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PostPosted: 08 Mar 2015, 21:49 

Joined: 08 Mar 2015, 21:00
Posts: 1
Location: Michigan, USA
Hello guys! I have posted the same story on the other “DIY audio forum” but got completely no response to date…
I had my audio system for nearly 16 years w/o any changes to it. In the mean time I have lost the ability to listen and enjoy it due to distractions at home and the actual placement of the system. Problem solved! Man-cave is in! I moved it all of it downstairs where I can finally enjoy it.
Now to the point; I have long suspected that these speakers (B&W P5 have an issue with high frequency reproduction. Great bass, and mid range but a lots of detail was just not there in high frequencies (yes the tweeters suffered from known maladies - but I have since replaced them with new OEM parts)
Recently I have decided I will try a cheap set of Pyramid TW28 tweeters ($19) – just to see what I am missing (to prove the point). To my surprise I have instantly realized that a lot of detail was just not reproduced by P5's. The amount of detail and "Air" now is incredible. I can now listen to my records at low volume w/o attenuating the high frequencies – which I really like BTW! I suspect the efficiency of these tw28 96DB vs P5’s 90DB is partially the reason…
TW28 are 3.3 Ohm with 3.3 uf cap installed
the P5's are 8 Ohm (as a whole unit) and HF crossover is as follows 1R7watt + 7 MFA cap +10.66 uf cap in series , 90DB (the tweeter itself is 4 ohm)
The amplification is Audiolab 8000S running bass and mid range and Audiolab 8000P running the high frequencies and add-on tweeter only. Mainly due to P5 crossover design (don’t want touch that yet) .
Question 1
Should I really worry about impedance issues? Tweeters are wired to HF posts on P5's that are fed from 8000P I have noticed 8000P a little warmer after the whole day but still cooler that 8000S is normally.
Question 2
Should I utilize an inline resistor to bring impedance up (added in between P5’s post and the (+) on the TW28 tweeter?
Question 3
Aside from a fact that these are considered throw away tweeter is there a better combination of caps and resistors I could use to match both better? For instance could/should I replace 3.3uf caps with a different value? A custom L – pad in addition to included cap? I did go to L- pad online calculator but how much damping should I use for those?

I know that there are better tweeters out there… I know that I could get fostex sub ($50) tweeters and realize much better performance.
In fact I am already looking for some way to make custom enclosures for these fostex tweeters. But for now I need to get through the basics.

Any help pretty please!

PostPosted: 09 Aug 2016, 15:08 
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Joined: 05 Aug 2016, 14:35
Posts: 227
It may be a good idea to find an electronic crossover and wire your speakers through it. This would insure the correct impedance and not risk either the amp or the speakers. There are dozens out there at many price-points, and they will not 'go bad' if you choose to break down and get a pair of "real" speakers eventually. ... t&tbm=shop

Most of these allow you to control the set-points and experiment for the smoothest response.

Now, if you have the room, and want a very high level of detail and very smooth response, look out for a pair of Magnepan speakers. Absolutely stunning - and just may ruin you for conventional speakers.

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