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Multi-Way Conventional loudspeakers with crossovers

TL cabinet rear port
TL cabinet rear port
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Old 31st March 2018, 01:38 PM   #31
Bill poster is offline Bill poster  Thailand
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A question I may have asked before- does a TL have better control of cone excursion at or under the resonant frequency than a MLTL?
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Old 31st March 2018, 03:40 PM   #32
Scottmoose is offline Scottmoose  United Kingdom
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No simple answer to that I'm afraid. Depends on what you're defining as a TL, and how the enclosures are tuned / their respective alignments. Generally they aren't like-for-like equivalents.

Assuming a TL in terms of a max-flat impedance line, then probably yes; it's likely to have tighter control over the driver and an LF rolloff that is largely 2nd order, the price being a higher F3. Whether you'd actually tune an MLTL or a mildly resonant line to the same frequency though is extremely unlikely though.
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Last edited by Scottmoose; 31st March 2018 at 03:46 PM.
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Old 2nd April 2018, 07:02 AM   #33
Williams Audio is offline Williams Audio  Jamaica
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HI ALL,
Attached Files
File Type: pdf TL QUARTER WAVE FRONT PORT.pdf (34.8 KB, 44 views)
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Old 2nd April 2018, 08:10 AM   #34
Scottmoose is offline Scottmoose  United Kingdom
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You don't appear to have used any driver offset, and the line cross section appears very small indeed, so I would expect the pipe to be very over-damped. Answers to your questions are to be found in Martin's alignment tables (and George Augspurger's, although the latter doesn't use tapers as large as 10:1) that I provided links to some posts ago. If you don't want to read those, then you can use the Excel file (also linked to) which calculates dimensions based on those alignment tables, your chosen driver's T/S parameters and preferred taper. Note that a highly tapered pipe (narrowing toward the terminus) is physically shorter than an untapered pipe for the same tuning frequency. The ratios are in Martin's alignment tables & Excel file for a given tuning frequency (as noted, they assume you are tuning to driver Fs). In practice as noted I would tune higher to get a bit more output, as you appear to be doing already.

'So' as Martin abbreviates it is the throat (sealed end) of the pipe, i.e. the opposite end to the open. In your drawing it would be directly above the woofer -the slightly angled panel that separates the line from the small sealed chamber.

End loading a pipe with the driver provides maximum excitation of the pipe fundamental resonance, but it also provides maximum excitation of all the harmonic modes (unwanted), hence the reason that a driver offset is usually preferred.
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Old 2nd April 2018, 08:19 AM   #35
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leonard audio also has a good article to help w TL design
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Old 2nd April 2018, 09:17 AM   #36
Scottmoose is offline Scottmoose  United Kingdom
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If it's the one on the defunct Leonard Audio site that was described as 'TL Basics' to be honest, it wasn't as good as it could have been. Especially because it continued to imply that driver Sd has any direct relationship to line CSA. It doesn't, and the focus on Sd is responsible for many poor performing QW / TL designs.

Pipe CSA should be determined, like any other vented enclosure, from the driver Qt, Vas, Fs and the target Fb / alignment.
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Old 31st August 2018, 10:39 AM   #37
Williams Audio is offline Williams Audio  Jamaica
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Default TL front port

Hello everyone,
Thanks for the criticism in the past; It guided me on the right path.
I decided to use King Martin's XCEL calculator, hoping it's close to his calculations. I have a built enclosure so I had to squeeze the TL inside as close as possible to the results from XCEL. Any advise is well come. Attached the basic drawings and the TL line from XCEL calculator.
Best regards,
Williams
Attached Files
File Type: pdf Visio-TL- SCAN SPEAK 8''.pdf (18.3 KB, 30 views)
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Old 21st September 2019, 04:56 AM   #38
Williams Audio is offline Williams Audio  Jamaica
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Default TL CALCULATOR

HI all,
I am back with a question.
I built the TL box using the Excel spreadsheet :
http://www.quarter-wave.com/TLs/Alig...tor_3_3_09.xls.
There is some one using this calculator? Is a good one, there are some updates to it?
Is kinde of a wild world design in this matheria, I use it for my pleasure and not commercial.
Best regards,
williams
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Old 21st September 2019, 05:37 AM   #39
GM is offline GM  United States
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Greets!

No updates: Transmission Line Theory

GM
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