Dan Dare

I wonder what the guitar player's take on this is.

Try Richard Hill at Electrohill in Palmers Green. Google will give you contact info.

The DBX Driverack does a similar job. There's a lower cost equivalent from Behringer and several other companies offer similar devices. They can be very useful, especially in awkward acoustic spaces. They frequency sweep the room and adjust the overall eq to compensate for anomalies. Makes set-up a lot easier.

Agreed and this is the important point. I want to know what a piece of gear can be set to do, how well it can cope with varying situations, etc. How it sounds "flat" is of little value, as I am unlikely to ever use it that way. When I bought my bass head, I didn't choose it on the basis of how it sounded "flat". I tried it with the actual cabs I use and experimented to find out how well it could be made to work with them. I did the same when auditioning PAs. I bought the PA I own because it is versatile and has very good onboard signal processing, enabling me to get a good result in a wide variety of environments. The problem with comparative tests such as the one above is that they can create a false impression of how equipment performs. Several have commented, for example, how the separate sub is "boomy", "muddy", etc. Given that it is on the floor, it isn't really a surprise that it will be more bass heavy due to coupling and boundary reinforcement. A box on a pole, by comparison, may sound cleaner. However, with proper adjustment, the separate sub could well prove to be superior if both it and the box on the pole are set up to perform to their full potential. The separate sub may have more to give. It's well known that some manufacturers will configure equipment to have showroom appeal, so it sounds good off the bat when set notionally "flat". The implication is "if that's how good it is flat, just imagine how good it will be with some tweaking". The truth could be that it's doing about as well as it can and has relatively little potential to give much more.

"Flat" is very much a notional concept, though. No piece of equipment, especially if it is built to meet a certain price point, is truly "flat". Even if eq is bypassed, there are limitations imposed by the room acoustics and shortcomings in the equipment itself. Perhaps if one is shopping at d&b Audiotechnik prices, these might not be so much of an issue, but for real world use by ordinary people (i.e. us), there is no such thing as "flat". No instrument is "flat". No microphone or instrument pickup is "flat". So even if you feed a truly "flat" system with a coloured signal from those mic's or pickups, you will get out what you put in, which won't be "flat". If the colourations in a faithfully rendered signal clash with the acoustics of the room, you are going to need to correct that via eq. If you play recorded music through a system, you are hearing the eq applied at mastering stage in the room where the mastering took place. It may well not suit the space you are in. Again, you need to correct via eq. Manufacturers try their best, within the limitations of budget and technology, to maximise the performance of the equipment they make. However, they test in anechoic conditions, which we never encounter in reality. They have to. Were they to test in a notional "typical room" and set gear up to work best in that environment, it would probably sound worse in conditions unlike the "typical room", because every space is different acoustically. Acoustic conditions in the same space can vary over time, according to how many people are in the space (lots of soft bodies soak up certain frequencies and reduce the volume of free air in a room), temperature, humidity and so on. The DSP on my PA has a variety of starter acoustic profiles, ranging from nominally flat, through settings for reverberant spaces and so on (there is even one for tents/marquees). They are handy to get you part of the way, but you need to tweak them further to suit the space you are in.

I notice that Phil stated above that no eq was used on any of the systems and several have commented that the separate sub caused boom. In a real world situation, surely one would employ eq to address issues such as this? We aren't hi-fi flat earthers, after all. I say that as someone whose hi-fi has no tone controls/eq, but I wouldn't dream of running my PA flat. None of the rooms/spaces I play in are acoustically perfect (many are downright dire) and I suspect that applies to pretty well all the gigs any of us does. In a perfect world, one might be able to run things flat(ish), but I've never encountered an acoustic space that good. I'm also using mainly dynamic, PA/live use mic's, which have anything but a ruler flat response. I run a sticks and subs PA and find I always have to roll the subs off by 2 or 3 db, as well as setting HPFs at around 40hz to keep the low end tight. I also do as Dave Natale recommends and pull back the pain frequencies - 160hz and 2.5khz - by as much as 12db (with more gradual roll-off on adjacent frequencies) and play around between 5 and 10 khz to remove grit and spit. The pattern of faders on the graphic or settings on the DSP can look a bit extreme, but we don't (or shouldn't) listen with our eyes.

I know. I was using the chart to illustrate the idea that impedance is frequency dependant. I did point out that the impedance of the driver to which the chart applies would be at or around 4 ohms through much of the useful part of the frequency spectrum. You are correct in all you say, of course. I was attempting, without being too technical, to re-assure the OP that he shouldn't worry as long as he is sensible. In his original post, he informed us that he uses an AG700 (as do I), which is stated to be able to drive loads down to 2.67 ohms min impedance.

This. A driver is a reactive, not a resistive load, hence the variation in impedance with frequency. Below is a typical impedance curve. You can see impedance is highest at the resonant frequency (the lowest frequency the driver is capable of reproducing). It drops to around 4 ohms through much of the useful frequency response, rising again at the upper end due to voice coil inductance. I pointed out earlier that the stated impedance of a speaker is an average (the term usually employed is mean impedance). In practice - again as stated above - there is a safety margin with any good quality amp, which means they will drive lower impedance loads as long as you don't push things (either via cranking the volume too much or presenting them with a very low impedance load). That means you don't need to worry as long as you are sensible. The danger signs are obvious - sound gets dirty, volume drops, amp gets too hot, etc.

Same here. The issue was not the bass DI, but the kit and vocal mic's and also the fact that the stage was a hollow wooden box that acted like a resonator. Even engaging HPFs didn't solve the problem.

No. London. "The Hog County" is an old nickname for Hampshire, where I live now following my retirement.

They look good. I like the idea of a 3x10. Enough grunt for most situations and lighter than a 4x10. A shame the MB isn't taller and slimmer, with the drivers in a line. I had an Epifani UL310, which I really liked, but it was pretty well the same size as a 4x10 and awkward to transport, store and carry up the stairs to my flat.

True, but just to confuse things a little, a tweeterless Super Compact makes a really nice noise with a P bass strung with flats. Being, er, compact, it lacks the really extended low end of the larger 12XN cabs. I think a lot of the hi-fi nature of BF 12XN cabs is to do with that and the tweeter. Really extended low end is not always a good thing in bass cabs for onstage use. A couple of years ago, I was engineering an event and one of the bass players had a Super Twin. Up close and in isolation, it sounded magnificent, but in the mix/room, the low end was just too much. I had a hell of a job persuading the bass player to roll off the bottom end. It was going down all the mic's, causing the stage to resonate and was generally a nightmare to control out front.

A problem with all Fenders, with their all-bolted construction. It's so easy to screw a load of parts together and make a few solder joints. I've always thought it likely that many "custom" builders use parts from Warmoth and similar to create "custom" Strats, etc. Sure, they will iron out any rough edges and finish them nicely, but essentially, they are offering assembled kit guitars, often at high prices. I'd certainly be wary of any bargain "Fender". Buying new is the safest option, or if used, from a dealer. Then you have some redress.

That'll likely be 4 ohms, which could cause impedance issues when combined with the others.

He does, but I'd be wary. It looks likely they are hire stock, which tend to get hammered. Given that they are not massively outdated models, it could be that his tech' has advised "it'll cost more than they're worth to fix them. Best to stick them on the 'Bay and get what you can for them".

You don't need to worry, as your amp is rated to drive 2.6 ohms. Unless you really cane it (in which case, you're likely to notice because it will distort), you'll be fine. An amp will only overheat if you try to drive a lower impedance load than it can cope with. There's a safety margin before issues crop up - the impedance of all speakers varies with frequency and the stated impedance is an average. You'll only have problems if you really push things.

I love the way advertisers think that saying "Ex Massive Attack" or similar will increase the desirability of an item. "Ex (add band name here)" usually means "has been chucked in the back of vans/trucks, kicked around and generally caned by someone who wasn't bothered about the cost or repair/replacement". A bit like advertising a used car as "Ex Lewis Hamilton".

At least the strap's Fender... Should be titled "Imprecise bass guitar"

I often run three 8 ohm cabs with an AG700 and it works well. It isn't so much louder as fuller sounding. As a general rule, running an amp into too low an impedance can cause it to overheat because it's being required to deliver more current than it is capable of providing. At low volume levels, it probably won't be an issue, provided the amp is adequately cooled and you aren't asking it to drive 1 ohm or similar. A low impedance load is easier for an amp to drive up to a point, but it's when you push things that problems can arise. Many modern amps have some sort of protection circuitry, which will shut down or mute them if you try to overdrive them. Obviously, you'll need to let the amp cool and address the issue that caused the shutdown before continuing. You're also likely to notice the sound gets dirty prior to the amp shutting off. Of course, if you like a dirty/over-driven sound, you may not notice that until there's a problem.

On that basis, maybe the OP should splash out on a vintage Alembic or Ken Smith...

Same. If it makes people happy and gets us booked back, it's only 5 minutes out of my life. I've got little time for those who turn up their noses at popular numbers. Aren't we supposed to be entertainers?

I had a set of 5 year old Chromes on my main gigging bass until recently. Tonally, they were still fine, but the intonation had started to become a bit vague, so I changed them. Am playing the zing off them. It's mostly gone after a month.

Never say die. I'm 70 (one of the reasons I bought a good trolley) and still doing it. If you do think you may not be playing for too much longer, that's another reason not to throw a lot of money at new gear.

If you like your existing cabs, buying a quality folding trolley is a lot cheaper than replacing them. Don't buy a Chinese 40 quid cheapie. For a little over £100, I got one that is rated to 150kg that makes shifting gear easy.