Amp questions

[codexp3]

I have a couple of questions about amplifiers for those of you in the know. One of the speaker systems I’m considering is the Paradigm Signature S8 which is an 8ohm speaker. The speaker’s suitable power range is 15-500 watts with a max input power of 250 watts. (What exactly is the definition of max input power, watts RMS?)

I want to power each speaker with a 250x2 stereo amplifier. Bridged the amp puts out 1000w. I’m not sure how the 1000w is derived. Is the 1000w at a 4ohm impedance? It’s not going to push 1000w to an 8ohm speaker is it? The speaker can be biamped, am I better off passively biamping and running 250w to the highs and 250w to the lows? My worry is I’ll be putting too much power to the tweeter. Which should I do bridge or biamp? Do I get more power with bridging or is 1000w only if I was running a 4ohm speaker. One last question…If I power my surrounds with a 250w/channel and their range is only up to 200 am I likely to encounter any long term problems. -Josh

 

[bandphan]

if you are using mac, you powerguard should limit any damage. I run a 250 watt 4ohm out to a 200watt 5ohm speaker

 

[Seth=L]

I don't have good explainations as to why you shouldn't worry so much about the power ratings on your speakers, but lets just say they are letting you know that you shouldn't under power them or over power them.

The Emotiva XPA-2 fits your bill perfectly. It comes out in a month or so and it's one monster amplifier for one low price.

 

[bandphan]

im pretty sure he already owns the amp

 

[fmw]

You shouldn't worry about speaker power ratings mostly because they are high enough that applying enough power to destroy them could possibly damage your hearing prior to that happening.

Normal peakers in norml rooms in normal homes don't need more than about 10 or 15 watts to play very, very loudly. Most speakers can take a lot more than that.

 

[markw]

Why?

First off, when you bridge an amp, it "sees" the speaker load as one half of it's rated impedance. So, your 8 ohm speaker will be a four ohm speaker to a bridged amp.

Second, you can drive any speaker wit has much poweras you want as long as you are careful to not overpower it. Yes, it can be done, but if common sense prevails, you don't oush it beyond reasonable limits and you listen for signs of distress and act accordingly, it should not bea problem.

Which brings me to my third point... how much power do you really need? I'm not an old fuddy-duddy, but your aspiritions here seem quite insane.

finally. tweeters can't absorb as much power as a woofer. Somrething to think about.

 

[codexp3]

I’m essentially moving to a dedicated home theater room. I currently have a Polk Lsi system in the living room which I’ve decided to keep in place. I have a 23x17 room which I’ve shielded with Owens corning 705 which is now the theater only room. I was going to move the LSIs into the theater room, but decided I wanted audiophile quality speakers. I was going to take the McIntosh monoblocks from my fronts in the living room and move them into the theater room when I got my new speakers.

While I was shopping for speakers I came across a used pair of McIntosh Mc252s which I got for 2500 for the pair! Not a scratch on the things and they tested fine. I haven’t decided on a speaker set for the amps yet, but at that price it would have been a sin not to buy them.

The leading speaker is the paradigm signature s8, but I’m still auditioning DefTech 7000s, B&W 803D, and Dynaudio (which I know nothing about). The 252s will power my two front stereo speakers, I’m just not sure the best way to hook up a stereo amp to one speaker. Do I bridge? Bassive bipamp (which I’m worried 250w is too much for the highs).

As to the emotiva, I’m considering their 200w five channel for my surrounds and center. I’d still like the center on a monoblock, but this project is already over budget! Have you been happy with emotiva?

 

[AcuDefTechGuy]

As to the emotiva, I’m considering their 200w five channel for my surrounds and center. I’d still like the center on a monoblock, but this project is already over budget! Have you been happy with emotiva?

I have the Emotiva MPS-2 (200 WPC x 7), and I think it is outstanding in terms of sound quality and build quality.

The XPA-5 should be just as great in terms of sound and build quality.

 

[jcPanny]

Amp Power

Also, it is more common to damage a speaker with too little power, exceding the amps capabilities causing it to clip and blowing the tweeter, than with too much power. The extra power above the 150-200 Watt range just adds headroom for better dynamics.

 

[fmw]

Also, it is more common to damage a speaker with too little power, exceding the amps capabilities causing it to clip and blowing the tweeter, than with too much power.

You are saying that low power will cause clipping more often than high power?

The extra power above the 150-200 Watt range just adds headroom for better dynamics.

The extra power above the 20 watt level just adds headroom for better "dynamics."

 

[Seth=L]

You are saying that low power will cause clipping more often than high power?




The extra power above the 20 watt level just adds headroom for better "dynamics."

Clipping is hard on speakers, especially tweeters. Woofers blow from overpowering and tweeters blow from underpowering (sometimes both go).

 

[AUtiger]

First, Emotiva is great to work with, lots of personal attention. Call them and discuss what you want to accomplish. Build quality is excellent as is CS.

Second, as stated underpowering causes more damage due to clipping when you push an amp to do more than its capapble. So more power allows clean signals at higher volumes, w/in the amps capabilities.

 

[jcPanny]

Amp Clipping

You are saying that low power will cause clipping more often than high power?
QUOTE]

FMW,
Don't read into it too much. You can exceed the capabilities of any amp, but more speakers are damaged by an exceeding the capabilities of a low power amp or receiver and causing it to go into clipping. Also an emotiva or similar amp will drive the speakers to ear bleading levels (in most rooms) before the amp give up.

 

[AVRat]

FYI, the upper frequency section of the S8 connects to the midrange driver and the tweeter and handles frequencies above 250 Hz. I believe the S8 is designed to split the incoming power evenly between the two sections so it doesn't matter which way you use the amp.

 

[codexp3]

FYI, the upper frequency section of the S8 connects to the midrange driver and the tweeter and handles frequencies above 250 Hz. I believe the S8 is designed to split the incoming power evenly between the two sections so it doesn't matter which way you use the amp.

So I'm safe biamping and sending 250 watts to the highs and 250 watts to the lows. My tweeter's not going to bite the dust?

 

[PENG]

So I'm safe biamping and sending 250 watts to the highs and 250 watts to the lows. My tweeter's not going to bite the dust?

Are you talking about passive bi-amp? Regardless, you still don't have to worry because the crossover of the S8 will pass mostly high frequency contents to the tweeter and will block most if not all low frequency contents. Even if the woofers are getting the full 250 watts your amp can deliver, the tweeters will get much less.

 

[mtrycrafts]

Clipping is hard on speakers, especially tweeters. Woofers blow from overpowering and tweeters blow from underpowering (sometimes both go).

No. Tweeters are blown bu overpowering, period.
When you clip it causes harmonics that spreads into the tweeters frequency band. As you i9ncrease the amount of clipping, you are increasing the power into the speakers, up to twice the rated RMS power of the amp. The extra power into the tweeters is what blows them just as well.

 

[PENG]

An interesting article:

http://www.audiovisualdevices.com.au/downloads/rane/note128.pdf

It does seem to make sense, hence the importance of having a competent subwoofer. For serious 2 channel music listening though, you may not need a ton of power if the room is not too big, you have reasonably sensitive speakers, you don't listen overly loud, and your low power amp has excellent headroom as well as the ability to drive difficult (low impedance/highly reactive) loads. Still more power cannot hurt in terms of minimizing the chance of blowing tweeters if used wisely.

 

[codexp3]

Are you talking about passive bi-amp? Regardless, you still don't have to worry because the crossover of the S8 will pass mostly high frequency contents to the tweeter and will block most if not all low frequency contents. Even if the woofers are getting the full 250 watts your amp can deliver, the tweeters will get much less.

Yes I have 250wx2 stereo Macs that I want to run one per speaker passive biamp. I just want to be sure that give 250 to the highs won't fry the tweeter on the s8s.

 

[AVRat]

Josh, not to worry. I'd be surprised if you pushed anywhere near 20W RMS total to the S8s in your (not overly large) room. My 170W Denon receiver has plenty of output left by the time I'm pushing deafening levels in a similarly sized space.