Big Sounds from a small speaker

Fatfingers

We've all seen the little iPhone dock type things that sound a lot bigger than they are. I'm considering a 1 watt amp build and need to keep it physically small. How can I get a big sound from a small combo? I had a Backstair HT1 and it sounded like a little box. I've had 20 quid iPhone docks that sound much bigger, with weeny little speakers in them.

Someone suggested using a 6x9 subwoofer enclosure designed for a car. 

Thoughts?

guitarfishbay

I'd imagine the theory would be to have a big bump just before the frequency response falls off in the low end. None of the docks I've heard have any sub bass at all. But they probably have a big bump before the roll off, which is why they sound 'bassy' - because you can hear the bass and kick. The enclosure and amp are probably both designed with this in mind 

Fatfingers

That sounds very likely. In which case replicating it could be tricky. Any audio engineers onboard?

Sporky

A good quality driver, well matched to the enclosure, is probably a decent start. You can get quite small drivers that go reasonably deep, and if it's for guitar you don't need a particularly low bass response.

If you then apply some EQ to flatten the response you can end up with something fairly respectable sounding. Also appropriate use of absorption inside the cabinet can improve bass response.

ICBM

guitarfishbay said:

I'd imagine the theory would be to have a big bump just before the frequency response falls off in the low end. None of the docks I've heard have any sub bass at all. But they probably have a big bump before the roll off, which is why they sound 'bassy' - because you can hear the bass and kick. The enclosure and amp are probably both designed with this in mind 

Yes. I'm pretty sure all the 'hi-fi' type stuff with small drivers uses very heavy EQ to compensate for the limitations of the speaker and the cabinet, as well as having very compliant speakers and tuned cabinets. You just don't get that with a guitar amp or a small guitar cab.

The problem with trying that for guitar is that it requires music of fairly well-known and constrained frequency content - ie a finished mix - to sound right… if you deviate from that it sounds terrible because frequencies you don't expect to be so boosted are then excessively so.

My little Vox Mini5 digital amp has that problem - it actually sounds very good on its own, but if you put any kind of drive pedal in front of it, it sounds *terrible* - unusably boomy and buzzy. I think that's because the amp is voiced with a lot more bass and treble than normal to correct for the speaker and cabinet.

A normal guitar amp is the exact opposite - the reason they sound the way they do, and good for distortion, is because the frequency response of a standard guitar speaker in a simple box naturally rolls off the frequencies that sound bad. If you want to hear how terrible a guitar amp - even a valve one - really sounds, just DI it.

Fatfingers

Agreed. In which case what's the smallest driver I can get away with and in what size cab, in order for it not to sound like a small box in the corner?

ICBM

I actually find that a small driver in a big cab (relatively) sounds better than the other way round. The problem with going smaller than 10" is that there just aren't very many good 8" guitar speakers to choose from.

guitarfishbay

I've not tried either of these, could be worth a look for some inspiration.  Bother are more powerful than 1w though

Blackstar ID Core Beam, 3" speakers https://www.blackstaramps.com/ranges/idcore-beam

I think this was recorded with mics on the cab.



Ashdown B Social - 5" speakers http://ashdownmusic.com/products/1/Bass-Amplification/21/BSOCIAL/131/BSOCIAL75W/

Fatfingers

ICBM said:

I actually find that a small driver in a big cab (relatively) sounds better than the other way round. The problem with going smaller than 10" is that there just aren't very many good 8" guitar speakers to choose from.

Are there any good 8in guitar speakers?

ICBM

Fatfingers said:

Are there any good 8in guitar speakers?

Not sure! The Weber ones designed for Champs seem OK... in Champs.

It may be that smaller than 10" just needs a different type of speaker with a more 'hi-fi' cone and suspension to give enough bottom end.

Winny_Pooh

I've got the big magnet 8' Weber in a Silverface champ and its excellent, big sound after a long break in period.

Fatfingers

Not sure I could fit an 8 foot speaker in!

Seriously - does it sound as good as a 10in speaker?

Winny_Pooh

Probably, but I can't say for sure unless its in a much larger cab to compare fairly. You can hear it 40secs in over here FWIW:

Fatfingers

Thanks. Which Weber 8in is it? There appear to be several - both alnico and ceramic magnet versions.

ICBM

The one I've tried which sounded the best was the Ferromax, but they don't seem to do that any more. It has a magnet the size of some 10" and 12" speakers.

Fatfingers

That's a shame. Maybe I'll have to stick with a 10in driver.

Winny_Pooh

Its the Ferromax, it made the champ way less portable : )

You may get a bigger sound on a small sealed cab with a tiny port but that gets complex to tune. Just look at the phil jones bass amps. If you've ever played an electric guitar through a recent peavey microbass you would be surprised how good they sound with guitar. I was jamming with one with a drummer last night.

BigMonka

There's also an 8" Celestion model called the 8-15 (as its 8" rated at 15W), it's the newer model of the Super 8. I've not got personal experience of it yet but was considering putting one in my Epi Valve Junior

downbytheriver

How about trying two 8 inch drivers in an isobaric configuration? 

ICBM

downbytheriver said:

How about trying two 8 inch drivers in an isobaric configuration? 

Interesting idea - it works for bass and pro-audio… although the problem is that the 'rules' that apply for that are usually the opposite of what works best for guitar.

Fatfingers

downbytheriver said:

How about trying two 8 inch drivers in an isobaric configuration? 

Would I need an underhand overshaft for that?

Er, isobaric? Two 8in speakers could be good though.