billybob Posted May 12 Share Posted May 12 50 minutes ago, MrT58 said: other speaker is sounding great- funny part is the one that sounds great has water damage and rust on box and grill, the one that sounds bad looks much better. go figure... Corrosion connection can be a problem from crossover to speakers like you know. Polyswitch damage may be answer. Can you bypass the switch... Quote Link to comment Share on other sites More sharing options...
Deang Posted May 12 Share Posted May 12 At first, he didn’t have a tweeter. After moving some things around, he ends up with no midrange or woofer. ¯\_(ツ)_/¯ Quote Link to comment Share on other sites More sharing options...
billybob Posted May 12 Share Posted May 12 25 minutes ago, Deang said: At first, he didn’t have a tweeter. After moving some things around, he ends up with no midrange or woofer. ¯\_(ツ)_/¯ That is the case...go figure. Quote Link to comment Share on other sites More sharing options...
MrT58 Posted May 12 Share Posted May 12 (edited) 1 hour ago, billybob said: Corrosion connection can be a problem from crossover to speakers like you know. Polyswitch damage may be answer. Can you bypass the switch... Opened the fuse holders and found corrosion in the springs, cleaned and sanded with 400 grit and the woofer and mid are back- tweeter is now there but low output- it ohms out at 7.6 ohms. Wiggled the polyswitch and no difference. I'll keep my questions to myself, thanks for the assist. Edited May 12 by MrT58 3 Quote Link to comment Share on other sites More sharing options...
MrT58 Posted May 12 Share Posted May 12 (edited) 1 hour ago, Deang said: At first, he didn’t have a tweeter. After moving some things around, he ends up with no midrange or woofer. ¯\_(ツ)_/¯ Sarcasm noted- thanks. I'll keep my questions to myself from here on. Edited May 12 by MrT58 Quote Link to comment Share on other sites More sharing options...
billybob Posted May 12 Share Posted May 12 2 minutes ago, MrT58 said: Opened the fuse holders and found corrosion in the springs, cleaned and sanded with 400 grit and the woofer and mid are back- tweeter is now there but low output- it ohms out at 7.6 ohms. Wiggled the polyswitch and no difference. Look for more corrosion, cool. Got any electronic contact spray , example deoxit or crc... Quote Link to comment Share on other sites More sharing options...
Deang Posted May 12 Share Posted May 12 It wasn’t sarcasm, I just didn’t understand. 1 Quote Link to comment Share on other sites More sharing options...
MrT58 Posted May 12 Share Posted May 12 2 minutes ago, Deang said: It wasn’t sarcasm, I just didn’t understand. My mistake- my apologies to you! Quote Link to comment Share on other sites More sharing options...
geoff. Posted May 12 Share Posted May 12 a little late to the party, nice day for yardwork up here Regarding the tweeter, I have one poly, two phenolic and one titanium diaphragm I just hooked up to the meter. It looks like 8.5 is an average reading between the lot. Parts Express has the polyswitches for peanuts, and if you are in the States the Crites and SimplySpeakers titanium diaphragms are free shipping (over $50). SimplySpeakers looks to have a phenolic “style” replacement too but they are not original equipment. I really liked the titanium TWEETER diaphragms, some don’t, so do your research on those. I recently put the phenolics back in the 301s to sell them and did not find anything immediately lacking in their presentation, they just sound better to me with Ti diaphragms. They sounded even better with Dave A’s LMAHL with the DE-120s, the same lens with the DE-10s needed a little attenuation, to my ears. If you are going to replace one, you may as well get a matching pair and have a spare, that you’ll never use, lol. When you get them up to snuff be sure and let us know your impressions. Cheers, 3 Quote Link to comment Share on other sites More sharing options...
MrT58 Posted May 13 Share Posted May 13 I got to spend some time with the pair last night, and am really impressed with the sound quality. For some reason my brain says "PA speaker" when I look at that beat up pair of boxes and expects to hear "ok" sound. But then my ears tell me its wayyyy better. I got these as a side deal when I wen to demo a pair of Cornwalls. I loved them but mentioned to the seller that I felt guilt at putting them in a dusty cold/hot shop, (Texas) when he mentioned he had this pair sitting in storage a few miles away. We grabbed them and did a side by side with the Cornwalls, and despite the one dead tweeter, the pedigree was there. My room is a woodshop 30x30x15, and I had a pair of Kg4 on a shelf around 8 ft high pointed down that were good but had nowhere near the output I wanted when working. Power is/has been a Onkyo HT receiver at 110 WPC, and a NAD receiver at 50. (Despite the lower output, the NAD sound has won the job for now). I strapped the -301's to a furniture dolly so I can move them around, and with that proximity the output is much better (uh-Doy), but that sound is IMPRESSSIVE. I have a pair of Heresy 1.5's and a pair of RP8000F's in the house and these are more similar to the Heresy but with the bass I want. I heard things from familiar songs that I never knew were there. I'm going to listen them for a bit more before I figure out the next step in this game. I will of course clean them up a bit, but these are shop speakers and will get their fair share of dirt and dust, so I wont go nuts on that. 1 1 Quote Link to comment Share on other sites More sharing options...
billybob Posted May 13 Share Posted May 13 Congrats... Quote Link to comment Share on other sites More sharing options...
MrT58 Posted May 17 Share Posted May 17 Welp- may have spoken too soon here. Last night I checked and found that there is no output from the tweeter at all... opend it up, recheked and got 8.2 ohms on tweeter. Found a free tone generator online and set up a 5000 hz tone, got nothing- bypassed the network and went straight to tweeter- yep, its working fine. took the crossover off, brought it in, cleaned all the contacts with cleaner and brass brush- no change. made a jumper wire and went point to point, at the stage where it goes to the first 2.uF cap, it has output at the solder joint, none on the other side; hmmmm ok. Checked capacitance and it shows 2.01 uF. ???? pulled out the soldering iron, re-flowed all the soldered points, no change. Kept playing around and it just comes back to the 2.0 cap set, I have output from the tweeter if I touch the side coming from the terminal block, none on the other side of the cap. Sure seems like the cap has gone bad but it reads 2.01 uF, which should mean its working? Stumped. of course no local shops that carry caps so its parts express I guess, but that is days aways and no sure answer. Any suggestions? Quote Link to comment Share on other sites More sharing options...
babadono Posted May 18 Share Posted May 18 With very low level signal at say 5kHz put your jumper across the 2uf cap. What happens? Quote Link to comment Share on other sites More sharing options...
MrT58 Posted May 24 Share Posted May 24 On 5/18/2024 at 7:03 AM, babadono said: With very low level signal at say 5kHz put your jumper across the 2uf cap. What happens? at the first connection point there is signal output, at the other end of the cap nothing. Quote Link to comment Share on other sites More sharing options...
MrT58 Posted May 24 Share Posted May 24 Update- looks like a bad cap was the issue. I had some 2.0 caps from a crossover rebuild kit I got from JEM audio for another pair of speakers, so I put them in and it has output now. Sound is improved but- depending on the tracks played it seems to be a bit of crackle at lower volumes that go away at higher levels- go figure? wonder is 1. Bad diaphragms? 2. Ferrofluid- is it in there? can it dry out? Switched amps btw since this started (issue was same with either amp used), now running a NAD 1300/2600 pre-amp-amp stack- it's quite powerful at 150 wpc rms and lots of current capacity. musically it is just loafing at regular listening levels. Quote Link to comment Share on other sites More sharing options...
babadono Posted May 24 Share Posted May 24 1 hour ago, MrT58 said: at the first connection point there is signal output, at the other end of the cap nothing. ? then your jumper is not a zero ohm short..... Quote Link to comment Share on other sites More sharing options...
MrT58 Posted May 24 Share Posted May 24 1 hour ago, babadono said: ? then your jumper is not a zero ohm short..... not sure what this means? I may not be stating this right. to troubleshoot the crossover I connected a wire from the HF - input straight to a small little full range. (acoustimass cube laying around). The other wire was connected to the test speaker, and I went point to point from that wire touching all th points I could Its a crummy diagram but this is what i found, green circles mean I had speaker output if it was placed there, red circles mean no output. Does that make sense? Quote Link to comment Share on other sites More sharing options...
babadono Posted May 24 Share Posted May 24 Ok, you had output from the mid at the green circles,correct? Not the tweeter. And the 2 uF on the right is what you replaced? I meant place your jumper right across the suspect 2 uF with a very limited input so you would not blow the tweeter. It's all good you found the problem. Quote Link to comment Share on other sites More sharing options...
coyote19702000 Posted May 27 Share Posted May 27 Hi Babadono I tried to reach you for the 4bx dbx service manual thanks Quote Link to comment Share on other sites More sharing options...
babadono Posted May 28 Share Posted May 28 @coyote19702000 put a @ in front of someone's avatar name and you have a much better chance of getting their attention. How did you try to reach me? There is no real service manual. Just some schematics and a half azzed poorly written cal procedure...you know written by hand before computers existed. 1 Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.