axis frequency response is similar. Third harmonic distortion and higher tends to make a speaker sound tipped up towards the upper midrange and highs, giving the impression of less bass. It's also very possible that the S2904 has less total distortion, again causing the same perceptual effect.

One thing is almost certain, the actual amount of bass generated by the speakers didn't change, unless you somehow removed obstacles (e.g. stuffing) from the path between the woofer and the port when you were changing the crossover board. It's either the speaker positioning or a perceptual effect, unless the new crossover adds some baffle step compensation (unlikely).

 

[Captain]

Quote:

Originally Posted by Wodgy There are several things that could explain what you're hearing. Before I get into that, you need to be realistic about what kind of bass you'll ultimately get out of those speakers. That's a fairly unusual driver combo; very high end ($400 each) tweeters combined with 4.75 inch midranges. The midranges are always going to be the limiting factor here. The Excels are good drivers, but even with aggressive porting, you won't get a large amount of deep bass out of 4.75 inch drivers. Also, judging from the sensitivity numbers and the other comments on the Wilmslow Audio website, your speakers have no baffle step compensation, which means they *must* be used against a wall or you'll get the impression of lacking bass. That also means that if you make minor changes to the positioning of the speakers, which you probably did when you made the changes to the tweeters and crossovers, you can make a significant impact on the amount of bass they generate in-room. Different positioning alone may explain your results. The tweeter you moved from (S2905) is quite different from the tweeter you moved to (S2904/7000). The tweeter you had before is actually a little flatter in the top octave, but it cannot be crossed as low. It's possible that the new crossover is crossed slightly lower, moving the Excel driver out of an area where its distortion increases, causing the overall sound of the speaker to become subjectively more bassy, even if its on-axis frequency response is similar. Third harmonic distortion and higher tends to make a speaker sound tipped up towards the upper midrange and highs, giving the impression of less bass. It's also very possible that the S2904 has less total distortion, again causing the same perceptual effect. One thing is almost certain, the actual amount of bass generated by the speakers didn't change, unless you somehow removed obstacles (e.g. stuffing) from the path between the woofer and the port when you were changing the crossover board. It's either the speaker positioning or a perceptual effect, unless the new crossover adds some baffle step compensation (unlikely).

Thanks for the info. Speakers were moved, but stands stayed were they were. When I put the new drives in I just sat them back on top. Just read a review by posative feedback on the Townshend super tweeters, they mention improved and lower bass when using these.

quote

"The really, really cool thing is that the Townshend STs have a very positive impact in another area—the bottom end. The highs are a given (these are super tweeters, after all!), but who would assume that adding the Super Tweeters to the all-the-way-down-to-20Hz Reimer Tetons would clean up the bass, which now comes across as even more defined and tactile. I am hearing more and better bass than ever before—cleaner, faster, with less boom but more slam, and the lower fundamentals have a greater sense of integration with the rest of the music. The overall bass-ness is now just stellar! Since I love my bass, this is a plus, and I think that this is where the STs are affecting my speakers to the greatest extent—by cleaning things up so that the rumble can really rattle! The bass now seems to go lower, though I know it really isn't. Very visceral! You want improved pitch definition and greater weight? You got it! Just don't ask me why, as this is hard to fathom—these are tweeters! How can the Super Tweeters affect the bottom end in such a positive way?! I know that adding a subwoofer can do this, but why tweeters?

Perhaps it is related to what they are doing further north. That is, their extended bandwidth does lock things into place, as Max suggests, allowing us to hear more and better—more of the good and less of the bad. Or is it that they are addressing phase error and driver integration, as suggested by Tannoy? Inquisitive people want to know!"

Wilmslow Audio pretty much said the same thing ( in a kind of I don't believe it sort of way) that they improved the bass, but they could not explain why either.

 

[Wodgy]

That review from Positive Feedback Online you're quoting is written by Dave Clark, the same guy who gave a rave review to the Clever Little Clock:
http://www.positive-feedback.com/Iss...lock_nespa.htm

When you spend a lot of money on a change to your system, be it $1500 supertweeters or $800 tweeters, there is a tendency to hear changes across the board, even when those changes are not really there. It's just human nature. Speaker building is not voodoo though (really, it's not), and the amount of actual bass generated by a speaker is determined by its woofer, woofer alignment, crossover, cabinet, and room placement, not by the tweeter.