Bill Fitzmaurice

I get whatever tonal changes I want with technique and occasionally the tone control on the bass. I seldom touch the amp on the fly. I do adjust the amp at sound check because close to half the result is dictated by the room. I always go out onto the dance floor to hear what it sounds like there, and if there's an FOH I check it there as well. I never trust the sound man to get it right, unless said sound man is me. 

The reason I said to take the RTA playing an open A is that your tone is a product of the amp EQ and the speaker. By using pink noise with the amp EQ flat you remove the amp EQ from the equation. You want the PA EQ to not only duplicate as much as possible the effect of the speaker but also the effect of the amp EQ. There's also the matter of whether the amp is actually flat when the EQ is set to flat. Most amps have built in voicing, so flat EQ may not give a flat result.   

Most top acts tend to over-use subs as well. I'd say three out of four FOH mixers have no idea how to mix bass. The fourth is a bass player. ☺️

1 hour ago, Al Krow said:

 

Hi Bill, excuse my ignorance but could you elaborate on what you mean by "rising mid range" for me please?

Look at the frequency response chart here, which is a typical high quality bass driver. Note the midrange that peaks at 2.5kHz. 

https://eminence.com/products/kappalite_3012ho#frequency-response

PA subs go as much as an octave lower than bass cabs, while PA mains don't have the rising midrange typical of bass cabs. Try high passing the desk bass channel at 60 to 80Hz, if it has that capability, or cutting back on the bass EQ if it doesn't, while boosting the mids in the 2 to 2.5kHz range. 

If you want to be more precise get this app for your phone. https://play.google.com/store/apps/details?id=com.dom.audioanalyzer&hl=en_US&pli=1

You can use it to see the frequency response of your rig. Play an open A and take a picture of the result, C weighting, slow response. Save it and compare it to the same test through the PA. Comparing the two will show where the PA EQ needs to be adjusted. 

6 hours ago, Dan Dare said:

The claimed advantage of stacking cabs with the drivers vertically in a line is that you get better "throw" (line arrays work on this principle). 

Longer throw, via the speakers being in the nearfield condition so the level drops by 3dB per doubling of distance rather than 6dB, only occurs when the line is at least three wavelengths high. That's easy enough at 5kHz or higher, not so much at 100 Hz, where three wavelengths is about ten meters. Wider horizontal dispersion, twice as wide above roughly 300 Hz, is the main advantage with other than Grateful Dead Wall of Sound back lines. 

3 hours ago, fretmeister said:

When you are really close you won't hear it.

You will, because it puts drivers closer to your ear level. It's one reason why 810s are so popular. 

To put that into context for the same output level you need at least twice the cone displacement with bass as you do with guitar. To realize twice the displacement requires double the voltage swing, which is four times the power. You may need as much as four times the displacement, which is four times the voltage swing, which is sixteen times the power. 

Surface area by itself means next to nothing. What matters is area x excursion, ie., displacement. BF lists it, Ashdown doesn't. In any event you're not going to get anywhere near what the BF you have is capable of with 30 watts. 300 would be more appropriate. 

27 minutes ago, David Morison said:

I'd disagree with Bill about the resistors, assuming I'm right in reading that you want to pair that tweeter with a one x 10" box, right? On that basis, it's likely that the tweeter will be too bright on its own without some attenuation.

Attenuation is likely required, but using series resistors, which is what it appears to be, is the wrong way to do it. An LPad is the right way, be it variable or using a fixed value with series/parallel resistors, just as using an NPE cap as a basic high pass filter is the wrong way to divide the frequencies and provide proper protection for the tweeter. Where the enclosure is concerned you can get a decent result with that driver, but because of the massive Vas not from 95L. 200L with 35Hz Fb is pretty good, but as the OP already has the box in hand that's probably not an option. 

Looks the same to me, other than the paint. If the OP's was an OEM that might explain it, as OEM very often left out cosmetic touches. 

1 hour ago, Hellzero said:

Calling @Bill Fitzmaurice.

I can't help, it's not familiar. 

The values of the resistors don't matter, you don't want to use them. As mentioned a crossover splits the frequencies to highs and lows. That capacitor isn't a crossover, it's a high pass filter, a very poor one at that. TBH I wouldn't bother with the tweeter, unless for some reason you feel the need for it. A fifteen doesn't reach high enough to be used with a tweeter of that sort. If you want improved upper midrange/lower high frequency response and dispersion a sealed back 6.5 inch will work far better...with a real crossover, of course. You can find full specs on the woofer here. The page is in French, but that doesn't affect the T/S parameter abbreviations. https://petoindominique.fr/php/mysql_thiele_seul.php?hp=5054

By and large a pair of 100mm ports would be good with a pair of tens, but port velocity goes up as driver excursion goes up, so you need a lot more area with 8mm xmax drivers than you do with 4mm xmax drivers. I model the box at the voltage that reaches xmax within the speaker passband and adjust the port dimensions as required to keep velocity no more than 20m/s. I never use pre-made ports anyway. Some recommend no more than 17m/s, but it's not like you're constantly hitting xmax. If you are you've got the wrong speaker/drivers. 

The number of ports doesn't matter, only the total area. I routinely use four corner ports, as they also brace the top, bottom, baffle and sides. That said 100l is huge for two tens. Two twelves would be more appropriate. 

This was common in the days before 3 wire mains cables were used, which insure that all devices are properly grounded. But it usually presented a problem only if one was holding a guitar and touching the mic. Just holding a mic should never present a problem. Even if the mic body is receiving current she would have to be a path to ground to feel anything. Have you had someone else hold the mic to see if they feel it? 

With regard to modeling software it only predicts response within the region of pure pistonic response, which is roughly to two octaves above the driver Fs. To see what happens above that use the SPL chart on the driver data sheet, which is not influenced by the cabinet. I can't comment on the Eminence software, as I've never used it. For direct radiating speakers I use WinISD 0.7. 

1 hour ago, Dan Dare said:

 Behringer owns Midas, which gives it access to some excellent mixer designs and explains why their stuff is decent.

Behringer has of course acquired many brands, giving it legal access to many designs. Go back to the 1990s and they blatantly copied other companies gear, like Mackie and Roland, without the benefit of owning those companies. They're still at it, the Klon Centaur pedal being one example. Not that plagiarism in the gear business is unusual. Jim Marshall copied Fender circuits, and there are innumerable clones of Strats, Les Pauls, P Basses and J Basses. Behringer was a bit different, as at one time it seemed that everything they made was a copy. 

Only with valve power stage. SS outputs have a minimum load, but no maximum. Valves have a maximum load, but no minimum. Many valve amps incorporate a switched output jack that will short circuit the output when nothing is plugged in, to prevent damage in that event. 

Make the internal volume and port area and length the same as the original box. Wire the drivers series/parallel, use whatever type jack is on your other cab. 

SS amps don't need a load, valves do. 

7 hours ago, Supernaut said:

Nothing wrong with Behringer. Their customer service is excellent from my experience. 

Behringer has good designs, if not original, so for the most part they work well. But they keep the cost down by using cheap hardware.

BTW, all the pots on your amp and bass should be cleaned once in a while. Otherwise dust inside can scratch the resistive track and once you do that replacement is the only option. 

It needs cleaning, with this or the equivalent. https://www.crcindustries.com/qd-electronic-cleaner/

16 minutes ago, agedhorse said:

As a bass guitar driver, it’s very limited. Some of this can be overcome by using multiples of this driver (410 and 810 for example)

+1. The original SVT had drivers with 1mm xmax. That's why it took sixteen of them to handle the SVT head. You can find ads from 1969 showing the SVT head with two SVT 810 cabs. As driver technology improved the need for that many drivers lessened. Today you can find tens that are the equal of eight of the original SVT drivers.