4ohms + 8ohms =??

[Cj_The_Dj]

Hi Folks,

I have a pair of peavey ul115 500w rms 1000w peak 4ohms
tops and I have now just got a pair of peavey bass bins loads with logic 600w rms drivers. but there 8ohms.

I have been given a digital crossover and logic corssover to go in the cabs (been removed as he used the digital one with two amps)

If i was to use one amp would i be better of bi-wireing them so i get my tops full range and bins just bass?

I would perfer to use one amp with the internal crossovers but i dont know what ohms i would be using can anyone help??

[Excalibur]

Second attempt. I misread the first post, and CJ has edited it also. :eek:
With 8ohm subs, if you use crossovers built into the subs, I think the tops will sound relatively louder than the subs. ( Though not absolutely sure. )
Definitely two amps and crossover. The amp for the subs should be capable of around 750w RMS into 8ohms. For value, I'd guess we're on the Thomann big one, model 2400?

Yes indeedy, that's the boy.

http://www.thomann.de/gb/t-amp_ta2400.htm

[Penfold42]

Mods can you change the title to 4ohms + 8ohms = ??

Done. :)

[Bouncy Dancefloor]

without knowing exactly how the crossover works, we are merely guessing

if this was a normal speaker to speaker daisy chain, you will be running at 2.6ish ohms, which is a no no!

with a digital crossover, you could run mono. Set the tops to full range or mid/high and put on one side of the amp. Then the bass is crossover and put onto the other side of the amp. Youll need an amp thats capable of 2 ohms though, perhaps try the PV2600 Amp which has built in crossover and is capable of running at 2ohms

[Cj_The_Dj]

I have been given a digaital crossover witch has 2 inputs left/right (from mixer and has 4 out puts 2 (left and right) for bass and 2 (left and right) for mids/hi witch means to amps.

but i dont really want to use two amps.
I want to link my tops from the bins so i have less leads ect and use the internall crossover but i dont know what ohms i'll be using and if my tops woulde be too loud.

[Bouncy Dancefloor]

the tops would be a fair bit louder, theres no way around this whilst using those bass cabs and not using my mono idea. The only way to get around this is to get 4ohm bass speakers, probably a matching set of UL118 speakers

[Sapphire Disco]

Just a thought to get him by until he can get another suitable amp , how would it sound to go into the tops first then into subs obviously if the amp he has is up to it ?

[Excalibur]

I have been given a digaital crossover witch has 2 inputs left/right (from mixer and has 4 out puts 2 (left and right) for bass and 2 (left and right) for mids/hi witch means to amps.

but i dont really want to use two amps.
I want to link my tops from the bins so i have less leads ect and use the internall crossover but i dont know what ohms i'll be using and if my tops woulde be too loud.
If you use normal passive bass crossovers, you'll be running at 8ohms, so you'll get nominally less power, and I still think the tops will sound too loud compared to the subs. I'd recommend two amps, you'll wonder why you ever tried with one.


Just a thought to get him by until he can get another suitable amp , how would it sound to go into the tops first then into subs obviously if the amp he has is up to it ?

Very toppy I guess, thus negating most of the benefit of having subs.

[Cj_The_Dj]

What if i got a pair of 8ohms 300w rms top say class D and only added my peavey as they are at extra at big big venues?

because i would be getting 4ohms right?

[Excalibur]

What if i got a pair of 8ohms 300w rms top say class D and only added my peavey as they are at extra at big big venues?

because i would be getting 4ohms right?

With all due respect, that's not a good way to do it compared to getting a second amp, and you'll only get 4ohms if you run them in parallel, as opposed to using the crossovers, so then you'll effectively have no crossovers, and the worst of all worlds. Buy the second amp, it's a lot easier, and way better.

[discomobiledj]

And you have a back up as well!

[Excalibur]

And you have a back up as well!

Exactly the point I forgot to make every time. :doh:

[Sapphire Disco]

CJ I really can't see why you don't want to use another amp other than the cost, if cost is the reason why on earth did you buy subs that don't match ?
To be honest if you are going out with just one amp you are taking a huge risk, if you run one for your subs & one for your tops & you had a problem within 10 seconds you could sort it out.
You don't have to use an active cross over you could just adjust the volumes on the individual amps, although obvoisly it would be better to have active cross over.

[Cj_The_Dj]

what amp would you recomend at 8ohms 600w rms a side? quite cheep.

[Sapphire Disco]

what amp would you recomend at 8ohms 600w rms a side? quite cheep.


This looks like a very good deal , although I have no doubt someone else may have a better suggestion.

Sorry if my last reply to you sounded a little sharp but I just can't work out your logic :)

http://www.whybuynew.co.uk/DA-1300-Warrior-DA1300-Power-Amp.html

[Cj_The_Dj]

I just dont like the factor of 2 amp beacause of the wieght and having to leads at each side.

i just wanted one amp and one as back up. with one leadf from amp to bass bin then to tops. and i dont know hopw to set the amps.

[Excalibur]

CJ I really can't see why you don't want to use another amp other than the cost, if cost is the reason why on earth did you buy subs that don't match ?
To be honest if you are going out with just one amp you are taking a huge risk, if you run one for your subs & one for your tops & you had a problem within 10 seconds you could sort it out.
You don't have to use an active cross over you could just adjust the volumes on the individual amps, although obvoisly it would be better to have active cross over.

Agreed totally.


what amp would you recomend at 8ohms 600w rms a side? quite cheep.


This looks like a very good deal , although I have no doubt someone else may have a better suggestion.

Sorry if my last reply to you sounded a little sharp but I just can't work out your logic :)

http://www.whybuynew.co.uk/DA-1300-Warrior-DA1300-Power-Amp.html

That's 600 at four. I refer the honourable member to my previous suggestion.
http://www.thomann.de/gb/t-amp_ta2400.htm


I just dont like the factor of 2 amp beacause of the wieght and having to leads at each side.

i just wanted one amp and one as back up. with one leadf from amp to bass bin then to tops. and i dont know hopw to set the amps.

That's the easy bit. It's suck it and see. :D

[djsteve10]

It all sounds awfully complex with all the different speakers & amps for what it's worth.
Why not just put the lot on ebay and then buy 1 good quality sound system that will cater for the functions that you need to do and run it off 1 amp using built in crossovers. I have used active crossovers before with 2 amps and its just all extra cables that you have to run to speakers and all the extra wiring you have to do wiring the crossovers up ect.

I would really personally have a good think about what you are going to do.

[Cj_The_Dj]

It all sounds awfully complex with all the different speakers & amps for what it's worth.
Why not just put the lot on ebay and then buy 1 good quality sound system that will cater for the functions that you need to do and run it off 1 amp using built in crossovers. I have used active crossovers before with 2 amps and its just all extra cables that you have to run to speakers and all the extra wiring you have to do wiring the crossovers up ect.

I would really personally have a good think about what you are going to do.


I agree this is what im saying im fed up of load of wires time to set up ect.

I want to keep my bins there 600w rms 8ohms, so would i need 300w rms tops for the best to link them with a 4ohm 900w rms a side??

I just want a simple but good setup. I was thinkin 4 speakers, 1 amp and 2 fightcases.


This is what i am thinking would it work?

one case = mixer,mic,pcdj contoller.
other case = one 4ohm 900w rms a side amp
4 speakers My bass bin link/poles to a pair of 300w rms tops

and sell the ull15 or keep them with my exsiting amp or sound renforcement at large venues.

[Excalibur]

I agree this is what im saying.

I want to keep my bins there 600w rms 8ohms, so would i need 300w rms tops for the best to link them with a 4ohm 900w rms a side??

I just want a simple but good setup. I was thinkin 4 speakers, 1 amp and 2 fightcases.


This is what i am thinking would it work?

one case = mixer,mic,pcdj contoller.
other case = one 4ohm 900w rms a side amp
4 speakers My bass bin link/poles a pair of 300w rms tops

Mate, I give up! What you have suggested will sound crap, won't do what you want or think, and won't give the volume you think. :(

[Cj_The_Dj]

Mate, I give up! What you have suggested will sound crap, won't do what you want or think, and won't give the volume you think. :(

sorry for being a pain but im just lost on what to do.

I just need a simple but effective rig.

[djsteve10]

sorry for being a pain but im just lost on what to do.

I just need a simple but effective rig.

Sell the lot and just buy a couple of 400w tops and a decent active sub, It will cover you for most functions your doing at your age!

[Cj_The_Dj]

Sell the lot and just buy a couple of 400w tops and a decent active sub, It will cover you for most functions your doing at your age!

I love the bins as they really rumble and with precision-devices drivers for £56

[djsteve10]

I love the bins as they really rumble and with perussion device drivers for £56

Look mate you dont need big sound systems with ground shaking bass, Just nice warm bass that just gives some sound enforcement and bottom end.

[Excalibur]

Sell the lot and just buy a couple of 400w tops and a decent active sub, It will cover you for most functions your doing at your age!

True. Not a plan which appeals to me, as he already has a pair of UL15's. I have suggested active subs as the easiest way of adding one before, and doubtless will again, but the lad apparently likes the ones he's got.


sorry for being a pain but im just lost on what to do.

I just need a simple but effective rig.

Simple. OK, we can do simple.
http://www.classd.ltd.uk/product.php?productid=16149&cat=23&page=1
Same amp as before.
Look at that, I've even saved two cabs, and two cables, how clever is that? :D

Right, now to be serious. CJ, you appear to like the cabs you've got, so let's start there. The UL15's are great cabs, and I assume you've already got a suitable amp. The subs are a pain, and personally I'd p/ex them, but again I assume you got a good deal on them, and quite like them also. So we now need to amplify them. The only sensible way to match up this hotch potch
of kit is active crossover, two amps. If you're going to buy an amp to sit there looking pretty and waqiting for the main one to fail, so be it, I'd rather let it drive the subs, and earn its money. Really the cabling isn't difficult. Put the crossover in a case, and leave the cabes in it, that helps a lot.
A thought occurs. ;) Is your main amp a Peavey by any chance? :D Many of those blighters have a crossover built in, which makes it an absolute doddle.


EDIT:
Look mate you dont need big sound systems with ground shaking bass, Just nice warm bass that just gives some sound enforcement and bottom end.

Steve, remember you're talking to a Young Person, not an old git like me. ;) :D :D

[Cj_The_Dj]

True. Not a plan which appeals to me, as he already has a pair of UL15's. I have suggested active subs as the easiest way of adding one before, and doubtless will again, but the lad apparently likes the ones he's got.



Simple. OK, we can do simple.
http://www.classd.ltd.uk/product.php?productid=16149&cat=23&page=1
Same amp as before.
Look at that, I've even saved two cabs, and two cables, how clever is that? :D

Right, now to be serious. CJ, you appear to like the cabs you've got, so let's start there. The UL15's are great cabs, and I assume you've already got a suitable amp. The subs are a pain, and personally I'd p/ex them, but again I assume you got a good deal on them, and quite like them also. So we now need to amplify them. The only sensible way to match up this hotch potch
of kit is active crossover, two amps. If you're going to buy an amp to sit there looking pretty and waqiting for the main one to fail, so be it, I'd rather let it drive the subs, and earn its money. Really the cabling isn't difficult. Put the crossover in a case, and leave the cabes in it, that helps a lot.
A thought occurs. ;) Is your main amp a Peavey by any chance? :D Many of those blighters have a crossover built in, which makes it an absolute doddle.


EDIT:

Steve, remember you're talking to a Young Person, not an old git like me. ;) :D :D

I am going to have to sit down with my mom and dad to talk about this one.

beacuse things are hard as we dont have much money. and i used to have a peavey pv1500 and i had to sell beacuse i needed the money :( worst thing i ever did.

I thought it would be easy as geting a pair of small tops half power of me bins and one big amp.

when i got the bins he gave me a active crossover and internall ones,

I thought this logic beacuse a guy called chris fox (foxprom) he is big in sheffield and thats what he dose on out door events but some times add more full range.


also dose justin use 2/3 amps on his stack?

[Tom]

I thought it would be easy as geting a pair of small tops half power of me bins and one big amp.



It can be dopne is all the speakers are the correct ohm like 8 for example.

If it was me I would sell all your speakers and amps and start fresh. Look at class-d and see what they have to offer.

You say you are tight for cash. If you sold your speakers and amps, at a realistic price how much would you get for them???

Once you have this, then sit down with your budget and look at whats on the market. I still think class-d would be your best opition price wise.

[Cj_The_Dj]

It can be dopne is all the speakers are the correct ohm like 8 for example.

If it was me I would sell all your speakers and amps and start fresh. Look at class-d and see what they have to offer.

You say you are tight for cash. If you sold your speakers and amps, at a realistic price how much would you get for them???

Once you have this, then sit down with your budget and look at whats on the market. I still think class-d would be your best opition price wise.

when i try selling my equipment i never get ood prices

[Tom]

when i try selling my equipment i never get ood prices


Is it that or you are asking to much???

What gear would you sell and I'm sure some of us lot can give you a rough price of what it's worth like condition and all that.

[Excalibur]

I am going to have to sit down with my mom and dad to talk about this one.

beacuse things are hard as we dont have much money. and i used to have a peavey pv1500 and i had to sell beacuse i needed the money :( worst thing i ever did.

I thought it would be easy as geting a pair of small tops half power of me bins and one big amp.

when i got the bins he gave me a active crossover and internall ones,

I thought this logic beacuse a guy called chris fox (foxprom) he is big in sheffield and thats what he dose on out door events but some times add more full range.


also dose justin use 2/3 amps on his stack?

Justin has one amp only, but it was bought as a balanced package. Don't ask me to explain how that works again, but believe me you can't do it easily with your gear. Normally he goes out with small tops and subs, but he too is asking Santa for a crossover and second amp. ( Might get my spare back then. :D :D )

If the guy who sold you the gear has taken the passive crossovers out what does that tell you? That active ones are better, and more versatile. If he's now got parallel sockets on the subs, he can add another pair to go to four ohms, and increase the sound that way. Thinking cap on I reckon. :D

[nigelwright7557]

without knowing exactly how the crossover works, we are merely guessing



Crossovers and speakers are highly complex when it comes to impedance.
They vary wildly from end of the frequency spectrum to the other.

For instance my 18 inch driver is 6 ohms at 100Hz yet is a few hundred ohms at 2KHz. Also the frequency response is far from flat with more curves than Pamela Anderson.

This is why prefer to stick to systems without crossovers.
The phase shifts introduced can end up having speakers out of phase and you get sound cancellation at certain frequencies !

[Cj_The_Dj]

Crossovers and speakers are highly complex when it comes to impedance.
They vary wildly from end of the frequency spectrum to the other.

For instance my 18 inch driver is 6 ohms at 100Hz yet is a few hundred ohms at 2KHz. Also the frequency response is far from flat with more curves than Pamela Anderson.

This is why prefer to stick to systems without crossovers.
The phase shifts introduced can end up having speakers out of phase and you get sound cancellation at certain frequencies !

so your saying ????

[nigelwright7557]

so your saying ????

Sorry, it seemed obvious to me !:bang:

[Cj_The_Dj]

Sorry, it seemed obvious to me !:bang:

are you just saying dont use crossovers ?? if so what it got to do with this thread?

[nigelwright7557]

are you just saying crossovers dont use them?? if so what it got to do with this thread?

Crossovers dont use what ?

[Cj_The_Dj]

Is it that or you are asking to much???

What gear would you sell and I'm sure some of us lot can give you a rough price of what it's worth like condition and all that.

it would be (if i was to sell everything)

pair of peavey pro 15 mint conditon
pair of ul115 500w rms
peavey ul115 bin loaded with precision-devices 600w rms
active crossover good condtion
prosound 1000w amp

i have light and cant seam to sell them :(

i dont really want to sell the bins :(

[Cj_The_Dj]

Crossovers dont use what ?

were you saying dont use cross overs if so what has that got to do with this thread??

[Cj_The_Dj]

http://www.precision-devices.com/ShowDetails.asp?id=14

this is the driver.

[Bouncy Dancefloor]

i give up on this thread

[Excalibur]

i give up on this thread

Oh no mate, we can't give up now it has rightly become a team effort. :D However, finding out that the main amp was the industry standard Prosound 1000 has made our task slightly trickier, when coupled with the funding problem. :(

Seriously, I'd be tempted to trade the Pro 15's in against a big amp to power the subs, use the active crossover, and let the Prosound drive the UL15's. Not ideal, but in my view it's probably the cheapest short term option, with the chance to upgrade he Prosound when funds allow. The most valuable items he has, the UL 15's are the most vital to keep. If he got £100 to £150 for the Pro 15's it would make the amp purchase less painful, and give him a system with total control of the sound balance.
This is probably the lowest cost option with reliability, but it's marginally undergunned for the subs. :(
http://www.ukdj.com/index.asp?PageAction=VIEWPROD&ProdID=21586
If money weren't such an issue, I'd suggest this for the subs as a temporary measure, and then when funds allowed, put it on the tops, and use its inbuilt crossover to feed a monstrous sub amp, such as the T-am2400! :D
http://www.ukdj.com/index.asp?PageAction=VIEWPROD&ProdID=28578

Chin up CJ, we'll get there somehow. :D

[Cj_The_Dj]

as an update i am keeping the bins, i will being using 2 amp with my logic digital crossover. i dont want to keep the ul115 as tops i might keep them as back up and use them in big venues as full rage for extra.

but I want a small/light but powerfull speakers (perferabley to be flying)

[Tom]

as an update i am keeping the bins, i will being using 2 amp with my logic digital crossover. i dont want to keep the ul115 as tops i might keep them as back up and use them in big venues as full rage for extra.

but I want a small/light but powerfull speakers (perferabley to be flying)

Just out of interest, why would you want them flown???

[Cj_The_Dj]

Just out of interest, why would you want them flown???

IMO it look nice and i would like to put my moves on the bins it loo really good :)

[Tom]

IMO it look nice and i would like to put my moves on the bins it loo really good :)

Do your current speaker tops have rigging point then???

Plus you would need some kind of speaker winch or a strong truss up high to get them above head level.

Dont forget the safty aspect of this.

I was thinking of doing this on my mackie speakers as they have flying rigging points on them but soon threw that idea out the window as I didnt see the point of flying them If I was on a stage for most of my gigs.

[Cj_The_Dj]

Do your current speaker tops have rigging point then???

Plus you would need some kind of speaker winch or a strong truss up high to get them above head level.

Dont forget the safty aspect of this.

I was thinking of doing this on my mackie speakers as they have flying rigging points on them but soon threw that idea out the window as I didnt see the point of flying them If I was on a stage for most of my gigs.

mine do not but like i say i want samller and lighter speakers!

[Tom]

mine do not but like i say i want samller and lighter speakers!

What speakers do you have???

If you want smaller and lighter speakers then you will loose the maximum volume output.

[Cj_The_Dj]

I have peavey ul115 but there big and heavey and 2 loud for tops is that right? my tops are 500w rms and my bins are 600w rms

or should i use my tops a full range and bin for just bass?

[Tom]

If it was me, I would look as a crossover. I don't know if that mas already been said already???

It depends on how much money you have to play with. I think something like this would be your best bet. http://www.behringer.com/DCX2496/index.cfm?lang=ENG

I will be looking at getting one of these to maximise the sound of my system.

So in your case, channels 1 and 2 can be top left and top right. 3 and 4 could be sub 1 and sub 2 but these would be in mono. That leave you channels 5 and 6 as spare or if you need to add more speakers then so be it.

You also have 3 inputs. You only need channels 1 & 2 which would be left and right input. You then go from the outputs in to the amps, then amps in to speakers. Have a look on the link and download the manual and have a look.

With this you can set to the crossover frequencies so you can have 100hz-20,000hz for your tops and 40hz up to 100hz for the subs or what ever they are capable of handling. That way, you should get a better sound as the frequencies are not crossing over with one another


As for the tops, just turn them down. Run them about just over half volume each and that should work well with your subs.

[Cj_The_Dj]

If it was me, I would look as a crossover. I don't know if that mas already been said already???

It depends on how much money you have to play with. I think something like this would be your best bet. http://www.behringer.com/DCX2496/index.cfm?lang=ENG

I will be looking at getting one of these to maximise the sound of my system.

So in your case, channels 1 and 2 can be top left and top right. 3 and 4 could be sub 1 and sub 2 but these would be in mono. That leave you channels 5 and 6 as spare or if you need to add more speakers then so be it.

You also have 3 inputs. You only need channels 1 & 2 which would be left and right input. You then go from the outputs in to the amps, then amps in to speakers. Have a look on the link and download the manual and have a look.

With this you can set to the crossover frequencies so you can have 100hz-20,000hz for your tops and 40hz up to 100hz for the subs or what ever they are capable of handling. That way, you should get a better sound as the frequencies are not crossing over with one another


As for the tops, just turn them down. Run them about just over half volume each and that should work well with your subs.

when i got my subs he gave me a logic system crossover 2 inputs left and right 4 out ups 2 bass left/right and 2 mid/trebble left/right.

is this no good? and the reason i want small speakers is beacuse the are to big/heavey to have poles from the bins but not tall enough to have stood on the bins :(.

[Tom]

when i got my subs he gave me a logic system crossover 2 inputs left and right 4 out ups 2 bass left/right and 2 mid/trebble left/right.

is this no good? and the reason i want small speakers is beacuse the are to big/heavey to have poles from the bins but not tall enough to have stood on the bins :(.

To get the best results, its a good idea to use an external crossover. That link is a dedicated job just for that. It also does EQ aswell which is a bonus.


Do you mean you want smaller speaker tops or smaller subs???

[Cj_The_Dj]

To get the best results, its a good idea to use an external crossover. That link is a dedicated job just for that. It also does EQ aswell which is a bonus.


Do you mean you want smaller speaker tops or smaller subs???

the tops and my crossover is an externall rackmount one

[Bouncy Dancefloor]

why are the tops too heavy to go on poles? The UL15's are surprisingly lightweight and are designed to go on poles and Speaker Stands

try 2 setups if you are getting 2 amps
1) Go from the mixer, into the UL15 amp, then daisychain into the Crossover, out of the Bass output and into the Bass Amp. This will let your peaveys full range and the bass will do just bass, probably give you a really nice thumping sound
2) Go from the mixer, into the Crossover, then from the Bass Output into Bass Amp. Then out of the Mid/HIgh output into the Peavey Ul15 amp. This will be a very LOUD setup

[Cj_The_Dj]

why are the tops too heavy to go on poles? The UL15's are surprisingly lightweight and are designed to go on poles and Speaker Stands

try 2 setups if you are getting 2 amps
1) Go from the mixer, into the UL15 amp, then daisychain into the Crossover, out of the Bass output and into the Bass Amp. This will let your peaveys full range and the bass will do just bass, probably give you a really nice thumping sound
2) Go from the mixer, into the Crossover, then from the Bass Output into Bass Amp. Then out of the Mid/HIgh output into the Peavey Ul15 amp. This will be a very LOUD setup

My peavey ul115 are the old version with silver grills same as them old hisys but better drivers.

they go on poles but there still heavey. im going to keep them for big venues. but i want small one for small venues.