Using two cabs rather than one.

[ritch]

Hi,

Up until recently I have been using an Ampeg SVT-3 (275w into 8ohms or 450w into 4 ohms) into a SVT410HE (8ohm) 500w cab, which sounded ace, but I wanted to use the full power of the amp so decided to buy a SVT15 (8ohm 200w) to go with it. So I've just recieved a second hand one from gcohen (Thanks Graeme) and plugged it in, which sounds incredible, just what I wanted.

Now, something that took me by surprise, was when i put my head infront of each cab, the 1x15 'sounds' louder than the 4x10. I think I was expecting the 4x10 to create more of the sound as it has more speakers and probably moves more air (maybe).

Has anybody else had a similar experience with a similar set up? Is this what I should expect?

Rich

[Mr. Foxen]

If you put your head by the side of them, does one sound louder? They probably have different sound dispersal, or the 15 is more sensitive, so makes more sound at the same power. Thats one of the things about mixing cabs, that and it causes the whole world to implode.

[johnnylager]

Run lads, he's mixing drivers...

[ritch]

[quote name='johnnylager' post='365515' date='Dec 29 2008, 03:15 PM']Run lads, he's mixing drivers...[/quote]

Is this a problem?

Here's what Ampeg Support said when about my choice of second cabinet:

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Hi Rich, The SVT 15E would be an excellent choice to add to this rig. Right now you're only putting out about 375 watts into that 8 ohm 410HE. Adding the 15 will bring your impedance down to 4 ohms and give you the full 450 watts out of the 3 PRO. You'll be getting about 450 watts into a 4 ohm load that is basically 500 + 200 watts. You should be fine! Hope this helps!!!! Feel free to hit me back here anytime! Best Regards, Dino Monoxelos. Global Ampeg Product Specialist. LOUD Technologies Inc. [email protected] [email protected] www.ampeg.com
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Edited December 29, 2008 by ritch

[warwickhunt]

[quote name='ritch' post='365520' date='Dec 29 2008, 03:22 PM'][b]Is this a problem?[/b]

Here's what Ampeg Support said when about my choice of second cabinet:

[font="Courier New"][size=1]
Hi Rich, The SVT 15E would be an excellent choice to add to this rig. Right now you're only putting out about 375 watts into that 8 ohm 410HE. Adding the 15 will bring your impedance down to 4 ohms and give you the full 450 watts out of the 3 PRO. You'll be getting about 450 watts into a 4 ohm load that is basically 500 + 200 watts. You should be fine! Hope this helps!!!! Feel free to hit me back here anytime! Best Regards, Dino Monoxelos. Global Ampeg Product Specialist. LOUD Technologies Inc. [email protected] [email protected] www.ampeg.com
[/size][/font][/quote]

...only if you think it is.

If it sounds good to you 'in the situations that you use it' then don't worry about it; unfortunately for you, the seed of doubt is planted!

[johnnylager]

[quote name='ritch' post='365520' date='Dec 29 2008, 03:22 PM']Is this a problem?[/quote]

Not if it sounds right, no. The 15 may appear louder becaues it's nearer it's excursion limit and moving more air [200w rated] vs. the 500w rated 4x10. And more sensitive. Please bear in mind I am no authority on this. Lager, yes. Wish I had an Ampeg stack!

Maybe trawl through [url="http://basschat.co.uk/index.php?act=Search&CODE=show&searchid=672a3240885582e1c2e7a0bf14b75162&search_in=posts&result_type=topics&highlite=%2Bcomb+filtering"]these[/url] if you're at a loose end!

BFM and Mr Claber are the men on this.

Edited December 29, 2008 by johnnylager

[Musky]

[quote name='ritch' post='365520' date='Dec 29 2008, 03:22 PM']Is this a problem?

Here's what Ampeg Support said when about my choice of second cabinet:

[font="Courier New"][size=1]
Hi Rich, The SVT 15E would be an excellent choice to add to this rig. Right now you're only putting out about 375 watts into that 8 ohm 410HE. Adding the 15 will bring your impedance down to 4 ohms and give you the full 450 watts out of the 3 PRO. You'll be getting about 450 watts into a 4 ohm load that is basically 500 + 200 watts. You should be fine! Hope this helps!!!! Feel free to hit me back here anytime! Best Regards, Dino Monoxelos. Global Ampeg Product Specialist. LOUD Technologies Inc. [email protected] [email protected] www.ampeg.com
[/size][/font][/quote]

It's not a problem if you like the sound - it's just that there have been several threads about the 'unpredictable' results of mixing speakers without a crossover. So it's something of an in joke around these parts.

That email from Ampeg is slightly misleading though. Although the total power handling of the stack is 700w, the 450w the SVT3 knocks out will be split equally between the two cabs ie 225w each. So that's 25w above the thermal power handling to the 15". In practice that's unlikely to be a problem though.

[ritch]

Yeah - I thought that. But If I'm using both cabs together there's no way I'll be running on full whack, so shouldn't ever excercise that last 25w. And I wouldn't ever use the 15 on its own just because the wattages wouldn't match closely enough.

Sound wise though, it sounds awesome to me - not far off a full 8x10 but with decent portability. Got a rehearsal tomorrow night so I'll have to see how it goes.

Rich



[quote name='Musky' post='365532' date='Dec 29 2008, 03:34 PM']It's not a problem if you like the sound - it's just that there have been several threads about the 'unpredictable' results of mixing speakers without a crossover. So it's something of an in joke around these parts.

That email from Ampeg is slightly misleading though. Although the total power handling of the stack is 700w, the 450w the SVT3 knocks out will be split equally between the two cabs ie 225w each. So that's 25w above the thermal power handling to the 15". In practice that's unlikely to be a problem though.[/quote]

[chris_b]

I had this stack and it sounded great. You will have no problems with it. I switched to mesa boogie 2x10 and 1x15 cabs and again the world didn't stop! You are putting half of the 450 watts into each cab, but I doubt you'll be running at full volume so you shouldn't get a problem with the 15. Good choice.

[ritch]

[quote name='chris_b' post='365537' date='Dec 29 2008, 03:46 PM']I had this stack and it sounded great. You will have no problems with it. I switched to mesa boogie 2x10 and 1x15 cabs and again the world didn't stop! You are putting half of the 450 watts into each cab, but I doubt you'll be running at full volume so you shouldn't get a problem with the 15. Good choice.[/quote]

Cheers Chris,

Here it is, in all its glory. The covers are going to go back on though.

Rich

[Bill Fitzmaurice]

[quote name='ritch' post='365548' date='Dec 29 2008, 11:09 AM']Cheers Chris,

Here it is, in all its glory. The covers are going to go back on though.

Rich[/quote]
As you have the cabs the highly directional high frequency output of the tweeter is passing you by around mid-calf. Barring your having a very odd genetic defect the 4x10 should be on top, so that you might hear those high frequencies.

[lowhand_mike]

[quote name='Bill Fitzmaurice' post='365584' date='Dec 29 2008, 04:59 PM']As you have the cabs the highly directional high frequency output of the tweeter is passing you by around mid-calf. Barring your having a very odd genetic defect the 4x10 should be on top, so that you might hear those high frequencies.[/quote]

yeah i thought that but in a much more simple minded way, "er the 15 should be on the bottom..."
bring the mids and top end up to you, where as the lows are less directional.
and maybe the 15 would benifit from the coupling with the ground more than the top of the 4x10 cab.
but what ever, sweet rig, and if you like the sound then ignore everything i just said.

but then maybe....

[bass_ferret]

Here we go again............................................................

Dino is talking such bollocks can you believe anything he says? There are two approaches to rigs:1 - use your ears; 2 - learn about what the specs all mean. If you trust your ears then bollocks to the science but you did ask about the different volumes of the cabs.

[b]410HE[/b]
Frequency Response (-3dB): 60Hz-18kHz
Usable Low Frequency (-10dB): 43Hz
Nominal Impedance: 8-Ohms
Sensitivity: 98dB
Maximum SPL: 122dB

[b]15E[/b]
Frequency Response (-3dB): 50Hz-3kHz
Usable Low Frequency (-10dB): 33Hz
Nominal Impedance: 8-Ohms
Sensitivity: 98dB
Maximum SPL: 123dB

So there is f*** all difference between the sensitivity but a huuuuuuuge difference in the frequency response, and I would expect the extra 3-18kHz of the 4x10 (depending on tweeter setting) to be more audible than the extra 50-60Hz of the 15. Sticking you ears in front of the cabs to check this out is not recommended though unless you are wearing ear defenders. A better test will be to get the longest lead you can so you can listen to the cabs in isolation and together at gigging volumes - preferably with both cabs on the deck to try seperately, and stacked both ways when combined, and use what sounds best.

If you are DI for FOH and the rig is just for monitor then who cares but you.

Edited December 29, 2008 by bass_ferret

[alexclaber]

[quote name='bass_ferret' post='365742' date='Dec 29 2008, 08:38 PM']So there is f*** all difference between the sensitivity but a huuuuuuuge difference in the frequency response, and I would expect the extra 3-18kHz of the 4x10 (depending on tweeter setting) to be more audible than the extra 50-60Hz of the 15.[/quote]

If you're not into tweetery bass sounds and those specs are close to honest then I'd expect the extra 10Hz extension for the 15" to be more worthwhile than those few octaves of treble from the tweeter on the 10".

I wonder what qualifications are required to be a "Product Specialist" at LOUD Inc?

Alex

[bass_ferret]

He used to have a column in BGM.

[Protium]

[quote name='Musky' post='365532' date='Dec 29 2008, 03:34 PM']It's not a problem if you like the sound - it's just that there have been several threads about the 'unpredictable' results of mixing speakers without a crossover. So it's something of an in joke around these parts.

That email from Ampeg is slightly misleading though. Although the total power handling of the stack is 700w, the 450w the SVT3 knocks out will be split equally between the two cabs ie 225w each. So that's 25w above the thermal power handling to the 15". In practice that's unlikely to be a problem though.[/quote]

No, you will be pushing 450W between all 5 speakers = 90W to each.

[chris_b]

My preference would be to have the 10's on top and not to put my ears in front of the speakers!
It looks like you have both the gain and master at about 12 o'clock? I find you get a better tone by backing off the gain, to about 9-10 o'clock and pushing the master to around 3 o'clock, or as far as it will go before the amp starts to hiss and then back off the volume on your bass. I aim to not have the clipping light on at all. I don't find the buttons very helpful and keep them off/out.
My bass is active so these settings might work differently for you.

Edited December 29, 2008 by chris_b

[bass_ferret]

[quote name='Protium' post='365781' date='Dec 29 2008, 09:19 PM']No, you will be pushing 450W between all 5 speakers = 90W to each.[/quote]
How do you work that out?

[Stewart]

[quote name='Protium' post='365781' date='Dec 29 2008, 09:19 PM']No, you will be pushing 450W between all 5 speakers = 90W to each.[/quote]

No, that would only be true if all the drivers were wired in series or parallel - they are a combination of both in the 4x10

[Protium]

[quote name='Stewart' post='365790' date='Dec 29 2008, 09:44 PM']No, that would only be true if all the drivers were wired in series or parallel - they are a combination of both in the 4x10[/quote]

Aye - quick check, and I've mucked it up slightly - works out as 150W to the 15", 75W to each 10" (assuming the amp is putting out the full 450W)

Edited December 29, 2008 by Protium

[bass_ferret]

[quote name='Protium' post='365793' date='Dec 29 2008, 09:47 PM']Aye - quick check, and I've mucked it up slightly - works out as 150W to the 15", 75W to each 10" (assuming the amp is putting out the full 450W)[/quote]
I dont think so. The amp only see's what is connected and that is two 8 ohm loads that get 225 watts each. The amp does not care if the cab is two parallel pairs of 4 ohm drivers wired in series or four 16 ohm drivers in parallel.

[Protium]

[quote name='bass_ferret' post='365812' date='Dec 29 2008, 10:11 PM']I dont think so. The amp only see's what is connected and that is two 8 ohm loads that get 225 watts each. The amp does not care if the cab is two parallel pairs of 4 ohm drivers wired in series or four 16 ohm drivers in parallel.[/quote]

The amp sees a 4ohm load which gets 450W. You have to treat both cabs as a single circuit.

[alexclaber]

Full power at 4 ohms will put 225W into each 8 ohm cab, thus 225W into the 15" and 56.25W into each 10". But it's all pretty irrelevant as you only hit full power on the loudest peaks and in that case it's the excursion limited power handling that matters, which unfortunately no-one specifies.

Alex

[ritch]

[quote name='alexclaber' post='365869' date='Dec 29 2008, 11:19 PM']Full power at 4 ohms will put 225W into each 8 ohm cab, thus 225W into the 15" and 56.25W into each 10". But it's all pretty irrelevant as you only hit full power on the loudest peaks and in that case it's the excursion limited power handling that matters, which unfortunately no-one specifies.

Alex[/quote]


Thanks for all the info, everybody. Out of interest, while I have been using the 4x10 on its own I usually have the master volume at max, and then up the gain until it's the right volume - that way I'm using the all of the power of the amp without overdriving too much. With my passive jazz's the clipping light usually comes on every so often (or when I turn on the bass synth) at 12 oclock, which is about right I think. I imagine I'll keep that gain setting now and be able to bring the master volume back down when I have both cabs running.

The gigs I play vary, from carling academy/festival size right down to 100 people pub backrooms - but my amp's always battling it out with a 100w orange 4x12 and 100w marshall 4x12 so the extra headroom onstage is going to be a real benefit even if the PA's looking after FOH.

I will swap around the 15 and 10's though when I play.

[Protium]

[quote name='alexclaber' post='365869' date='Dec 29 2008, 11:19 PM'][b]Full power at 4 ohms will put 225W into each 8 ohm cab[/b], thus 225W into the 15" and 56.25W into each 10". But it's all pretty irrelevant as you only hit full power on the loudest peaks and in that case it's the excursion limited power handling that matters, which unfortunately no-one specifies.

Alex[/quote]

Surely the amp "sees" a 4ohm load, not two 8ohm ones?

If you draw the full circuit out and calculate, it works out as 75W to each 10" and 150W to the 15"