Amp power with lesser power rated speakers

[Lozz196]

Am after a bit of advice, re having an amp that is of a higher power rating than the speakers used with it.

Currently have 2 Ampeg cabs, an SVT 410HLE 8ohm cab, 500 watts RMS, and an Ampeg 210 AV 8ohm cab, 200 watts RMS.

Am looking at getting an Ampeg SVT-7 Pro, which puts out 600 watts at 8ohms, 1000 watts at 4ohms.

For regular 100 capacity sized venues, would only look to using the 410, at bigger venues, would add in the 210, not increasing the volume on the amp (we always play to the volume of our drummer) just to add more speakers, so more presence.

Am I gonna be ok? I`m aware that I wouldn`t be able to push the amp, but I don`t on my current amps, with volume rarely going above 2/3 at max.

[Tdw]

As long as you keep the output of the amp low youll be fine, but many amps do not sound there best while working at a comparitively low volume so id personally say the 1000 watt amp is overkill and you would be better off with a lower powered model really.

[warwickhunt]

[url="http://basschat.co.uk/index.php?showtopic=3730"]http://basschat.co.uk/index.php?showtopic=3730[/url]

[icastle]

[quote name='Lozz196' post='1060840' date='Dec 16 2010, 06:25 PM']Am after a bit of advice, re having an amp that is of a higher power rating than the speakers used with it.

Currently have 2 Ampeg cabs, an SVT 410HLE 8ohm cab, 500 watts RMS, and an Ampeg 210 AV 8ohm cab, 200 watts RMS.

Am looking at getting an Ampeg SVT-7 Pro, which puts out 600 watts at 8ohms, 1000 watts at 4ohms.

For regular 100 capacity sized venues, would only look to using the 410, at bigger venues, would add in the 210, not increasing the volume on the amp (we always play to the volume of our drummer) just to add more speakers, so more presence.

Am I gonna be ok? I`m aware that I wouldn`t be able to push the amp, but I don`t on my current amps, with volume rarely going above 2/3 at max.[/quote]

1) If you use both cabs you have the potential to overpower the speakers by 30% (ish).
2) If you use the 4x10 on it's own you have the potential to overpower it by 20% (ish).

Watching your volume whilst using scenario 2) shouldn't be too much of a risk, but scenario 1) is really pushing your luck!

[warwickhunt]

[quote name='icastle' post='1060867' date='Dec 16 2010, 06:58 PM']1) If you use both cabs you have the potential to overpower the speakers by 30% (ish).
2) If you use the 4x10 on it's own you have the potential to overpower it by 20% (ish).

Watching your volume whilst using scenario 2) shouldn't be too much of a risk, but scenario 1) is really pushing your luck![/quote]

Sorry I have to disagree. Yes on paper you have 30% more power available but that is what your volume control is for; you don't have to (and you wouldn't) use anywhere near the full power... if you have a car capable of 180 mph do you have to drive it at 180mph everywhere you go? Added to which the speakers ratings are thermal ratings and your amps ratings are hardly spot on for power available across the frequency range.

I used to have a 2,000watt Yamaha power amp (think cd-david still has it to this day) and I drove a 250w cab with it absolutely no problem, I sold the Yamaha to buy a 1U Peavey digi power amp and continued to drive a variety of speakers with no problems whatsoever. In fact I think my current setup is the first where my amp and speakers have been anywhere near matched.

Honestly if you use your ears and a bit of common sense you are fine driving speakers with higher rated amps.

[icastle]

[quote name='warwickhunt' post='1060883' date='Dec 16 2010, 07:15 PM']... if you have a car capable of 180 mph do you have to drive it at 180mph everywhere you go?[/quote]

Yes

[quote name='warwickhunt' post='1060883' date='Dec 16 2010, 07:15 PM']Honestly if you use your ears and a bit of common sense you are fine driving speakers with higher rated amps.[/quote]

I thought I'd put a comment along the lines of [i]"amp's don't blow speakers - the person twisting the volume control does"[/i] but seems I thought it without writing it...
Not sure if that's senility or xmyth overload setting in...

[JTUK]

Not something I ever like to do..have more amp than cab power. Maybe this is throw back to a time when speakers weren't that great and lower powered anyway, and I blew a few.

Now I ALWAYS have more cab... and I am not a loud digging in player either.

Who is to say when an amp vol control relates to what power it puts out.
Your ears are your best guide, but sometimes when all hell is breaking loose you might not hear the chassis struggling.

I never get someone saying a 400w or whatever rated speaker needs to be driven by a more powerful amp.

If it were me, I wouldn't do this...but then my amp is stereo and that makes if easy to regulate and match output.

My rule would be for a 1000w amp to have 2 600w 4x10's at 1200w min taking the impedence into consideration.

With your suggestion of a matchup there is too much leeway, IMO, and the Ampegs never seem to have any power anyway..
I assume it is a VERY conservative rating but 10" seapkers at 100w is pretty poor by todays standards. I'd want a better look at the chassis..are they pressed or cast..how big is the voice coil etc etc ??

Edited December 16, 2010 by JTUK

[Cat Burrito]

Are you no longer happy with the Orange Terror or just looking for an alternative?

[Mr. Foxen]

Problem with feeding a 4x10 and a 2x10 with the same impedance from the same amp is you are stuck with the upper limit of the 2x10, they'll both get the same power, but the 2x10 will only deal with half, and the 4x10 will be louder, potentiall drowning out the sounds of the 2x10 complaining. Better off with a 16 ohm 2x10 so each speaker gets the same.

[Lozz196]

Both OCD & GAS are getting the better of me, Tim.

I`ve always wanted the Precision/Ampeg set-up, and since buying the Ampeg speakers, think its only a matter of time, so doing some research. The Terror is great, makes life so easy, and coupled with my Sansamp sounds great, so I`m hoping I can resist this OCD-GAS-evilness.

Edited December 16, 2010 by Lozz196

[Cat Burrito]

[quote name='Lozz196' post='1060936' date='Dec 16 2010, 08:03 PM']The Terror is great, makes life so easy, and coupled with my Sansamp sounds great.[/quote]
Good to hear I'm still yet to get mine in rehearsal as my mob stop in December. Roll on the New Year!

[Phil Starr]

As Mr Foxen has pointed out the problem is with the 2x10 which potentially get 500W. However you can't strictly speaqking compare amp watts with speaker watts as they are rated differently.

Amp ratings are the maximum they can reach without distorting. They are a peak rating, If you have a VU meter on your amp you'll see the signal going up and down. A thousand watt amp only produces a thousand watts for a fraction of a second at a time on the peaks.

Speaker ratings are basically about heating 500W through a speaker coil has almost the same effect as 500W through an electric heater. Speaker coils get really hot and will potentially melt the glue holding them together or even the wires themselves and this is why they fail mainly. The rating is given by passing that much power in the form of filtered noise ,meant to simulate music, through the speakers for several hours. If none of the samples fail that is the rating. When you play bass though you don't play flat out all the time. You play loud bits and quiet bits and sometimes nothing at all. Even if you are hitting the strings really hard with a pick and pumping out a non stop 8-beat the front of each note may hit the amps peak but it will decay quickly and at the end of the song you will stop and the speaker starts to cool. If you play without compression you might have a dynamic range of 40dB and this means your average level could be 20dB less than your peak. This is a ratio of 100:1 so the thousand watt amp could be only producing an average of 10W! So long as you keep out of distortion and don't use a limiter/compressor you'll be way away from the limits of your speakers. If you look at the Eminence website you'll see that as well as the RMS (EIA) rating of their speakers they also give a program rating of double this and a 6dB 'crest' rating for short term peaks.

There is one more hazard for a speaker though. The power rating is for general 'music' and you play bass which has a lot more low frequency. The speakr can only move so much before it hits the grille or the back of the magnet or moves out of the magnetic gap and this can definitely damage the speaker depending on it's exact design. Ported cabs are particularly prone to this sort of over-excursion as are certain speakers. There are 200W speakers that cannot handle 50W in the wrong cab at low enough frequencies. Really it is almost always worth filtering out very low and subsonic bass. If you use an over powered amp with a five string, no bass filter and use a lot of bass boost on your eQ then all bets are off.

So. the answer is that if you avoid distortion, keep the volume down and either filter the subsonics and or go easy on the EQ then there should be no problems and by over-powering you should get a great clean sound. If not you may have to recone at some stage.

[TimR]

I don't think that the 2x10 and the 4x10 can have the same drivers in them - the sonic results are going to be very unpredictable. I've mixed lots of different cabs, some work some don't.

You'll be fine running a larger power amp into smaller speakers. If you get distortion from the speakers back off the volume and don't EVER lend your rig to someone who doesn't understand this.

I think (from fag packet workings) that you will be limited to 400watts total (200W+200W) As has already been said the power will be equally split. This is less than the 500W you could get from the 4x10 on its own.

The 200W, 500W etc don't really have a lot of bearing on anything other than they give an indication of what you [b]can't[/b] do electrically rather than how loud it will be or what the resulting sound will be like.

If its dispersion you are after, consider taking a line or Di out from your amp to the PA and EQ all the bass out of this DI.

Edited December 17, 2010 by TimR

[LawrenceH]

[quote name='Phil Starr' post='1061168' date='Dec 16 2010, 11:54 PM']If you play without compression you might have a dynamic range of 40dB and this means your average level could be 20dB less than your peak. This is a ratio of 100:1 so the thousand watt amp could be only producing an average of 10W! So long as you [b]keep out of distortion and don't use a limiter/compressor[/b] you'll be way away from the limits of your speakers. If you look at the Eminence website you'll see that as well as the RMS (EIA) rating of their speakers they also give a program rating of double this and a 6dB 'crest' rating for short term peaks.[/quote]

This, along with the low-frequency excursion, is the make or break aspect. It's actually pretty easy to clip some amps momentarily without really noticing through tweeterless bass speakers, and you can therefore be driving them much closer to the maximum than you'd think for the rest of the time in a manner that you'd never get away with for full-range drivers reproducing, say, vocals.

Given that you want extra volume, I can't see adding the 2x10 being all that useful, unless you find that having the smaller cab (which will be louder per-driver assuming equal driver sensitivity thanks to the impedence) on top gets them firing more into your ears for monitoring purposes.

[Lozz196]

All great replies, thanks very much. Some are way beyond me, as am not the most technical person around.

Seems from the replies that this amp would be better paired with just the 4x10. I was really after adding the 2x10 in at larger venues, not to be louder, but to have more speakers chucking out the same volume, so to give more presence, but it seems from the advice that this won`t be workable.

As I said, I`m not a volume merchant anyway, I just like the look of it as it is relatively light, and Ampeg - am just gassing for my first ever Ampeg set-up.

Maybe the SVT3-Pro is more where I should be looking? Problem here is I`m slighly concerned that it won`t be powerful enough without both cabs, so when I play bigger venues, I`ll still need a bit more "oompphh" than usual, but have no way of getting it.

[chris_b]

I agree with JTUK. I don't want to risk damaging my gear so I always make sure I have a lot more speaker watts than amp watts.

On paper you have the potential to run a 6x10 but in reality you don't have very compatible cabs. I think the SVT3PRO would be a better match for the cabs you have, but in order to safely run a much more powerful amp and a 610 rig you'll really need a 4 ohm 410, which will match with the 8 ohm 210.

I agree with the others, the AV 210 isn't my favourite Ampeg speaker cab, but if you have to own the SVT7 then I'd get another 8 ohm 410.

[Ghost_Bass]

I'll be having the same situation because i'm going to drive my STL-9.0 (arrived this morning) - 900W@4ohm/500W@8ohm - trough a STL-12T - 300W@8ohm - and it'll be safe if i listen to the speaker for signs of farting. I'll probably add a second 1x12 in the future and still will be under the amps power rating - x2 1x12 = 600W@4ohm. I'm not a bit woried about it

TimR made a good observation, you'll probably get less volume with both cabs than using the single 4x10 but i think you'll have a bit more headroom.
IMO buy the 1000W amp - you never know when it's going to be usefull - and trade the 2x10 for a 4x10 or keep it for quieter gigs and get another 4x10 or 1x15 - 500W@8ohm - to add to your 4x10 for bigger venues.

[chris_b]

[quote name='chris_b' post='1061496' date='Dec 17 2010, 12:49 PM']....but in order to safely run a much more powerful amp and a 610 rig you'll really need a 4 ohm 410, which will match with the 8 ohm 210....[/quote]
Ooops, that won't work!! You'll need an amp that goes down to 2 ohms and the SVT7 only goes to 4 ohms minimum!

[Musicman20]

Hmm, not sure what I would do.

Sell the 2x10, get another 4x10?

Or, get an amp to drive that 4x10 nicely at 8 ohms, eg the Pro 7, or a Genz Shuttle 9.0.

Alternatively, wait around a little and get the 900w Genz Benz Streamliner.

Im not anti-Ampeg, I just think you can get the same thing from a smaller/lighter box.

You could sell both your cabs and get a 6x10 or 8x10...

My friend uses the SVT Pro 3 in a VERY loud band. He also uses a 410E, and finds he REALLY has to crank the amp to almost full master to get it to cut through. Not sure what the deal is there. I think the modern Ampeg amps are given higher wattage ratings than they are capable of.

Edited December 17, 2010 by Musicman20

[JTUK]

The only way I can see this working would be if the 2x10 was 16ohms... then that would give a degree of protection on
a split output.
I know everyone says you can hear the breakup but for whatever reason you can't..then it could be too late. the 2x10 is the most vulnerable here.

If you must have a 1000w amp, then you are going to need a big cab and it you want to plug both in, then trade the 2x10 for a 4x10.

For a benchmark, I think 200 watts per 10" is ok so a 4x10 should be around 800, no less than 600..otherwise I'd worry what chassis were actually in the cabs..

FWIW, I can recall the 8x10 being rated at 300w..that is a pretty poor return and the cabs were often shot after trying to put up with a big valve amp on hire.

2x4x10 = practical

1x8x10 = iconic stylistic compromise, IMO.

[algmusic]

or the TB1000 :-):-):-):-):-):-):-):-):-):-):-)

[TimR]

If 4x10 volume is fine, why not just get 2 2x10s and stack them vertically. Similar volume might give you more presence.

[Lozz196]

Guys this is exactly what I was after finding out, its really appreciated.

Looking at the comments, it seems that:

SVT 7Pro with the 410HE cab will work, as it will be 600 watts at 8ohms into a 500 watt 8ohm cab, but I won`t be able to use the 210, as it may blow as the power will prob be too much.

SVT 3Pro would work, but I would need to use both cabs all the time, to obtain the 450 watts at 4 ohms, due to under-powered issues.

Overall, think SVT 7Pro, its lighter, and has plenty of power (too much for me really). I`ll have to live with only one cab, am sure it should be okay on its own. Plus, can`t afford to buy any more cabs, and didn`t really want too many large cabs to cart abt anyway, hence the 210.

[chris_b]

Don't think about 1000 watts!!!

I have no scientific proof of this, but I gig with a 500 watt amp and might be regularly using about 100 watts through 2 cabs. On a really loud gig I might get up to 200 watts but I doubt it!

The SVT7 might be capable of 1000 watts (probably closer to 800 watts than you think!) but I don't believe you'll be able to stand in front of much more than 200 watts anyway, so your 210 won't explode on your first note!

And with a cab up at chest level you'll hear and project your sound better and probably won't turn up as loud anyway.

[Lozz196]

Cheers Chris. Been looking at Clarkys TC Classic 450 - wondering if that will do what I`m after. Nothing wrong with my Terror mind, just thinking of other options. Only thing that concerns me is only one speaker output at 4ohms - my 4x10 is an 8ohm cab.