PA Audio System Discussion

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Jump to Latest
Iron-Wizard

Iron-Wizard

Member
Joined 2006
Eva said:
The lowest exhaust noise frequency that you can get from a 4-stroke 4-cylinder car engine is in the range of 40Hz at 1200 r.p.m. (do the math if you want). Double that value for 8-cylinder engines.

I sound like you should do some research by yourselves in order to gather some experience, because you are obviously mistaking 40Hz or higher tones as lower frequencies.
Click to expand...

I don't need another job, I never said anything about a domestic car engine now, DID I? LOL, that is not what i was talking about anyway, the infra sound from the road noise and tyres in the cabin, jet engines, tunnels, freeways all sources of infra sound.

Getting punching in the head feels like 20Hz at 160db, :devilr:
 
ShinOBIWAN

ShinOBIWAN

diyAudio Member
Joined 2004
Eva said:
The lowest exhaust noise frequency that you can get from a 4-stroke 4-cylinder car engine is in the range of 40Hz at 1200 r.p.m. (do the math if you want). Double that value for 8-cylinder engines.

I sound like you should do some research by yourselves in order to gather some experience, because you are obviously mistaking 40Hz or higher tones as lower frequencies.
Click to expand...

Ah good old Eva, putting your foot in your mouth once again.

Also check out Eat Static's BWorld album and the track 07 - Dionysiac.

Definitely some sub 20hz bass on the opening section. Its actually a ~20hz tone overlaid on top of one around 40hz. It woobles the entire room on a good system.
 
Eva

Eva

Member
Joined 2003
burnedfingers said:
First of all someone needs to show you what a signal generator is and how it works. Secondly you need to learn that the material
you preceve as being 20hz isn't. Lastly you need to get educated
in the world of sound reinforcement.

I really suggest listening to EVA ( a voice of reason here) because of the reality and fact being presented.

This thread really reminds me of the normal car stereo buffs that have themselves convenced that a 100hz bass note is actually 20hz.
Click to expand...

Do you imagine those arrogant newbies claiming to hear 20Hz tones in their music facing a 1/3 octave stereo graphic equalizer with 62 frequency sliders during some live performance? :D:D:D
 
ShinOBIWAN

ShinOBIWAN

diyAudio Member
Joined 2004
ShinOBIWAN said:


Ah good old Eva, putting your foot in your mouth once again.

Also check out Eat Static's BWorld album and the track 07 - Dionysiac.

Definitely some sub 20hz bass on the opening section. Its actually a ~20hz tone overlaid on top of one around 40hz. It woobles the entire room on a good system.
Click to expand...

20hz.JPG


I was mistaken, I've just done an RTA on the 'Dionysiac' track and there's actually strong content between 10hz and 20hz :)

On many systems you simply don't feel this but with a very good sub you can feel the room pulse.
 
J

JohnnyJ

Member
Joined 2005
Thanks for all the input so far, I think this thread went slightly off topic though! Just to make absolutely clear, this is for a home audio system.

I still need to get this sorted out.. I need subs than can produce 20hz @ 'decent' db [I'm not asking for 20hz @ 150db or something crazy, just DECENT :clown:] and sound quality, I don't want constant distortion when I'm listening to my every-day beats that go down to 20hz minus.

That JBL SRX728S set looks nice, but:
frequency rage = 27hz - 220hz
frequency response = 33hz - 220hz
^ not liking - I love everything else about that set but not the above.

Any other suggestions for subs?
Cheers :)
 
AJinFLA

AJinFLA

Banned
Joined 2005
Johnny,

that's the JBL SRX728 anechoic response, NOT in room reponse, which is much more difficult to predict. Plus that's the drivers response in that particular cabinet (SRX728. You don't have to use that same tuning). Room gain will add significantly to the JBL's spec'd response. Exactly how TBD. As I said, a single Adire should give more (unequalized) output @ 15hz vs a single JBL (both tuned for max. low freq. bass output). But room modes (lowest) are difficult to model accurately because real rooms are lossy.
Check out the 15hz bass of this Tumult (15): http://www.htguide.com/forum/showthread.php4?t=19034
When/if the 18" Tumult materializes, I'm sure it will be a terrific, low distortion, huge xmax, low efficiency driver. For $650. Quite capable of 15hz output. The JBL 2268HPL is a formidable 18" low distortion, high xmax, high efficiency driver. Currently available. For $450. Three of them in the right cabinet(s), in a bedroom, with room gain, barring a major mode, will give you huge output @ 20hz and permanent hearing damage levels 30hz on up. VERY hip-hop friendly, chest compressing bass. Its your money.

cheers,

AJ
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Top Bottom