sunfire subs

ronaldo141 · January 2003

i was just checkin out the sunfire website and I saw that one of these bad boys has a 2300 watt amp! is this peak power or RMS? are these subs any good or just powerful?

goingganzo · January 2003

the reason they have so much power is caues they are so small and you need it to make the sub sound like a sub in a bigger box. it has alot of power and alot of eq aplyed to it. but i have herd they are not that good for the price.

Frank Z · January 2003

Gonzo,
You heard wrong! They are fantastic! I got mine for half price cuz I bought the store demo. I went into the store ready and willing to pay full price. But, just like all things audio, beauty is in the ear of the listener.

ronaldo141,
My MkII has a 2700watt amp, and it literally rocks the house!!

scottvamp · January 2003

They are very good sounding subs for the "size".
The reason they need so much power is the size and the they are sealed. They do ROCK!!!!

Tour2ma · January 2003

Ronaldo,
Seem to recall that 2700 is a peak power output rating. This would be consistent with Carver's past amps', ad and product naming practices. At Sunfire Bobs gotten near as complicated with his specs as he has his designs. RMS rating is likely in the range of 1000 to 1500 w. In any case its all the power youd want. For comparison the Velodyne HGSs all employ a 1250 w RMS/ 3000 w peak amp.

If you've never seen a True in action, do so. The drivers look more like bladders than they do the cones you see in traditional subs and woofers. The throw, i.e., the total distance the radiating surface travels, of the Sunfire Subs is something you have to see to believe (I want to say something like 4.5"; ½ out and ½ in). A 2 throw is more common in traditional subs. The longer throw and the employment of a 2nd driver, on the opposite side in their sites pics, are how the Trues get so much out of their 8 driver. What they lack in surface area to move air, they make up for in throw.

Frank,
You've apparently have a manual, am I right here on the 2700 w being peak?
When I auditioned the first generation model years ago, I think the dealer had showing off the throw more in mind than its sound. The speaker was literally dancing on a double layer of carpet, no nearer than 5' to any wall. This hurt the sound and left me less impressed than I expected to be.
What set up did you find best for yours and did you have to anchor it?

Dr. Spec · January 2003

Gonzo is correct, the Sunfire design uses huge power because it has a tiny enclosure and applies massive amounts of EQ against the natural roll-off to obtain a flat FR down low.

This is simply Hoffman's Iron Law at work. Sunfire cannot ignore the laws of physics.

Applying this level of power and EQ to a 10" driver doesn't come without drawbacks, though. THD is much higher at these power input and cone excursion levels. Bob Carver certainly knows this, but he also knows he has a viable niche in the market - the SPL and extension the Sunfire is capable of achieving is remarkable for its size.

Frank Z · January 2003

Doc,
The output is rated at 2700w RMS (peak, time limited). Frequency response is 18-100hz. Output levels are greater than 110db peak SPL from 18 to 80Hz The sub itself is 11"x11"x11" and weights 48lb!

Dr. Spec · January 2003

Originally posted by Frank Z
Doc,
The output is rated at 2700w RMS (peak, time limited). Frequency response is 18-100hz. Output levels are greater than 110db peak SPL from 18 to 80Hz The sub itself is 11"x11"x11" and weights 48lb!

Amazing. Carver really is a unique designer. That little bugger can really belt it out for its size!

Anyway, the terms RMS and peak are mutually exclusive. RMS is a fraction (.707) of the maximum voltage value generated by a continuous sine wave at whatever distortion level is being specified.

I would venture that you are referring to the power capable of being generated over a brief period of time (not a continuous sine wave) as calculated with the peak voltage readings into a given impedance load at a higher than usual distortion level.

I'm guessing something like:

2700 watts into a 4 ohm load as calculated using the peak voltage measured over 40 milliseconds at <5% THD from 10-200 Hz.

This type of power rating is usually about twice the continuous power rating as calculated with the RMS voltage into a given impedance load and THD.

I'm guessing something like:

1300 watts into a 4 ohm load as calculated with RMS voltage at <0.5% THD from 10-200 Hz.

Anyway you cut it, it's a monstrously powerful amp, which is needed for that kind of massive EQ curve.

goingganzo · January 2003

if you want a real small sub this sounds like the ticket. i was saying like bang for buck thing my velo can acheave 110 db but not 18 and up. my new sub if i ever get the drivers will be able t put out 124 db at 16 hz and that is for around 1000 bucks

in the thing where i said they were not that good. what i ment to say was i read a good deal of revews that said they were on the boomey side and not as clean.

everyoune has their cup of tea that is not mine and i hope i dident ofend you.

Dr. Spec · January 2003

Gonzo, I meant to tell you - your Velo almost certainly has a SS filter that kicks in around 18 Hz. You probably can't bypass it or adjust it, but it's there nonetheless. Almost all powered subs have them. That's why you can't get any decent SPL readings below 18 Hz.

If I set my SS filter to 20 Hz, it takes a 24 dB/octave nosedive starting at 19 Hz.

Frank Z · January 2003

No offense taken. The True Sub can be boomy, no doubt about it. But like all subs, location and proper set up can correct that problem.

Tour2ma · January 2003

Originally posted by Tour2ma
Seem to recall that 2700 is a peak power output rating... At Sunfire Bobs gotten near as complicated with his specs as he has his designs. RMS rating is likely in the range of 1000 to 1500 w...
... What they lack in surface area to move air, they make up for in throw.

Frank, What set up did you find best for yours and did you have to anchor it?

Doc,
Good to know my power estimate was close. Bob does muddy the waters with the way he's spec'ing now, i.e., combination of max peek-to-peek current output per channel and max. output volts RMS (I believe this is total for all channels).
Questions:
I've always thought of the bottom line on power requirement as the work you ask of a speaker, i.e., the amount of air that you want to move. Is this correct?
When you talk of the demands EQ circuitry adds, isn't the significant impact the added work you're asking for (vs. the inefficiency of the circuitry)? May be this is what you meant in your reply, but I want to be sure I'm on the same page as you

Frank,
What about your "True's" set up? Difficult? Require anchoring?

Frank Z · January 2003

You can add spikes if needed, but so far mine has stayed put. The house bounces around alot, but the sub stays put! Setup was easy, I use a Rat Shack meter and the internal test tones from my receiver. My Sunfire manual even lists the Capacitors to swap out in the Rat Shack meter to make it flat down to 20Hz. Pretty cool! Here's a pic for ya to compare sizes.

Tour2ma · January 2003

Whoaaaa there pardna...

Want to share this capacitor info???

Dr. Spec · January 2003

Originally posted by Tour2ma

When you talk of the demands EQ circuitry adds, isn't the significant impact the added work you're asking for (vs. the inefficiency of the circuitry)? May be this is what you meant in your reply, but I want to be sure I'm on the same page as you

A sub like the Sunfire might need upwards of 20 dB of EQ (on a slope inversely proportional to the natural roll-off) to achieve a flat FR down to 20 Hz. Adding that much EQ takes an immense amount of power, none of which increases the overall volume of the sub - it all goes to flattening the curve.

A sub with a huge enclosure and a naturally low tune point needs no EQ to achieve a flat FR. That's why a sub like Ron-P's ported Tempest can kick out upwards of 120 dB with a 250W Parts Express amp. All the power goes towards volume. Cone excursion is much less, VC temp is way lower, and THD is considerably lower. Sunfire's and their clones work their little asses off in comparison.

ronaldo141 · January 2003

so why not just use a bigger box and woofer? sounds like it would make things a lot easier. is it all done to get tighter bass ?

goingganzo · January 2003

dam but farnk has some sweet mains i would like to have them one day. and that is a cool color. and continuous is .634 i think of peak

Frank Z · January 2003

Here ya go. This info applies to the Radio Shack SPL meter model #33-2050 ONLY. This information comes directly from the Sunfire TrueSub MkII Owners Manual. No I have not tried it...yet.

"C1, C2, C3, C4: stock is 1uF Electrolytic.
Change to 10uF Electrolytic at 16v minimum

C7: stock is 10uF Electrolytic.
Change to 100uF Electrolytic at 16v minimum

C9: stock is 22uF Electrolytic.
Change to 100uF Electrolytic at 16v minimum

All other capacitors are left at stock values.Take great care to install the new capacitors withthe same polarity as those being replaced."

Dr. Spec · January 2003

Originally posted by ronaldo141
so why not just use a bigger box and woofer? sounds like it would make things a lot easier. is it all done to get tighter bass ?

No, it's done to make the sub easy to hide if you have a tough to please interior decorator. Tight bass has nothing to do with it. Invisibility with still decent SPL is Sunfire's claim to fame.

Dr. Spec · January 2003

Originally posted by goingganzo
dam but farnk has some sweet mains i would like to have them one day. and that is a cool color. and continuous is .634 i think of peak

The RMS value differs for different types of input configurations. For a sine wave (which is how amps are FTC rated for power), it is 0.707.

Dr. Spec · January 2003

Originally posted by Frank Z
Here ya go. This info applies to the Radio Shack SPL meter model #33-2050 ONLY. This information comes directly from the Sunfire TrueSub MkII Owners Manual. No I have not tried it...yet.

"C1, C2, C3, C4: stock is 1uF Electrolytic.
Change to 10uF Electrolytic at 16v minimum

C7: stock is 10uF Electrolytic.
Change to 100uF Electrolytic at 16v minimum

C9: stock is 22uF Electrolytic.
Change to 100uF Electrolytic at 16v minimum

All other capacitors are left at stock values.Take great care to install the new capacitors withthe same polarity as those being replaced."

Frank, that is some damn useful data - well appreciated. I'm storing this one on my hard drive.

goingganzo · January 2003

rms is .707 but average or continuous .634

Dr. Spec · January 2003

Originally posted by goingganzo
rms is .707 but average or continuous .634

Ya lost me, Gonzo. A sine wave is - by definition - continuous. Therefore, the power rating for a sine wave is continuous.

You can either take the peak voltage of the sine wave, or some fraction of it, to calculate your power, as long as you specify which.

But the FTC requires the RMS value of the voltage reading of the continuous sine wave to be used for calculating amp power ratings. And RMS is 0.707 x Peak Voltage.

I think what you are referring to is the AVERAGE value of a sine wave, which is 0.637 x Peak Voltage.

RMS and Average are both continuous by definition. RMS is slightly higher and this is what FTC requires.

Check this out:

http://www.electronics123.com/amazon/catalogue/permanent/watts.pdf

Doc

goingganzo · January 2003

yes that is what i was getting at. thanks. i tend to sometines mix up my lingo. just rember P=I*V and I=V/R

Tour2ma · January 2003

and... PV=nRT... (for you ChemE's out there)...

Gonzo,
Above is useful if you decide to install refrigeration in your new monster... besides tightening up its bass you can keep your beer cold and handy, but be careful opening it... will likely be shaken up a little...

Doc,
Keepin you a little busy keepin us all straight arent we? I think you finally got the principle through my thick head with your last replies, i.e., enclosure volume easing power requirement to go deep at constant SPL, but I still have to work on the physical translation a bit. Going to pull out Hoffmans again today just to confuse me again

And forgive, but I'm looking at my "smart-a$$" opening and suddenly wondering if there's something in the ideal gas law that could lead a couple of ChemE's to a new subwoofer design that could make them rich, i.e., can you use the IGL as a means of fooling an enclosure into thinking that it is bigger than it really is? :eek: Might have to throw the "z" in there somewhere, but WTH, I think I could still handle that...

Frank,
Thanks for reply. Like Doc, I have filed for reference. Did Sunfire address meter correction factors below 20 Hz with the mod in place?

Frank Z · January 2003

No, the data that I posted is all there was. Did you get my PM?

Tour2ma · January 2003

Frank,
Got two e-mails from you, but no message. I'll hit "reply" with a "whazup".

sunfire subs

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