So my next big building project is gonna be simpler than a full amp. I've decided to build my own 4X8 speaker cabinet. I see a 4X8 as being a good configuration, considering it's half a Commando, or a full SJ1.
Ideally, I'd love to get my hands on a quartet of the Pyle ceramics that Sonny put in his first two amp models, but apparently they're extinct from new production. I found a couple on eBay, but I don't think I'm gonna grab them. There's no guarantee as to their present condition after all.
I have a short list built. I am on a budget right now, but I'm open to any suggestions to see what would be ideal. My main three contenders right now are:
A: Peavey Blue Marvel 8", 3.2 ohm, 25W - the cheapest of the three, but also the highest rated for power. I have experience with this speaker, and I always got better results out of it for harp than I did for guitar surprisingly enough.
B: Celestion Eight 15, 8 ohm, 15W - I've read good things about this speaker, but mostly from guitarists who are nuts for the British sound. I'm kinda dubious about this one.
C: Maaaaaayyyyybe...big maybe...a Jensen MOD 8-20, 4 ohm, 20W - I have an innate aversion to current production Jensens, for obvious reasons. But I've listened to sound clips of this one. Pretty good low end response on them, so it made my shortlist by the skin of its teeth.
Webers are a little out of my price range right now, as are the new Eminence Patriot 820H's that are due for release next month. But if the sounding board here rings in that I should wait and save up for them, I'll take it under advisement.
You may have noticed that they're all ceramics. I do love my alnicos, but I'd like this cab to be useable with guitar too should the need ever arise, and ceramics can deliver better responses to higher power input in my experience.
Also, any suggestions on the layout of the speakers? I have a Commando square pattern in my head, but if anyone recommends a staggered pattern, please voice the suggestions. ----------
Okay....that one replaces the Jensen on my list. But I still hesitate at the 15W rating. I could very well run a pretty high power guitar amp through it. I'll hafta do some figgerin' on that detail. ----------
I did say the cab might be used for guitar as well. Our lead guitarist has a DSR, one I admire a great deal. He seldom uses it, favoring his BF Bandmaster. I also have a bead on a Silvertone 1485. Both of those are 100W beasts. So it looks like I have a choice between tone and versatility before me when it comes to my speaker selection.
Rick, any thoughts on the positioning factor? ----------
Not simply guitar per se, but as I said, rather high powered guitar amps. To my ears, alnicos tend to do the equivalent of a reed choking out when pushed to hard. ----------
@HK. You're correct that the Pyle speakers aren't available as they are out of business. Finding vintage 8"s is difficult. Maybe a combination of weber sig, both alnico and ceramics might work.
I am embarking on a similar project, I'm toying with the idea of either 4x8" or 2x8"plus 10".
Good luck HK!
As for using it for guitar and harp. I have had problems doing that as I swap out 12ax7 for 12au7 when I play harp. Those tubes don't work so well for guitar. I'd be interested in anyone's comments regarding that issue.
Last Edited by on Jan 24, 2013 5:34 AM
I've heard alnicos work great for guitar before. Hell, my Alamo has a single 15" alnico and sounds great with guitar. A guy I know has a single 12" Altec alnico in his Marshall cabinet, sounds great with his Bandmaster. But those are big speakers with according power ratings. If I'm to try an old 100W head through this cab like a DSR, 1485, or Dano DS-100, I'd rather the speakers I use have the most rated power behind them. Just sayin'...
@6SN7 "You're correct that the Pyle speakers aren't available as they are out of business."
Actually....they're not. It's most likely under completely new management or another company purchased the Pyle name, but there is still a Pyle Audio in existence. One thing to note though....their slogan is "High End Performance at an Affordable Price". So something tells me whatever they sell is a far cry from the quality of the Pyle of old.
@6SN7 "As for using it for guitar and harp. I have had problems doing that as I swap out 12ax7 for 12au7 when I play harp. Those tubes don't work so well for guitar. I'd be interested in anyone's comments regarding that issue."
The channels in a Dual Showman Reverb (or any 2 channel Fender tolex amp) have a preamp tube for each channel & pretty independent tone/volume controls, so if you used the Normal channel for harp you could stick a 5751/12AY7 in V1 and leave a 12AX7 in the Vibrato channel (V2)...or leave 12AX7 in both preamps and try different tubes in V6...5751 again, maybe even a 12AY7 would work if you liked headroom on the guitar?
Power section would also be a bit of a compromise, I'd see how 30mA per tube worked for both applications? The 8"s should help tame feedack some...one or two Eminence Alphas are possible candidates on that front. ---------- www.myspace.com/markburness
Thanks for the Alpha suggestion, Mark. At 125W, that blows everything else I was looking at outta the water. Do you recommend the 8MRA or the 8A? As far as I can tell, the only difference between the two is the sealed basket on the 8MRA, and the 8A has a shallower surface with a bigger dustcap.
And here's another factor I didn't bring up for the poll....
Speaker wattage is just how much heat the voice coil can take before melting, there is no direct correlation to tone. Look more at efficiency & frequency curves (you can't beat listening though). I used an 8A in my 0.4W harp amp and it breaks up just fine.
I wouldn't go mad and use a whole bunch of 'em though, just one, or two absolute max. ----------
I can't find much on the Bobcat maker...just directory listings for Charley Powers of Guitar CPR. No dedicated websites to speak of. Just give him a call do you think? ----------
Unless you're using one for an extremely low powered amp of 10 watts or less, 8's tend to have serious problems cutting thru the mix even in low volume situations. ---------- Sincerely, Barbeque Bob Maglinte Boston, MA http://www.barbequebob.com CD available at http://www.cdbaby.com/cd/bbmaglinte
I may build a 4X10 at some point as well. But first I want a 4X8, cause at this point, 8" speaks are MY preference. :-) Half of me is tempted to just go all out and build an 8X8 folding suitcase cabinet! ----------
Hawkeye Kane
Last Edited by on Jan 24, 2013 10:37 AM
Mark, I once spoke to Gary Onofrio about this: It was his philosophy that blues harp speakers should be driven right at their wattage rating. Does that sound right to you?
@ Rick "Mark, I once spoke to Gary Onofrio about this: It was his philosophy that blues harp speakers should be driven right at their wattage rating. Does that sound right to you?"
Many of the old, great sounding Fenders had speakers that were rated at, or often below the amp's rated clean output Fender knew that the amp would kill the speaker given enough time (but hopefully outside warranty), Mark Baier had the theory that the 1x15" Pros had tiny OT's specifically to shelve bottom end and give the speaker an easier time (look at the size of the OT on a Vibrasonic, same circuit & voltage as a 6G# Pro, with a JBL and you'll see a big difference, these flagship 40W amps were given 100W transformers!)...so, in the context of old amps with 50's speaker technology, exceeding the amp's W ratings, with speaker W ratings was often very costly & not typical.
Today, modern materials make it easy to make a very similar speaker with at least twice the W (heat tolerance, the W rating of an amp is when it distorts, for speakers it's when they die) of the old speakers. Obviously materials can affect the sound but lots of good sounding low power amps have speakers of up to x10 the amp's W RMS rating, sometimes more.
Gary may have been talking with respect to "tonal ideal" with his preferred vintage speakers, his amps typically had speaker arrays with wattage ratings well beyond the amp's clean RMS rating. It's normal practice to double the speaker's, or array's, W rating with respect to the amp, because unlike SS amps, tube amps can make twice their rated power when dirty (as you well know from seeing 50W output on your 32W 32-20).
Good sounding speakers are good sounding speakers, quoted Wattage isn't specifically why they sound good or bad, it's coincidental based on construction & materials. The wattage might dovetail, it might not...and yes, if you push to the limits with 100W, 60-70oz magnets, 2.5" or bigger voice coils, you will start to find speakers that fit the clean/harsh stereotype, but with harp it's possible to overshoot with efficiency (SPL) and just have a bright, feedback prone speaker that will stay clean, but the next one on the shelf, similar W rating & moderate efficiency, might be fine?
Listening tests trump everything else.
Also consider some manufacturers rate their speakers differently if using tube or SS amps, a 150W SS speaker may be offered as a 75W "tube" speaker. Conversely Celestion's "Vintage 30" is a 60W speaker.
---------- www.myspace.com/markburness
http://www.facebook.com/markburness
Last Edited by on Jan 24, 2013 12:23 PM
"I think the thing that sometimes saved Showman cabinets was the closed back, everyone I ever knew that had a high power tweed twin, or a blond twin was constantly having to replace speakers, but when they were good, they sounded great!"
True enough. My man with the DSR has three speaker cabs that he uses. One is a semi-closed back Marshall cab with a single 12" Altec alnico. The other two are closed back Crates, each with a single 12" Celestion ceramic. He usually uses both Crate cabs with his Bandmaster, all three cabs if it's a big room or outdoors. But the few occaisions he's had his DSR out (which of course is the exact same chassis and circuit as the SF Twin Reverb), NEVER have I seen him use the Marshall cab. Always the Crates. Now I can see why. LOL
Sidenote on that detail...I happened to experiment with my Alamo two weeks ago. As I mentioned in my thread about it, the 15" alnico in it had a thick fiberglass insulation wrapping behind it. I took it out to see what it'd do to the sound. It sounded a little more punchy, but when the volume went up on it, I could hear little clipping noises beating through the air. I immediately put the fiberglass back. Now I know what purpose it serves. :-) ----------
So if I were to take the speaker enclosure panel off and remove the fiberglass, would that possibly eliminate the clipping and give me a different sound? ----------
I think I see what you're getting at. I kinda used to play the same game with my Peavey Vypyr which was completely open backed. That sucker backwashed like a mofo. Sometimes I could play the wall behind me, other times I was too far up from it. Our drummer used to fuss about the backwash overwhelming him. So once or twice, I played a joke on him and switched the speaker leads so it phased back at him. :-)
I'll try to make a split back panel for the Alamo, and keep these factors in mind when building the enclosure for the 4X8. ----------
Just interesting why 4x8, not 2x8+12, or 8+10+12 for more wide frequency range? ---------- Excuse my bad English. Click on my photo or my username for my music.
@Boris "Just interesting why 4x8, not 2x8+12, or 8+10+12 for more wide frequency range?"
You can find any of those speaker sizes in all useful frequency ranges, mixing sizes really mixes speakers with different tones & dynamics...e.g. for *a given speaker motor* a 12" will typically have more efficiency, possibly a shade more high end, than an 8", so you could use the 12" to add punch & clarity to the softer sound of the 8" for a more complex tone. The 12" would only have a significantly different frequency response, if that particular 12" was design to do so.
I agree with the principle though...for stage work I'd be looking to mix the 8" with something else, perhaps design as 2x10" + 2x8" and make a couple of 10" to 8" converter rings?
I have 3 8" alnicos and 1 8" ceramic speaker in both of my Dano cabs. I think the ceramic gives a little punch to the sound. Gary was doing this with his latest SJ's too.
