shortened Half Chang

minhaj · 23rd November 2010, 07:22 AM

For some reason I can not go beyond 42'' hight. Now, can I increase depth to maintain 45 ltr chamber volume and done?? What about throat size! in the org drawing it is 100x19mm.

Should I do as above what sacrifice I will have to accept soundwise, scottmoose, dave, gm pls help me. I will drive it with homebrew 300b se.

Regards

planet10 · 23rd November 2010, 07:56 AM

Scott eill have to chime in on what is really doable (and he is a bit scarce at the moment, being a Professor is eating into his diyA time)... you do need to keep the slot vent & it's horn the same.

I'd guess that if needed one might increase the width or depth of the main chamber, and shorten the box... that will thou throw off the driver offset.

I guess one could also rotate the slot vent so that it fires out the back, and hang the horn off the back, giving an L or J shaped cabinet.

dave

minhaj · 23rd November 2010, 10:59 AM

Thanks Dave for your reply. I have not understood "....that will thou throw off the driver offset" this clearly, can you please enlighten?

I had/have a gut feeling that due shortened line lenth bass may suffer a bit, your opinion on this please.

I greatly appreciate your contribution to DIY community, thanks again. I await for words from scottmoose. I have built a pair of curvy chang and I love them. HC is for another room where space is a bit tight. Pls note I will be running Fe206e with 4 ohms series resistor.

Regards

planet10 · 24th November 2010, 08:06 AM

Quote:

Originally Posted by minhaj

Thanks Dave for your reply. I have not understood "....that will thou throw off the driver offset" this clearly, can you please enlighten?

The driver is very purposely placed a certain distance from the closed end of the box. Shifting it can cause some resonant peaks/ripple (as we found out the hard way with the 1st builds of thirlmere).

dave

minhaj · 24th November 2010, 08:35 AM

Ok, loud and clear though it is bad news for me.

WHAT SHOULD I DO NOW? (this question addressed to my poor soul)

Regards

rjbond3rd · 24th November 2010, 12:46 PM

If I were in your situation, personally, I would do either:

(a) A BR a la Bob Brines (he designed one for that driver), or
(b) a folded TL where you go for greater depth to gain shorter height. If you've ever seen a diagram of Onur's Singular cab, he bends the top of the cab at 90 degrees, then does the same with the bottom. But that's a TL as opposed to MLTL, so it's more buik / longer line length overall but it shows the folding principle.

minhaj · 25th November 2010, 01:56 AM

Hi

Pls do not misunderstand me, I gone through BR, MLTL, TL things many times. Even we (myself, my diybuddy) built Anur's signature once the design was out. Still the boxes are with my friends.

I tried OB and I like the sound. Due to limited space I have not tried CD/front horn. However I am a BLH/BVR, OB, CD/front horn guy.

I am feeling discouraged for shortened bib because Dave showing red flag reg resonant peaks due to shifting driver from closed end, specially fe 206e is peaky itself at certain frequencies.

Thank you for your suggestion I could do it should I not been gone through this rout.

Regards

23rd November 2010, 07:22 AM	#1
minhaj diyAudio Member Join Date: Dec 2004 Location: Dhaka, the capital of Bangladesh	shortened Half Chang For some reason I can not go beyond 42'' hight. Now, can I increase depth to maintain 45 ltr chamber volume and done?? What about throat size! in the org drawing it is 100x19mm. Should I do as above what sacrifice I will have to accept soundwise, scottmoose, dave, gm pls help me. I will drive it with homebrew 300b se. Regards

23rd November 2010, 07:56 AM	#2
planet10 frugal-phile(tm) diyAudio Moderator Join Date: Oct 2001 Location: Victoria, BC, NA, Sol III Blog Entries: 4	Scott eill have to chime in on what is really doable (and he is a bit scarce at the moment, being a Professor is eating into his diyA time)... you do need to keep the slot vent & it's horn the same. I'd guess that if needed one might increase the width or depth of the main chamber, and shorten the box... that will thou throw off the driver offset. I guess one could also rotate the slot vent so that it fires out the back, and hang the horn off the back, giving an L or J shaped cabinet. dave __________________ community sites t-linespeakers.org, frugal-horn.com ........ commercial site planet10-HiFi p10-hifi forum here at diyA

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23rd November 2010, 10:59 AM	#3
minhaj diyAudio Member Join Date: Dec 2004 Location: Dhaka, the capital of Bangladesh	Thanks Dave for your reply. I have not understood "....that will thou throw off the driver offset" this clearly, can you please enlighten? I had/have a gut feeling that due shortened line lenth bass may suffer a bit, your opinion on this please. I greatly appreciate your contribution to DIY community, thanks again. I await for words from scottmoose. I have built a pair of curvy chang and I love them. HC is for another room where space is a bit tight. Pls note I will be running Fe206e with 4 ohms series resistor. Regards

24th November 2010, 08:35 AM	#5
minhaj diyAudio Member Join Date: Dec 2004 Location: Dhaka, the capital of Bangladesh	Ok, loud and clear though it is bad news for me. WHAT SHOULD I DO NOW? (this question addressed to my poor soul) Regards

24th November 2010, 12:46 PM	#6
rjbond3rd diyAudio Member Join Date: Jan 2007	If I were in your situation, personally, I would do either: (a) A BR a la Bob Brines (he designed one for that driver), or (b) a folded TL where you go for greater depth to gain shorter height. If you've ever seen a diagram of Onur's Singular cab, he bends the top of the cab at 90 degrees, then does the same with the bottom. But that's a TL as opposed to MLTL, so it's more buik / longer line length overall but it shows the folding principle.

25th November 2010, 01:56 AM	#7
minhaj diyAudio Member Join Date: Dec 2004 Location: Dhaka, the capital of Bangladesh	Hi Pls do not misunderstand me, I gone through BR, MLTL, TL things many times. Even we (myself, my diybuddy) built Anur's signature once the design was out. Still the boxes are with my friends. I tried OB and I like the sound. Due to limited space I have not tried CD/front horn. However I am a BLH/BVR, OB, CD/front horn guy. I am feeling discouraged for shortened bib because Dave showing red flag reg resonant peaks due to shifting driver from closed end, specially fe 206e is peaky itself at certain frequencies. Thank you for your suggestion I could do it should I not been gone through this rout. Regards

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