Underpowering JBL 250TIs....??

[Storm]

Hey there.

Just had a quick question.

I am currently running a Nakamichi PA-5, 100 watt per channel into my 250TIs.

Am I underpowering them? Am I damaging anything? What would benefit getting an amp with more watts?

Thank you.

-Storm.

[mike]

If you were truly underpowering them you would notice the amp distorting.
250Ti's do not really require a whole lot of power for most listening. They do however need a quality power amp even if it is a small one.

Mike

[Andyoz]

I have only ever tried two amps with my 250Ti's.

The main one is a Bryston 4B SST. Sounds great and is a perfect match really.

The other was a Quad 606 that was purchased to drive another (smaller) system. That sounded quite different to the Bryston, much less low-frequency extension in particular (it's a >100 Watt mosfet design so no real slouch).

You won't damage anything using the Nak, but I don't think you would be getting the true low-freq. potential of the 250's with it either.

[opimax]

Now a set of 120TIs that would be the perfect amp.

I have run mine on a Sony 9000 receiver digital amp somewhere between 100 and 200 and the Perreaux 6000b is a MOSFET 300 per . both are thin in the bass but don't show much difference til higher volumes. I also have charge coupled XO . both MOSFET and CC XO are both suppose to contribute to a thinner sound... and then you add some SUBS

The Nak is really fine for the 250s but you also can do more if you have the money and the inclination. The 120s can handle a bigger amp too but needed ?not except a frat party or maybe home theater w/o a sub IMHO

Mark

[Robh3606]

You should be fine with 100 watts. About the only thing you should be missing is some headroom but only if you are pushing your amp to begin with.

Rob

[gerard]

hello

If you have the possibility to try :
use biamp with an electronic xover and tube amp for the upper level
it makes your 250 ti a dream speakers

Gerard

[edgewound]

Hey there.

Just had a quick question.

I am currently running a Nakamichi PA-5, 100 watt per channel into my 250TIs.

Am I underpowering them? Am I damaging anything? What would benefit getting an amp with more watts?

Thank you.

-Storm.

Hey Storm,

You won't hurt anything as long as you listen at moderate and low levels.

If you crank up your 100 watt amp you'll quickly run out of headroom and run the risk of burning up your very valuable 044ti's that no longer have a repair kit available....so you have to be careful.

Upgrading to 200-400 watts per channel will make your music....well....more musical...more detailed in all respects. Of course with a good quality amp

[opimax]

I think his amp would do fine, you are probably making him worry. I would bet his set up could damage your ears before truly running out of ompf(hitting audible distortion). the speakers certainly can do more but 100+ watts of quality amp will do fine but for the most critical situation. I have read a couple places that in general these are a relatively easy load on the amp too, helps

as far as damage goes I don't think he will have any issues unless a drunk at his party grabs the volume contrtol and challanges his system.

I am not as educated as many here in the physics of all this but I do have the speakers and have had a few amps on them. my experience is what i am going by.

But lastly I must again say I have a quality 300 per side amp on mine

Mark
PS the 120TIs would just shine on that Nak (shameless plug)

[edgewound]

It only takes once...to indulge a 100 watts with your favorite heavy hitting track to completion to fry the tweeters.

Especially with a very dynamic movie soundtrack, you need all the headroom and dynamic range you can get.

I have many customers that did just that.

"It's only 100 watts";

[Storm]

So, I should get the PA-7 that has 200 watts per channel in order not to damage the 044TI tweeters?

Thanks for all the advice.

-Storm.

[kingjames]

I am running my 250's with my Pioneer SX 1250 and have no problem with them. This receiver is 160 watts per side and the 250's love it.Half way up on the volume and I can rattle the windows.I don't believe my speakers lack anything and I'm not afraid to blow anything with my receiver. 100 watts of music is awful loud and not too many people can stay in the room when you're that loud.I just don't see running only 100 watts will damage my speakers.

[Robh3606]

So, I should get the PA-7 that has 200 watts per channel in order not to damage the 044TI tweeters?

No not really. That is 3db increase in maximum SPL. 3db is barely noticeable. You would want at least 6db or 400 watts to make any kind of substantial difference. The whole point is not to push your amp into clipping. An extra 3db or 6db of headroom is no guarantee you won't. Just use some common sense. No speaker is safe from a careless owner.

Rob

[johnaec]

The whole point is not to push your amp into clipping.

And to clarify that statement, what clipping does is chop off the top of the waveform, resulting in a "wave" that is "squarer". What that means is the top, (flat), portion of this squarewave is a steady voltage signal, instead of varying, and this is what quickly overheats and melts voice coils, since as it switches polarity, it's basically going from one extreme to the other, instead of a normal "smooth" transition. More power means it's less likely to go into clipping towards a squarewave.

John

[edgewound]

Storm,

Here's a link to JBL Pro Website on amp power and what happens.

Maybe this will clarify things....no-pun intended.

http://www.jblpro.com/pub/technote/lowpower.pdf

[Storm]

I am still confused..

If JBL recommends one to power speakers with more than needed watts, then why do they only state the "MAXIMUM WATTS PER CHANNEL" in their catalogs?

You would think they would have a minimum watts per channel.

So, am I really underpowering them or am I fine?

Thanks.



-Storm.