matching impedances

novarock

Quick question, i have this:

http://www.ashdownmusic.co.uk/bass/detail.asp?ID=103

and I want to buy this:

http://www.thomann.de/thoiw2_artikel-156648.html?sn=076c6e34398ab60718670a0c3332f866

will there be any problems running that cab off the Ashdown. My amp is all vibration and low end, and want to have the 2x10's for a little more range.

feylya

Minimum impedance for that combo is 4ohms so the 8 ohm cab should be ok although I always forget which way the impedance goes. Wait til someone confirms before ordering.

Doctor J

That cab is fine. Never go below the minimum impedance of your amp, you will kill it. TBH that 15" should be well capable of throwing out as much mids and highs as you need, realistically. How have you got the EQ set up?

novarock

it is capable, I usually set bass to half, mids to half, high to 3/4, I have an eq on my guitar thats set to bass full, mids half, highs full. My problem is that at high volumes, say input half, output 3/4, it loses all its punch. In a live situation i cant hear anything really, was looking for that little extra to punch through?? If im wrong advise me!!

Doctor J

Leave all your eq flat (ie 12 o clock on all the knobs - don't boost or cut anything) and turn your output gain all the way on the amp. Start by bringing the input gain up on the amp until you find a volume you're happy with and then do subtle changes to eq to shape the tone to what you want. By turning the bass all the way up you're boosting your low end by as much as 20dB before it even gets to the amp and I'd say it's clipping (even if it's not, it's way too much low end). Setting the amp and guitar like this will mean the amp is a long way away from clipping (having too hot a signal going in) and you should notice changes to the eq. Your bass amp amp will have plenty of low end beofre you do anything with the eq anyway. The way you're doing it is sending an insanely low-end boosted signal into the amp and then hoping the amp's eq and speaker can deal with it. It won't work and you definitely won't hear that kind of tone on a stage, when it's competing for the same frequencies witht he bass drum. Mids are where you'll hear your bass, espeically at a gig. Sometimes it helps to stand a few feet away from your amp too, but still in the way of the speaker, if you know wHat I mean.

As I said, set the eq flat on the instrument and on the amp. Make subtle changes on the amp's eq first until you're near the tone you like and use subtle changes on the instrument's eq to shape the tone from there. TBH I have never needed more than about 20% Cut or boost from an instrument's eq. Try it and see if it helps.

Giblet

Yeah, Standing away from the amp will make it sound less muddy.

novarock

cheers lads, ill give it a bash. thers just so much on my actual guitar, it makes setting up a pain, there's also a coil tap switch that makes the pickup ultra sensitive, my quest continues for that elusive perfect tone!!

Doctor J

What is the bass, out of curiosity?

novarock

have two:
aria pro igb-68
kramer Baretta 522s/p

Its the aria that has all the active circuitry

Doctor J

That Aria is nice. I was just trying to see some more info on the active circuit. Usually they go from anywhere between +/- 15 to 20dB, which is a lot. If you look at the specs of your amp, it's eq section offers +/- 15dB per eq channel too, so at your current settings you're playing through a classic "mid-scoop" tone - ie all low end with some high (which you may not even hear depending on your playing technique) which will explain why you can't hear yourself. With the bass eq like that, you'd have to trun the low and high eq on the amp all the way down just to get close to the natural tone of the bass.

Eoin Madsen

All the actual tone comes from the mids. Even psychoacoustically - it's very hard to perceive pitch at low frequencies like the fundamentals in the lower bass range. We actually need the higher harmonics (in the mid range) to be able to differentiate low notes. If you shelf off everything but bass then notes like E and F become atonal.