psb Stratus Mini tweeter replacement

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Hello,

I'm looking for a direct drop in soft dome tweeter to replace the aluminum tweeters in my psb Stratus Mini's. I want to keep the overall balance of these speakers intact as I mostly like them, but would prefer them to sound less metallic and have slightly less high end energy ( I listen in the nearfield in a small bedroom). From what I understand I may have to add a resistor to lower the new tweeters a feq db's. I'm looking for a laid back musical smooth tweeter that is somewhat forgiving of equipment and poorly recorded music. Basically the same performance as my current tweeters but a silk/soft version. The current tweeters are Vifa d19ad-08 6ohm and I've attached a few pics in case this helps. Thank you in advance for any help.
 

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A new tweeter has the potential to sound like anything and solve nothing. Also metal dome tweeters don't sound metallic either and it's as Lojzek says above a crossover modification is what would really be needed.

2-2.2kHz as an xover frequency seems a bit too low for that tweeter though. It's a 19mm unchambered tweeter. I am sure it would work well at lower volumes but turn it up a bit and I cannot imagine it being quite so civilised.
 
Well, since I've already committed to changing the tweeter anyways I snipped off the plastic "diffusers" or whatever they're called. This mod has been mentioned several times on forums by Charles Hansen who I believe once designed speakers. Also, Pierre Sprey of Mapleshade recommends this on his website. There is definitely a change in the sound and am still deciding if it's a positive one. Allegedly the only function of this plastic plate is to resonate at a certain frequency.
 
A quote about Mapleshade speaker cables from Mapleshadestore website:

"A well-designed speaker wire can hugely improve the sound of any speaker.
...Stranded conductors always degrade stereo imaging and transparency. Thicker
insulation makes speakers sound sluggish and smeared. "

:key::xfingers::$:

Good luck!
 
Allegedly the only function of this plastic plate is to resonate at a certain frequency.

No, that's not what a phase plug does. Removing it may drop the very highest audible frequencies a bit, but could also make the ultrasonic metal dome resonance stronger due to losing some damping.

Since you have essentially ruined the tweeters, go ahead and replace them with whatever ~6 ohm tweeter strikes your fancy.
 
Yes the plastic phase shield is supposed to block the sound coming from the tip of the dome which is out of phase with the sound radiating from the outer perimeter of the dome. Effectively it gives you a more extended and smoother response at the very top end. Removing it likely just gives you a severe null in the top octave which will probably make them sound a bit duller than they would otherwise.

You don't see this on non-metal domes because they experience breakup modes which change the phase/amplitude of the tip radiation, at least partially fixing the problem.
 
I cut the plastic phase ring off carefully so that I could glue it back on just in case the mod didn't work out. This was for sure a risky procedure but I've owned two different pairs of these speakers since 2004 and have always wondered about this tweak. The speakers definitely don't sound "ruined" now and would almost say have more fluid sounding treble than before. I still need a few days of critical listening before I complete judgement.
 
Here's a tweeter I was recommended by someone-http://www.amazon.com/Vifa-D27TG-35-06-Silk-Dome-Tweeter/dp/B002WCSXQC


In addition I would also like to lower the high frequencies by a few db's. I really think my room is just too small for this type of speaker and that my ears are extra sensitive to metal tweeters. I've read someone else who has sucess going this route with psb Stratus Silvers so I think I'm on the right track. I'm willing to work with this speaker because I like %90 of it's sound and love the way the cabinets look in black gloss.
 
After some intense listening sessions I came to the conclusion this "mod" wasn't for me. For some reason removing the phase ring gave me MORE treble which is the exact opposite of what I
wanted. Maybe some tweeters benefit from this, but certainty not mine. Carefully I re-glued the rings back on the tweeters. Even though this tweak didn't work out, it was fun taking apart my speakers and doing the mod myself. Since the resale value on these is now severely dimin ished, I've decided to make these my dedicated diy project. There is one thing that always bothered me about these speakers is that they are biwirable, don't like to use jumpers ( I feel this is just one more obstacle from the original signal) and am not interested in biwiring. Based on this I've always wanted to solder both wires together to make it a single wire speaker, but have no idea how to do this. Here is a picture of the crossover and if anyone could give me advice id be appreciative and maybe start another thread asking for more specifics.
 

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There is one thing that always bothered me about these speakers is that they are biwirable, don't like to use jumpers ( I feel this is just one more obstacle from the original signal) and am not interested in biwiring. Based on this I've always wanted to solder both wires together to make it a single wire speaker, but have no idea how to do this. Here is a picture of the crossover and if anyone could give me advice id be appreciative and maybe start another thread asking for more specifics.

Metal tweeters don't have a "sound" that comes from the material. Some of the nastiest sounding tweeters I have heard are soft domes (Infinity Polycell) Soft dome tweeters actually often have a boosted top octave in comparison to metal. You could be listening on the wrong axis, or you could have a lot of early reflections if the speakers are near flat surfaces like a desk, etc... The caps in the crossover could have changed value.

Probably the best thing is to do is measure them and see if something stands out. If they measure well free-field (well away from any boundaries with reflections windowed out) then the next is to measure them in situ and look for changes. If they measure poorly free-field, perhaps the caps need replacing, but doing this without measuring before and after could be an issue. Manufacturers sometimes trim or hand select component values in speakers to get them to match better.

Worrying about biwiring straps messing with the signal is silly, even more than just willy-nilly cutting off a phase plug.

Your speakers were carefully developed in an anechoic chamber in ottawa. The right way to go about modifying is to measure, tweek, measure and listen. Try to correlate what you hear and measure. You might become a better listener.
 
David:

Your best bet is a tweeter replacement. The ring radiators XT19 and XT25 would probably work for you, but being able to do so without rework in the crossover would be a real stroke of luck.

The Tymphany/Vifa XT25 ring radiators would fit in that space, they'd be actually a little small, they use a 4 1/8" flange cut out, and 2 7/8" or so hole. Extremely smooth and flat. On the plus side the line is inexpensive and crossover well down to 2 kHz or so. The dual magnet XT25 even lower, or the same with possibly lower distortion.

Two other useful tweaks might be to try different tweeter caps. Looking at the Stereophile reviews and the published specs for that tweeter I doubt they would help, but the Mundorf MKP or Clarity ESA's are my go-to's for agressive sounding treble (Clarity ESA moreso than the Mundorf MKP since the ESAs are a little dark to me). Another very useful tweak is to add felt around the tweeter itself. I think Madisound sells felt rings, but you can make your own with a little patience and a hole punch.

Again, I think your best bet really is a new tweeter. You could probably make something listenable with an XT19 or XT25 and adjustments to the overall level. If nothing else it may be a good place to start.

One final possible solution is a very small value inductor near the tweeter. 0.1 uH or lower. It may point it downwards, but this is conjecture. Ideally you'd be working from the crossover schematic and driver measurements in XSim or similar already.

Best,

Erik
 
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Here's a link to a thread on analyzing and building a 2-way crossover. I point this out because the process of evaluating what you have already and replacing the tweeter will follow much of the same steps. Maybe you will find this simple enough to try.

If you get to the point where you have measured your two drivers as described you'll find lots of folks here who will help you modify or create a new high pass filter for your speakers.

Best,


Erik
 
Thanks Erik,

Those ring radiators look like the ones on my ex gfs Polk lsi9 ( which I bought for her). I do remember them sounding smooth and flat- no metallic etch/brightness I'm hearing with the psb's.

I think I'm going to try the felt around the tweeter idea as it seems the easiest. If that doesn't satisfy me then I will look more into the ring tweeters.

This brightness is really bugging me, especially at lower volumes where the woofer isn't working as hard to balance the sound. I've tried everything and it seems I can't tame the highs on these. I'm suspecting more and more that these speakers, in their stock form, just aren't meant for small rooms and low volumes. They seem to have very wide dispersion and need a little volume to open up- which is a bad combo for how I have them set-up.

In the end, cutting my loses and just getting into headphones or some kind of custom speakers (single driver maybe?) may be the only way to go.
 
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I suspect that the issue is the ragged top end. Looking at the review I know they'd drive me nuts. At best you can lower the tweeter level to the point it won't be noticeable, but that will end up being a rather dull top end.

Keep in mind, not all ring radiators are alike. :) I just happen to know the XT25 is great, so I'm hoping the XT19 being it's smaller sibling could also be a good choice. :) There may be just as good soft-dome replacements, but since we're already in Vifa//Tympnany territory these seem like a good first suggestion.

Also, the rings have rather narrow dispersion, to my ears, which don't match the specs. :)

Best,


Erik
 
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