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MusicLover
04-11-2016, 09:53 PM
Hey everyone, I was thinking of hooking up both of my bass cabinets together to see how my 1x12 would sound with my 1x15. The only way I can do that is to run the cabinets in series (due to the limited power handling of the 1x15 in comparison to the head I plan to use) and wanted to see if this would work and not damage anything.

I am running my Aguilar Tone Hammer 500 (which is 250 watts at 8 ohms/500 watts at 4 ohms) into an Aquilar SL112 (8 ohm, 250 watts continuous/500 watts peak) and from that cab into my GK Backline 115BLX (8 ohm, 200 watt power handling, according to the manual).

Following the example in this link (http://www.activebass.com/a42--Understanding-Basic-Electricity-of-your-Amp-and-Speakers), in series, you add the ohms, so 8+8=16 ohms. The Tone Hammer manual says you should have at least an 4 ohm load, so I think I am good there.
You would also add the wattage handling of the speakers. So 250 + 200 = 450 watts of power handling.

Does doubling the resistance (going from 8 ohms to 16 ohms) cut the wattage from the head in half (going from 250 watts at 8 ohms to 125 watts at 16 ohms)? Is the power equally spread between both cabinets when in series?

I just want to make sure I don't fry the GK cabinet that can only handle 200 watts.

Thanks in advance for your help!

kimgee
04-12-2016, 07:43 AM
Hi Musiclover, how do you like the Tone Hammer 500? I read that the Aguilar Tone Hammer is the closest thing to a tube amp, without the tubes. I have never heard one, but they sure get good reviews. Anyway, the first thing I would do is verify the internal wiring of the speakers. If you are daisy chaining them, it may appear, physically, they are in series, but they may in fact be parallel. If you look at the parallel example wiring diagram from the link you supplied (thanks for that interesting link) you can see that both wires branch off BEFORE they reach the first speaker. I would expect the extension speaker jacks on the speaker cabinets to be wired like that, but I do not know for sure. In other words the wires from the main input jack split and one set go to the speaker and the other set go to the extension jack, creating a parallel setup. I could not find any wiring info on the Aquilar SL112 and it's too early for Aquilar to answer the phone it seems, but here is their phone number - (212) 431-9109. I would not make any assumptions regarding electrical connections, as that could get rather expensive very quickly. The real danger is you may damage the amp. Whatever you do, start with the volume off and turn it up very slowly at first. Good luck!

JohnMSchiavone_Bass
04-12-2016, 08:16 AM
First, to answer your question, yes, doubling the IMPEDANCE will reduce the output of the head ROUGHLY by half. I say roughly because other factors such as frequency come into play. If this were a DC circuit, doubling the RESISTANCE would reduce the voltage (and so power by half). But this is an AC circuit, you use the term impedance, not resistance because it a different situation and more complicated than DC.

But don't bother trying to run the cabinets in series. Although the amplifier will put out 500 watts, because the cabinets are the same impedance, each being 8 ohms, the 500 watts will be distributed evenly as 250 watts to each cabinet. The Aguilar will be fine and the GK will be OK as long as you don't turn the volume too far up.

Caveat - I'm a little rusty at these calculations. I'm sure I'm correct about the power distribution to the cabinets, but it wouldn't hurt to have a sound engineer or electrical engineer confirm this.

TobiasMan
04-12-2016, 11:51 AM
If memory serves me right, John has given you the right info. Most current, and even not so current cabs when combined are connected in parallel. It takes a rewiring of the cab or an external series connector to try to run them in series.

You will be getting the most out of your amp/cabs combination with the two cabs operating in parallel and sharing 500 watts between them. Setting up a 16 ohm impedance will cut the power output of your amp, probably to about the 125 watt level, and that would be feeding two cabs. Way less output!

Listen to your 115 and if you hear any "farting" (technical term :)) or distress, turn the amp down. You should have sufficient volume for most medium sized venues.

MusicLover
04-12-2016, 07:01 PM
If memory serves me right, John has given you the right info. Most current, and even not so current cabs when combined are connected in parallel. It takes a rewiring of the cab or an external series connector to try to run them in series.

You will be getting the most out of your amp/cabs combination with the two cabs operating in parallel and sharing 500 watts between them. Setting up a 16 ohm impedance will cut the power output of your amp, probably to about the 125 watt level, and that would be feeding two cabs. Way less output!

Listen to your 115 and if you hear any "farting" (technical term :)) or distress, turn the amp down. You should have sufficient volume for most medium sized venues.

TobiasMan,

Thank you so much for your insights. I traded emails with tech support at Aguilar and they confirmed what you mentioned that daisy-chaining the SL112 cabinet put things in parallel, not serial.

I was looking for serial as a way to use the extra cabinet without worrying about sending too much wattage through the 115 cabinet. I was only going to run that configuration in a small practice space at low volume, so wasn't worried about the loss of volume.

So far, I have been taking the SL112 and the TH 500 to play at church as a personal monitor and add more bass to their overall PA output (they don't have subs yet). At 250 watts, that was more than enough power for that situation. I would eventually get a second SL112 or other light weight cabinet that could handle the wattage of the TH 500 so I had more power available to me for larger events (if the need arose).

Thanks for the technical terms for distress so I know when to turn the amp down. :D

MusicLover
04-12-2016, 07:02 PM
First, to answer your question, yes, doubling the IMPEDANCE will reduce the output of the head ROUGHLY by half. I say roughly because other factors such as frequency come into play. If this were a DC circuit, doubling the RESISTANCE would reduce the voltage (and so power by half). But this is an AC circuit, you use the term impedance, not resistance because it a different situation and more complicated than DC.

But don't bother trying to run the cabinets in series. Although the amplifier will put out 500 watts, because the cabinets are the same impedance, each being 8 ohms, the 500 watts will be distributed evenly as 250 watts to each cabinet. The Aguilar will be fine and the GK will be OK as long as you don't turn the volume too far up.

Caveat - I'm a little rusty at these calculations. I'm sure I'm correct about the power distribution to the cabinets, but it wouldn't hurt to have a sound engineer or electrical engineer confirm this.

Thanks John!

I appreciate your information.

MusicLover
04-12-2016, 07:17 PM
Hi Musiclover, how do you like the Tone Hammer 500? I read that the Aguilar Tone Hammer is the closest thing to a tube amp, without the tubes. I have never heard one, but they sure get good reviews. Anyway, the first thing I would do is verify the internal wiring of the speakers. If you are daisy chaining them, it may appear, physically, they are in series, but they may in fact be parallel. If you look at the parallel example wiring diagram from the link you supplied (thanks for that interesting link) you can see that both wires branch off BEFORE they reach the first speaker. I would expect the extension speaker jacks on the speaker cabinets to be wired like that, but I do not know for sure. In other words the wires from the main input jack split and one set go to the speaker and the other set go to the extension jack, creating a parallel setup. I could not find any wiring info on the Aquilar SL112 and it's too early for Aquilar to answer the phone it seems, but here is their phone number - (212) 431-9109. I would not make any assumptions regarding electrical connections, as that could get rather expensive very quickly. The real danger is you may damage the amp. Whatever you do, start with the volume off and turn it up very slowly at first. Good luck!


Kimgee,

I really like the tone from the Tone Hammer 500. This is only my fourth bass amp (and only the second head that I have owned), but I like it the best as far as sound is concerned. It doesn't have as many features as my GK head, but I like the tone better than the GK that I own. It has a warmer sound whereas my GK head is more trebly and not warm at all.

If you turn up the 'drive' control, it will warm up the mids and if you play with the gain control as well, I was told that you would get 'tube-like break up'. The funny thing was that most of the YouTube videos I could find with people reviewing it in depth were in any language except English (ha, ha). I pulled down the manual from Aguilar and watched what settings the reviewers changed and then listened to how it sounded.

The Tone Hammer heads have the same circuits of the Tone Hammer pedal, so you can download the manual for the pedal and learn more about the settings for the head. There are videos on the Aquilar site that show several different artists who show you the settings they use for the pedal and then you can hear a song that they played using those settings. Also, you can find a pair of Aguilar factory tours on YouTube and one of them actually shows you the steps to build a Tone Hammer 500, so you get an idea of how it is built and what parts go into it.

The Tone Hammer 500 + my SL112 together only weighs 29 pounds, so it is very back-friendly!

Thanks for the Aguilar phone number. I had been in contact with their tech support before when I first bought the gear and was looking for documentation for the SL112 cabinet. I contacted them again today and they confirmed what you mentioned that daisy chaining the cabinets would still put them in parallel.