Using Sub for Bass Guitar

[bobonut301]

hey, I just built a 15 sub woof cab, run it out of lowout and into a separate power supply. then go full range with 6 10's. adjust the lows easliy on the separate amp to suite.

[Minion]

Ive got a 12 in 600w car sub in one of my amps , it sounds quite good with the low notes but the high notes are practicly non-existant , would work better with a tweeter or a horn with the sub with some sort of crossover ....


Cheers

[bishopdante]

sure you'll get sound coming out of any speaker. However, if you're looking for a conventional ampeg fridge woolly cardboardy sound, these drivers won't do it.

Back in the old days of selmer & stuff, there was no distinction, and having worked my way through loads of bass cabs, cardboard speakers just aren't tough enough. You show me a conventional cab, I'll blow it up.

There's a big difference between quality sub speakers and cheap ones. JL audio, MTX, kicker, all of these speakers are *wild*. They aren't the cheap option, though.

So if you take like 2 15s, and horn or slot-reflex load those, then put a little cab on top with a pair of conventional 10 inch kevlars, a 6 inch metallic driver and a Selenium PA compression driver... what you've got there is very similar to my favourite Mesa Boogie cab, but even more overbuilt.

Active crossovers and independent power amps is the ideal, but if not, passive crossovers are a must.

You want to cross over roughly as follows:

15s: 30Hz-180Hz
10s: 180Hz-1kHz
8: 1kHz-4kHz
Compression driver: 4kHz

All should have approx 12dB/oct slopes on them.

Here are some ideal drivers:

15: MTX T9515-04 / JL Audio 13W7 (13.5")
10: Parts-Express.com:*HiVi D10G 10" Kevlar/Paper Woofer | d10g 10 inch woofer midbass woofer 10" driver sheilded woofer midwoofer kevlar cone
8: Parts-Express.com:*Pyle Pro PDMR8 8" 360 Watt Sealed Back Midrange Driver | Pyle PDMR8 Midrange Driver 8" Midrange Driver 8" Driver driver 360 watt driver
Tops: Parts-Express.com:*Selenium DH200E-E 1" Titanium Horn Driver 1-3/8"-18 TPI | compression driver tweeter horn driver high frequency 1" exit 1" throat HF PA driver tweeter driver

This will *not* give you a normal bass sound, this will rip your head off like hiphop.

These babies are good stuff, properly shaming ashdown, ampeg, everything: Mesa boogie bass cab image by dtkdemongene on Photobucket

What I'm suggesting is... even ruder!

The thing about cabs like that is that the bass sound is not what one expects from bass guitar, it's deeeeep, and trebly, sounds more like a very low electric guitar than what people expect from a woolly bass sound a la beatles.

The handy thought is that the cab is built much as you would a PA fullrange, in this case you want to get the sonic character from the preamp/head, or even use a computer with VST processing.

But I tell you, it's the only way to go.

[bishopdante]

This is what car subwoofers can do. Bass guitar amps don't do that.

YouTube - JL AUDIO 13W7==(2)** WINDOW BROKE***

Remember, bottom string of a 5 string bass is about 30Hz. On a vintage bass amp, the loudest not is a C 3rd fret on the A string, on a conventional trace elliott 1x15 + 4x10 the A or the G are the loudest.

On the really prime stuff, and car subs, it just keeps on getting better all the way down to B. And then start turning the machine head. Yup, it just keeps on going.

You do definitely need tops to complement the subs though.

[bishopdante]

also, should you want a nice small amp, one 10 inch JL audio sub combined with a 10 inch PA driver and a passive crossover, that'll be surprisingly good, will easily keep up with a loud jazz drummer, but not a crazy rock one.

[awedio]

codswallop - isn't that a prime ingredient in British ice cream? right then, guv...

bishop, I don't know what you're using for power, all you mention is the drivers. You're absolutely correct that audio-grade drivers will play much lower than conventional pro-sound/MI drivers. Even an Ampeg catalog I was perusing last night stated low freq. extension on most of their cabs as only 40Hz, that includes the venerable 8x10. Low E is 41Hz; so much for the B string on a 5 or 6 string.

BUT, the bass drivers you mention are waaaay less efficient than typical bass guitar drivers, like 82dB/W vs. 97dB/W. that is a HUGE gap, that must be filled in with POWER and lots of it, especially when comparing multiples of drivers, and esp. for live sound. I guarantee you will never see a stack of JL Audio subs backing up a raging live band. Or maybe you've done it, and you are sponsored by Crown, and there's a rack filled with 1200W power amps right behind that.

Also, your list of likely hi-fi suspects are all over the map in terms of efficiency, active crossovers and multiple amps are a must IMO.

As others mentioned, you will also get no upper harmonics/overtones if you rely solely on sub drivers, even a horn tweeter won't fill in here, you need to add 6" or 8" ers...

Same goes for subwoofer drivers - really low extension traded off for poor efficiency and little or nothing above a few hundred Hz in most cases.

[Nigel Goodwin]

Originally Posted by bishopdante

The handy thought is that the cab is built much as you would a PA fullrange, in this case you want to get the sonic character from the preamp/head, or even use a computer with VST processing.

But I tell you, it's the only way to go.

As the bass cab should only be for on-stage monitoring, it's the PA which is important - DI through the PA, no need for a silly size bass cab.

[phase_accurate]

AMEN !

Regards

Charles

(using DI since ages)

[Nigel Goodwin]

Originally Posted by phase_accurate

AMEN !

Regards

Charles

(using DI since ages)

As my daughters band dropped down to a duo (the drummer left - AGAIN!!), we just used to DI both bass and guitar directly in the PA, no monitors at all.

Both good musicians, play together really well, don't seem to need monitors.

[phase_accurate]

I think things will change a as soon as a drummer is involved. Then one can't avoid having higher SPLs on stage.

OTOH I can't stand the usual bass-amp sound with the exaggerated high bass / low mids combined with heavily used compression.

As I always say: Bass for grown-ups is felt in your stomach and not in your chest.
But the engineer in me also knows that this is only achievable with large and heavy equipment. Large and heavy multiway systems are definitely fun to play through but they are no fun for your back etc.

So the best compromise is one of these clear-but-ugly sounding contraptions on stage and going to the PA from the pre-amp's balanced DI output.

And yes, don't overdo it in terms of loudness on stage !

Regards

Charles