Speakerplans.com Homepage
Forum Home Forum Home > Plans > HD 15 horn
  New Posts New Posts RSS Feed - Hd15 - Beyma 15LX60 loading
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

Hd15 - Beyma 15LX60 loading
 Post Reply Post Reply Page  12>
Author
Message
  Topic Search Topic Search  Topic Options Topic Options
norty303 View Drop Down
Old Croc
Old Croc
Avatar

Joined: 18 August 2004
Location: Eastbourne
Status: Offline
Points: 8800 		Post Options Post Options   Thanks (0) Thanks(0)   Quote norty303 Quote  Post ReplyReply Direct Link To This Post Topic: Hd15 - Beyma 15LX60 loading
    Posted: 02 August 2005 at 9:37am

Has anyone tried this or modelled it?

Just looking through the T/S parameters and it looks like they should be good however i'm probably missing some major point here.  The PD154 is considered to be a great driver in these and the LX60 looks better in a lot of areas.

PD154

 Fs   39 Hz 
 Xmax   6.5 mm 
 Revc   6.2 Ohms 
 Vd   5.78 x10-4 m3 
 Qts   0.205
 No   3.94%
 Qms   4.32
 Pmx   500 Watts 
 Qes   0.216
 Cms   133 µM/N 
 Vas   149 Litres 
 Mms   125 grams 
 Sd    890 sq cm 
 BL  

29.65 T/m 

 

Beyma 15LX60

 

Resonant Frequency, fs 35 Hz

D.C. Voice Coil Resistance, Re 5.5 ohms.

Mechanical Quality Factor, Qms 8.7

Electrical Quality Factor, Qes 0.36

Total Quality Factor, Qts 0.35

Equivalent Air Volume to Cms, Vas 215 l

Mechanical Compliance, Cms 175 µm/N

Mechanical Resistance, Rms 2.9 kg/s

Efficiency, ço (%) 2.3

Effective Surface Area, Sd (m2) 0.091 m2

Maximum Displacement, Xmax 9 mm.

Displacement Volume, Vd 820 cm.3

Voice Coil Inductance, Le @ 1kHz 1.2 mH
My laser stuff: Frikkin Lasers
Back to Top
ben influence View Drop Down
Registered User
Registered User
Avatar

Joined: 26 February 2004
Location: United Kingdom
Status: Offline
Points: 59 		Post Options Post Options   Thanks (0) Thanks(0)   Quote ben influence Quote  Post ReplyReply Direct Link To This Post Posted: 02 August 2005 at 5:27pm
shouldn't it have a low qts and high bl to work in a horn?

pd 154:
qts - 0.205
bl - 29.65

15LX60
qts - 0.35
bl - 20.35

       ?

Ben
Back to Top
norty303 View Drop Down
Old Croc
Old Croc
Avatar

Joined: 18 August 2004
Location: Eastbourne
Status: Offline
Points: 8800 		Post Options Post Options   Thanks (0) Thanks(0)   Quote norty303 Quote  Post ReplyReply Direct Link To This Post Posted: 02 August 2005 at 5:41pm
Yeah, but its not strictly a horn is it, that's why i'm curious, and the LX series are supposed to be good in BP boxes
My laser stuff: Frikkin Lasers
Back to Top
rastaman View Drop Down
Registered User
Registered User


Joined: 20 May 2005
Location: United States
Status: Offline
Points: 421 		Post Options Post Options   Thanks (0) Thanks(0)   Quote rastaman Quote  Post ReplyReply Direct Link To This Post Posted: 02 August 2005 at 5:56pm
Probably, but then there's the whole, it's not really a horn, it's a horn bandpass cab. Whats the rule a true horn has to be at least a quarter of the lowest wavelength it's trying to produce (path length from driver to mouth) I think.

Pulling stuff out the FAQ:
Originally posted by Rog Rog wrote:

With short folded horns, or bandpass horns like the HD15 the effect is even more pronounced. A short folded horn with horn length of around 85 cm and a mouth area of 3300 sq cm, so a horn with an 85 Hz cutoff (quarter space) will sound really hard with high EBP drivers in them. The PD 1850 will rip your head of in one of these bins, but lower EBP drivers (though not as low as the PD 186) will smooth the sound out and make it more listenable.

Originally posted by Rog Rog wrote:

Drivers like the PD 184 will work in a short folded horn because the cab is not really a horn. For the driver to be properly loaded by a horn means a horn length of over 5.5 feet, something none of the Turbo or Funktion bins have. When the horn is less than 5.5 feet long we have what I call a horn assisted design. Basically the horn just adds a bit of gain from around 80 to 150 Hz, the cab will produce notes above and below these frequencies, just at a lower volume. You want a driver with a low resonance a powerful motor system and good damping, the PD 184 has all of these. Most of my short horn designs will work down to 50 Hz because I design them to be sealed boxes first that just have a bit of extra gain and kick from the horn in the 80 to 150 Hz range. Below the horn cutoff most of these short horns will still produce a useful output down to the cutoff point of the sealed box


So it looks like there may be some middle ground, but the Beyman may not be in it. That said, the rule of thump was below 0.28 Qts for a 18" driver, but that may not hold for a 15" driver, you'd expect a higher Qts (I think).

The Kappa Pro 15 LF has a Qts of 0.31 and a BL of 20.36
Fane Colossus 15XB has a Qts of 0.32 and a BL of 37
The JBL E-140 has a Qts of 0.17 and I can't be bothered to calculate the BL, check the spec sheet here http://www.jblpro.com/pages/pub/components/eseries.pdf

Looks like the Beyma maybe just inside the ballpark for BL, but just outside it for Qts. Don't forget though driver specs are never absolute. Suck it and see when it's close I suppose.

It may even be with a bandpass horn whatever it actually is, the parameters required change, it's got a nice low resonance, and an average BL and below average Qts.
Back to Top
norty303 View Drop Down
Old Croc
Old Croc
Avatar

Joined: 18 August 2004
Location: Eastbourne
Status: Offline
Points: 8800 		Post Options Post Options   Thanks (0) Thanks(0)   Quote norty303 Quote  Post ReplyReply Direct Link To This Post Posted: 02 August 2005 at 6:04pm

Yeah, it was just a thought as i can get them cheap and PD are out of stock of PD154's and factory is off on hols until 23rd August......

...and i wanted them for a gig for the 12th but i'll make do with 4 until then as the dancefloor is only 4m x 6m but i wanted puke factor bass if needed.

Thanks for your time Rastaman 

My laser stuff: Frikkin Lasers
Back to Top
rastaman View Drop Down
Registered User
Registered User


Joined: 20 May 2005
Location: United States
Status: Offline
Points: 421 		Post Options Post Options   Thanks (0) Thanks(0)   Quote rastaman Quote  Post ReplyReply Direct Link To This Post Posted: 02 August 2005 at 6:13pm
Hey don't take my word for it, it's not like I've ever built them yet. Was just offering what info I have gleaned from this site and others.

What about the MaxPro drivers from Nightfire they usually have similar specs to the PD's you can probably find a useable 15" there, thats what I'm aiming for when I finally build some 1850's, they seem to be close to the PD line, at least the 18"'s do.


Edited by rastaman
Back to Top
norty303 View Drop Down
Old Croc
Old Croc
Avatar

Joined: 18 August 2004
Location: Eastbourne
Status: Offline
Points: 8800 		Post Options Post Options   Thanks (0) Thanks(0)   Quote norty303 Quote  Post ReplyReply Direct Link To This Post Posted: 02 August 2005 at 6:51pm
Nah, i'm just being stupid really, i'd like to keep them all the same loading and i do love the PD's 
My laser stuff: Frikkin Lasers
Back to Top
soundgodwannabe View Drop Down
Registered User
Registered User
Avatar

Joined: 22 January 2005
Location: United States
Status: Offline
Points: 89 		Post Options Post Options   Thanks (0) Thanks(0)   Quote soundgodwannabe Quote  Post ReplyReply Direct Link To This Post Posted: 02 August 2005 at 7:49pm
Is it just me? Or is everyone trying to build speakers of their own, trying to do it cheaper rather than better? Almost every subject has got one or more members trying to build these designs with cheaper speakers than what the plans call for (myself included). Is there not someone out there that is building better speakers rather than cheaper speakers? I had to ask myself this question. Do I want cheap speakers (which I have bought and have blown). Or will I take pride in building the speakers in these plans. I am with the understanding that if you build these plans with the recommended speakers that are given that you will not only have great speakers, but you will have great speakers you will be proud to say "Yeah, I built these". This is just my opinion and my soapbox time. If I have offended anyone, it was not my intention. I have spent hours upon hours trying to find cheap woofers for the plans. The time I spent looking for cheaper speakers I could have used building them.
Back to Top
Dom View Drop Down
Old Croc
Old Croc


Joined: 25 February 2004
Location: United Kingdom
Status: Offline
Points: 1700 		Post Options Post Options   Thanks (0) Thanks(0)   Quote Dom Quote  Post ReplyReply Direct Link To This Post Posted: 02 August 2005 at 8:19pm

Originally posted by soundgodwannabe soundgodwannabe wrote:

Is it just me? Or is everyone trying to build speakers of their own, trying to do it cheaper rather than better?

Well said... 

The way I see it is by building my own cabs, I can spend my money on components...  Why people insist on taking great designs and sticking the cheapest possible drivers in them is beyond me...   

"It sounded like a million fire engines chasing ten million ambulances through a war zone and it was played at a volume that made the empty chair beside me bleed."
Back to Top
norty303 View Drop Down
Old Croc
Old Croc
Avatar

Joined: 18 August 2004
Location: Eastbourne
Status: Offline
Points: 8800 		Post Options Post Options   Thanks (0) Thanks(0)   Quote norty303 Quote  Post ReplyReply Direct Link To This Post Posted: 03 August 2005 at 4:20am

Hey, when i said cheap, they're still a £100 driver and a good one at that.

Just perhaps not the most suited to the box which is why i asked.

And if you look, i'm asking because of lack of availability rather than price - i've got no problem sticking my hand in my pocket (deep though they are!)
My laser stuff: Frikkin Lasers
Back to Top
rastaman View Drop Down
Registered User
Registered User


Joined: 20 May 2005
Location: United States
Status: Offline
Points: 421 		Post Options Post Options   Thanks (0) Thanks(0)   Quote rastaman Quote  Post ReplyReply Direct Link To This Post Posted: 03 August 2005 at 9:46am
Originally posted by soundgodwannabe soundgodwannabe wrote:

I am with the understanding that if you build these plans with the recommended speakers that are given that you will not only have great speakers, but you will have great speakers you will be proud to say "Yeah, I built these".

Just curious, but you're in the US too, where PD drivers are very hard to come by, almost all the Speakerplan designs have a PD driver as their first choice, so what do you use instead? Or do you import PD drivers?


Edited by rastaman
Back to Top
Dom View Drop Down
Old Croc
Old Croc


Joined: 25 February 2004
Location: United Kingdom
Status: Offline
Points: 1700 		Post Options Post Options   Thanks (0) Thanks(0)   Quote Dom Quote  Post ReplyReply Direct Link To This Post Posted: 03 August 2005 at 3:32pm

Originally posted by norty303 norty303 wrote:

i've got no problem sticking my hand in my pocket (deep though they are!)

Lucky you have long arms then...
"It sounded like a million fire engines chasing ten million ambulances through a war zone and it was played at a volume that made the empty chair beside me bleed."
Back to Top
 Post Reply Post Reply Page  12>

Forum Jump Forum Permissions View Drop Down

Forum Software by Web Wiz Forums® version 12.08
Copyright ©2001-2026 Web Wiz Ltd.