Need some Impedance help Hartke

[Orphius75]

A couple of months ago I bought a Hartke HA3500 complete with a 4.5XL and 215XL cabs.

The previous owner used the two cabs with the one head for some reasonable sized gigs (also DI’d into PA to give you an idea).

I’ve not used the two cabs together (not needed the 215XL as only in rehearsal situation at the moment, looking to gig in the next month or two).  

I’ve since learned that the 215XL is 4ohms and the 4.5XL is 8ohms so together to total impedance of 2.66ohms 😲😲, the amp is only rated down to 4! 

Any suggestions what to do next?-

The 215XL also has a faulty 15” driver- (He gave me that cab free when we found the fault). I’ve got a replacement on order.

Im guessing the advice would be to not use the two together BUT if anyone can offer any wisdom it’ll be much appreciated.

Having played the 4.5xl on its own it feels like it’s missing some low end grunt (I play metal and use a SR500 bass).

Is there anyway to rewire the 215xl to become 8 Ohms? They are individually 8 ohm speakers. However they are only rated as 200 watt apiece so I’m guessing just using one driver and disconnecting the other is not possible?

if I wired them in series with each other then wouldn’t that be 8 + 8 = 16 ohm?

then

add the 4.5 cab

(16x8) / (16+8) = 5.3 ohms safe ohmage for the head?

Watt(!!) would the amp be delivering power wise (it’s 300W @ 4 ohm).

 

Maybe just sell the 215xl when mended (after trying it for myself obviously!!) and use the money to put towards a 115xl?

 

Any suggestions welcome!!

[Jack]

Yeah but if you make the cab 16R then it'll get half the power the 4x10 gets, so is it worth bringing for the tiny amount of volume it'll create?
I know metal is loud, but do you really need more than that 4x10? They're LOUD! If I really needed more I'd just get another matching 4x10, they can be had for quite cheap these days as people don't want to move them.

 

[bazzbass]

even if you could get the two cabs to work, each speaker in the 410 will get half the power of each 15" speaker. It's a crapshoot if this will sound good, but you won't be utilising all your power

[Orphius75]

So far the consensus seems to be keep either the 4.5xl or the fixed 215xl not use both and sell the other!!

Any other suggestions- starting to look like fix up the 215xl and sell to fund a 115xl is the best option.

Even if I upgrade the head it still won’t run both cabs!!

[Lozz196]

I’d echo the posts above about not mixing speaker sizes, it can work but can also be hit & miss. I’d look for a 2.5XL (210) cab, yes this will get the same amount of power as the 410 but as long as you don’t push the lows you should be fine. Additionally as it’s more than likely that this cab would be on top you’d be able to hear it if it struggles - not so easy with a 115 at the bottom. The added bonus is that this cab in theory should be similar sounding to the 4.5, so for rehearsals and smaller gigs just take the 4.5, for the bigger stuff take both. This is what I do, though with Ashdown cabs not Hartke.

[Bill Fitzmaurice]

10 hours ago, Orphius75 said:

Maybe just sell the 215xl when mended (after trying it for myself obviously!!) and use the money to put towards a 115xl?

Then you'll end up with a 115 that can't keep up with the 410, so whatever additional low end it might have, and that's not much best case, won't be of any benefit. If you had a clean slate what you should do is find the 8 ohm cab that sounds the best to you, and if one wasn't enough add a second.

Quote

I know metal is loud, but do you really need more than that 4x10?

+1. Your stage rig drives the stage, the PA drives the room. No one needs more than a 4x10 or 2x15, unless it's to impress the kiddies in the audience.

[Orphius75]

Thanks guys- I’m a relative newbie to bass- this is the first gigging/ serious rehearsal rig I’ve bought. 

Im old enough not to be out to impress with my gear just interested in getting the best possible sound.

my band tune to C, it’s a three piece Death Metal band so I need to be heard to support the single guitar. I’m finding the 4.5xl a little nasally sounding but I got to admit I have not had much chance to play with the eq. (I’ve not bought any pedals/preamps yet). This is why I thought the addition of a 15” or 2 would help!!

Anybody out there playing similar music? What do you use both gear and EQ wise.

The EQ on the SR500 is quite powerful so could that be the issue?

much appreciated guys for all suggestions!!

[Bill Fitzmaurice]

1 hour ago, Orphius75 said:

This is why I thought the addition of a 15” or 2 would help!!

That's a common misconception, even among those who really should know better. The size of the driver does not determine how low the speaker will go. A dozen or so other factors, Thiele/Small parameters, along with the cabinet design do. A 115 might go lower than a 410 but it also might not. That would be revealed by the measured SPL charts for the cabs in question, if there were any, but sadly there are not. In any event, Hartke lists the low frequency response limit of both the 4.5xl and 115 xl as 30Hz, although they don't say if that's down 3dB, 6dB, 10dB or more from the base line sensitivity, which is another bit of critical information.

[Lozz196]

Very true, Bill, I’ve read a good few comments especially regarding Orange cabs where their 410s appear to be voiced lower than their 115s.

[Phil Starr]

Proverbially 'if that's where you want to go, I wouldn't start from here.

Where you are though is someone with a 4x10 and soon to have a 2x15. They probably won't work well together and the low impedance of the combination may cause a premature failure of the amp. Though the HA3500 is fairly tough I wouldn't knowingly abuse mine. On the plus side either cab on it's own is quite capable of drowning out the drums and causing long term damage to your ears so do you really need all that hardware? Once you have both cabs working and assuming you are happy with the sound in rehearsal go and give each of them a run out at a couple of gigs. Keep the one you like best and sell the other. I'ts worth getting out in the audience area with a long lead during soundcheck if you can or have someone in the audience you trust having a listen. They may well be hearing a different sound to the one on stage you are hearing.

Personally I doubt you'd need an extra cab but if you did you'd need two 8ohm cabs. 

[Orphius75]

Thanks guys, I’m going with the last option- fix up the 2x15 and try them both out and keep the one I prefer!!

ive seen a few Hartke users with the 4.5 cab and the 115xl underneath- I could always sell the 2x15 cab to fund a 1x15 (the 115xl is 8 ohms so works perfectly with the head)!!

 

thanks all!!

[Stub Mandrel]

On 21/04/2019 at 08:48, Orphius75 said:

A couple of months ago I bought a Hartke HA3500 complete with a 4.5XL and 215XL cabs.

The previous owner used the two cabs with the one head for some reasonable sized gigs (also DI’d into PA to give you an idea).

I’ve not used the two cabs together (not needed the 215XL as only in rehearsal situation at the moment, looking to gig in the next month or two).  

I’ve since learned that the 215XL is 4ohms and the 4.5XL is 8ohms so together to total impedance of 2.66ohms 😲😲, the amp is only rated down to 4! 

A

 

As you are already sourcing on 15" driver, personally I'd get two 16 ohm units and wire them in parallel or two 4 ohm in series. Then sell the spare driver to offset the cost.

 

Or you might want to read this;

http://hyperphysics.phy-astr.gsu.edu/hbase/Audio/imped.html

and then decide if 2.66 vs 4 Ohms is really worth losing sleep over?