Speaker size v. Tone: I don't hear any correlation

[billfitzmaurice]

I am pretty sure whoever told you that was blowing smoke up your ass. .

+1. HP filtering protects the drivers from over excursion. But most cabs are tuned in the 45 to 50 Hz range, and excursion is at a minimum at the tuning frequency. If you do high pass it should be at 35 to 40 Hz, so it protects the drivers and keeps the amp from working too hard while not filtering out useful content.

if you just use a straight up cap for the 6db slope they give, you get some sort of bump elsewhere, which may explain what you were told.

A cap won't give a bump elsewhere, 6dB HP filtering is as boobies to a bull, and a cap large enough to filter at 30Hz costs a king's ransom. IMO rpsands hit the nail on the head if the quote was accurate, but then again it might not have been.

 

[Zooberwerx]

+1. HP filtering protects the drivers from over excursion. But most cabs are tuned in the 45 to 50 Hz range, and excursion is at a minimum at the tuning frequency. If you do high pass it should be at 35 to 40 Hz, so it protects the drivers and keeps the amp from working too hard while not filtering out useful content.
A cap won't give a bump elsewhere, 6dB HP filtering is as boobies to a bull, and a cap large enough to filter at 30Hz costs a king's ransom. IMO rpsands hit the nail on the head if the quote was accurate, but then again it might not have been.

Here's the earlier reference from alexclaber regarding 30 vs. 50 hz HP filtering:

"If you use a filter on the Acmes make sure it's set at ~30Hz. If the filter is set much higher than that, like at ~50Hz, you could actually increase the risk of over-excursion and cone creasing by increasing the power demands an octave above the tuning frequency where the excursion is greatest.

Alex"

Riis

 

[billfitzmaurice]

Here's the earlier reference from alexclaber regarding 30 vs. 50 hz HP filtering:

"If you use a filter on the Acmes make sure it's set at ~30Hz. If the filter is set much higher than that, like at ~50Hz, you could actually increase the risk of over-excursion and cone creasing by increasing the power demands an octave above the tuning frequency where the excursion is greatest.

Alex"

Riis

There's no inherent danger in high passing an octave above Fb. But there's no benefit either. Acme is tuned lower than the average cab, probably in the 30 to 35 Hz range, so high passing it at 50Hz serves no purpose. 30 Hz would probably be appropriate.

 

[Zooberwerx]

There's no inherent danger in high passing an octave above Fb. But there's no benefit either. Acme is tuned lower than the average cab, probably in the 30 to 35 Hz range, so high passing it at 50Hz serves no purpose. 30 Hz would probably be appropriate.

Thanks for the clarification. I learn something new every day.

Riis

 

[rpsands]

High passing at ~40-50hz with an Acme does a lot of good, claims to the contrary are not looking at the whole picture. Say you're using a 350 watt micro amp; not amplifying frequencies that can barely be heard will decrease power demand significantly. Do it before amp at line/instrument level.

At least, it's been my experience that turning down the bass will allow you to get more usable volume, and removing sub-bass has done the same.

 

[billfitzmaurice]

High passing at ~40-50hz with an Acme does a lot of good, claims to the contrary are not looking at the whole picture.

IMO if you don't have any need for response well below 50 Hz you shouldn't be running Acme to begin with.

 

[rpsands]

IMO if you don't have any need for response well below 50 Hz you shouldn't be running Acme to begin with.

Acme's are flatter than any other bass cab out there even down to 50hz. I realize they give up in sensitivity to achieve this, but for someone who wants a studio monitor style response (crazy flat all the way up) the Acmes are a valid way to go.

It's something you can correct for with EQ, but some guys don't want to screw around with it.