raising cabs off the floor?

[tbonepete]

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Edited June 7, 2012 by tbonepete

[Ian Savage]

Auralex Gramma Pad seems to be a solution many around here are very happy with; never used one myself, but the principle of 'em's sound and I HAVE used very similar pads for my studio monitors.

I tend to find that the castors on my cabs help with de-coupling to some degree, although be aware that you're probably not going to want your cab as far off the stage as a guitarist might due to the weirdness which can result from the longer bass wavelengths interferring with their reflected counterparts from the stage.

[JTUK]

Don't need to ..but if I did..I'd make do with something at the venue as it isn't a problem 99% of the time.

A beercrate or something

[nick]

Used a few housebricks on the rare occaisions I've needed to isolate a cab.

[warwickhunt]

+1 for the Auralex Gramma Pad.

[EssentialTension]

[quote name='JTUK' post='1356873' date='Aug 30 2011, 09:13 PM']Don't need to ..but if I did..I'd make do with something at the venue as it isn't a problem 99% of the time.

A beercrate or something[/quote]
Do beercrates still exist?

[Monckyman]

Yes but they`ve all been confiscated by Carling on Health and Safety grounds.

[Bill Fitzmaurice]

[quote name='Ian Savage' post='1356855' date='Aug 30 2011, 04:01 PM']Auralex Gramma Pad seems to be a solution many around here are very happy with; never used one myself, but the principle of 'em's sound and I HAVE used very similar pads for my studio monitors.[/quote]
IME if it works the cab is defectively flimsy. The floor vibrates in response to acoustical pressure, unless the cab itself vibrates excessively. Otherwise all the pad can absorb is the vibration that it might impart to the cab. Lifting the cab 2 to 3 feet will reduce some of the boundary coupling in the midbass, and that can help reduce midbass boom. A parametric EQ is perfect, allowing you to notch the precise frequency of the boom at the source so the floor won't vibrate and/or boundary reflection modes are compensated for, without killing broadband response.

[Bankai]

Having had to do similar things with turntables, we had best results by first placing a paving slab on the stage, a block of insulation foam on top of that, and then tennisball halfs on the four corners of the cab where it makes contact.

[Bill Fitzmaurice]

[quote name='Bankai' post='1357083' date='Aug 30 2011, 07:52 PM']Having had to do similar things with turntables, we had best results by first placing a paving slab on the stage, a block of insulation foam on top of that, and then tennisball halfs on the four corners of the cab where it makes contact.[/quote]
That's a very different situation. Vibration of the floor induced by its resonating in concert with the acoustical output of the speakers is transferred mechanically through the stand to the turntable to the cartridge, which results in a feedback loop. Isolation as you did will fix that. There's nothing in a speaker cab or amp that will cause a mechanical feedback loop.

Edited August 31, 2011 by Bill Fitzmaurice

[Bankai]

No, but the practice of isolating an object from a stage is the same.

[lojo]

Very untechnical, but last time I didnt like the sound of my cab on the stage , I used a crate found by the kitchen and a bit of black cloth from the caterers to tidy it up cosmetically, and it did the trick, dont know why but it worked:)

Edited August 31, 2011 by lojo

[JTUK]

[quote name='EssentialTension' post='1356897' date='Aug 30 2011, 09:30 PM']Do beercrates still exist?[/quote]


Do you know, I haven't had to use one so haven't tested this recently, but I guess I would then pack something under each end of the cab..but since I have a semi para EQ on all amps, I'd would go for Bill's suggestion first.

The last time this was an issue, I just took most of the bass off the amp and that worked.

[Prime_BASS]

[quote name='JTUK' post='1357135' date='Aug 31 2011, 07:58 AM'] Do you know, I haven't had to use one so haven't tested this recently, but I guess I would then pack something under each end of the cab..but since I have a semi para EQ on all amps, I'd would go for Bill's suggestion first.

The last time this was an issue, I just took most of the bass off the amp and that worked.[/quote]

Indeed.
A lot people EQ at home at a reasonable level, then when they turn up at a gig and the volumes sore, you wonde why's wrong. Too much bass in most cases, I find.
It's the reason I go everywhere with flat EQ and then go from there, and if I have to make a change it's usually on the bass part.
Gramma pad makes sense when your cab is pretty huge though and or naturally bass heavy.

[Bill Fitzmaurice]

[quote name='JTUK' post='1357135' date='Aug 31 2011, 02:58 AM']The last time this was an issue, I just took most of the bass off the amp and that worked.[/quote]
It works, but the bandwidth of a bass EQ, or for that matter even a graphic EQ, is so wide that you remove a lot of desired content along with the boom. A parametric is much better. Lifting does the same, removing the boundary reinforcement in the midbass without bothering the lows, but finding the right cab lift height for the boom frequency of the room is a chore.

[Spike Vincent]

[quote name='EssentialTension' post='1356897' date='Aug 30 2011, 09:30 PM']Do beercrates still exist?[/quote]


Yup.I have a few in stock from my sound engineering days.There was one venue I worked in that had a hollow stage area,and inevitably the bass amp had to be raised off the floor,otherwise really low feedback put the punters off their beer,regardless of EQ settings. It all depends on the individual venue.

[dave_bass5]

[quote name='warwickhunt' post='1356892' date='Aug 30 2011, 09:27 PM']+1 for the Auralex Gramma Pad.[/quote]

Same here.

Having played the same few boomy stages of the past few years my tone has become a lot cleaner, with no loss of low end, since i got my GP.
Now i wouldn't gig without it, even if i dont actually always need it.