Regarding Danley labs spec sheets

[osse]

Hello, reading on Mr. Danley's website about his woofers and looking at the spec sheets, quoting him "Referenced to 2.83v@1m ½space, measured as 28,3v @ 10m"

Does this mean that he did the measurements at 10 meters and the result is equal as the result given from 2.83v@1m?

[Bill Fitzmaurice]

Does this mean that he did the measurements at 10 meters and the result is equal as the result given from 2.83v@1m?

Yes.

[osse]

Holy moly... his shit seem effective. for example his 40 x 22.5 x 28.5 inch 152 lbs 1x15 tapped horn delivers 104 db at 40 hz! He doesn't state any Vd values, but the driver itself is capable of handling 1000 watt RMS value, so I bet it's rather powerful.

Bill, If I'm not wrong you've mentioned in some thread here that all that matters when comparing cabs is the sensitivity(correct me if I'm wrong here), but isn't it the relationship between sensitivity and power handling that tells the story about sheer spl?

I mean, a 10 inch in the tuba has almost the same sensitivity but only half the power handling compared to 3012LF which won't be told by the sensitivity chart?

Is danleys tapped horn designs as monstrous as they look at the charts? Have anyone compared them to Bf designs?

[Bill Fitzmaurice]

The Danley designs work well, but no better than ours. If you want to use 1,000 watt drivers in our cabs feel free to do so, if the specs are OK they'll work.

I mean, a 10 inch in the tuba has almost the same sensitivity but only half the power handling compared to 3012LF which won't be told by the sensitivity chart?

The only thing the charts tell you is what 2.83v will do. How many volts can be applied is the product of xmax.

[osse]

How come the SPL charts is so different then? for example, the Th 118, a 40 x 22.5 x 28.5 160 lbs box, giving 101 dB's at 30 hz and 105 dB's at 40 hz. compared to the T39 with approx the same cubicfeet volume(but lower weight) that's much more effective.

Is there anything I've missed?

I know you have to hear the cabs in particular to actually make a valid comparision. So the real-life comparision might be different.. or the SPL charts might be flawed

[Bill Fitzmaurice]

Is there anything I've missed?

Excursion. Tapped horns have somewhat better sensitivity at the lower end of their pass band. They obtain that sensitivity at the expense of excursion. That's why Danley uses 1kW and higher long xmax drivers, and that's why few can afford a TH118. There's no such thing as a free lunch.

[osse]

Is there anything I've missed?

Excursion. Tapped horns have somewhat better sensitivity at the lower end of their pass band. They obtain that sensitivity at the expense of excursion. That's why Danley uses 1kW and higher long xmax drivers, and that's why few can afford a TH118. There's no such thing as a free lunch.

Does this mean that the effect curve is logarythmic, the more power you put into it the "less" compared to linear(are there such?) or more linear designs?

That's what i really love with Bf designs... extremely effective.. I'm using a friggin 300 RMS watt/ 1khz amp and they deliver the goods very satisfying! my tops have even stronger amps in them

Thanks Bill!

[osse]

Sorry for draggin up an ancient thread, but I found these numbers over at diyaudio regarding SPL/wattage and got a bit curious:

Base line 90 db one watt.
1-2-4-8-16-32-64-128-256-512-1024-2048 watts
90-93-96-99-102-105-108-111-114-117-120 -123 in db

It translates how many db's you get... yeah yeah you know all this! but I wonder, does this apply to all cabs(flh, th, bass reflex, sealed) and drivers? up to the point of xmax?

are the only way to determine however a design is effective by the sensitivity chart, or will they react differently(better or worse, like power compression, distortion and heat buildup) to various voltage load too? or is this merely driver specific attributes?

Thanks!

[Bill Fitzmaurice]

does this apply to all cabs(flh, th, bass reflex, sealed) and drivers? up to the point of xmax?!

It would if there were no such things as mechanical and thermal power compression. But there are, and that's why calculated maximum SPL figures are a fantasy.

[osse]

does this apply to all cabs(flh, th, bass reflex, sealed) and drivers? up to the point of xmax?!

It would if there were no such things as mechanical and thermal power compression. But there are, and that's why calculated maximum SPL figures are a fantasy.

And the treshold for mechanical and thermal compression differs from driver to driver I suppose? Or do all/most designs(be it FLH, TH, reflex and so on) achieve the same SPL increase if the voltage input and impedance is the same(offcourse, up to the driver's xlim)?

Also, you said that the trade off from the increased sensitivity of the TH design is excursion, is this due to cabinet design to actually limit the excursion of the driver before the driver reaches it's mechanical xmax?

I guess what I want to know is if the danley TH designs drop in efficiency(compared to FLH's) whenever they are loaded with voltage... or they stay as effective/sensitive as their sensitivity charts!

Thanks Bill!

[Bill Fitzmaurice]

I guess what I want to know is if the danley TH designs drop in efficiency(compared to FLH's) whenever they are loaded with voltage... or they stay as effective/sensitive as their sensitivity charts!

No speaker will have a linear voltage to SPL relationship. THs are no different than any other design in that respect.