Dbs farting

[Steve_Mitchell 0]

I was doing a smaller venue on sat , so I decided to leave my sub in the car..

 

When working I had the bass up and my cabs started to fart. When I turned the bass down it went.

 

My bass bin has a cross fader which takes all the bass out of the tops.

 

Are my cabs designed for just top and minimal bass?

 

My top cabs

 

 

 

 

http://img150.imageshack.us/img150/5119/dbcab2159gn.jpg

 

 

over to you ladies and gentlemen .

Edited July 5, 2005 by Gary

[Kingy 0]

That looks like either the 10" or 12" top cab. Neither of them are ideal for bass reproduction at high levels.

 

Usually a good cab though!

[jeffwall 0]

your using 15 inch cabs arnt you ste?

 

I think it maybe an inherant prob with all powered cabs without a bin, the difference in the mackies with the bin is awesome...must be the same for the db's

[Steve_Mitchell 0]

QUOTE (Kingy @ Jul 5 2005, 12:18 PM)

That looks like either the 10" or 12" top cab. Neither of them are ideal for bass reproduction at high levels. Usually a good cab though!

Kingy I knew you would be there with an answer. I remember you sorted my mic out. To be honest I was going to address this thread to you.

 

cheers again fella.

 

Ps its an opera 15 and I do have a 15 bass bin.

[Kingy 0]

If its a 15" top, you should have had no probs unless you were a bit over the top with the bass on your eq.

 

I never advise a 15" top cab. Simply because a 12" or 10" moves faster than a 15" so they are better at reproducing the mid/top frequencies. 15" are always good for most bass frequencies, some 18" are even better going down to the sub regions! And then there are a few 21" SUBS, MEGA LOW!

 

Check it again and if it still flaps, try taking it back to your retailer for a quick check up incase its cone is off centre (usually caused by a drop).

[superstardeejay 0]

We used to use the DB Opera 15s as DJ monitors in a 2000 capacity club in Birmingham. Very loud speakers indeed, they should sound very sweet, they usually do. Maybe you've overdriven them or they're faulty? They should be quite happy driven full-range. Are they the passive ones or active? Maybe you've clipped your amplifier.

 

 

[norty303 0]

QUOTE

Simply because a 12" or 10" moves faster than a 15" so they are better at reproducing the mid/top frequencies

 

That myth has come about as a result of big 18" and 21" drivers in big ported boxes sounding 'mushy' and 'slow'. Usually a bigger diameter driver has a larger excursion and so at at any given frequency will have to move faster in order to move from out point to in point within the same time frame. Thats why a large motor on a lightweight cone structure is far more critical in larger drivers than smaller ones.

 

Manufacturers often have to use a compromise driver in a 15" + Horn configuration by using a mid-bass driver instead of a bass design so that it will play correctly up to the crossover point (around 1-2khz depending on whether its a 1", 1.4" or 2" compression driver) In subs or bass speakers they can get away with a driver that doesn't need to play that high and is much more single minded in its design brief.

 

What you're experiencing is a driver that is either bottoming out or its exceeding its xmax (the voicecoil is starting to come fully out of the magnet gap and being out of control) I tend to see this much more in active cabs than passive ones. What's probably happening is that the signal you're putting into the cab is lower than the tuning frequency of the port and the driver is becoming unloaded (no air resistance preventing high excursion).

 

Most dual use top boxes will be tuned for 50-60hz and probably won't reproduce much below that. If you can you should try to cut the bass frequencies below 60hz (most 31 band graphics will have a band at 63hz) completely. You probably won't notice the missing frequencies (because you weren't hearing them much anyway), the speakers will probably go a bit louder and they won't fart (or break!)

Edited July 5, 2005 by norty303

[ToXiC 0]

Yes most simply way to get round that is cut everything below 70hz off.

Most 12 inchers in 2 way cabs start to sound distorted below 100hz, and 70hz for high quality cabs.