How to get good headroom?

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How to get good headroom?

Postby bcresci » Wed May 14, 2008 4:13 pm

I chasing my dream of having a sweet Jerry-like sound system.
Step 1 - The Cabinet. I'm in the process of bulding my own speaker cabinet. Thanks to Dozin and Playingdead for the tips on parts. That whole piece of my project seems to be under control with the exception of some minor labor disputes with the cabinet maker (my father).

Step 2 - The Power Amp. Now I'm on to looking for a power amp. I recently read an article online that seemed to indicate the key to getting good headroom was to have a power amp rated two to four times higher than the speaker capacity. So if you have a 100 watt speaker, get a 200-400 watt power amp. There were some other references to 6dB which went over my head.The article also seemed to indicate that having a power amp rated lower than the speakers might lead to trouble (which was counter intuitive for me).

Anyone have thoughts on whether this is correct? Is there an ideal wattage ratio that gives big headroom? If you aren't driving speakers super load does it even matter?

Any advice would be much appreciated.
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Postby jenkins » Thu May 15, 2008 12:48 am

Are you sure that isn't backwards?
I think it should be twice the speaker size for the amps rating.
I have a mcintosh mc2120 (120 watts) and I push 250 watt speaker cabs with it. Just the 120 watts on 2 channels gives shitloads of headroom. It is realy hard to get the 250w speakers to break up using a 120w amp. I would think If I had 60w speakers it would sound like crap, but maybe im wrong. It should give you less headroom to have a speaker half the size of the rated amp.
If you have the money definetly go with mcintosh. My mc2120 definetly gives me more clean headroom than my Crest 3150 which is 375 watts per channel. Sounds so much sweeter too. I can really crank it up without getting the feeling that Im about to bleed from my ears. once I finally got the mac it was like a whole nother world. No power amp that i'ver heard come's close as far as sound quality.
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Postby bcresci » Thu May 15, 2008 4:09 am

Thanks. What you said is what I would have guessed, but the write-up I found seemed to indicate something different.
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Postby playingdead » Thu May 15, 2008 6:11 am

If you're using a JBL E120, it will blow before it breaks up sonically, or your ears will break up. The E120 is all about clean uncolored sound.

Other speakers -- Celestions, etc. -- are valued because they break up and sound dirty at low wattage, this gives certain amps their tone characteristics.

There's a big difference between tube power and solid state power, as well. My 85 watt Twin Reverb tube section was much, much louder than a 200 watt solid state power amp driving my E120s.

For a solid state power amp, I would get a bigger one and, obviously, not turn it up too high.

For a tube power amp, where you are looking to get a tube-saturated sound with the attendant compression and overdrive, smaller is better ... which is why lots of guitar tube power amps can be run at half power or full power, so you don't split your ear drums trying to get the tone you want. A Fender Deluxe Reverb is 22 watts ... and to get it to sound great, you turn it up to 10. Try that with a Twin Reverb and you'll damage your hearing.

Note that the McIntosh tube amps are not guitar power amps, they are audio power amps and they are not designed to add distortion to the sound. Jerry used a solid state amp so it would not color the guitar sound, he wanted headroom -- read lots of clean power with zero distortion.

A 1000 watt power amp -- Weir's Godzilla, for example -- will give you miles of headroom that you'll never use.
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Postby Jon S. » Thu May 15, 2008 7:38 am

I agree.

As a practical matter, zero distortion - even zero audible distortion to a discerning ear - is near if not actually impossible plus a truly completely undistorted guitar tone normally sounds like crap. To test this, plug your guitar into a pedal steel amp like a Fender Pedal Steel King - I'll bet you you don't like what you hear at all.

For leads, myself, I like to take a relatively clean amp with decent headroom for the application at hand (this can be, e.g., a 40W 1X12 combo if it's a small jam room or club, the amp need not be monstrous) and add a touch of compression instead of the usual overdrive/distortion that most lead players use.

I'll end by admitting - hope this doesn't get me kicked out of the forum - that of the literally hundreds of different recordings of Jerry I've heard over the years, the tone varies considerably and there plenty of examples I would not want to emulate. The above recipe just works for me. YMMV.
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Postby Tennessee Jedi » Thu May 15, 2008 7:49 am

Well ,if someone recorded you as you learned how to to play you might have some tone issues as well.
:smile:
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Postby jenkins » Fri May 30, 2008 9:42 am

Jon s please point me in the direction of these recordings you are talking about of his tone that you would not want to emulate.

His tone did vary over the years but overall his sound was very consisten. it was that same signatur jerry tone. It really wasn't untilt he last few years that I heard anyhting that I did't think was awesome sounding.
There are isolated songs, parts of songs where jerry's tone isn't right. But I can not think of 1 show that I've ever heard where his guitar doesn't sound right for the whole show.


Please show us some examples of jerry's guitar sounding like crap for more than a song or two.

To me there are way more examples of where jerry's playing is not on point, not his gear.
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Postby ELPManticore » Fri May 30, 2008 10:49 am

If you're like me and are 6'4", stay out of basements and older houses with low ceilings. Outside is best. Watch those doorjambs too. :D


Just letting the inner pankster out to play today.
-Peace,

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Postby Jon S. » Sat May 31, 2008 4:35 am

ELPManticore wrote:If you're like me and are 6'4", stay out of basements and older houses with low ceilings. Outside is best. Watch those doorjambs too. :D

Tell me about it (I'm 6'5")! FWIW, here's my jam space. The ceiling are a luxurious 6'8" or so - no problem there if I play wearing my slippers and don't jump too much ;) - but where the I-bar goes along the middle of the ceiling (you can see part of it to the top right) it's much lower and if I'm not careful it's BUMP!

Image

BTW, speaking of my slippers (and Tele!), that Jerry, he was constantly borrowing them. :p

Image
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