Speakers and headroom . . .

[GuitarStv]

If you had a greally great sounding 15 - 20 watt amp with a single 10 or 12 inch speaker . . . and then you figured out a way to replace the 10 with two 12 inch speakers, would it be louder (and thus have more clean headroom)? IF so, would it be a lot louder? I've got a couple small amps that I love the sound of, they're even loud enough with a drummer, but I lose all my volume (and clean headroom) when playing with drums/bass/rhythm guitarist . . . and I like to use my effects, so I need a relatively clean amp a lot of the time . . .

[greendy123]

Re: Speakers and headroom . . .

Actually volume will not increase, but the percieved volume will because more sound is spread around in the area. On the topic of clean tone the amp and speakers in combination give that overdriven tone. I'm sure if you get a high wattage speaker you would increase your headroom, but I don't know if it may be enough because that is just one part of the formula in your setup.

[GuitarStv]

Re: Speakers and headroom . . .

hmm . . . crap . . . I really love the sounds that my little amps make . . . may have to ebay them then and look for somthing new . . .

[SlyFoxx]

Re: Speakers and headroom . . .

Depending on the efficency of your current speaker, your volume potential could be increased quite a bit. Try and find out the efficency spec of your current speaker. If it's for example 98dB, you could easlily jack up the volume with a pair of 104dB units. If you can get a 6dB swing the change will be pretty big.

[Baltar]

Re: Speakers and headroom . . .

two speakers on a surface do increase the volume by additional 3db.

what does that mean ... eg a speaker with spl 92db 1w/1m :
one speaker, which is driven by one watt pruduces 92dB
two speakers mounted on one surface, driven by each one watt produce 98dB
(so two speakers on a surface do increase +6db instead of +3 -> physics)

if your amp handles the load of the additional speaker, it should
be louder.

((two speakers of the same f-range of course. 2 woofers of same model eg))

also ake care of the impedance. if you consider to replace one 8ohm
speaker, you need to replace it with two 16ohm-seakers in parallel

[GuitarStv]

Re: Speakers and headroom . . .

Umm, the speaker is part of a really old (40-50 year old) tube combo that I have . . . is there any way of testing what the speaker volume is? Or and way of testing if the amp can handle a more efficient speaker?

[SlyFoxx]

Re: Speakers and headroom . . .

The amp doesn't handle the speaker, it's the other way around. So a more efficent unit will pose no danger provided that the speaker's impedance is correct for the amp. If you don't know the impedance of the old speaker and it's marked no where on the amp, measure it's DC resistance with a mulitimeter. The DC resistance should measure a bit lower than the actual impedance. ~3 for a 4 ohm...~6.5 for and 8 ohm and ~14.5 for a 16 ohm.

As far as a test to measure the efficency of the old speaker...it takes the proper tools which not too many people have. But if the speaker is VERY old I'm gonna go out on a limb and figure it's efficency is very low compared to standard speakers of today. If you want to try before you buy I'd suggest determining the correct load (impedance) for the amp and find a friend with a compatible modern speaker cab or a store that will let you try it out. If the current speaker is really weak you might find that swaping for a single very efficent modern unit does the trick w/o the need to get a seprate cab.

[Scott_F]

Re: Speakers and headroom . . .

Hmm... sounds like a recent discussion I"ve been having. 15-20 watts, no matter who makes the amp, will have a hard time giving up the kind of clean headroom you want. at least that is how it sounds to me.

[Marcel]

Re: Speakers and headroom . . .

loudness is different
for example a vintage 30 is about 3db louder than most of the other celestion...

[GuitarStv]

Re: Speakers and headroom . . .

Hmm... sounds like a recent discussion I"ve been having. 15-20 watts, no matter who makes the amp, will have a hard time giving up the kind of clean headroom you want. at least that is how it sounds to me.

I don't actually know what the wattage of this amp is . . . but it's class A and has four tubes, one 12ax7, two 6av6, and one 6bq5 (which I think is an el84). Does anyone know how to calculate the wattage from that?

It seems to be a lot louder than my 40 watt SS amp . . . and I've been bringing them both along when jamming with buddies. I was just hoping that I could put the amp in a newer bigger box with another speaker, and only bring the one amp.

[SlyFoxx]

Re: Speakers and headroom . . .

With only a single 6BQ5/EL84 I'd guess about 10 watts. But Scott_F would be sure to know more than me.

[GuitarStv]

Re: Speakers and headroom . . .

. . . yeah, I guess that I do need a louder amp then . . . it's too bad, because that little guy really sounds awesome.

[drew_half_empty]

Re: Speakers and headroom . . .

if you really don't wanna sacrifice tone at all & can't find something else you like, maybe you could buy a PA & just mic it

[Baltar]

Re: Speakers and headroom . . .

if you really don't wanna sacrifice tone at all & can't find something else you like, maybe you could buy a PA & just mic it

agree. changing the speakers will definately change the sound, which
seems to be what you want to avoid.

[Merodack]

Re: Speakers and headroom . . .

If you want to try before you buy I'd suggest determining the correct load (impedance) for the amp and find a friend with a compatible modern speaker cab or a store that will let you try it out.

How would one go about determining the correct load? I bought an old 30W or 40W head at a flea market with a 2x12 cab, and I'd like to know whether they really match.