stones
8 posts
Nov 17, 2010
7:57 AM
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OK so I've read that the alnico magnet speakers that jensen made where to be better a sounding speaker then the ceramic speakers that celestion and emmenince made. I'm thinking of changeing two of the speakers in my bassman RI. I know the magnets do not make the sound they only work in conjuction with the electrical pulses being sent to the speaker producing a frequency that moves the cone/cones of the speaker.and that the construction of speakers vary, different type/weight paper used in the cone.and the type and flexability of the surround attaching the paper to the frame.Lots of folk believe that the alnicos sound warmer then the ceramics ? I want to fiddle around alittle bit with my rig but am looking for some advice . has anybody done a speaker swap in their amp and has any advise on the matter. I think my amp sounds pretty good but I just like to tinker some times. My thought is to keep the jensen P10's on top and put two vintage celestion G10's on the bottom. Alnico vs ceramic one is said to be more efficient at reproducing the electrical frequency then the other ?? any thoughts.
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5F6H
387 posts
Nov 17, 2010
8:34 AM
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Original bassmans came with Chicago Jensen P10Rs, these were 1" voice coil speakers with permanent alnico magnets (some very late bassmans reputedly came with P10Qs, which are more efficient & have 1 1/4" inch voice coils, these speakers were fitted to early brown 10" speaker amps too). The P10R was the lowest grade speaker in Jensen's Concert line, Fender never used the "S" & "T" designated speakers. Alnico magnets tend to have more of an envelope of compression than ceramic speakers. Vintage Jensens have a brassy, slightly raspy character when driven.
However, the Italian SICA Jensen P10Rs that you have are not really anything like them. They are much more scooped in the mids and have a thinner, more metallic sound. I don't like these speakers in tweed amps, but they can sound OK in more mid scooped tolex style Fenders. I would replace them in a tweed bassman.
I have heard great sounding Oxford Alnico speakers from the early 60's too. Later gold frame Oxford ceramics can be a bit dull/lifeless, nevertheless I have heard great sounding amps with them. Any of these 50 yr old speakers should be reconed (if they haven't already been) if you intend to use them live.
That's basically where practical comparisons end because many speakers have so many different parts, voice coils sizes, magnet sizes & shapes, materials that simple Alnico vs. Ceramic doesn't really have much meaning. You should be looking more at what specific 10" speakers people find popular for harp, rather than dividing everything up into Alnico/Ceramic. there are inefficient and very efficient speakers with both kinds of magnet material. Be aware that speakers with a very high efficiency are very efficient at feeding back too!
Of the Alnico 10" speakers that I like are the Eminence 102 blueframe that came in early Fender Bassman RIs, Blues Devilles & Custom Vibrolux Reverbs. These aren't available new anymore (Angela instruments have some in from time to time), but the higher wattage blackframe 102 is. It's a little darker than the blue, but still a good speaker. John Kinder used in his line of amps. I have a few in different amps. The Emi 102 don't sound like any Jensens, new or old.
Fane make a great 10" Alnico, with a huge sound, but it's very expensive & very heavy, I'd only use 1 of these in a 4x10" (maybe 2 if you're a weightlifter?).
Fane also make a great 10" ceramic, the Medusa 75, a bit pricey, & still quite heavy but 2 in the bottom of a 4x10" can be killer.
Kendrick Blackframe 10" are good speakers. Eminence make a couple of useful ceramics too, the 105 is middy with plenty of cut, the Alpha 10" is darker with more low end. More than one Alpha 10" might be overkill?
The Celestion G10 Vintage seems to shelve quite early and only has a resonant frequency around 115Hz. The Tube 10 is very cheap...reasonable efficiency...maybe a couple might work, for characte rather than efficiency, I don't really know...
Note that in a tweed Bassman that space in the upper baffle can be tight, especially around the cap pan, so a plug magnet alnico (like the 102 Emi)is a good bet here to avoid clearance issues.
There's also Weber's range of speakers, others have more experience with these than I do.
Last Edited by on Nov 17, 2010 8:36 AM
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tmf714
348 posts
Nov 17, 2010
8:54 AM
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I have four blue-frame alnico speakers from my early RI Bassman I sold-contact me off list for pricing if interested.
Thomas Fiacco III
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hvyj
832 posts
Nov 17, 2010
9:09 AM
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Don't really know much about the difference between alnico and ceramic speakers. My Fender Super
Reverb RI has four 10" alnicos. My Fender Princeton Reverb RI has one 10" ceramic. Both amps sound great for harp.
Subjectively, I think the sound of the Princeton is a little sweeter and cleaner than the Super, but that may be due to factors other than the difference in the speaker magnets.
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Greg Heumann
893 posts
Nov 17, 2010
9:15 AM
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I thought for a long time that the only thing that mattered was the static strength of a magnet- gauss is gauss, right? Then I read an article by Ted Weber about Alnico vs Ceramic magnets and why they're different. Turns out that as the voice coil's field strength increases, the field of an Alnico magnet actually gets dynamically polarized - in effect, the larger the signal, the weaker the magnet becomes. Therefore AlNiCo magnet speakers provide some natural compression, while ceramic magnets do not. I don't know about you, but i thought that was fascinating. Yes, there really IS a difference.
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/Greg
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shbamac
25 posts
Nov 17, 2010
9:40 AM
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If it were me, I would get one of each (or a few) from Weber. I've got a few Webers of various configs and all of them sound great. The ceramics tend to be brighter with less compression and the alnicos more smokey.
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stones
9 posts
Nov 17, 2010
10:53 AM
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thanks guys it's nice to hear some others opinions on this issue. I've thought long and hard about which speakers to choose. I wish that I could have several types on hand to try. vintage celestions are not cheap!!! and reconning an already high priced core might put the reasonnable cost out the window. I found a pair of Eminence blus frames on line for about 250. a pr. WOW!!! the seller said that they might need to be reconed? as I stated earlier my amps sounds pretty good I'm looking for a little more bottom to my sound. I've changed the tubes in my amp. my rectifier tube is an NOS early russian 5U4G this sucker is about 4" long and looks like and old light bulb. that one of all the tubes I've installed made the biggest difference in the sound. the power tubes are a matched set of JAN tung-sol 5881's. my inverter-v3 I like the most is a 12au7 groove tube, in v2 is a fender 12ax7, and v1 is a 12au7. I know that the tubes have a hugh inpact on the amps sound. and depending on if I play with a crystal mic or a CM/CR I change the v2 tube. again thanks for the info.
Last Edited by on Nov 17, 2010 10:54 AM
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hvyj
833 posts
Nov 17, 2010
11:35 AM
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I'm no expert on tubes, but I put JJs in both of my tube amps and, to my ear, they sound warmer and fatter than the the groove tubes and ruby tubes that came stock on these amps. Never tried NOS tubes, though.
I don't use a bullet mic. I use a 545 Ultimate. If I set the volume control on the amps at 6-7 and back off the volume control on the mic, among other things, the tone of the amps will DEEPEN considerably. Don't know if this technique works with a bullet mic, though.
But it seems to me that a speaker swap is a drastic step to solve a problem that may have a much simpler solution.
Btw, Bob Pletka, the owner of Eurotubes (where I bought the JJs) is VERY knowledgeable about re-tubing guitar amps to voice them for harmonica. Nothing on the Eurotubes website indicates this, but Bob can tell you a lot, and is well worth talking to. Nice guy, too.
Last Edited by on Nov 17, 2010 12:15 PM
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harpwrench
361 posts
Nov 17, 2010
11:51 AM
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I have a quad of 50's vintage P10R's I'd part with for what I have invested (500). Freshly reconed by Neil's. They're loud and warm. Not cheap, but no experiments needed- if you want it to sound right and be done with it, drop me a line through my website contact form at spiersharmonicas.com.
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strawwoodclaw
126 posts
Nov 17, 2010
12:45 PM
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IMO,Weber speakers are much better replicas of Vintage Jensen compared to the modern Italian Jensens. much better tone new Jensen s are too bright , unless you have a amp that needs bright speakers.
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stones
10 posts
Nov 17, 2010
2:21 PM
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I know the p10q's that are in there right now are way too bright. p10r's where in the earlier verion of the reissue weren't they? all of the mic's that I use have been built by me. I don't use VC's on them. and with the current tubes in there now I can run my bright channel on # 6/7 with the mic in the #1 channel and gets good distortion when I play alittle harder. if I open up the cup on the mic when I play it will sound nice and clean. with the mic in the normal channel. I keep the bright volume up to at least 5 or 6 I do this to keep the amp overdriven and can get a real dirty sound if I really compress the mic.I've heard of JJ's tubes but I figured the gain ratio of a rated tube would be the same regardless of make??? (shows what I know..) but that older/vintage (read that used) tubes or JAN or NOS make a warmer sound. I have bullet mic and some off the wall stuff, since I do my own mic's I go for comfort not looks.. providing the mic body is big enough to hold the element and rubber gasket tightly.... I love to tinker with my stuff, I have a note book that I write all the different combo's of tubes that I've tried over the years.. same with the mic's so I thought that with the sound that I have now, some different speakers would be fun to start expirimenting with. I will look on the net for eurotubes and see what I see. and harpwench be on the look out for an e-mail from me. thanks guys
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rharley5652
278 posts
Nov 18, 2010
12:33 PM
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@ stones,..
Have a question about speakers, but haven't been able to get an answer?
Here is the first question on this site:
OK, let's start with basics. What are the main differences in sound between comparable speakers, one with a ceramic magnet, one with AlNiCo? Also, how does the size of the voice coil affect the sound ?
Hope this site Helps ya out,.Lotta Q&A's ,.diagrams tricks & tips
http://www.webervst.com/sptalk.html
HAGO
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Simply Unique Kustom Mic's By Rharley
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stones
12 posts
Dec 03, 2010
7:30 AM
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Thanks for the link to the website it was very useful lots of great info. sometimes it seems one could get abit confused with all the different information out there on this subject. It sure does give me food for thought, and has gotten my brain smoking again.....HMMMMMMMMM.......thanks RHARLEY.
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tmf714
374 posts
Dec 03, 2010
7:52 AM
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Have you tried bridging normal 2 to bright 1? This worked well for me-when bridging normal 2 to bright 1,then plugging your mic into normal 1,it gives you a true master volume knob.
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5F6H
416 posts
Dec 03, 2010
8:46 AM
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Hi Thomas, "This worked well for me-when bridging normal 2 to bright 1,then plugging your mic into normal 1,it gives you a true master volume knob." Whilst bridging channels like this is a good trick to know, & definitely affects gain, it's not really a master volume because both channels/volumes are in parallel & in phase. In a master volume set up, one volume would follow the other at a later stage in the circuit, in series. Turning either pot to fully CCW in a master volume set up kills the sound (or is designed to anyway).
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7LimitJI
221 posts
Dec 03, 2010
9:34 AM
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5F6H is correct in his analysis of speakers.
Before spending lots of money on speakers, why not try a few amp mods. These are very cheap and have a significant effect on tone/volume.
5F6H has a list of superb mods on his myspace site specifically for the RI bassman.
Try biasing the amp cold first, then reduce the pre amp voltage.
This will cost you little even if you get a tech to do it.
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Those Dangerous Gentlemens Myspace
Youtube
Due to cutbacks,the light at the end of the tunnel has been switched off.
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walterharp
497 posts
Dec 03, 2010
5:18 PM
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i can vouch for 5f6h's bassman experience, really helped me when building a weber kit...
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Cisco
164 posts
Dec 03, 2010
5:44 PM
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I have a hand built point to point tweed 59 Bassman clone built by Sligo Amps (to the original 59 Bassman schematic not the Fender RI specs) and it uses Weber 10A125 speakers and they sound so warm and crunchy. Not bright and harsh like the Fender RI. I also owned two of the Fender RI's, one an early model with the Eminence speakers and the newer LTD with the Jensens. The Eminence speakers were way better BUT the Weber 10A125 are even better.
Last Edited by on Dec 03, 2010 5:45 PM
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strawwoodclaw
142 posts
Dec 03, 2010
6:19 PM
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I don't think there is a perfect speaker for blues harp different speakers sound good on different amps.
It's getting the right combination .
I like 8" smooth cone alnico but I also like my 15" 50 watt Weber Ceraimic that is ribbed & has very heavy duty magnet.
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5F6H
417 posts
Dec 03, 2010
6:49 PM
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@Cisco, was no "59 Bassman" schematic until it was issued with the RI...the 50's 5F6A schematic predates the '59. There is a wide disparity in '59 Bassman RI plate voltages, this probably has more to do with any harsh, bright sound than anything else.
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Cisco
165 posts
Dec 03, 2010
6:53 PM
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5F6H - whatever, this amp sounds way better than any Fender RI amp I've owned!! But I believe you.
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5F6H
418 posts
Dec 03, 2010
7:03 PM
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Cisco, don't doubt the amp sounds great. Didn't mean to imply otherwise. Just being my usual OCD self!
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tmf714
379 posts
Dec 04, 2010
5:27 AM
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I think this is a link for the 58-60 "Bassman" schematic.
http://www.ampwares.com/schematics/bassman_5f6a.pdf
Last Edited by on Dec 04, 2010 5:29 AM
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Pluto
114 posts
Dec 04, 2010
6:38 AM
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Greg,
Wow. That AlNiCo description explains so much, and makes perfect sense. Thanks
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Cisco
166 posts
Dec 04, 2010
7:47 AM
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5F6H - no problem. I always enjoy hearing about historical data on tube amps.
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5F6H
422 posts
Dec 04, 2010
8:27 AM
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@ TMF714 - There were several configurations of the tone stack implemented throughout the run, by '59/60 the 5F6A also had a different presence pot and phase inverter tail resistor. These are reflected in the RI schem, but the RI schem also has a larger value for the preamp filter cap.
Fender amps were subject to frequent updates that never made it onto schems at this time, plus they had a habit of throwing in the "nearest reasonable match" if a part ran out during a production run. Things didn't really settle down in that respect until the BF amps. The blonde/brown amps seem to have been updated as often as changes in wind direction in the early 60's ;-)
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Cisco
167 posts
Dec 04, 2010
7:34 PM
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5F6H - you might enjoy this thread over at the Fender Forum where I hang out.
http://www.fenderforum.com/forum.html?db=&topic_number=749268&lastpost=2010-12-0417:39:47
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