Cab sensitivity . . .

[Vandy]

Hi gang . . .
Search hasn't helped, blah, blah, blah (could be operator error)
Cab sensitivity question/clarification, please . . .
What is the interpretation of the following "differences":
Bergantino's HD410
• Sensitivity: 104db @ 2.83v /1meter
• Impedance: 4 ohms
• Power handling – 800 watts
• Frequency response: 44hz-15khz
Hartke's HyDrive 410
• Sensitivity: 99 dB @ 1 W/1 m (meter?)
• Impedance: 8 ohms
• Power Handling: 1000 watts
• Frequency Response: 30 Hz to 17 kHz

[rpsands]

Both of those are shenanigans.

The HD410's specs require a single 10" woofer with 96db sensitivity and the ability to be -10db by 44hz at best. Impossible. That is just barely achievable with a 12" woofer. If the claim is in reality -3db @ 44hz, it's even more impossible.

The HyDrive requires a 10" woofer that's 93db and -10db @ 30hz, also impossible.

The Berg is probably closer to reality but 100db is probably a more realistic number.

edit: Ohh, I see. I think there might be something weird going on with the Berg--if they're measuring 2.83V @ 4 ohms, that's a bit different than how woofers are normally measured. Normally it's 2.83v @ 8 ohms. So you can interpret their "8 ohm equivalent" sensitivity as closer to 101db...which is possible, theoretically, at the -10db number. Means 95db for a single woofer which is vaguely possible depending on the box size.

[kraigo]

I defer to RPSands. One thing, the four ohm Berg would gain 3dB sensitivity by virtue of the impedance (vs an identical eight ohm cab). Correct me if I'm wrong.

KO

[Vandy]

There must be a unit conversion that you guys (thanks for answering, BTW) can understand, but I'm allowing myself to be confused.
Why does one manufacturer use "volts/distance" while the other uses "watts/distance" as measures of "sensitivity"?
watts = volts X amps, right?
P.S. side issue > Hartke's frequency range is awesome (but we're mostly aware of harmonic generation, right?)

[Arjank]

2.83v@8ohm = 1 watt
2.83v@4ohm = 2 watts

And, remember, double the power(watts in this case) is a 3dB gain.

[lbwdog]

It's still a meaningless spec unless the measured frequency range is specified.

[billfitzmaurice]

Originally Posted by Vandy

Hi gang . . .
Search hasn't helped, blah, blah, blah (could be operator error)
Cab sensitivity question/clarification, please . . .
What is the interpretation of the following "differences":
Bergantino's HD410...Hartke's HyDrive 410

Without measured response charts to back up and quantify their claims none of those specs are of any value.

Why does one manufacturer use "volts/distance" while the other uses "watts/distance" as measures of "sensitivity"?

Using volts gives a direct comparison of how two speakers compare with the same amp at the same setting. It's left to the user to be knowledgeable enough to realize the difference between voltage sensitivity and power sensitivity.

[Marty Forrer]

Originally Posted by kraigo

I defer to RPSands. One thing, the four ohm Berg would gain 3dB sensitivity by virtue of the impedance (vs an identical eight ohm cab). Correct me if I'm wrong.

KO

The only thing a 4 ohm load does is allow the power amp to pump more watts. It's not gaining sensitivity, it's gaining more power from the amp, which in this case will manifest itself as more volume.

[Arjank]

Originally Posted by Marty Forrer

The only thing a 4 ohm load does is allow the power amp to pump more watts. It's not gaining sensitivity, it's gaining more power from the amp, which in this case will manifest itself as more volume.

The manufacturer does nothing wrong when he puts these numbers on paper (2.83v@4ohms), it's very beneficial for them since it "looks" like the cabinet has a higher sensitivity and this is what most people see first. And high spl is what sells.... Lots of powerhandling sells too.....

[BogeyBass]

A Eminence Delta10 has a TS calculated 96dB
in a decent alignment will have a 97dB peak.

so 4 of those will get you close to 103/104dB
Dont know if they are using Deltas, but they do have the same greyish cone.

Bergantino does not say the 44hz is the -3dB
it just says frequency response.
that is a common thing for skewed manufacture speaker ratings, the bergantino can go to 44hz, but yah way down at maybe 85dB.

I cant verify what speakers are in there but it is possible to have a 104 dB 4x10.

[rpsands]

Originally Posted by BogeyBass

A Eminence Delta10 has a TS calculated 96dB
in a decent alignment will have a 97dB peak.

so 4 of those will get you close to 103/104dB
Dont know if they are using Deltas, but they do have the same greyish cone.

Bergantino does not say the 44hz is the -3dB
it just says frequency response.
that is a common thing for skewed manufacture speaker ratings, the bergantino can go to 44hz, but yah way down at maybe 85dB.

I cant verify what speakers are in there but it is possible to have a 104 dB 4x10.

96db 10s in a 4x10 is 102db, not 104db.

If you model the delta 10a a little bit you'll see that it's really near impossible to get it to even -10db @ 44hz without slaughtering your response below 100hz.

At least, that's my recollection - the Fs of the Delta is just too high to get reasonable performance down there. Once you start lowering the Fs I believe the sensitivity will drop significantly.

[kraigo]

Originally Posted by Marty Forrer

The only thing a 4 ohm load does is allow the power amp to pump more watts. It's not gaining sensitivity, it's gaining more power from the amp, which in this case will manifest itself as more volume.

Correction appreciated. To rephrase, "sensitivity in the specs".

KO

[Mr. Foxen]

Originally Posted by Marty Forrer

The only thing a 4 ohm load does is allow the power amp to pump more watts. It's not gaining sensitivity, it's gaining more power from the amp, which in this case will manifest itself as more volume.

It gains voltage sensitivity, which along with the 'watts mean nothing, its all about voltage swing' sort of makes its own sense to use.

[AstroSonic]

Originally Posted by Vandy

Hi gang . . .
Search hasn't helped, blah, blah, blah (could be operator error)
Cab sensitivity question/clarification, please . . .
What is the interpretation of the following "differences":
Bergantino's HD410
• Sensitivity: 104db @ 2.83v /1meter
• Impedance: 4 ohms
• Power handling – 800 watts
• Frequency response: 44hz-15khz
Hartke's HyDrive 410
• Sensitivity: 99 dB @ 1 W/1 m (meter?)
• Impedance: 8 ohms
• Power Handling: 1000 watts
• Frequency Response: 30 Hz to 17 kHz

First off, with the exception of weight and size (can I lift it and will it fit into my vehicle) specs are of little use for determining which cab is 'best' or which one you will like the best. However, nominal impedance can be useful in choosing a cab that will pull the most power from your amp. Most ss amps deliver substantially more power into 4 ohms vs 8 ohms.

The sensitivity specs can be used with (much) caution. Sensitivity is the spl directly in front of the speaker, at a distance of 1 meter, at a specified power level - usually 1 watt. In this case Hartke has specified a 1w drive level into a nominal 8 ohms, while Bergantino has specified the drive level as 2.83v. The knowledgable GAS-crazed bass player will at once recognize that 2.83 volts is the same as 1 w because power can be calculated a volts squared divided by the impedance. 2.83 squared equals 8. So a 2.83 volt drive level into 8 ohms is a 1w drive level. But the Bergantino cab is 4 ohms, so the spl for their cab was measured with a 2w drive level (8/4). If it had been driven by 1w, the spl would have been 3 db less. If both cabs were measured with a 1w drive level then the Hartke would produce 99 db (at 1m) and the Bergantino 101 db (at 1m). Interesting, but of little use for choosing a cab.

Frequency response range specs. such as '40-12,000 hz' are of little use without range of variation (like +/- 3db from 40-10,000Hz). Response generally declines at the high and low ends. So... how many db down is the 40 Hz relative to the average midrange level? The most common specs for deep bass are for the frequency where the response is down by 3db or 10 db. So, does the Hartke cab have deeper bass than the Bergantino, as the specs imply? It's impossible to tell from those specs. The best way to learn about the sound of a cab is to play through it, using your instrument, cable and head.

Regards,

Bob

[rpsands]

For the record on the Delta 10--

tuning it low enough to get -10db @ 44hz means you're -6db by 60hz and -3.5db @ 100hz. in other words, totally useless for electric bass.

[Arjank]

Originally Posted by rpsands

For the record on the Delta 10--

tuning it low enough to get -10db @ 44hz means you're -6db by 60hz and -3.5db @ 100hz. in other words, totally useless for electric bass.

By mistake I once ordered a pair of these delta 10's. Indeed useless for bassguitar, even the mid/bass sounded way to honky. And this driver also farts out wayyyyyy to fast.

[rpsands]

Originally Posted by Arjank

By mistake I once ordered a pair of these delta 10's. Indeed useless for bassguitar, even the mid/bass sounded way to honky. And this driver also farts out wayyyyyy to fast.

yep, which goes to the point that a 96db 10" woofer that's seriously useful for bass is pretty much not in the cards right now. So claims of 102db sensitivity and such are mostly misleading.

[will33]

Ya, for bass, the delta10 = fartbox. They're best used for vocals. I built a pair of little monitor wedges with 1 delta10 and 2 piezo's in each, they work great there. Their thermal rating lets you blast them if you need to although dispersion and clarity is such I never do. Plenty left in the tank although our stage volume is pretty well controlled.