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Topic: Delta-Lite in a Twin? |
Steve Blazek
From:
Lincoln, Nebraska, USA
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Posted 13 Jan 2006 6:11 am |
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| I'm tring to find some use for this 8 ohm, 15in. Delta Lite speaker. If I stick it in my black face twin will I end up with a very light, 50ish watt twin? |
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Donny Hinson
From:
Glen Burnie, Md. U.S.A.
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Posted 13 Jan 2006 7:01 am
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No, it'll only save you about 10 or 12 pounds, so your Twin still won't be a lightweight. It has good low-end response and efficiency, though, something any Fender will benefit from. By the way, your B/F Twin oughta be good for 60-70 watts...not "50ish".
p.s. Should you find you don't like it the speaker, I'll buy it from you!  |
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Jay Ganz
From:
Out Behind The Barn
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Posted 13 Jan 2006 7:13 am
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Those Deltalite's are great sounding speakers for sure. That's what I'm using in the video clips I posted a few days ago in the "Steel Players" section. Here
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David Doggett
From:
Bawl'mer, MD (formerly of MS, Nawluns, Gnashville, Knocksville, Lost Angeles, Bahsten. and Philly)
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Posted 13 Jan 2006 8:09 am
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If your BF Twin is like most, it is designed for a 4 ohm load (two 8 ohm 12s in parallel). Since the Delta Lite 15 is 8 ohms, that will reduce the output of your Twin by about 1/3 (from what I have read in other posts here on the Forum). And as Donny says, you will only lose about 10 lbs. - most of the weight is in the amp chassis and cabinet. You will still have a very heavy amp with a weak output of about 40 watts. - about the same as a BF Pro, or a silver face Vibrolux, which is much smaller and lighter.
Other options are:
Replace the transformer or have it altered with an 8 ohm tap.
Get another Delta Lite 15 and run it in an extension cabinet in parallel with the internal one. That will allow you to almost double the output, and have a lightweight extension cabinet.
Replace the Delta Lite 15 with two Delta Lite 12s, 8 ohms each, in parallel, the stock Twin configuration and output, with a small saving in weight.
If you can find a silver face Vibrosonic (not the later Vibrasonic), it takes a single 8 ohm 15" speaker. The Delta Lite would be ideal for it. [This message was edited by David Doggett on 13 January 2006 at 08:12 AM.] |
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Donny Hinson
From:
Glen Burnie, Md. U.S.A.
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Posted 13 Jan 2006 11:35 am
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"Things are seldom what they seem."
So it is with speakers. Perhaps no other simple electrical device (a speaker's just a magnet, a coil of wire, and a cone) is quite as hard to understand as a speaker.
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| ...it is designed for a 4 ohm load (two 8 ohm 12s in parallel). Since the Delta Lite 15 is 8 ohms, that will reduce the output of your Twin by about 1/3... |
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| You will still have a very heavy amp with a weak output of about 40 watts. |
What our esteemed forumite David Doggett says is true...theoretically. However, in the real world, things aren't that simple. For one thing, a speaker's impedance varies considerably with frequency. A speaker rated at a nominal eight ohms might vary fifty percent or more at different frequencies. Therefore, the actual losses in audio output are rather hard to compute, especially with an instrument with the frequency range of a pedal steel! Also, the speaker's efficiency has to be taken into account to make a valid statement about any losses which may or may not occur when speakers are swapped. Speakers are notoriously inefficient devices, the efficiency of different speakers might only vary a couple of percent, but when you consider that a really good speaker has an efficiency of only two to four percent, a single percentage point in efficiency can make drastic differences in perceived loudness, and this is what we should really be concerned with.
So, let's say that the stock Fender speakers are two percent efficient (not bad, really), and the replacement speaker has an efficiency of three percent. The resultant increase in efficiency (fifty percent) of the replacement speaker would more than offset any losses in the impedance mismatch.
We can state vague generalities about speakers, but it should be noted that the sound is what we're really concerned with, and often the only way to determine if a speaker will sound better in a certain application is to try it. Specs and equations are only a rough starting point in discovering the sound we really want, or determining how a speaker will sound in our particular application.  [This message was edited by Donny Hinson on 13 January 2006 at 01:45 PM.] |
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David Doggett
From:
Bawl'mer, MD (formerly of MS, Nawluns, Gnashville, Knocksville, Lost Angeles, Bahsten. and Philly)
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Posted 13 Jan 2006 9:23 pm
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Donny is right. My comment about the drop in output between an 8 ohm and 4 ohm speaker assumes they have the same efficiency, and the only difference is the impedance. I don't know the relative efficiencies of the Delta Lite and your other speaker options.
Speaking only of the weight issue, even though the Delta Lite may be half the weight of other speakers, it only shaves a little weight off the total weight of a combo amp. The Delta Lite 15 weighs 8.6 lbs. (http://www.usspeaker.com/delta%20lite2515-1.htm). Other 15" speakers weigh from around 8 to over 15 lbs., depending on the power they are designed to handle. I have a Jensen MOD 15 rated for 80 watts RMS that weighs 8 lbs. A JBL D130 rated for 60-80 watts weighs 13 lbs. A conventional Eminence 15 rated for 300 watts weighs 15 lbs. So if you swap the Delta lite for the JBL or Eminence, you shave 4.4 to 6.4 lbs. off the weight of a combo amp weighing around 70 lbs. - not that big a deal. Replacing two stock JBL 12s in a Twin with the single Delta Lite 15 would save about 11.4 lbs., or about 15% of the total weight. That's beginning to be something you will feel. If the Delta Lite is more efficient (not saying it is, since I don't know), that might compensate for the impedance mismatch to some extent. You're the only one who can tell if there is enough headroom with the Delta Lite for your needs.
My main point is that, using the 8 ohm Delta Lite in a 4 ohm amp, you are saving a few lbs. but not getting the optimum output from the amp, compared to a 4 ohm speaker of similar efficiency. If I were going to do that, I'd look into getting an 8 ohm transformer for the amp. If you don't need the maximum output of a Twin, then there are lighter Fender tube amps you could use, such as a Pro or a Hot Rod. Tube amps are heavy enough. I just don't like to carry more weight than I need, and I don't like to have weight that is not being used optimally. I wish they made a 4 ohm Delta Lite 15 for use with the old Fender amps. But until they do, the 8 ohm Delta Lite is a mixed blessing - it saves a few pounds, but doesn't give you optimum output unless you change the tranny. [This message was edited by David Doggett on 13 January 2006 at 09:28 PM.] |
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David Nugent
From:
Gum Spring, Va.
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Posted 14 Jan 2006 2:38 am
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| I was wondering if you had tried the speaker in the Twin as yet to see if you liked the results? The beauty of your situation is that the speakers in the Twin plug into the rear of the amp utilizing a 1/4" phone plug. By placing the Deltalite in a separate cabinet and plugging it into the Fender using a standard guitar or speaker cord, you can determine if the speaker is suitable without initially altering the Twin. |
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Donny Hinson
From:
Glen Burnie, Md. U.S.A.
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Posted 14 Jan 2006 3:10 am
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(Dave Nugent)I'm certain it's "usable", but hooking it up to the extension speaker jack might not tell you the whole story. Since it's an 8 ohm speaker (vs. the two 8 ohm factory speakers hooked in parallel - equaling 4 ohms), it wouldn't get as much of the amp's power as the stock speakers, and that might lead you to believe it's not that impressive. Better to unhook one of the stock speakers if you want to use this test.
Should anyone desire to change the transformer (a I did), the Fender part number for the 8 ohm B/F transformer is 022897. [This message was edited by Donny Hinson on 14 January 2006 at 06:24 AM.] |
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Steve Blazek
From:
Lincoln, Nebraska, USA
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Posted 14 Jan 2006 7:48 am
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| Man you guys are good. I love this forum! I would be replacing 2 - 12in. JBL's with the Delta-Lite. call me old fashioned, but I am just wanting to use a tube amp with a real spring reverb again. |
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David Doggett
From:
Bawl'mer, MD (formerly of MS, Nawluns, Gnashville, Knocksville, Lost Angeles, Bahsten. and Philly)
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Posted 14 Jan 2006 8:48 am
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Well, as long as we are dreaming about all your options, you might consider getting another Delta Lite 15 (or any other 8 ohm 15) in an extension cab. For low volume needs you just use the Twin with the internal DL 15 (probably about 50 watts output as you guessed). To almost double the volume, plug the extension DL 15 in parallel. I'm not sure how the extension jack on your model works. If it is in parallel, just plug into that. If not, get a Y connector and plug both speakers into the internal jack, the same as the two JBL 12s.
The ideal option is to put the chassis in a head cabinet (like Lloyd Green), and put both 15s in extension cabinets. For low volume, you bring along the head and one 15. For more volume, plug them both in as above. That's lighter loads, but more trips. But even keeping it to one trip, the head in one hand, and the speaker in the other is easier than a Twin combo in one hand. I have a Dual Showman head with two JBL 15s in extension cabinets - easy handling and great sound. |
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David Higginbotham
From:
Lake Charles, Louisiana, USA
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Posted 14 Jan 2006 10:16 am
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I just love reading such informative responses such as these. One can always count on Donny's response to be as such. I can only imagine the amount of time spent learning these particulars. Keep it up guys for the novices out here! 
Dave[This message was edited by David Higginbotham on 14 January 2006 at 10:17 AM.] |
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David Nugent
From:
Gum Spring, Va.
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Posted 14 Jan 2006 10:28 am
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Donny,
I believe the purpose of Steve's post was to find if the Deltalite would suit his purposes in a particular application. I was my suggestion that he disconnect the stock speakers, plug in the Eminence and thus be able to reach his own conclusions as to its pros and cons.....In my opinion, placing it in tandem with one of the stock speakers would defeat the purpose of the test, because if I understand his post correctly he plans on using the Deltalite as a single unit...Later, if he is pleased with the results, the transformer upgrade is definitely the way to go. |
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Donny Hinson
From:
Glen Burnie, Md. U.S.A.
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Posted 14 Jan 2006 11:35 am
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| Sorry, I thought you were talking about using the extension speaker jack to try them side-by-side. Either method will probably suffice to determine the tonal differences. |
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