My very old empirical on ear adjusted ML-TQWT need to be replaced.
I want to design a d'Appolito ML-TQWT with two Peerless HDS exclusive mid-woofers and a B&G ribbon tweeter in dipole. How do i handle the TSP with 2 drivers in one enclosure, Vas, Qts, Qm divided by 2?
I have a TQWT excel spreadsheet to calculate it. Have been searching for a spreadsheet to design a ML-TQWT, anyone know one?
Thanks
I want to design a d'Appolito ML-TQWT with two Peerless HDS exclusive mid-woofers and a B&G ribbon tweeter in dipole. How do i handle the TSP with 2 drivers in one enclosure, Vas, Qts, Qm divided by 2?
I have a TQWT excel spreadsheet to calculate it. Have been searching for a spreadsheet to design a ML-TQWT, anyone know one?
Thanks
Using Martin King's MathCad worksheets might be a better start. They do cost $25, but you get the set, and they are accurate, which is more than can be said for the few TQWT sheets for Excel that are lurking around.
Wired in parallel, Vas & Sd double, Re & Le /2. In series, Vas, Sd & & Bl double, everything else remains ~constant.
Wired in parallel, Vas & Sd double, Re & Le /2. In series, Vas, Sd & & Bl double, everything else remains ~constant.
I want to use 2 of these in a d'appolito configuration.
I see now res freq. is 52Hz, on other pdf's it was allways 41.8Hz
HDS Exclusive 180 (830883) order no. I-1381432 EUR 86,00
16 cm midrange driver with high quality cone.
* resonance frequency fs = 52,3 Hz
* impedance R = 8 Ohm
* sound pressure level SPL = 87,5 dB (2,83V; 1m)
* DC resistance Re = 5,8 Ohm
* force factor BL = 8,2 N/A
* voice coil inductance L = 1,3 mH
* effective piston radiating area Sd = 134 cm2
* effective mechanical mass incl. air load 17,7 g
* equivalent volume of compliance Vas = 13 l
* total Q factor Qts = 0,42 (Qms=2,79, Qes=0,5)
* maximum peak linear excursion vibration xlin = +/- 5,5 mm
* mounting diameter d = 145 mm
* overall diameter d = 180 mm
* mounting depth (not countersunk) t = 82 mm
See? : (from Peerless factory itself)
http://www.tymphany.com/datasheet/printview.php?id=3
I see now res freq. is 52Hz, on other pdf's it was allways 41.8Hz
HDS Exclusive 180 (830883) order no. I-1381432 EUR 86,00
16 cm midrange driver with high quality cone.
* resonance frequency fs = 52,3 Hz
* impedance R = 8 Ohm
* sound pressure level SPL = 87,5 dB (2,83V; 1m)
* DC resistance Re = 5,8 Ohm
* force factor BL = 8,2 N/A
* voice coil inductance L = 1,3 mH
* effective piston radiating area Sd = 134 cm2
* effective mechanical mass incl. air load 17,7 g
* equivalent volume of compliance Vas = 13 l
* total Q factor Qts = 0,42 (Qms=2,79, Qes=0,5)
* maximum peak linear excursion vibration xlin = +/- 5,5 mm
* mounting diameter d = 145 mm
* overall diameter d = 180 mm
* mounting depth (not countersunk) t = 82 mm
See? : (from Peerless factory itself)
http://www.tymphany.com/datasheet/printview.php?id=3
I wouldn't loose any sleep over it. Most drivers exhibit variation in their Fs & no two are ever exactly the same.
When you use two drivers, if wired in parallel, remember, Sd & Vas double, Re & Le /2. If wired in series Sd, Bl, Vas, Re & Le all double.
You could try something like this straight MLTL (assuming the drivers are paralleled). All internal dimensions: 45in x 7in x 10in (HxWxD). Tweeter mounted 12in down from the top. 3in diameter x 2in long vent mounted 4in up from the internal bottom. Either line the cabinet with damping material, or stuff 0.4lbs ft^3 of hollow-fibre material from the top 30in down. And no, it's not a bass refex box even if it does look like one.
~flat to 40Hz, you can damp to taste in-room, which is always the best approach given that every room is different. I always prefer max-flat for DIY designs -it just gives more tuning lattitude.
When you use two drivers, if wired in parallel, remember, Sd & Vas double, Re & Le /2. If wired in series Sd, Bl, Vas, Re & Le all double.
You could try something like this straight MLTL (assuming the drivers are paralleled). All internal dimensions: 45in x 7in x 10in (HxWxD). Tweeter mounted 12in down from the top. 3in diameter x 2in long vent mounted 4in up from the internal bottom. Either line the cabinet with damping material, or stuff 0.4lbs ft^3 of hollow-fibre material from the top 30in down. And no, it's not a bass refex box even if it does look like one.
~flat to 40Hz, you can damp to taste in-room, which is always the best approach given that every room is different. I always prefer max-flat for DIY designs -it just gives more tuning lattitude.Attachments
Thanks for thinking Scottmoose!
When a line is added, one woofer on about 1/5 and one at 1/3 of line length, line output on front and bottom, it could possibly reach the 32Hz. I have build several of those lines, all on ear, only simple line length calculation with good results (one bassunit though) The first TL i made from a thrown away pub used 3-way with 25 cm woofer. It could reach +/- 20 Hz easy, my friend listened to it, on a particular deep bass musictrack he had a jaw-dropping listening
When a line is added, one woofer on about 1/5 and one at 1/3 of line length, line output on front and bottom, it could possibly reach the 32Hz. I have build several of those lines, all on ear, only simple line length calculation with good results (one bassunit though) The first TL i made from a thrown away pub used 3-way with 25 cm woofer. It could reach +/- 20 Hz easy, my friend listened to it, on a particular deep bass musictrack he had a jaw-dropping listening
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