Bill Fitzmaurice

Amps and cabs have a built in tone. The purpose of an emulator is to duplicate that tone playing straight through a power amp and FRFR speaker. Playing one through a bass amp and cab isn't what they're made for. OTOH a PA with the EQ set flat is the same as going direct through a power amp and FRFR speaker. If I was to use one I'd send it's output to a power amp and FRFR cab for me to hear and to the PA for the audience to hear.

Compression is good if you don't overdo it. The idea is to reduce high level peaks. Gating is just as useful, to reduce the level of mics not in use, but again you don't want to overdo it.

3 hours ago, Pirellithecat said:

The context of this is the band's attitude ... "why do you fiddle about with the PA?   Why don't you just use the settings from last time and then we wouldn't have to do anything other than adjust the volume if the space is bigger" .

Because the same settings will sound different in every room. Sometimes you really have to wonder how guys who make money creating sound have no idea how sound works.

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  I obviously teleport from there to the stage to adjust the EQ .... zip back to check it's OK (whilst playing bass), repeat as necessary in the allotted 4mins of the song,

That's why you take an RTA with your phone. You don't need to guess which frequencies need adjusting or by how much. It's right there for you to see.

4 hours ago, Pirellithecat said:

I don't think using the Graphic is going to be realistic in terms of having time (or offstage ears) to adjust it from the stage during a gig ........  

You can't adjust EQ from the stage, you have to do it listening or measuring, preferably measuring, out front during sound check.

You might want to consider retiring those cabs. A Barefaced 212 has the same output capability as that of a 3620.

First off, chaining them in series would be 16 ohms. When amps have two outputs they're almost always wired parallel. That's how you get a 4 ohm load from two 8 ohm cabs.

The brand doesn't matter, the specs do. In this case that driver works best in a 300 liter cab, not 90, while the short 3.4mm xmax is barely adequate for electric bass.

4 hours ago, Alan Wilkes said:

There is a thread going around where you can have a ratio of 2 watts amp to 1 watt cab and they 'll be fine.

You can have a ratio of a ten watts amp to one watt cab and they'll be fine, just don't turn the amp up past the point where the speaker distorts.

The Jensen is not very good. Response is boomy, while it's mechanically limited to 150w.

4 hours ago, Acebassmusic said:

Hey @Bill Fitzmaurice, I like the idea of the Audio Analyser on my phone to be able to guide me when tuning EQ. From what I know (not much! 🤣) RTA's are usually calibrated etc. How does using the in built mic on the phone affect the readings or is it "near enough for a guide"?

You only need to calibrate it if you want an SPL reading, which you don't need for seeing the system response.

12 hours ago, Pirellithecat said:

Indeed, the Graphic Equaliser might be best used to tailor the monitor(s) leaving the FOH EQ with more options.

Did I fail to mention you need separate EQs for monitors and mains? 🫢 EQ adjusts the response to suit the room. However, the room consists of two separate entities, on the stage and in the audience. On the stage you're trying to get maximum intelligibility without feedback, in the audience you're trying to get the best overall sound quality. Seldom the twain do meet. 

Bass, and for that matter any instruments, though the PA isn't about volume so much as it's about dispersion. Dispersion is a midbass and higher frequency concern, so high passing the bass at 60 to 80Hz doesn't interfere with it.

High passing both would be double filtering. But that's not necessarily a bad thing. PA pros with high quality DSP crossovers usually use 48dB/octave slopes for maximum mains protection and minimal pass band overlap. It's unusual for the slopes in powered speakers to be that steep, so your thought of trying it both ways is valid. 

If you don 't high pass the mains you're at least doubling the stress on their amps and drivers; taking the load off them is one of the reasons for using subs. You also open the possibility of low frequencies from the mains cancelling low frequencies from the subs.

Just now, Pirellithecat said:

So maybe the Graphic equaliser will be the answer in the short term - although it'll be greeted with derision by he rest of the band! 

What's the name of the band? The Luddites?

Harshness very often is the result of high THD. That can be sourced with too high a signal level anywhere in the chain, going all the way back to the channel input trim.

37 minutes ago, warwickhunt said:

Conversely I've ran 60w amps into 1600w speakers and despite dire warnings from others, neither amp or speaker has come to harm.  

+1. That's the myth of underpowering, the notion that clipped signals will kill speakers. If that was the case there could be no such thing as distortion effects. Distortion can toast tweeters, but not because the amp lacks enough power. It's because the abnormally high harmonic content over-powers them.

55 minutes ago, Phil Starr said:

Some digital desks will analyse the room and do the final eq for you but with an analogue desk it's a common trick/hack to play a recording you know well and do the final eq on the graphic to make that sound 'right'.

I did that too, until 20 years ago, when I went to DSP with auto EQ. But you can manually tune EQ almost as easily with one of these on your phone https://play.google.com/store/apps/details?id=radonsoft.net.rta&hl=en_US

and one of these for your mixer http://www.flatkeys.co.uk/P!NG.php

1 hour ago, Pirellithecat said:

  I have the chance to add a friends Stereo Graphic EQ unit to the outputs - any thoughts on trying this?

EQ isn't optional, it's mandatory. Without it you can't compensate for the room acoustics or tune out feedback. There was a time when I didn't have EQ. That would have been in the early 1980s. 😲

Anywhere between 1/2 and 2x the speaker rating is good for amp power. What manufacturers don't tell you is the mechanical power capacity of cabs, which can be as low as half the thermal rating. Very few have mechanical capacity equal to thermal capacity. To get a meaningful increase in amp headroom requires a 6dB increase. That's four times the power.

Tossing random drivers into a box is a time honored tradition, started by Leo Fender, continued by Jim Marshall. 🤪

Adding a 4" mid will do the job, but 200Hz is too low for the crossover. 800 to 1200Hz is the appropriate range. Read this: https://www.basschat.co.uk/topic/496512-replacement-hi-mid-driver-for-tecamp-puma-110-combo/

3 hours ago, Downunderwonder said:

Bill's subs are folded horns.

Most, but not all. The Simplexx subs are ported boxes, but still employ well braced 12mm construction.

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Woe if you try to make a frequency that is too low. It behaves the same as a regular ported sub would with the same driver. Uncontrolled flapping but not very audible back around multiple horn folds so no warning.

That's the scenario if precautions aren't taken, so we do, using DSP to high pass and limit the signal from the amp. 

Oh, it has to be Penn and Teller. The sound is pure magic.

Morecambe and Wise?