25 replies to this topic

[Shreknos]

hey guys, i just purchased a set of 8 ohm mids and woofers... i want to give both the mids ad woofers at least 400 watts each rms, that is 4 x 400wrms...

problem is, wihout spending more then 2500 on amps, i dont know how im going to acheive this...

the few contenders i have found, are the eclipse 4 channels bridged, the d class ice ones, or the big tarantula soundstream ones...

audiosystem come close, but even these are only 2 x 400 at 4ohms....

can anyone help as to how i can power the drivers adequately to get loud loud....

budget isnt fixed, but im not fussed on amps, as long as its not a noise generator, and it makes power im not too fussed...

any help will be much appreciated

charlie

[TheyDontWantMusic]

why do you want 400watts to a mid?

[shizzle]

You could look at some PG Xenons 200.4. You would need 2 though, as they 'only' give 200w/channel, so you would need to bridge them.
Also, they are huge, and expensive.

on seconds thoughts, not the best idea, but it would work.

[Gonadman2]

Most D class amps can run sub bass and mid bass these days, what about 4 x $500 mono's? Should give you that sort of power fairly easily!

[Shreknos]

the efficiency of the mids and woofers are similar, tweeters arequite a bit more efficient, so i think they will need it, plus , more never hurt, id hate to install it all and find i under did the mids...


wasnt there a rule about efficiency goin up when running lower impedance or something?

[Gonadman2]

Umm I'm entirely sure on the specifics but isn't power a logarithmic response with respect to frequency? So as the frequency increases, power required decreases?

I've noticed that in every system I have built that my tweeters are something like 10db lower in gain than my midrange/midbass.

I don't have any problems with my subs @ 500wrms, midbass @ 150wrms, midrange and tweeters @ 75wrms. I like overkill but 400wrms @ 8 ohms is huge ($$$) and is going to gain very little imo.

[hardyards]

400 wrms is a lil overkill for most speakers (not regarding subs) isn't it??

I had 8 ohm mids so i bought a 6 channel to bridge 120 wrms to the mids and 60wrms for the tweets.

but as someone mentioned I thought most higher impedance speakers were generally more effecient, what speakers are you actually planning on running?

ok now hte drunken shenanigan talks are over check out hte diamond audio d7402

[br85]

Bridging is your solution. Clarion DPX2251 as an example will give you 360 watts at 8 ohms. You can get them for ~$300 each if you look hard enough.

$300 for 360 watts of non class D power at 8 ohms is probably about the best you'll get if you don't want to by jaycar or noisy rubbish like boss/us audio etc.

Edited by br85, 05 November 2009 - 02:04 AM.

[268669♫]

As br85 said the clarions are your best bet, I just picked up 3 of the DPX2251 for $239 each. See ryda for the great price. My mids are 4 ohm and i'm giving them an amp each for 600wrms. and the other one is for the horns at 180wrms x 2. For that price why not get the headroom.

Ant

[~thematt~]

Shreknos, on Nov 4 2009, 08:26 PM, said:

wasnt there a rule about efficiency goin up when running lower impedance or something?

Nah, its the other way around. Efficiency usually goes up with higher impedance because the windings are smaller, and therefore so is the gap.

Gonadman2, on Nov 4 2009, 08:36 PM, said:

Umm I'm entirely sure on the specifics but isn't power a logarithmic response with respect to frequency? So as the frequency increases, power required decreases?

Yes. Energy is inversely proportional to frequency. The higher the frequency, the lower the energy content.

You dont need 400W RMS to drive any speaker, lest of all mids or highs. But each to their own. I have 460W RMS driving each midbass, but they'll never see that power output. Its just ensuring I run the amp in its linear output zone.

In the end, you're not going to use all that power. All you need to do, is ensure that you have enough capacitance on the rails to deliver the power you need, at the output levels you want, with the speakers you have. Anything beyond that is expensive candy.

[fuddbutter]

you could do what has been done for the last 30 years and use an impedance matching transformer.. but what would i know.

[Matt VIP]

or read this article...

[Luke352]

Matt VIP, on Nov 5 2009, 11:16 AM, said:

or read this article...

The exact thread I was thinking of.

I currently have my midbass running off 50wrms temporarily and trust me it is plenty loud! I will be getting an amp capable of 150w continuous, but that will be way and above anything they are ever going to need.

[Fury♫]

Charlie, just double up on your midbasses, parallel them to 4ohms

[Shreknos]

hmm, ok....

i thought i read somewhere that matt had suggested giving a proper midbass no less than 400 watts and seeing the true meaning of midbass...

the drivers are xt 25's big versions, exclusive hds 4's, and SLS 8's...

im pretty sure dual sls 8 will ruin my door...


i was under the impression that true dynamcis neeeded massive power, as does realism at high volumes...?

working out without cabing gain, 86 db efficiency barely cracks 100db with 400 watts... thats a far cry from what i consider loud...

so as we say in the trade, better to look at it, then look for it...


any more amplification ideas??

ill give that article a read, thank you rob