My Altec 421s sound lousy (V4B/B25B)

Discussion in 'Amps and Cabs [BG]' started by Soulfinger, Nov 15, 2017.


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  1. Soulfinger

    Soulfinger

    Sep 20, 2004
    Houston, TX
    I was very fortunate to find an Ampeg B25B cab that left the factory within months of my 73' V4B (a mile from my house much less). I was excited as it has original Altec 421A's in it. I've had it for a while now, and unfortunately, I've come to the conclusion that it just doesn't sound very good (p-bass with flats). It doesn't have a ton of low end, which is fine, because neither does my B-15, and no one ever complained about that. The mids I would describe as "stuffy", and the highs I would call "non-existent". The speakers aren't blown, but I'm wondering---have 45 years of humidity and who knows what else taken their toll on the cones? Or is that just what the Altecs sound like?

    I will probably replace them with Beta 15s, as that is the usual replacement for the cab, and I happen to really, really like the sound of the Beta 15, so I'm guessing I'll be happy with it. However, am I missing something with the Altecs? I could get them re-coned, which might improve them (or it might now), and it would certainly be expensive.
     
  2. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa, Product Support-Genz Benz
    The altecs will, if overdriven, tear the spider as it is not reinforced in any way. Real world power handling for bass is maybe 100 watts "RMS". It's common to see them damaged, no original parts are available so you want to use a recone shop with a good reputation when having to use aftermarket parts. Some parts are ok, many are pretty bad.
     
    Bassmec likes this.
  3. Your discription does not sound like my memory of 421s at all.
    I always found them to be nice, hifi, full range speakers.
    If you replace them, try to sell them to someone who will
    recone and enjoy them.
    I forgot the name, but there was a place in Oklahoma that
    specialized in reconing them.
     
    Bassmec likes this.
  4. Jim C

    Jim C I believe in the trilogy; Fender, Stingray, + G&L Supporting Member

    Nov 29, 2008
    Bethesda, MD
    I've got an old Peavey 2x15 with Altec 421's.
    I've had it for about 30 years and I like the sound; they are fragile though and will let you know when to back the F off both low freqs or power.
     
    Bassmec likes this.
  5. coreyfyfe

    coreyfyfe Supporting Member

    Nov 19, 2007
    boston, ma
    I've owned a B25B cab and ran it with a few different speakers. I don't think the 421s are your issue.
     
    bobyoung53 likes this.
  6. beans-on-toast

    beans-on-toast Supporting Member

    Aug 7, 2008
    agedhorse and Bassmec like this.
  7. Arjank

    Arjank

    Oct 9, 2007
    Above Amsterdam
    If I check the specs of the 421A it doesn't look like a bad driver (on paper) and it has a peak around 2khz which would fit nicely with a P-bass. So if you experience mediocre mid/highs I suspect the driver is in a bad shape.
     
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  8. Bassmec

    Bassmec

    May 9, 2008
    Ipswich UK
    Proprietor Springvale Studios
    The Altec 421a are actually one of my favorite ceramic magnet speakers and have always appeared to be very clear and bright especially in comparison with Eminence beta 15's.
    Are they non original cones or are they just ruined originals.:)X
    PS A recording of the cab and quality photos of the cones would tell us far more.
    Parts - Great Plains Audio
     
    Last edited: Nov 16, 2017
  9. Soulfinger

    Soulfinger

    Sep 20, 2004
    Houston, TX
    I'm pretty sure they are original cones, but they are definitely not "clear and bright". They have "21353 3" printed on the cone---not sure what that code means. They aren't blown, and I'm not overpowering them (at least I don't think so...they're not distorting). I'll pull it apart this weekend and gets some pictures of the cones from the front. One has to wonder what Texas humidity does to paper cones.
     
  10. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa, Product Support-Genz Benz
    Look closely, with these drivers when the suspension gets damaged the cone will not sit in the neutral position but typically will look like it's sitting inward due to the stretching of the fibers within the spider. Sometimes it's really obvious but not always.

    I spent a lot of time reconing Altec and JBL speakers for the cinema industry a few decades ago, and went through the factory service programs. Each manufacturer has some unique aspects about their product lines, so knowing what to look for is half of the battle.
     
  11. I used to use a B-25B with a B-25B cab at a rehearsal space with one of my bands years ago, I was not impressed with the cab's sound, you pretty much described it, no bottom, no top and just kind had a of blah sound, don't know what it had for speakers though but I was psyched when I saw the Ampeg sitting there but was not impressed after i played through it. I've played through a lot of different Ampegs and this is the only one I haven't liked, I would give one a second chance though:laugh:. Original V4-B cabs on the other hand were some of the best sounding cabs I've ever played through.
     
  12. BassmanPaul

    BassmanPaul Inactive

    I tried an Altec in my B15N. I preferred the tone of it’s original driver. I sold the Altec to someone in Australia of all places! :D
     
  13. Soulfinger

    Soulfinger

    Sep 20, 2004
    Houston, TX
    Update: I opened up the cab and pulled the 421s. They are backloaded and so it's a real pain. While it may not be the best engineered cab ever, the construction is sure impressive. I guess that's why it's still solid after 45 years. The Altecs look fine---I can't see anything wrong with them (I'll take some pictures and post them). I put in the Beta 15s that I had in some other cabs.....OMG what a difference! The cab lost about 20 lbs physically, but gained about a megaton sonically. It sounds sooooo much better----with the V4B cranked it sounded like a B15 crossed with a freight train. I plugged in my Shuttle 6.2 just to see what it did with some more power and it just sounded fabulous. So, while it doesn't appear that anything is "broken" per se on the Altecs, I'm guessing age, use, and humidity has had their way with them.
     
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  14. beans-on-toast

    beans-on-toast Supporting Member

    Aug 7, 2008
    It shows how it never hurts to experiment with speakers. And on top of it all, the Beta 15’s are quite affordable. Thanks for the update.
     
    DaveDeVille likes this.
  15. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa, Product Support-Genz Benz
    Except when you damage speakers in the process because you don't understand where the real world limits and what they mean.

    There's almost certainly something wrong with the Altecs, but they may not be suitable to the player's taste as well.
     
  16. beans-on-toast

    beans-on-toast Supporting Member

    Aug 7, 2008
    When performing experiments, it never hurts to have a little common sense.

    In this case the Beta 15A is often recommended as a replacement so it’s a good bet.
     
    agedhorse likes this.
  17. Soulfinger

    Soulfinger

    Sep 20, 2004
    Houston, TX
    You're both right. I designed and built the cabs that I pulled the Betas from. On paper, those cabs are far superior in terms of size, porting, etc. to the old Ampeg. The Beta likes a big box. On paper, I wouldn't have thought it would sound as good as it does in the B25B, given it's really small volume (~5.5 ft^2) and that's kind of ported but not really....best I can figure, it's "tuned" to about 30 Hz, and the reponse is very close to sealed. So in this case, experimenting (carefully) had a good result, and I'm glad I didn't just soldier on with the Altecs because they are supposed to sound good even if my ears tell me otherwise. It goes to show that bass tone isn't always about the best frequency response, but I'm definitely from the "flat ain't fat" school of tone.

    Looking closer at the Altecs, the spider is not flat....it's deflected inward maybe 1/3" of an inch from the outside to the inside. It's hard to see if that's bad or not because I don't have anything to compare them to. I guess it looks like the surround is deflected by about the same amount.
     
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  18. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa, Product Support-Genz Benz
    That's the number one symptom of playing with too much power for the mechanical limitations of that driver. That's why it became obsolete for bass guitar use as the available amp power began to increase.

    I tried selling some nice clean baskets and had a tough time getting any real money for them. Some hi-fi geek bought them for his "home" A-7's, I think I got like $25 each... so much for a vintage windfall right? (Shipping is a bitch on this kind of product).
     
    staccatogrowl likes this.
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