PK Sound

Re: PK Sound

Tim Duffin said:
I should further point out that no 18" sub currently manufactured meets or exceeds the capabilities of a JBL 2269. The Neo-Drive subs are no longer being manufactured, so you can cross that off your list of comebacks.

And yeah, the sub you found on the site is the wrong one...duh.
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Tim,

The sub on the PK site is the only one they manufacture for sale presently, for good reasons.

A bit of history:
Very few of us had ever heard as much LF as was produced by the Cerwin Vega L-48SE Sensurround subs for Earthquake in 1974, that movie (moving) experience brought subwoofers to the mainstream.

Eugene "Gene" Czerwinski (who passed away in 2010) sub designs influenced Tom Danley, who's Servodrive drivers in a similar "W" bin of a similar size to the L-48SE, but had even more output due to the increased driver excursion.
Later Servodrive horns of the same standard truck pack size of 45 x 45 x 22.5 increased the horn path length by using a spiral, rather than "W" path. Spiral horns have been used in amplified audio for nearly a century.
The availability of commercial high excursion drivers and the increasing cost of servo motors ended their dominance as the most powerful sub drive.

After Tom Danley had developed his Tapped Horns, which pack more LF output in to a smaller package, he provided plans for the LabHorn, very similar to the SDL BT7.

Although large horns are quite efficient, with the high excursion drivers and high power amplifiers available today, more SPL per cubic foot of truck space can be achieved with ported cabinets than horn loaded cabinets.

Technology marches on, the Lab 12 at 13mm Xmax (maximum linear excursion) was quite an achievement for a low cost driver around the turn of last century.
As a growing company, easy to see why PK would have started with an inexpensive, yet potent style of horn.

The JBL 2269, with 19 mm Xmax, also was quite potent in an era when 6-8 mm was considered high excursion.

Those drivers displacement have now been eclipsed by the likes of the neodymium magnet B&C 21SW115-8, a 21" driver, or the ferrite slab magnet TC Sounds LMS Ultra 5400 which has 33.66mm Xmax.

If JBL's 2269 is their most potent 18" driver, they have a lot of catch up to do, regardless of which continent their manufacturing and design work takes place.

Art
 
Re: PK Sound

Art Welter said:
Tim,

The sub on the PK site is the only one they manufacture for sale presently, for good reasons.

A bit of history:
Very few of us had ever heard as much LF as was produced by the Cerwin Vega L-48SE Sensurround subs for Earthquake in 1974, that movie (moving) experience brought subwoofers to the mainstream.

Eugene "Gene" Czerwinski (who passed away in 2010) sub designs influenced Tom Danley, who's Servodrive drivers in a similar "W" bin of a similar size to the L-48SE, but had even more output due to the increased driver excursion.
Later Servodrive horns of the same standard truck pack size of 45 x 45 x 22.5 increased the horn path length by using a spiral, rather than "W" path. Spiral horns have been used in amplified audio for nearly a century.
The availability of commercial high excursion drivers and the increasing cost of servo motors ended their dominance as the most powerful sub drive.

After Tom Danley had developed his Tapped Horns, which pack more LF output in to a smaller package, he provided plans for the LabHorn, very similar to the SDL BT7.

Although large horns are quite efficient, with the high excursion drivers and high power amplifiers available today, more SPL per cubic foot of truck space can be achieved with ported cabinets than horn loaded cabinets.

Technology marches on, the Lab 12 at 13mm Xmax (maximum linear excursion) was quite an achievement for a low cost driver around the turn of last century.
As a growing company, easy to see why PK would have started with an inexpensive, yet potent style of horn.

The JBL 2269, with 19 mm Xmax, also was quite potent in an era when 6-8 mm was considered high excursion.

Those drivers displacement have now been eclipsed by the likes of the neodymium magnet B&C 21SW115-8, a 21" driver, or the ferrite slab magnet TC Sounds LMS Ultra 5400 which has 33.66mm Xmax.

If JBL's 2269 is their most potent 18" driver, they have a lot of catch up to do, regardless of which continent their manufacturing and design work takes place.

Art
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I own the best B&C 18 and the best Faital 18" woofer, both of them are less efficient than the high end JBL, regardless of what the spec sheet says. Unfortunately, I just found out that you cannot buy the 2269. It is for the line array boxes only, so nevermind.

But, here is an interesting development with regards to the original post: I am no longer doing a stage at the how weird street faire because someone is showcasing their Funktion 1 system and paying to bring it out. You decide what that says about Funktion 1.
 
Re: PK Sound

Tim Duffin said:
I own the best B&C 18 and the best Faital 18" woofer, both of them are less efficient than the high end JBL, regardless of what the spec sheet says. Unfortunately, I just found out that you cannot buy the 2269. It is for the line array boxes only, so nevermind.

But, here is an interesting development with regards to the original post: I am no longer doing a stage at the how weird street faire because someone is showcasing their Funktion 1 system and paying to bring it out. You decide what that says about Funktion 1.
Click to expand...


That they operate like most of the major manufacturers in the product placement category?

Nothing new under the sun, many here have had that happen. It sucks, but it is what it is. Looks like it was your turn.

Best regards,

John
 
Re: PK Sound

Tim Duffin said:
I own the best B&C 18 and the best Faital 18" woofer, both of them are less efficient than the high end JBL, regardless of what the spec sheet says. Unfortunately, I just found out that you cannot buy the 2269. It is for the line array boxes only, so nevermind.
Click to expand...

Tim,

Where have you found a spec sheet for the JBL driver? I presume we're talking about the 2269H, and I can't find information on it easily. Also, I'm curious what you consider B&C's best 18" woofer so I can use it as a comparison.
 
Re: PK Sound

Bennett Prescott said:
Tim,

Where have you found a spec sheet for the JBL driver? I presume we're talking about the 2269H, and I can't find information on it easily. Also, I'm curious what you consider B&C's best 18" woofer so I can use it as a comparison.
Click to expand...

I also have not seen an actual spec sheet on the JBL 2269H.
My previous comments were based on the 2009 TS parameters posted below.
It is now common knowledge that the posted 2268 "Xmax" specs were actually "Xlim" (Xmax is less than half of the misprint), but the 2269H specs may be correct.

If they are, not difficult to see that the "best" B&C can easily surpass the JBL 2269H.

But the "best" B&C 18" does not appear to come close to the TC Sounds LMS Ultra 5400 in terms of displacement.
 

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Re: PK Sound

Art Welter said:
I also have not seen an actual spec sheet on the JBL 2269H.
My previous comments were based on the 2009 TS parameters posted below.
Click to expand...

How does one convert their efficiency spec into dB?

The misprinted Xmech instead of Xmax is unfortunate, a coil length spec would resolve that but of course anyone who had actually done a driver comparison would figure out whether that spec was correct.
 
Re: PK Sound

Bennett Prescott said:
How does one convert their efficiency spec into dB?
Click to expand...
Efficiency "Eff" on the JBL T.S.specs is nominal reference efficiency in %, (half space acoustic load).

I think "Eff" is the ratio of acoustic watts to electrical watts, somewhere in the middle or average of of the speaker's response curve.

A speaker like the old D131 is super "efficient" at 8.4%, but largely at upper frequencies where it beams like a flashlight.
The lower in frequency the woofer goes, the less the nominal efficiency.

EV used to use nominal efficiency and what is now generally referred to as sensitivity (1 watt at one meter), the EVX-150A was rated at 4.32% and an average of 98 dB 100-800 Hz.
Obviously, either of those figures would be much lower if the rating was averaged from 30-100 Hz.

As always, comparing efficiency or sensitivity without seeing a frequency response and deciding the range of use to be averaged tells very little.
 
Re: PK Sound

Well, here is an example: Though not a true spec sheet.

http://www.jblpro.com/BackOffice/ProductAttachments/SSASB7118.0609.pdf

It says that the cone is capable of 89mm of excursion. Which, if true beats everything else out there because it is way more efficient at low freqs. The TC sounds product looks great on paper, but is so inefficient you will never get near its claimed excursion because it simply does not move.

I consider the Best B&C to be the: B&C Speakers

and the best faital to be: FaitalPRO | LF Loudspeakers | 18XL1600

Both of them are not as loud or efficient at low frequencies, in all circumstances I have tested.

BTW-- I don't consider testing subs at 3 watts and 1000Hz for 1 minute a valid test. I only want to know what the sub sounds like with 3x RMS for 8 hours playing 50hz and getting so hot you can't touch it.
 
Re: PK Sound

Tim Duffin said:
I only want to know what the sub sounds like with 3x RMS for 8 hours playing 50hz and getting so hot you can't touch it.
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In which case you simply dont have enough rig for the gig. If we are talking gig conditions.
If you talk testing, whats the purpose of that test?
And when JBL publish their power compression figure then we can talk. Till then ill stick with my 18sound drivers :-)
 
Re: PK Sound

Tim Duffin said:
BTW-- I don't consider testing subs at 3 watts and 1000Hz for 1 minute a valid test. I only want to know what the sub sounds like with 3x RMS for 8 hours playing 50hz and getting so hot you can't touch it.
Click to expand...

Fortunately the AES has published a power handling standard, and revised it recently, which is what we use for power testing.

P.S. I consider our best 18" subwoofer to be the 18SW115.
 
Re: PK Sound

Bennett Prescott said:
Fortunately the AES has published a power handling standard, and revised it recently, which is what we use for power testing.

P.S. I consider our best 18" subwoofer to be the 18SW115.
Click to expand...

The SW115 is a very stout 18". It seems to be probably about as good as there is available today period. In testing a sub I built with a 4 Ohm 18SW115 I inadvertently caused the bridged MA2400 driving it to shut down but the driver was making no complaints at all. It sounded the same at that level as 10db quieter, just a lot louder. B&C provides comprehensive specs on their products and they are trustworthy. JBL products I'm sure are perfectly good in many ways but if you are looking to use a driver for a particular application (building your own cabinets or putting replacement drivers in an existing cabinet) it gets tough to know whether a product will work well for you if you can't see the specs you need to model it. But clearly JBL's main emphasis is on selling complete loudspeaker systems, not raw drivers to DIY builders or other manufacturers for the most part.

That LMS5400 is a great driver for your home theater project for sure. Probably the best available for that application. But that low FS with a relatively small Vas and Mms that is nearly twice the number for the SW115 costs efficiency even with its strong motor. 8 db less efficient than something like the 18SW115. You would need a lot of extra amps and subs to match the output capability. If you want stupid deep LF extension to shake your room down while watching movies though, it is the one you want (assuming you've got $$$$ burning a hole).

Loren Jones

Reason for edit: added Mms comment
 
Re: PK Sound

Every time I see a Tim Duffin appearance I am immediately reminded of his first post on the old LAB, Dave Stevens era.
"Why do Macro-Tech suck?"

He set an all time low first impression mark, and has astonishingly managed to go down hill from there.
 
Re: PK Sound

Loren Jones said:
That LMS5400 is a great driver for your home theater project for sure. Probably the best available for that application. But that low FS with a relatively small Vas and Mms that is nearly twice the number for the SW115 costs efficiency even with its strong motor. 8 db less efficient than something like the 18SW115. You would need a lot of extra amps and subs to match the output capability.
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Loren,

Efficiency aside, the TC LMS 5400 18" at 33.66mm Xmax, 47.6 Xlim (95.2 mm peak to peak, that's 6.2 mm more than the JBL 2269H, Tim) has more than double the linear excursion than the BC 18SW115, so it's low frequency output potential is 6+ dB more than the 18SW115.

You do need far more power using the LMS 5400, but fewer subs to match the LF output capability of the BC 18SW115.

There is a trade off, probably around 50 Hz and above where the LMS 5400 would not handle enough power to keep up with the 18SW115's sensitivity.

You can't have everything in from one cone design, for most PA use the 18SW115 rules, but for musical genres that require the most output below 40 Hz, the the LMS 5400 wins.
 
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