Bill Fitzmaurice

FWIW the power amp class has very little to do with clean versus colored. That's mainly the product of the pre-amp section.

Post a picture of the original driver.

Quite right. However, consider why some cabs are rear ported. For the most part it's because the cabs are too small to fit the ports on the front. In that case bass response won't be as strong as a larger cab, not because of the port location, but because the cab is smaller. I don't rear port cabs as I don't make them too small to give the best possible result.

It comes down to understanding why subs exist. Well implemented PA systems use mains that are elevated to project mids and highs. For maximum efficiency their response only extends to between 80 and 125 Hz. That means subs are needed to handle the lows. Bass cabs go to 50 Hz or lower, so they don't need assistance from subs. As to what happens outdoors, that relates to boundary reinforcement and room pressurization, which enhance low frequency response indoors. Since you don't have boundary reinforcement or room pressurization outdoors you need to use at least double the cab count to compensate.

If anyone here could it would be me, and I don't. The natural response of the electric bass doesn't go low enough to need them. For that matter even when the PA has them the electric bass channel strip should be high passed no lower than 60Hz. Otherwise the gosh awful cacophony that sounds like a teenager with a 5,000 quid system in a 500 quid car driving past can be the result.

JBL has used aluminum voice coils for seventy years, many others do as well. Aluminum is used where light weight is the main consideration, copper where power handling is. Since the wire on voice coils doesn't flex the stiffness of aluminum doesn't matter.

CCAW has the same current capacity and resistance as pure copper if you go up one gauge. However, it's more prone to breaking from repeated flexing, so it should only be used in permanent installations.

An oldie but goody: Peter Walker arrived at a press showing with a new set of his Quad speakers. Realizing that he forget speaker cables, and not having time to drive back to the shop to get a pair, he went around the corner to a hardware store, where he bought what he knew would work well. At the press conference later the press seemed as interested in the cables as the speakers, being captivated by the bright orange color. Prodded to reveal the brand of what they assumed were very expensive bits of wire Walker replied: 'Black and Decker!'.

They're better than 1/4", but still never should have been used for speakers as they're too easily confused with mic and interconnect connectors.

Most likely only two are active. The only reason for three is if the associated speaker has multiple drivers and the amp has dual power amps separately powering them, with the third wire a common ground.

With respect to gold and silver, gold has less conductivity than copper, so it's not suited for wire. Any non-tarnishing metal coating of connectors is OK, as it's too thin to offer resistance. Silver has 10% higher conductivity than copper, which means copper need only be 10% larger or 10% shorter to give the same resistance. That makes silver a waste of money.

Theoretically current capacity can be a concern, but in the real world that only applies to mains cables. What matters with speakers is resistance. Even with a 6 metre cable keeping the resistance well less than 5% of the load impedance doesn't take a large cable, 18 gauge/1 mm will do with a 4 ohm speaker; the main benefit of going larger is durability. In PA use very long cables don't have as much of a problem with resistance as they do capacitance and inductance, which can cause high frequency losses. For this reason 15 metres is the practical limit for speaker cables. To that end major PA rigs keep the amps close to the speakers.

I should have been more clear. If the input device, like an active electric bass, provides 0dBv then the OdB mark would be the right position for the pot. If it provides -50dBv, as might be the case with a mic, then the -50dB mark would be the right position. This may help: https://radio.co/blog/differences-between-mic-level-and-line-level

It's adjusting the input sensitivity to match the dBv output of the source. All input pots do, but seldom do you see it shown that way.

'It's not the size of you pencil that counts, it's how you write your signature.' - John Hancock, 1776.

No. You can't even go by size, at least where the insulation is concerned. http://www.roger-russell.com/wire/wire.htm#misleading

You're never going to get a good bass result with pole mounted PA boxes. They lack the boundary reinforcement provided by being close to the floor, they don't get the boundary reinforcement provided by being close to the rear wall, they may even have bass cancellations from the bounce off the wall and off the floor. You need a cab for the low frequencies that can be placed on the floor close to the rear wall, be it a sub or your own bass cab.

The only way to know for sure without buying drivers is to use speaker modeling software to model both what's in there already and proposed replacements. The replacements are easy, most have the required Thiele-Small specs available. That's probably not the case with the Fender driver. With only 100 watts there may be no improvement to be had.

Depending on the size of the room putting them in more than one corner, even in four corners, may give the best result. The only way to be sure is via trial and error, though software like REW (roomeqwizard) makes it much easier.

On the 6dB lift from being on the floor speaker response is a half-space result. If the baffle is less than a wavelength in dimension, which below 100Hz is a minimum of 3.4 metres, the speaker must be on the floor for half-space loading. Where wall and corner loading are concerned the additional sensitivity gained means you can use less power and/or a smaller sub for the same result, but of far more significance doing so eliminates the potential for boundary reflection cancellations as much as 24dB deep where the sub is a quarter wavelength from said boundaries.

You should high pass subs, at their lower corner frequency. That's typically between 30 and 40Hz.

It's OK, we knew what he meant. ☺️ The best FOH mixers in pro-touring sound high pass the bass channel between 60 and 80Hz, so the bass sounds like a bass and not a 30 ton dump truck dropping a load. There's still bass content in the subs, but not so much that it drowns out everything else.

True, but it's all about the wavelengths. The shorter the wavelengths the less the power alley effect. Having the mains at least two wavelengths apart at 100Hz is only some 7 metres, while at 200Hz it's only some 3.5 metres. Since the bulk of the content from mains lies above 200Hz to the extent that power alley exists it doesn't matter all that much. It's a different story with subs, where all of the content lies below 100Hz. Also true, but when the space is that small chances are you either don't need subs or you only need one.

Some basic sub placement notes: While it’s customary with PA to have speakers to either side of the stage that’s usually not the best way to place subs. Subs work best when they’re placed either close together for mutual coupling, or spread very wide to cover large areas. The basic rule is to have them either less than a quarter-wavelength apart or more than two wavelengths apart for their pass band, which for 40 to 100 Hz means less than 1 metre or more than 20 metres. Boundary loading should be used whenever it’s practical to do so. Having subs next to a wall gets you 6dB of additional sensitivity, putting them in a corner an extra 12dB. In most cases you’ll have best results aiming the subs towards the wall or corner from about 30cm away from the boundary. The long wavelengths from subs are omnidirectional and cannot be directionally located, so there's no need to have them near the mains or even near the stage. Yes, subs to the left and right with mains on poles above them is convenient. But more often than not that gives the worst possible result. https://www.fulcrum-acoustic.com/wp-content/uploads/2019/10/3_The-Subwoofer-Power-Alley-1.pdf

IME when a room is so small that sub placement is an issue you don't need subs. Good quality ten or twelve inch mains shouldn't have any problems, as they should always be high passed no lower than 80Hz. As for central placement of subs, that should very seldom be employed anyway. The beauty of omnidirectionality is that subs can be placed out of the way.