Advent 5012 crossover issue

[Les Yeux]

I am having an issue with my Advent 5012/W's (1983 era - no tweeter switch) after a crossover change.
The old 7uF electrolytic in the tweeter was replaced with Jantzen Audio 0.22uF 1200V Z-Superior and Dayton Audio 6.8uF 250V polypropylene caps.
The old 32uF electrolytic in the woofer was replaced with Jantzen Audio 2.2uF 800V Z-Superior and Dayton Audio 30uF 250V polypropylene caps.
I also replaced the resistor with a Dayton Audio 3 Ohm 10 Watt Precision 1% Audio Grade one (exactly the same specs as what was replaced).
The only other changes I made were to replace the old terminals with new banana plugs. All connections were soldered with silver solder. I am running the 5012's through a NAD C740 receiver (35wpc) that I can barely turn up the volume past 3 because it is so loud and doesn't sound great. At low volume everything sounds much better, with greater detail, clarity and a wider sound stage. I know the receiver is fine because I previously ran a pair of NHT SuperZero XU's with a Cambridge Audio Basscube 10 Subwoofer through it and that sounded great. I suspect that I have affected the crossover adversely somehow. Any help would be appreciated. Thanks!

 

[crazy-in-az]

Can you describe the sound? Is it harsh, too much treble, scratchy bass, etc?

Have you checked the tweeter fuse? Sometimes the fuse holder gets corroded and needs to be cleaned.

Are the woofer foam surrounds still in good shape? Lightly run your finger around the edge and see if it starts to crumble or fall apart.

 

[WillMeyer]

Polypropylene caps take a while to break in. I've changed them out before and at first power the sound quality was very poor - actually it was downright terrible.

After 3 hours, the quality improved significantly.

I read postings that say they need 250 hours to fully break in - My experience is that after 3 hours they will sound as good or better than the original and will continue to improve after that.

After I do a recap like what you've described, I run the speakers for a couple of days (most at very low volumes). The idea is that the speakers are getting an AC signal, causing the cap to exercise (charging and discharging). This seems to work well for me. Loud volumes are not going to help them breaking in faster, most of these caps are rated at 250 or 600v. With a 35 watt amp, these speakers will probably never see more than 50v. Its the charging and discharging cycles that mainly contribute to breaking in the new caps.

Recapping is straightforward - I'm doubtful that you wired them incorrectly. I'd let it run a bit at low power and see if it improves in a couple of hours.

 

[Les Yeux]

Can you describe the sound? Is it harsh, too much treble, scratchy bass, etc?
Yes, a bit harsh when louder and with a bit too much treble. I think that might be attributed to the perceived brightness of the new polypropylene caps after the change? I also think that I might need to up the resistor from 3ohm to 3.5 to help balance out the sound. The tolerance of the old electrolytics were 10% and the new caps are either 1 or 2%

Have you checked the tweeter fuse? Sometimes the fuse holder gets corroded and needs to be cleaned.
Good idea! I have not checked that.

Are the woofer foam surrounds still in good shape? Lightly run your finger around the edge and see if it starts to crumble or fall apart.

Yes, the surround are in very good shape as they were redone some years ago.

 

[Les Yeux]

Polypropylene caps take a while to break in. I've changed them out before and at first power the sound quality was very poor - actually it was downright terrible.

After 3 hours, the quality improved significantly.

I read postings that say they need 250 hours to fully break in - My experience is that after 3 hours they will sound as good or better than the original and will continue to improve after that.


After I do a recap like what you've described, I run the speakers for a couple of days (most at very low volumes). The idea is that the speakers are getting an AC signal, causing the cap to exercise (charging and discharging). This seems to work well for me. Loud volumes are not going to help them breaking in faster, most of these caps are rated at 250 or 600v. With a 35 watt amp, these speakers will probably never see more than 50v. Its the charging and discharging cycles that mainly contribute to breaking in the new caps.

Recapping is straightforward - I'm doubtful that you wired them incorrectly. I'd let it run a bit at low power and see if it improves in a couple of hours.

I think at this point I must have at least 60-70 hours in and the sound seems consistent in a good way.
I forgot to mention that the issue seems most noticeable when I am playing 320kpbs MP3s through iTunes on my iMac out to a Schitt MODI DAC out to the NAD receiver out to the Advents. My CD player also runs through the MODI too, but the issues aren't as apparent there. I've lowered the volume in iTunes from around 75 (out of a 100 scale) to 25 and the sound is much better. I completely missed that before as a possible issue and not even related to the speakers. Ugh~
Thanks for the information and thoughts about this. Much appreciated to you Will Meyer and crazy-in az!