Heavy Duty Bass with minimal distortion

[Gilbert]

Images like those prove I am not at all crazy with a pair of Velodyne DD-18s.

I am not sure, even here two DD-18's is alot of subbage !

Subbage, I love it.

Laager, your already well beyond crazy with dual 18" velodynes. What's the point, you trying to scare away underground moles by vibrating the earth?

I would love to listen to a pair of Jubilee's, and might even consider owning a pair if they weren't so godawful ugly. I'm certain they sound devine, but dammmmm fugly speakers..... sorry coytee.

[dtel]

Subbage, I think DrWho who came up with that, I stole it from him. [] It sounded right when talking about TWO 18" Velodyne subs in one room.

I don't doubt the 18" velodynes would go deeper, and sound different, two different designed subs. I would think that Klipsch sub is made for a much bigger room "theater" and is not trying to go extremely low.

I have never heard the velodynes, only the 684's in a normal size room and it was a single, and was impressive.

You can somewhat see from the numbers what it was designed for.

Max Continuous Output 130 DB at 34Hz or lower [:|]

KPT-684

FREQUENCY RESPONSE	34Hz - 1.8kHz(+-)4dB (-10dB @ 25Hz)
POWER HANDLING	600 watts (65V) per woofer 25-250Hz
recommended amplifier power	600 watts continuous / 2400 watts peak per woofer
SENSITIVITY	105dB @ 1 watt/1 meter
NOMINAL IMPEDANCE	8 ohms, 3.6 ohms minimum at 22Hz
MAX CONTINUOUS OUTPUT	130dB
DIMENSIONS	48.5" (123.2cm) x 24" (60.9cm) x 31" (78.7cm)
WEIGHT	190 lbs. (86.2kg)

[hobie1dog]

Falling off that fast at 25hz wouldn't work too well on one of my pipe organ recordings, that has a sustained 20 second duration 8hz note, or the many recordings that have a 32 ft pipe frequency of 16hz (tons of them around in the pipe organ world).

a bass guitar has a bottom note of 40 hz and a piano of 27hz, and a Velodyne is -4db at 34hz? Doesn't really qualify itself as a true subwoofer does it? And they cost how much?[:$]

and it would have very low output for Home Theatre use...submarine depth charges, T-Rex dinosaur stomps at 14hz

Don't start flaming me right away. Today, I'm only playing the ever popular internet numbers game that everyone uses on each other.[]

[dtel]

a bass guitar has a bottom note of 40 hz and a piano of 27hz, and a Velodyne is -4db at 34hz? Doesn't really qualify itself as a true subwoofer does it? And they cost how much?

If you were talking about the spec's in my post that is for the Klipsch KPT- 684, I don't know the spec's on the Velodyne's ?

[hobie1dog]

OOPS[8-)] Sorry, came into this late in the game,yep, I do see the model number right above the specs....silly me.[:S]

I thought those specs were for the Velodyne as that was what the last 10 posts were talking about.

So the Klipsch are very efficient, but lacking in low frequency extension....got it.

[laager]

The Velodyne is specced at +/-3dB @ 14Hz so with two it could be around 13Hz for the -3dB point. I think that's ground plane. That said, with the KPT-684 the quoted specs need adjustment for comparison as they are for 3m, half space anechoic. Room gain and a pair could get them digging a lot deeper before being overtaken on the deep bottom end.

[hobie1dog]

true, a pair of 684 should do well into the low 20's with room gain....maybe 4 of them is for serious bass...like this guy.

[dtel]

When you see an 18" out in the open they look huge !

[hobie1dog]

" When you see an 18" out in the open they look huge ! "

That's what she said.

[dtel]

" When you see an 18" out in the open they look huge ! "

That's what she said.

Well I would hope so. [:S]

[twistedcrankcammer]

I feel confident that these 684's would crush the Gotham sub and the klipsch subs are much less expensive than the $11,000 JL Gotham

What about the KRELL sub that MSRP's for $28,000 and weighs almost 500 lbs? How do the others stackup against it?

Gilbert,

Hopefully,It won't take to long for me to find a third KPT-684 sub and buy it. We are talking simple physics here. After I get another KPT-684 and own two at the same time like Kevin, you go buy a 500 pound Krell, and bring it on over, and we'll see how it stacks up against two KPT-684s at 190 pounds each, and two HGS-18IIs at 105 pounds each, for a total of 590 pounds minus amps for the KPT-684s, and see how the Krell stacks up against six 18 inch drivers for output. As for the Jubilee being ugly, isn't that a case of the Ostrich calling the Pheasant ugly? Have you seen the Jubilees with the optional venered beuty pannel, or you could send a pair to Greg in Main, and he could veneer the whole thing, plus build veneered boxes for the 402 horns. Personally, I always found the sound to be the most important to myself, probably why I like the Jubilee over cute little Bose 901s!!! []

Roger

[twistedcrankcammer]

true, a pair of 684 should do well into the low 20's with room gain....maybe 4 of them is for serious bass...like this guy.

That looks like six Electro Voice EV30-W woofers to me.

Roger

[hobie1dog]

" What about the KRELL sub that MSRP's for $28,000 and weighs almost 500 lbs? How do the others stackup against it?"

The Krell uses a standard large overhung motored woofer, I believe it was made by TC Sounds and that is their standard design that they have been using in the car audio business for years. It has long throw, but has very high BL and requires alot of power. Once again, you cannot mess with the laws of physics, as the far ends of the sub design world, is the Sunfire,(very small box, long throw woofer, extremely inefficient) or the Klipsch ( large box, short throw woofers, extremely efficient)...each one of them will displace X amount of cubic inches of air, with different sound quality as well. The trouble with the PA designs is that they have problems in the low frequency bands....send them a 20hz note and they tend to bark and bottom out as the drivers have very little throw (Xmax)...as in 6-9 mm of travel, so you have to have lots of the woofers so that each woofer doesn't have to work very hard and reach it's limit. The long throw ( 30-50mm) woofers will handle frequencies down in to the single digits and still pump out craploads of bass, but require huge amounts of power(which is cheap today) to do so, and usually have alot higher distortion to go with it.( which many people simply cannot hear anyway).

Anyway, what we all need is this speaker setup and then we can all quit wasting our lives away on the Internet and just listen to our music.

[dtel]

I would say that guy is compleatly SOLD on the Line-Array design !

[michael hurd]

" What about the KRELL sub that MSRP's for $28,000 and weighs almost 500 lbs? How do the others stackup against it?"

The Krell uses a standard large overhung motored woofer, I believe it was made by TC Sounds and that is their standard design that they have been using in the car audio business for years. It has long throw, but has very high BL and requires alot of power.

The Krell MRS is extremely overpriced, it uses a derivitive of the TC1000 driver, 28 mm throw. It is an overhung design, but is still more linear than other commercial offerings. Shorting rings in the motor keep flux currents low. Take those two 15" drivers, drop them in 10-12 cuft ported enclosures tuned to around 16 hz, apply 700 watts each and you will have 10x the sub.

[twistedcrankcammer]

" What about the KRELL sub that MSRP's for $28,000 and weighs almost 500 lbs? How do the others stackup against it?"

The Krell uses a standard large overhung motored woofer, I believe it was made by TC Sounds and that is their standard design that they have been using in the car audio business for years. It has long throw, but has very high BL and requires alot of power. Once again, you cannot mess with the laws of physics, as the far ends of the sub design world, is the Sunfire,(very small box, long throw woofer, extremely inefficient) or the Klipsch ( large box, short throw woofers, extremely efficient)...each one of them will displace X amount of cubic inches of air, with different sound quality as well. The trouble with the PA designs is that they have problems in the low frequency bands....send them a 20hz note and they tend to bark and bottom out as the drivers have very little throw (Xmax)...as in 6-9 mm of travel, so you have to have lots of the woofers so that each woofer doesn't have to work very hard and reach it's limit. The long throw ( 30-50mm) woofers will handle frequencies down in to the single digits and still pump out craploads of bass, but require huge amounts of power(which is cheap today) to do so, and usually have alot higher distortion to go with it.( which many people simply cannot hear anyway).

Anyway, what we all need is this speaker setup and then we can all quit wasting our lives away on the Internet and just listen to our music.

I agree with what you say about the PA Woofers vs the long throw design, hence that I own a Klipsch KPT-684, have owned two so far, one pictured on the right in Kevins Man Cave, and I also own two Velodyne HGS-18IIs, and I want to buy another Klipsch KPT-684, so that I have two of them, and two plus my two Velodynes. The Klipsch KPT-684 plays flat down to 35Hz, Velodyne DD-18 will play flat to 13Hz, My HGS-18IIs play flat down to 15Hz. If they have a pipe organ that plays an 8Hz note, you could not hear it anyway. I have competition Bass CDs with both sustained frequency notes and sweep notes that go clear to 0Hz, and have demonstrated true Sub-Sonic Bass to many people. Below 20 Hz, you should be able to feel your seat vibrate like h@ll, but you should not hear any audible sound other than windows rattling, or crap bouncing on shelves. If you have any other noise coming from your speakers on such a competition disc, you have a distortion problem. As far as "hearing" an 8Hz pipe organ, anything one is "hearing" is NOT 8Hz. PERIOD!!

Oh, and those Electro Voice EV-30Ws, while being Extremely efficient and having low excusion will play flat down to 20Hz.

Roger

Roger

[hobie1dog]

If they have a pipe organ that plays an 8Hz note, you could not hear it anyway. I have competition Bass CDs with both sustained frequency notes and sweep notes that go clear to 0Hz, and have demonstrated true Sub-Sonic Bass to many people. Below 20 Hz, you should be able to feel your seat vibrate like h@ll, but you should not hear any audible sound other than windows rattling, or crap bouncing on shelves. If you have any other noise coming from your speakers on such a competition disc, you have a distortion problem. As far as "hearing" an 8Hz pipe organ, anything one is "hearing" is NOT 8Hz. PERIOD!!

Roger

I guess that my 7 years of building custom pipe organs was just an "illusion" as they say everything here on Earth is an illusion in the world of Metaphysics. Funny, when you are in a pipe organ chamber and they go down the pedalboard and reach the low C on a 32ft pipe (which is 16hz), you are not supposed to "hear" the note because you can only hear down to 20hz right??????? Well, you can hear the note, because it is also made up of overtones at 32 and 64hz. But what the hell do I know? I guess when you have made the statement PERIOD in capital letters, the discussion has ended and all the rest of us Morons know NOTHING.[]

I have once again wasted the valuable remaining minutes of my life on the web, instead of being out on the water where I should be.[]

Continue on Gentlemen

[twistedcrankcammer]

If they have a pipe organ that plays an 8Hz note, you could not hear it anyway. I have competition Bass CDs with both sustained frequency notes and sweep notes that go clear to 0Hz, and have demonstrated true Sub-Sonic Bass to many people. Below 20 Hz, you should be able to feel your seat vibrate like h@ll, but you should not hear any audible sound other than windows rattling, or crap bouncing on shelves. If you have any other noise coming from your speakers on such a competition disc, you have a distortion problem. As far as "hearing" an 8Hz pipe organ, anything one is "hearing" is NOT 8Hz. PERIOD!!

Roger

I guess that my 7 years of building custom pipe organs was just an "illusion" as they say everything here on Earth is an illusion in the world of Metaphysics. Funny, when you are in a pipe organ chamber and they go down the pedalboard and reach the low C on a 32ft pipe (which is 16hz), you are not supposed to "hear" the note because you can only hear down to 20hz right??????? Well, you can hear the note, because it is also made up of overtones at 32 and 64hz. But what the hell do I know? I guess when you have made the statement PERIOD in capital letters, the discussion has ended and all the rest of us Morons know NOTHING.

I have once again wasted the valuable remaining minutes of my life on the web, instead of being out on the water where I should be.

Continue on Gentlemen

Hmmm? You said it not me....fitting though! You said yourself, overtones! I will bet that you cannot hear a clean 16 Hz signal, let alone a sigle digit clean signal, anything else by definition would not be a pure signal, and hence distortion, and just think, it only took you 7 years to understand that, or do you?

Roger

[DrWho]

For musicality,
the KPT-684 kills my velodynes on Rock, for Home theatre on shot gun
blasts like Open Range, or explosions, or extremely low sythesized
stuff, the Velodynes still own the extremely low frequencies.

That's
a little surprising. I would have thought that although the sheer
output of the KPT-684s in the higher frequencies used for general rock
would be much higher than the HGS, the accuracy of the HGS would be
better due to the servo control. The ultra low frequency dominance of
the HGS is not surprising at all.

For what it's worth and
since I'm a geek about control systems, the servo approach is going to
improve the low frequency behavior more than the high frequency
behavior. This is because any natural distortion requires the ability of
the driver to slew faster in order to correct itself quickly enough. At
the very minimum, you need at least 10x the intended bandwidth....so
for a clean 100Hz, you need a driver that will get up to 1kHz cleanly.
That's a lot to be asking of an 18" driver. However, a 20Hz signal
"only" needs to be capable of 200Hz, which is easily acheived with an
18" driver.

Btw Kevin, that's some major subwoofage
you've got going on there...

[laager]

Hmmm? You said it not me....fitting though! You said yourself, overtones! I will bet that you cannot hear a clean 16 Hz signal, let alone a sigle digit clean signal, anything else by definition would not be a pure signal, and hence distortion, and just think, it only took you 7 years to understand that, or do you? Roger

Don't you have anything better to do than cruise the forums abusing people?