Hello, first thread post here.. been reading for years. I have retrofit 2 Peavey 115 cabs to fit a BW 15o2-4 speakers, and plug into the external cab jack on back of a Combo 300 to get 300 watts at 2ohm's otherwise, its @ 4ohm's and 210w. My question is can I plug a 8ohm cab into the back external cab jack? Will it be lower volume? Or do damage?.. can't find the silver cone 1502-4 BW any more.. im still looking if y'all have one you can part with...thanks in advance.
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Unmatched external cab's
- Thread starter Ray1502-4
- Start date
This needs some clarification. Are asking if you can plug an 8Ω cab into the external speaker out in addition to the two 4Ω cabs? (That's a firm no.) Or are you asking if you can use an 8Ω cab by itself, along with the combo's internal speaker? Or something different than either of these two scenarios?
Addendum: Are you bypassing the combo's internal speaker when you are plugging in the two 4Ω speaker cabs, or trying to use both external speakers AND the internal speaker? (Also a firm no.)
Addendum: Are you bypassing the combo's internal speaker when you are plugging in the two 4Ω speaker cabs, or trying to use both external speakers AND the internal speaker? (Also a firm no.)
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You can plug anything that’s 4 ohms or greater into the extension cab jack.
As far as volume, most of the volume increase comes from increased speaker cone area, not the wattage.
The volume is not just a factor of wattage, it also depends on speaker efficiency (how much sound output per watt).
As far as volume, most of the volume increase comes from increased speaker cone area, not the wattage.
The volume is not just a factor of wattage, it also depends on speaker efficiency (how much sound output per watt).
If you've got two external cabs that are now 4 ohm then you can only plug one of them into the extension cab jack. If you connect both cabs then you will have three 4 ohm drivers in parallel, giving you 1.3 ohms, so the impedance will be too low and you will damage the amplifier section.
Before someone else says it, it is theoretically possible, with some tricksy custom cabling, to make two 4 ohm cabs behave like an single 8 ohm cab. I strongly recommend against this,
firstly because tricksy solutions have a habit of getting misconfigured and breaking something when one is rushed, and
secondly because it would be very unbalanced, with the driver in the combo getting two thirds of the power and the other two one sixth each.
I doubt it would be noticeably louder then two cabs, maybe even quieter.
Before someone else says it, it is theoretically possible, with some tricksy custom cabling, to make two 4 ohm cabs behave like an single 8 ohm cab. I strongly recommend against this,
firstly because tricksy solutions have a habit of getting misconfigured and breaking something when one is rushed, and
secondly because it would be very unbalanced, with the driver in the combo getting two thirds of the power and the other two one sixth each.
I doubt it would be noticeably louder then two cabs, maybe even quieter.
I ran one of those 300's ( . . . all those knobs . . . . ) and sat it on top of a matching Peavey 4-ohm 115BW cab, for 300w at 2 0hms. That was a hot ticket back then, probably still potent today, if not heavy.
