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[Art Welter]

If I were to decide to swap drivers with the type ports the Tls have,I would need to just add a flat piece of 3/4 ply to extend the existing peice that sits accross the whole three port area??By three ports I mean all three sections were the two divider peices are that go all the way back?

I couldn't find that eighteen sound driver that was in the link Peter Morris left no one seems to stock it when I google searched it.Upon searching I found some old topics on TL505s were it was mentioned the RCF L18P300 and B & C 18TBX100(this one had more Xmax) how would I know how much port extension to install If I were to drop the dime for one of these pairs?
Also would a JBL 2241 or 2245 work in these boxes?? cause a freind of mine has a few layin in his garage.He says they need 8cu ft,the TLs are 7.1cu ft.

Extending the port by simply adding a piece of 3/4 ply lowers tuning, as mentioned in reply #16.
The difference between 7.1 and 8 cubic feet is not much.

Any speaker will "work" in the box, the speaker's VAS (and other TS parameters) determines the ideal box size, but to get more output requires more displacement. Displacement is cone area (Sd) x travel, Xmax.
More displacement requires larger port volume (port area x port depth) to avoid "port compression" which happens at high port velocities.
Larger port volume also reduces cabinet size...

The B&C 18TBX100 is a good cone, 11mm Xvar (Xvar is a measured parameter B&C uses and is generally equivalent to other's Xmax) the BC TBW100 has 14mm Xvar, almost double the JBL 2241 at 7.62 and the 2242 at 7.87mm Xmax.

[sam saponaro]

He has 2245s w/ 9.65mm xmax.
As much as I'm starting to lust for a set of B&Cs or RCFs.Being budget concious,I could probably buy the 2245s at half there price. If I didn't mind changing the 45Hz tuning.Could the ports be lengthened to make them "work well" as far as reducing cabinet count? If I could get equal or greater kick thump out of 2 boxes vs 4 18B boxes for some of the smaller venues I freqently use this setup in,I'd be happy. I can allways use 4 as needed.
The 2245s specs are way differant Vas is 821.2 Qts .27 and FS 20 as per theilesmall.com were as the 18bs are 516 .36 and 33.
Sorry if I'm not getting it,I'm showing my ignorance in speaker box TS specs.

[Art Welter]

Could the ports be lengthened to make them "work well" as far as reducing cabinet count?
The 2245s specs are way differant Vas is 821.2 Qts .27 and FS 20 as per theilesmall.com were as the 18bs are 516 .36 and 33.
Sorry if I'm not getting it,I'm showing my ignorance in speaker box TS specs.

Sam,

If you are going to learn, you need to DIY, rather than have me repeat the same answers over and over .
One hint, a speaker with an Fs of 20 Hz is not a good choice when you want to use a Fb of 45 Hz.

Time for you to download Hornresp, David McBean's  free simulation program, and start plugging in the various speakers TS parameters and tunings you are considering to see how they compare for output and frequency response.
You can also leave box and port the same and compare each speaker.

Also compare port velocity, you don't want more than around 15 meters per second at Xmax.
Big ports for big Xmax.

Have fun!
Art

[Peter Morris]

If I were to decide to swap drivers with the type ports the Tls have,I would need to just add a flat piece of 3/4 ply to extend the existing peice that sits accross the whole three port area??By three ports I mean all three sections were the two divider peices are that go all the way back?

I couldn't find that eighteen sound driver that was in the link Peter Morris left no one seems to stock it when I google searched it.Upon searching I found some old topics on TL505s were it was mentioned the RCF L18P300 and B & C 18TBX100(this one had more Xmax) how would I know how much port extension to install If I were to drop the dime for one of these pairs?
Also would a JBL 2241 or 2245 work in these boxes?? cause a freind of mine has a few layin in his garage.He says they need 8cu ft,the TLs are 7.1cu ft.

Hi Sam,

I thought this may be of interest ...

http://www.usspeaker.com/

•   THE NEW B&C 18 TBW100 IS A VERY HIGH POWER 18" WOOFER THAT HANDLES 1,500 WATTS AES STANDARD & 3,000 WATTS PROGRAM
•   EXTENDED XMAX OF 12.0MM FOR A VERY DEEP TIGHT CHEST POUNDING BASS SOUND
•   ALUMINUM DEMODULATION RING KEEPS FLAT RESPONSE & DISTORTION LOW
•   CONE IS WATERPROOF ON BOTH SIDES
•   FEATURES A DOUBLE SPIDER, VENTILATED VOICE COIL GAP & A LARGE 4" VOICE COIL
•   THE B&C 18 TBW100 SPEAKER IS OPTIMIZED FOR EXTREMELY HIGH OUTPUT SUBWOOFER SYSTEMS IN CONCERT, SOUND REINFORCEMENT SYSTEMS, THEATER, ETC.
•   Enclosure Type - Bass Reflex/Ported
•   Cabinet Size - 7.0 cu. ft. / 200 Litres
•   Tuning - 32Hz
•   Frequency @ -3dB - 32.2Hz
•   Port Area - 133.7" / 3396mm
•   Port Depth - 12.48" / 317mm

Check this design out…..looks very much like you TL505, especially the port design and size but with more length. http://www.eighteensound.com/staticContent/applications/kits/kit18_front.htm

And this one … very high Xmax driver, slightly bigger box with a smaller port than your TL505 http://bcspeakers.s3.amazonaws.com/2013/02/12/16/15/09/156/file

All of the speakers used for these designs would work ... you just need to lower the tuning frequency to around 35Hz.

[sam saponaro]

Thanks I've been looking at the 18TBW100 and the 18TBX100.
I think I've decided to sell off one set of TL505 and the 18B speakers from the other to fund this project.I just gotta wait till some down time so I'm not out subwoofers come gig time.
 Now which set to upgrade and which to sell,is the question.One set is glued and bradded and the other set is screwed together every 2" w/ screws but this set has nicer handles etc...

[sam saponaro]

I was comparing specs on us speaker.Would the EMI Definimax 4018 LF be a good match if I lengthen the ports?? The Fs and Qts are very close to the 18B and B&C drivers and still have 7.9mm xmax.And they are like $100+ cheaper than the B&Cs(budget is a bit tight).

BTW I stuck those Carvin 18s I had lyin around in and they stunk.Found the TS specs and they are kinna far off.Sounded better in step down but still not as good as 18B.

Sorry to keep this thread running like the energizer bunny...I'm too dumb a guitar player to figure the box programs out....LOL

[Art Welter]

I was comparing specs on us speaker.Would the EMI Definimax 4018 LF be a good match if I lengthen the ports?? The Fs and Qts are very close to the 18B and B&C drivers and still have 7.9mm xmax.And they are like $100+ cheaper than the B&Cs(budget is a bit tight).

So saving $100 for a speaker with about 55% of the output sounds like a good deal to you?

[sam saponaro]

I dunno? Really I have no complaints about the 18B as is,cept it takes 4X to get were I want to be. I just like the idea of not having to lug 4 cabs if I can get there with 2. That and its two less cabs I need to recover/refinish and regrill as there all somewhat ugly right now.
The B&Cs would be great and would get the max from these boxes,but with an 11mo old baby and other stuff its a long way off for me. I'm just thinking the EMI can be had for $199ea on ebay so saving $300+ for the pair of driver w/ more than double my existing xmax might be worthwhile for my needs.

[sam saponaro]

So saving $100 for a speaker with about 55% of the output sounds like a good deal to you?

After test running my system befor the first gig with my new 3 way setup,I popped one of my 18Bs it fizzled and went dead no voice coil rub just dead.So giving it some real thought now that I'm on the line the EMI Difinimax is less sensitive and takes less wattage so inturn would mean almost 6Db less output.So I'm gonna go B&C you are right for a couple $100 dollars I'm just being CHEAP.
Thanks for the help and patience.

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