Will they blow?

[DJWilson]

Hi,

I have two gigs in a huge hall and need to fill it, im thinking my 2x 400W RMS wont fill the room so if i have my 2x 200W rms to the system will they blow?

My amp can hold it just wondering about the speakers.


Amp - 400 - 200 - Hall
" " - 400 - 200 - Hall

They are both 8Ohms

Thanks.

[Sapphire Disco]

Don't quite understand quite what you are saying but it sounds to me like you need another amp and a pair of subs, put your 200w speakers on-top of the subs and put your 400w speakers with a bigger amp high up on stands, to be honest I wouldn't do a gig like that with just one amp anyway.

[Jays karaoke]

Your speakers will only blow if you over drive your speakers. If the hall is as big as you say 600w per side wont fill the room any how it will just bounce all over and sound shocking. My advice would be to run a seperate amp with some beefy subs but like i say if the hall realy is so big you'd probably need 2 or 3k to fill it right.

[A1DL]

Hi,

I have two gigs in a huge hall and need to fill it, im thinking my 2x 400W RMS wont fill the room so if i have my 2x 200W rms to the system will they blow?

My amp can hold it just wondering about the speakers.


Amp - 400 - 200 - Hall
" " - 400 - 200 - Hall

They are both 8Ohms

Thanks.

Two 8r cabs in parallel = 4r resistance load at the amplifier
What amplifier are you using?
With an amp that can deliver 1,000 watts or more into 4r, you should be fine.
If the amp is smaller, be careful not to clip.

[super-hero]

What you could do is run your 400w speakers off one side of your amp and the 200w ones off the other. You can then adjust the volume levels as needed. You would need to run the system in mono. You may have a mono/stereo switch on your mixer.

Also just because it's a big room you may not need loads of speakers. If you are doing a 60th birthday for example they might not appreciate night club sound levels.

[ppentertainments]

Sorry to be thick, but I still don't understand the question.

[A1DL]

Sorry to be thick, but I still don't understand the question.


I took the question to be "can you run 2 x 8r boxes off one channel of a power amplifier?"

[ppentertainments]

I took the question to be "can you run 2 x 8r boxes off one channel of a power amplifier?"

You may be right, I not got a clue. I thought it was 2 amps, each running a
400w and a 200w speaker :confused: :confused:

[Excalibur]

I took the question to be "can you run 2 x 8r boxes off one channel of a power amplifier?"

As did I. However, I'd be worried in case you blew the lower rated cabs, since both will receive the same power as each other. It's not something I think is a good idea. I'd suggest hiring/borrowing a bigger PA. ;)

[A1DL]

You may be right, I not got a clue. I thought it was 2 amps, each running a
400w and a 200w speaker :confused: :confused:

Looking at the OP again, and that funny diagram, you could be right.
:dunno:

[djsteve10]

You should have budgeted for a PA hire or not took the job on if you cannot provide sufficent PA without running risks.

[DJWilson]

Ok so the 200wrms will blow, ok my 2x 400wrms should cover the hall. ill go over the road later and try it out before hand.

[Corabar Steve]

I've got nothing to add to this thread, I just wanted to put an ohm symbol on the forum for people to use if they wanted & here seemed fairly appropriate.

Ω

[Sapphire Disco]

Ok so the 200wrms will blow, ok my 2x 400wrms should cover the hall. ill go over the road later and try it out before hand.

I don't think you would blow them, as I said before I think you need a pair of subs if you came from your amp into your 400 w speakers then out into a pair of 300/400w subs then out through the built in filter into your 200w speakers as you are filtering the sound you are not driving the smaller speakers so hard, you would need a good amp for this that's why I say use 2 amps but you could get away with it if you feel brave.

I've got a pair of class D 15" subs for sale for £100 if you are interested :D

[One Vision]

I don't think you would blow them, as I said before I think you need a pair of subs if you came from your amp into your 400 w speakers then out into a pair of 300/400w subs then out through the built in filter into your 200w speakers as you are filtering the sound you are not driving the smaller speakers so hard, you would need a good amp for this that's why I say use 2 amps but you could get away with it if you feel brave.

I've got a pair of class D 15" subs for sale for £100 if you are interested :D

Love the avatar :D
http://www.mobilediscodirectory.co.uk/forums/image.php?u=11&dateline=1223892813

[ppentertainments]

I don't think you would blow them, as I said before I think you need a pair of subs if you came from your amp into your 400 w speakers then out into a pair of 300/400w subs then out through the built in filter into your 200w speakers as you are filtering the sound you are not driving the smaller speakers so hard, you would need a good amp for this that's why I say use 2 amps but you could get away with it if you feel brave.

I've got a pair of class D 15" subs for sale for £100 if you are interested :D

Would this not mean running your amp at 2Ω (note use of the symbol :D ). Not sure what amp is being used but most only run down to 4Ω

[Sapphire Disco]

Would this not mean running your amp at 2Ω (note use of the symbol :D ). Not sure what amp is being used but most only run down to 4Ω

No you are going into the subs and only coming out through the cross over so you are only going down to 4 Ohms.
Sorry I don't have a Omega sign on my keyboard.

[mldiscos]

I've got a pair of class D 15" subs for sale for £100 if you are interested :D[/QUOTE]


has you got any piccys of your class d's i might be intrested if they aint too abused.

[ppentertainments]

No you are going into the subs and only coming out through the cross over so you are only going down to 4 Ohms.
Sorry I don't have a Omega sign on my keyboard.

You can't help some people can you steve ?? :D :p :D


I've got nothing to add to this thread, I just wanted to put an ohm symbol on the forum for people to use if they wanted & here seemed fairly appropriate.

Ω

[Sapphire Disco]

I've got a pair of class D 15" subs for sale for £100 if you are interested :D


has you got any piccys of your class d's i might be intrested if they aint too abused.[/QUOTE]

No pics of the actual ones but they are in good condition, haven't used them much.

[Corabar Steve]

You can't help some people can you steve ?? :D :p :D

It's now a smilie. If you type : r : without any spaces you get :r:

[Sapphire Disco]

It's now a smilie. If you type : r : without any spaces you get :r:

Thanks I didn't know that just tried and it works :)

:r:

[Excalibur]

I don't think you would blow them, as I said before I think you need a pair of subs if you came from your amp into your 400 w speakers then out into a pair of 300/400w subs then out through the built in filter into your 200w speakers as you are filtering the sound you are not driving the smaller speakers so hard, you would need a good amp for this that's why I say use 2 amps but you could get away with it if you feel brave.

I've got a pair of class D 15" subs for sale for £100 if you are interested :D

Excellent advice, probably the best way to potentially avoid damage.


Would this not mean running your amp at 2Ω (note use of the symbol :D ). Not sure what amp is being used but most only run down to 4Ω


No you are going into the subs and only coming out through the cross over so you are only going down to 4 Ohms.
Sorry I don't have a Omega sign on my keyboard.


Diamond is almost bang on again. With 8:r: subs, you'll still be running at 8 if you use the crossovers to connect. This one comes round pretty regularly. :D

[ppentertainments]

Learn something new everyday.:D :D

[Jiggles]

Typing 8R is the same as writing 8:r:

[nigelwright7557]

Your speakers will only blow if you over drive your speakers. If the hall is as big as you say 600w per side wont fill the room any how it will just bounce all over and sound shocking. My advice would be to run a seperate amp with some beefy subs but like i say if the hall realy is so big you'd probably need 2 or 3k to fill it right.

I worked for a disco for 3 years whose amps were only 100WRMS !
We worked pubs, clubs and public halls and had no problems.
It wasnt really loud but people want to be able to talk to each other too.
There are no awards for making people go deaf !

[A1DL]

The wattage is immaterial. A C7 top is rated at 200wrms and will do 138db at 1m because it is very very efficient.

[nigelwright7557]

The wattage is immaterial. A C7 top is rated at 200wrms and will do 138db at 1m because it is very very efficient.

Was the C7 invented in 1977 ?

The speakers were home built.
Instead of using 12 inch or 10 inch drivers the boxes had numerous 6 inch drivers in them.

[Sapphire Disco]

I worked for a disco for 3 years whose amps were only 100WRMS !
We worked pubs, clubs and public halls and had no problems.
It wasnt really loud but people want to be able to talk to each other too.
There are no awards for making people go deaf !

I don't think it's about being so loud that you make people deaf Nigel I think if you are going to drive your set up on the edge all night it won't sound good & may blow up.

[nigelwright7557]

I don't think it's about being so loud that you make people deaf Nigel I think if you are going to drive your set up on the edge all night it won't sound good & may blow up.

In the early 1980's I got away with a Maplin amp DIY kit 225WRMS and four 50WRMS 12 inch Fane speakers and they were very loud. On a couple of occasions I was asked to turn it down a bit and that was at quite big venues.

[Sapphire Disco]

In the early 1980's I got away with a Maplin amp DIY kit 225WRMS and four 50WRMS 12 inch Fane speakers and they were very loud. On a couple of occasions I was asked to turn it down a bit and that was at quite big venues.

Do you think that may have been because it sounded a bit harsh & tinny rather than loud ?

I think sound quality had changed since the old days, years ago the old Motown sounded OK on the big mono speakers, now some of the old Motown songs sound quality doesn't sound so good on modern quality equipment.

[nigelwright7557]

Do you think that may have been because it sounded a bit harsh & tinny rather than loud ?

I think sound quality had changed since the old days, years ago the old Motown sounded OK on the big mono speakers, now some of the old Motown songs sound quality doesn't sound so good on modern quality equipment.

The system sounded fine to me.
Never had any problems with it.
It cant have sounded tinny as the Fane speakers only went upto 5KHz.

The Maplin amp was a pretty standard design with differential amplifier and standard VAS and bias circuits. The output transistors were 2N3055's and MJ2955's. The power supply was +/- 48 volts at a few amps so it was good enough for the power it was required to deliver.

I have moved on a bit since those days and use MOSFET's now for my designs.

[A1DL]

Was the C7 invented in 1977 ?


1992/3 IIRC



The speakers were home built.
Instead of using 12 inch or 10 inch drivers the boxes had numerous 6 inch drivers in them.

what speakers are you talking about Nigel? :confused:

[nigelwright7557]

1992/3 IIRC



what speakers are you talking about Nigel? :confused:

The speakers on the first disco I worked on with the 100WRMS amp.