|
|
Post by bod on Aug 17, 2023 12:38:21 GMT
Hi,
I’ve a 5 watt valve combo with a very small speaker and am toying with putting it through a larger speaker in an external cabinet. A possible candidate cab has come up, but it has a 70 watt speaker in it. Reading around online more generally, it seems pretty clear that amp and speaker ohms should match (and they do), but I’m not finding much on the advisability of running a low wattage amp into a rather higher wattage speaker.
Can anyone here advise?
Thanks
|
|
|
|
Post by pete1951 on Aug 17, 2023 13:32:21 GMT
As long as the impedance match you’ll be fine. I think that if your 70 watt cab has more efficient speakers it may well be louder.
Pete
Some speakers are not very efficient,
The efficiency of speakers is measured in dBs ( that’s the theoretical loudness of 1watt at 1M) a 5watt amp through a 100dB speaker ( as long as the wattage rating is over 5) will be louder than a 15watt amp through a 90dB speaker .
Speaker efficiency is the reason an AC30 can hold it’s own against many 50 watt amps
Of coarse,a 70watt amp into a 5 watt speaker will end in a fried coil!
|
|
|
|
Post by bod on Aug 17, 2023 15:32:32 GMT
Thanks Pete, appreciated 👍🎸
|
|
|
|
Post by mitchfit on Aug 17, 2023 20:02:28 GMT
what Pete said, with additional warning. do not play your amp into hi-fi quality speakers as in may damage them.
[yes even 5 watts]
not a power problem, but Hz.
mitchfit
|
|
|
|
Post by Bo Grohl on Aug 17, 2023 21:26:30 GMT
I cut the speaker out of a cheapo stagg 30w amp and wired in two jack sockets for a pair Marshall 2x12s, for use as a PA. It's now really loud (or has a much bigger volume) and sounds fab. I might try it with a microcube next.
|
|
|
|
Post by tomgiemza on Aug 17, 2023 23:20:27 GMT
Speaker wattage > amp wattage.
Speaker can make a significant change to the sound. That's why it's fun to try various cabs. In theory, a higher wattage speaker should sound clearer than a lower wattage speaker with the same amp.
For example, when I was building myself a cab, my goal was to recreate dirty 50's style sound, so I was looking for a speaker rated just a little more watts than my amp and not very efficient one (dBs), so I could crank it up without going deaf... On the other hand, people who like a crystal clear sound usually would choose a speaker with much more wattage reserve.
|
|
|
|
Post by mitchfit on Aug 17, 2023 23:36:41 GMT
have an olde "AT 412B" B-52 brand 4x12 slant cab with 120 watt speakers. [480 watts max rating] made it into a right and left pair wired cab with two each separate 8 ohm input jacks.
built a single speaker cable from 12 gauge nonresistance wire and 3 each 1/4" phone jacks. one on both ends with one in the center.
can use cable in parallel for 4 ohm. can use one side only for 8 ohm use. can use cable in series for 16 ohm.
easy way to replace {less than ideal} OEM switching printed circuit board on the back panel with something more reliable than a sledge hammer.
these came new with a factory covering that seems like felt fuzz adhered to cab with contact glue. prone to look like a short haired labrador hound dog with mange in short order. sell cheap due to poor visual appearance and bad reputation of the 4 X 12 cabinet that followed AND POOR speaker chosen to populate that cab.
make sure you get "AT 412B" model! could be hidden in the back corner of a music shop near you.
but the main message--
a single ended 6973 amp [11 or 12-ish watts] sounds like Gabriel's Trumpet when pushing four 12" speakers.
mitchfit
|
|
|
|
Post by pete1951 on Aug 18, 2023 7:10:00 GMT
Speaker wattage > amp wattage. Speaker can make a significant change to the sound. That's why it's fun to try various cabs. In theory, a higher wattage speaker should sound clearer than a lower wattage speaker with the same amp. For example, when I was building myself a cab, my goal was to recreate dirty 50's style sound, so I was looking for a speaker rated just a little more watts than my amp and not very efficient one (dBs), so I could crank it up without going deaf... On the other hand, people who like a crystal clear sound usually would choose a speaker with much more wattage reserve. Normally I go for highly efficient speaker but I have used less efficient ones as a dummy load. I have an 18 watt head ( with no master volume) that sounds best at about 6 which is too loud for some gigs. Inside the head is a 25watt 16ohm 8” car speaker rated at ( if memory serves me) 86dB. I can use the head as a practice amp with no extra cab or I can pug it and a 96bB 16ohm cab into the 8ohm sockets. You can’t hear the car speaker and the main cab gets half the power. It works for me though I haven’t come across anyone else using this method. Pete |
|
|
|
Post by Pickers Ditch on Aug 18, 2023 8:20:45 GMT
Do you remember those cigarette packet amps?  Did a pub gig with one of them plugged into a 1970s Marshall 2x12 cab. ...and we had a drummer playing with us! |
|
|
|
Post by bonzo on Aug 18, 2023 8:59:41 GMT
Must have been a drag, did you run out of puff? 🙂👍🎸
|
|
|
|
Post by Michael Messer on Aug 18, 2023 9:06:20 GMT
|
|
|
|
Post by Pickers Ditch on Aug 18, 2023 9:13:31 GMT
Blimey Moses - and I got two of 'em for 15 squid, decades ago.  Best check they're still operational. |
|
