PA speakers for bass???

[Russ]

I've been toying with the idea of putting together a more "hi-fi" kind of bass amp, using either one or two PA speakers, a power amp and a preamp of some description. Basically, a system that will have a wide, full frequency response, without the colouring that bass-specific cabs add to the sound. Has anyone else gone this route? If so, what types of PA speaker would prove suitable? I would have thought something with multiple drivers for the bass, midrange and treble would work best. I'm mostly unfamiliar with the different PA speaker models available, so can anyone recommend something good for this purpose?

Won't be doing this for a while, but best to get the research done early.

[bass_ferret]

This idea gets floated from time to time and the general consesus is dont. The only PA speakers that can handle bass are ones designed to reproduce a fully miked/Di'd band and that needs big speakers and lots of watts.

Ashdown used to do some PA style cabs they made for the Ox. Using BFM designs is the other obvious suggestion.

[BB2000]

Russ, BFM cabs are the way to go. No question. And don't buy a cab from anyone if they're not prepaired to provide a SPL chart for that cab.

[Dood]

Ah! A subject close to my heart!! All of what John said above is pretty spot on. I ended up travelling up and down the country to find cabs that had the least amount of colour and had the guts to produce a good clean sound.

Its interesting as what I ended up with has a 'hifi tone' but I suspect isn't 'flat response'. As I have mentioned elsewhere.. 2 rather different response curves.

I *think* BFM and other similar designs could be the way to go.. OR you are looking at lugging more gear around. Hmmm.. I'd like to see a company doing active bass cabs that are of a PA design. Internally bi/tri amped with preset poweramps internally So that the optimum response is provided from the cabinets.

I like that idea!

[lukeward2004]

THe closest thing ive found to a "PA-Like" bass cab was Dood's old Tech Cabs - which I will soon be te proud owner of!

[Bill Fitzmaurice]

[quote name='Russ' post='57273' date='Sep 7 2007, 09:45 PM']I've been toying with the idea of putting together a more "hi-fi" kind of bass amp, using either one or two PA speakers, a power amp and a preamp of some description. Basically, a system that will have a wide, full frequency response, without the colouring that bass-specific cabs add to the sound.[/quote]
IMO the best bass cabs and the best PA cabs are interchangeable, because they share the same requirements: wide bandwidth, high output uncolored response. The vast majority of bass cabs don't fit that description, being in reality modified guitar cabs. For that matter, until the '70s most bass cabs [i]were [/i]guitar cabs, sharing the same drivers and design. Bass players just used more of them to get the same output levels. With the advent of bass specific drivers and T/S cab tuning in the '70s bass cabs became more bass friendly, but the basic design has remained in the mold of guitar cabs, as has the sound, with restricted bandwidth and a lot of coloration. For all intents and purposes mainstream bass cab technology has not advanced in the last 30 years. If one looks at a 1970s bass cab and the current crop they look the same, and for the most part sound the same, the only improvements being those resulting from better drivers.

The PA industry never stagnated, with improvements coming at a regular rate. Today's concert bass sound is defined by the PA, not the backline, and the bassplayer who wants that same tone on stage has to look to PA gear or bass gear designed according to PA standards to get it.

[Chopthebass]

I've often considered the idea raised in this thread. I see no reason why a PA speaker can't work with bass. A PA system is just there to make things a lot louder, and do it at the best quality possible. Take the Mackie SA1530Z, it's 3-way tri-amped and 1300w RMS, and has a frequency range of 38hz to 20khz. But Mackie in the UK told me that won't be suitable for bass guitar, but they couldn't back it up with a technical reason! Surely a Pod or any bass pre-amp plugged into that Mackie will be a cracking bass rig? Also it would work out pretty cost effective.

[Bill Fitzmaurice]

[quote name='Chopthebass' post='58952' date='Sep 11 2007, 03:27 PM']But Mackie in the UK told me that won't be suitable for bass guitar, but they couldn't back it up with a technical reason![/quote]That's because they're clueless pencil pushers, not engineers. Assuming it's properly constructed it should work very well, I can't think of a commercial electric bass cab that would work as well. But it will sound quite different than what you're used to, and that may or may not be to your liking, so try one before you buy one.

[Dood]

Funny you should mention those Mackies. They were defintely on my hotlist when I was looking for a 'pa like' rig. I had been warned off them by a local shop who said they'd all but one of the several pairs they sold back in for repair. Obviously this is only one shop and there maybe more to it.. but I was a bit gutted really, as they had quite an impressive sound for the money.

I reckon the POD straight into them would be pretty massive. Especially if you added some stereo chorus in 50% ;o)

[bass_ferret]

They do look the business. Remind me of a souped up active version of the original Electrovoice Eliminators that used to be my favourite PA cabs, though the EV had horn loaded bass as well. Once upon a time a 2KW pa rig would consist of large folded horn bass bins and seperate mid and high frequency amps driven by a rack of power amps - now its just 2 (very heavy) cabs. Large PA rigs are often made up of big arrays of full range cabs rather than separate cabs. Some bass players have used PA style rigs like

[DrGonzo]

I'm still not too sure why people are always going on about a flat frequescy response as being an "uncoloured" sound.

In my experience, no matter how flat the response is, different components, boxes and construction methods always sound different, as do different parts in amplifiers, no matter how flat their response is. I work as a sound engineer, and this is most obvious when you compare top-flight PA systems.

That's why different PA companies still exist. There isn't really a top class PA out there that isn't virtually flat response, but they still sound radically different (to my ears at least). A Funktion One system sounds very brittle at the top end, EV X-Array is a little woody-sounding, Meyer MILO sounds like the worlds biggest Hi-Fi speaker, Nexo Alpha is very in-your-face and gutsy. I could go on, but I sense you're already bored.

My point being, forget about frequency response curves and acheiving a perfectly flat spreaker cabinet or amp. Go out and try a load of different amps. Sooner or later you'll find one that sounds just right to you, then go buy it (if you can afford it... )

Edited September 11, 2007 by DrGonzo

[alexclaber]

[quote name='DrGonzo' post='59015' date='Sep 11 2007, 10:43 PM']I'm still not too sure why people are always going on about a flat frequescy response as being an "uncoloured" sound.[/quote]

The PA systems you refer to are close to flat response. However they are far enough from flat response that you can hear a difference between them. They will also have other distortions in the sound which differentiate them further. If you saw the frequency response plots for most bass cabs, especially off-axis, you would be astounded how far from flat they are.

I've used my Acme cabs as a PA system with great success for lower volume gigs. They have the huge clear sound of a top quality PA system with proper subs - their downside is they don't go terribly loud, particularly in the mids and highs. But for quieter situations, especially with recorded music, they are amazing. With bass guitar where the power demands are skewed more towards the bottom, they go as loud as cabs that size can ever be expected to.

There is currently a thread on talkbass documenting what great bass cabs Carvin's LS1503 3-way PA speakers make. Anthony Jackson has been using Meyer cabs for ages. Jonas Hellborg's interview in this month's BP magazine also discusses how great this kind of rig can be. I certainly do not envisage returning to conventional bass amps for the forseeable future!

Alex

[Bill Fitzmaurice]

[quote name='DrGonzo' post='59015' date='Sep 11 2007, 05:43 PM']I'm still not too sure why people are always going on about a flat frequescy response as being an "uncoloured" sound.[/quote]
Perhaps not in absolute terms, but if the response chart of the average PA resembles the view of the horizon in Cornwall then that of the average bass cab looks like St. Moritz.

[gypsymoth]

that's pretty funny that a PA co would say "unsuitable", as bass DI'd to the PA is pretty common.
but you wouldn't need the full spectrum of a PA, unless you are after cymbal frequency harmonics.

plenty of speakers will handle either task quite well - as mentioned the cabs are the "issue" - and less of an issue than amp & speaker choice - which is likely why tradition, appearance, and convenience are bigger issues for most.

[bass_ferret]

I think it would be useful to clarify the context of the discussion. The question usually asked is:

Can I use cheap PA cabs instead of expensive bass cabs because they have 15 inch drivers to save money? The answer is no.

What I think is being asked here is:

Can I use expensive PA cabs instead of expensive bass cabs to get a better sound? I think that is what we are discussing here.

[charic]

Mackies will definately not have a problem. As for uncoloured sound... make a recording and listen to it on a home system. Then listen to it through genelec monitors. The genelecs are known for being one of the best companies around for that flat sound. This is most probably why they cost a BOMB. But hey you pay for quality. BTW a flat sound is NOT a nice sound. Its flat. HIFI have raises in different frequencies to MAKE it sound nice despite them being CR@P

[lowhand_mike]

i tried this with one cab from a pair that our guitarist picked up on ebay, they looked home made with 15" drivers full range, yeah they sounded loud but really struggled with the low end as they farted a bit, needless to say as soon as they did that they got disconnected and will just be used in our PA setup. bit gutted really as if it had worked they would have made a cheap alternative to buying a new bass cab.

[G-bitch]

I was going to suggest ACME cabs - Alex describes them very well.

[Bill Fitzmaurice]

[quote name='lowhand_mike' post='59214' date='Sep 12 2007, 07:35 AM']i tried this with one cab from a pair that our guitarist picked up on ebay, they looked home made with 15" drivers full range, yeah they sounded loud but really struggled with the low end as they farted a bit, .[/quote]Which only goes to show you that a big driver does not a bass capable cab make.

[theosd]

Look into MarkBass amps and combos.

[Dood]

[quote name='theosd' post='59387' date='Sep 12 2007, 05:14 PM']Look into MarkBass amps and combos.[/quote]

I would say markbass are far from a 'HiFi' sound. They are very good, but in AB tests there are plenty of others that are more suitable for the application asked for above.

[bass_ferret]

[quote name='lowhand_mike' post='59214' date='Sep 12 2007, 12:35 PM']i tried this with one cab from a pair that our guitarist picked up on ebay, they looked home made with 15" drivers full range, yeah they sounded loud but really struggled with the low end as they farted a bit, needless to say as soon as they did that they got disconnected and will just be used in our PA setup. bit gutted really as if it had worked they would have made a cheap alternative to buying a new bass cab.[/quote]


[quote name='Bill Fitzmaurice' post='59288' date='Sep 12 2007, 02:22 PM']Which only goes to show you that a big driver does not a bass capable cab make.[/quote]
Exactly!