Look through a speaker catalog at the efficiency ratings of several guitar and pro audio speakers. 6 inch drivers range from the 80 to 90 db SPL at 1 meter fed by 1 watt. 12 inch drivers range from 90 to 100 db SPL. This means if all other factors are equal the 6 inch driver will need 10 times the amplifier power to produce the same sound level. All other factors are not equal. The 12 inch driver will handle more power. The SPL ratings are at 1KHz. Look at the response curves in the 100 to 400 Hz range where much of the guitar's output is and the smaller speaker will be lower still in SPL output compared to the big one.
About 15 years ago I stuffed a pair of Electro Voice EVM-10M guitar speakers into a 12 inch tall, 24 inch wide, by 10 inch deep sealed box. The speakers are 99 db efficient and can eat all the power I can feed them. A 100 watt guitar amp can send a cheap Radio Shack SPL meter into the 122 db range from 1 meter in a small room. This cabinet is small, not much bigger than a Marshall 100 watt head, but heavy. It weighs almost 60 pounds.
I recently stuck a pair of 6 inch speakers that claim to be loud into an 10 inch tall, 16 inch wide, by 8 inch deep sealed box. They are rated at 92 db SPL. The claim:
Dayton Audio PA165-8 6" PA Driver Speaker 295-015
I am building a small amp head of the same size as the speaker cabinet that should make 80 to 100 watts, but I fed the speakers with the same 100 watt amp as before. They are loud, and make a reasonably good lead guitar sound, but are not in the same league as the 10 inch EV's. The cabinet will run the SPL meter up to 110 at full crank in the same small room. Take both cabinets outside and from 50 feet away the 10 inch speakers are much louder.
A pair of larger cabinets each containing an $15 Ebay Eminence driver of unknown specs is louder than both small cabinets by a noticible amount. No SPL readings are possible due to the high ambient noise levels.
About 15 years ago I stuffed a pair of Electro Voice EVM-10M guitar speakers into a 12 inch tall, 24 inch wide, by 10 inch deep sealed box. The speakers are 99 db efficient and can eat all the power I can feed them. A 100 watt guitar amp can send a cheap Radio Shack SPL meter into the 122 db range from 1 meter in a small room. This cabinet is small, not much bigger than a Marshall 100 watt head, but heavy. It weighs almost 60 pounds.
I recently stuck a pair of 6 inch speakers that claim to be loud into an 10 inch tall, 16 inch wide, by 8 inch deep sealed box. They are rated at 92 db SPL. The claim:
Dayton Audio PA165-8 6" PA Driver Speaker 295-015
I am building a small amp head of the same size as the speaker cabinet that should make 80 to 100 watts, but I fed the speakers with the same 100 watt amp as before. They are loud, and make a reasonably good lead guitar sound, but are not in the same league as the 10 inch EV's. The cabinet will run the SPL meter up to 110 at full crank in the same small room. Take both cabinets outside and from 50 feet away the 10 inch speakers are much louder.
A pair of larger cabinets each containing an $15 Ebay Eminence driver of unknown specs is louder than both small cabinets by a noticible amount. No SPL readings are possible due to the high ambient noise levels.
So today I got myself one of the little Faital Pro drivers. Small driver, big magnet, was my first impression. No vented pole piece was the second.
Plugged it into a 50w (into 8ohm) mixer-amplifier (driver sat on the floor), and it made sound. Good start. However, it sounded like something was clipping slightly when turned up a little.
Switched to a bigger amplifier. Same problem, definitely excursion related.
Put a low frequency sine wave through. Cone moved slightly, no rattly noise. Turned it up a bit, cone movement got to a few mm, and the rattle was back.
Turned it up slightly more, the rattle got worse still, and then there was the smell. We've all been there, and know that smell. Cooked speaker smell.
Disconnected the speaker, measured the voltage output on the amplifier. 32v RMS. Into a 6ohm load, that's 171w. The speaker failed in seconds. 260w rated? I think not. Grrr...
As I'd cooked it, it was out of warranty, so I opened it up and found a couple of loose bits of metal in the magnetic gap. That might explain the rattle, I suppose.
So now I'd wondering whether to try the Eminence speaker (which needs a larger cabinet to perform), or just to say stuff it, I'll do it the old-fashioned way and quit complaining about the weight.
Hmmmmmmmmm...
Chris.
Plugged it into a 50w (into 8ohm) mixer-amplifier (driver sat on the floor), and it made sound. Good start. However, it sounded like something was clipping slightly when turned up a little.
Switched to a bigger amplifier. Same problem, definitely excursion related.
Put a low frequency sine wave through. Cone moved slightly, no rattly noise. Turned it up a bit, cone movement got to a few mm, and the rattle was back.
Turned it up slightly more, the rattle got worse still, and then there was the smell. We've all been there, and know that smell. Cooked speaker smell.
Disconnected the speaker, measured the voltage output on the amplifier. 32v RMS. Into a 6ohm load, that's 171w. The speaker failed in seconds. 260w rated? I think not. Grrr...
As I'd cooked it, it was out of warranty, so I opened it up and found a couple of loose bits of metal in the magnetic gap. That might explain the rattle, I suppose.
So now I'd wondering whether to try the Eminence speaker (which needs a larger cabinet to perform), or just to say stuff it, I'll do it the old-fashioned way and quit complaining about the weight.
Hmmmmmmmmm...
Chris.
Sticking with the small driver idea for the moment, how much will a vented pole-piece help matters?
The Eminence driver has a vented pole piece, and appears to have more demanding thermal tests: 8 hours at 100w instead of 2 hours at 130w.
The Faital Pro driver has no vented pole piece, but has more excursion, more claimed power handling, and will take a smaller cabinet with a decent frequency response.
For those interested in the amplifier this will replace, the bass (according to Hornresp, simulating a U-frame) rolls off steeply at about 200Hz.
Chris
The Eminence driver has a vented pole piece, and appears to have more demanding thermal tests: 8 hours at 100w instead of 2 hours at 130w.
The Faital Pro driver has no vented pole piece, but has more excursion, more claimed power handling, and will take a smaller cabinet with a decent frequency response.
For those interested in the amplifier this will replace, the bass (according to Hornresp, simulating a U-frame) rolls off steeply at about 200Hz.
Chris
My guess would be, not much. Few guitar speakers have them. Then again, few guitar speakers are rated for more than 100 watts.
Keep in mind, guitar speakers are rated with distorted signals so you'll have to downgrade the power ratings of "pro" speakers. Even still, most advice suggests having speakers with twice the amp's power rating.
The rated excursion is also suspect. Guitar speakers decrease their compliance at higher power levels, so it's not an apples to apples comparison.
An update...
Take #2.
I got myself another of these speakers, and (after ensuring it works) built a 6L (net) box out of bits of MDF I have lying around. There's a slot port, tuned to ~80Hz, which keeps excursion down while providing bass headroom. There's no shortage of low end here: I usually turn the bass down on my multi-fx.
Using a head that gives an entire 30w into 8ohm, it goes pretty loud. Certainly loud enough to annoy people at range in a domestic environment.
Given the LF compression/limiting I'm yet to install, I suspect this'll go rather loud with more power.
The design spec has also changed a little - the intention now is to have a high power head (say 300w @4ohm) that happens to have a speaker built in.
More power!!
Chris
Take #2.
I got myself another of these speakers, and (after ensuring it works) built a 6L (net) box out of bits of MDF I have lying around. There's a slot port, tuned to ~80Hz, which keeps excursion down while providing bass headroom. There's no shortage of low end here: I usually turn the bass down on my multi-fx.
Using a head that gives an entire 30w into 8ohm, it goes pretty loud. Certainly loud enough to annoy people at range in a domestic environment.
Given the LF compression/limiting I'm yet to install, I suspect this'll go rather loud with more power.
The design spec has also changed a little - the intention now is to have a high power head (say 300w @4ohm) that happens to have a speaker built in.
More power!!
Chris
Tinitus, it's a 6FE200.
Keriwena, it does actually sound quite nice.
- its smooth and extended through the high frequencies - I was trying to avoid the peaky upper mids typical to guitar speakers (tried a 10" Celestion, hated it because it was so prominent).
- it has enough low end to practice bass through. This bodes well for having some headroom at higher volumes - excursion stays minimal.
- with a little eq (turn the lows and highs down), I can get the open-backed bass, smooth highs sound, perfect for sounds like the solo on You Do Something To Me by Paul Weller.
I do rather like it. When I get my recording gear back, I'll mic up the original combo so you all know the sort of sound I'm talking about.
Cheers
Chris
PS - for reference, FaitalPRO - Professional Loudspeakers Made in Italy
Keriwena, it does actually sound quite nice.
- its smooth and extended through the high frequencies - I was trying to avoid the peaky upper mids typical to guitar speakers (tried a 10" Celestion, hated it because it was so prominent).
- it has enough low end to practice bass through. This bodes well for having some headroom at higher volumes - excursion stays minimal.
- with a little eq (turn the lows and highs down), I can get the open-backed bass, smooth highs sound, perfect for sounds like the solo on You Do Something To Me by Paul Weller.
I do rather like it. When I get my recording gear back, I'll mic up the original combo so you all know the sort of sound I'm talking about.
Cheers
Chris
PS - for reference, FaitalPRO - Professional Loudspeakers Made in Italy
Tinitus, it's a 6FE200.
Keriwena, it does actually sound quite nice.
- its smooth and extended through the high frequencies - I was trying to avoid the peaky upper mids typical to guitar speakers (tried a 10" Celestion, hated it because it was so prominent).
- it has enough low end to practice bass through. This bodes well for having some headroom at higher volumes - excursion stays minimal.
- with a little eq (turn the lows and highs down), I can get the open-backed bass, smooth highs sound, perfect for sounds like the solo on You Do Something To Me by Paul Weller.
I do rather like it. When I get my recording gear back, I'll mic up the original combo so you all know the sort of sound I'm talking about.
Cheers
Chris
PS - for reference, FaitalPRO - Professional Loudspeakers Made in Italy
Keriwena, it does actually sound quite nice.
- its smooth and extended through the high frequencies - I was trying to avoid the peaky upper mids typical to guitar speakers (tried a 10" Celestion, hated it because it was so prominent).
- it has enough low end to practice bass through. This bodes well for having some headroom at higher volumes - excursion stays minimal.
- with a little eq (turn the lows and highs down), I can get the open-backed bass, smooth highs sound, perfect for sounds like the solo on You Do Something To Me by Paul Weller.
I do rather like it. When I get my recording gear back, I'll mic up the original combo so you all know the sort of sound I'm talking about.
Cheers
Chris
PS - for reference, FaitalPRO - Professional Loudspeakers Made in Italy
ah, ok, from their cheap range
Im looking at it
its a midrange driver, and never meant to be fullrange
I notice its with just 2mm Xmax, one way
and combined with a 120hz Fs, I would say not to be used below 300-500hz
unless you use a steep active high pass filter
and/or, live with much less SPL, and power handling
btw, of personal interest, how much did you pay fore this driver ?
Yeah, the limited Xmax is a problem for all pro 6" drivers.
I paid just over £30 for it.
I'll be using a second order crossover ~300Hz, sending the low passed output through a limiter (set earlier than the main limiter), recombining the signals, and then adding an overall limiter.
This ought to keep excursion sane, allowing it to go louder for the rest of the range.
The method described above is different from how ZT did their amplifier - they just put a steep filter at 200Hz. Seems to me that more could be had in the low end, even if only at practice/rehearsal levels.
Chris
I paid just over £30 for it.
I'll be using a second order crossover ~300Hz, sending the low passed output through a limiter (set earlier than the main limiter), recombining the signals, and then adding an overall limiter.
This ought to keep excursion sane, allowing it to go louder for the rest of the range.
The method described above is different from how ZT did their amplifier - they just put a steep filter at 200Hz. Seems to me that more could be had in the low end, even if only at practice/rehearsal levels.
Chris
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