Lab 12 Based Offset Driver - Mass Loaded - Transmission Line (OD-ML-TL) Design by Bj - Page 7 - diyAudio
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Old 15th October 2012, 11:42 AM   #61
DrDyna is offline DrDyna  United States
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Quote:
Originally Posted by NWCgrad View Post

I have not modeled Don's tapped horn, I thought about building one but it is larger than I wanted. I know it will play significantly louder and I defer to others who have heard examples of each enclusure type (OD-ML-TL vice TH) to offer opinions on sound quality differences.
I'm curious to know as well, but I'd really have to build a pair of these to compare to Don's TH. My build of Don's TH is a little different because I've got the TC Sounds driver in there. I ended up not using the series inductor. It makes the Hornresp prediction better, but in real use, it didn't change the output significantly. I ended up just measuring the room response with REW, exporting an EQ profile and loading it into the MiniDSP. Room response is pretty much ruler flat from 18hz to 80hz.

The thing I like the most about them is their efficiency. I have the subwoofer output on my HTR set at -10 and the gain knobs on the sub amp set at 1 o'clock and they'll still lift the hair off your head if you aren't careful.

I also have a pair of T-TQWT subs and several pairs of vented subs, all of which I swap around from time to time just for fun. The vented subs tend to be easier to integrate, partially because the efficiency is more in line with my main speakers (mid 80's I'd suspect), and also partially because you really don't have to worry much about delay and such. The larger of my two pairs however, really don't do much lower than about 24-26 hz.

The T-TQWT is the middle ground, decent efficiency, reasonably flat without EQ, and the delay is easy to manage with a little placement dancing. The T-TQWT wins out on "quality" I guess, they seem very strong, but also very pleasant to listen to. They're very well behaved.

Now, the TH is just a monster. It doesn't care, it says "Hey, I'm here" and it grabs you by the hair and kicks you in the chest, a bit like sitting on stage at a concert, halfway between the bassist's cab and a double drum kit. It's visceral, mean, and it'll knock the breath out of your chest if asked to.

The video in my sig was done with them.

I would suspect that the OD-ML-TL is probably somewhere between the T-TQWT and the TH, but I very much want to make a pair just to know for sure. Of course, I'd probably use the TC Sounds drivers as I'm quite, quite fond of them now.
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Last edited by DrDyna; 15th October 2012 at 11:45 AM.
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Old 15th October 2012, 04:37 PM   #62
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Dr.Dyna, your comments on the sound quality of the T-TQWTs are very interesting. Could you please point a link to the design and layout. Thanks.
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Old 15th October 2012, 06:10 PM   #63
DrDyna is offline DrDyna  United States
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Originally Posted by Samuel Jayaraj View Post
Dr.Dyna, your comments on the sound quality of the T-TQWTs are very interesting. Could you please point a link to the design and layout. Thanks.
Sure, here's the build thread.

Fiddling with Hornresp - Peerless 831759
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Old 16th October 2012, 03:59 AM   #64
NWCgrad is offline NWCgrad  United States
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Quote:
Originally Posted by DrDyna View Post
I'm curious to know as well, but I'd really have to build a pair of these to compare to Don's TH. My build of Don's TH is a little different because I've got the TC Sounds driver in there. I ended up not using the series inductor. It makes the Hornresp prediction better, but in real use, it didn't change the output significantly. I ended up just measuring the room response with REW, exporting an EQ profile and loading it into the MiniDSP. Room response is pretty much ruler flat from 18hz to 80hz.

The thing I like the most about them is their efficiency. I have the subwoofer output on my HTR set at -10 and the gain knobs on the sub amp set at 1 o'clock and they'll still lift the hair off your head if you aren't careful.

I also have a pair of T-TQWT subs and several pairs of vented subs, all of which I swap around from time to time just for fun. The vented subs tend to be easier to integrate, partially because the efficiency is more in line with my main speakers (mid 80's I'd suspect), and also partially because you really don't have to worry much about delay and such. The larger of my two pairs however, really don't do much lower than about 24-26 hz.

The T-TQWT is the middle ground, decent efficiency, reasonably flat without EQ, and the delay is easy to manage with a little placement dancing. The T-TQWT wins out on "quality" I guess, they seem very strong, but also very pleasant to listen to. They're very well behaved.

Now, the TH is just a monster. It doesn't care, it says "Hey, I'm here" and it grabs you by the hair and kicks you in the chest, a bit like sitting on stage at a concert, halfway between the bassist's cab and a double drum kit. It's visceral, mean, and it'll knock the breath out of your chest if asked to.

The video in my sig was done with them.

I would suspect that the OD-ML-TL is probably somewhere between the T-TQWT and the TH, but I very much want to make a pair just to know for sure. Of course, I'd probably use the TC Sounds drivers as I'm quite, quite fond of them now.
Thank you for the detailed review of the different designs, it is great to hear from someone who has experience with bot TH and T-TQWT. It will be interesting to hear the Mal-X design that bjorno came up with and tb46 put into final configuration.

Those TC Sound drivers model really well in this enclosure, with the extra throw translating into higher SPL. I think I will build 4 enclosures, two for my current Lab 12s and two for TC Sound drivers. I have both an HT and a two channel setup (Magnapan MMG's) so I have a need for multiple subs.
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Old 1st November 2012, 11:01 PM   #65
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Default Single fold design

Does anyone see a problem with folding these in this configuration?
I have space for one or two, tall subs with a small footprint.
Trying to decide if I should make the Don Snyder design recently showcased by Layertone and unfolded by Oliver Lab12 - Tapped Horn -
Or, maybe unfold this OD-ML-TL like this................... Here is the original design below.
Click the image to open in full size.

Or, even have the 45 degree mouth like this.
Click the image to open in full size.

Both of these are slightly different, mostly in port length, but also where the driver mounts in relation to the port and the fold.
Hrsp. says they both perform identically to the original design shown at the right.

Help me decide,

Dave
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Old 2nd November 2012, 12:44 AM   #66
NWCgrad is offline NWCgrad  United States
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Dave,

That looks really good, I hope that bjorno and tb46 chime in as they are the brains behind the design. I have been looking at the Welti multi-sub AES papers and the taller design may work very well to place where his research indicates as optimal for a rectangular room.

Steve
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Old 20th December 2012, 04:57 PM   #67
DrDyna is offline DrDyna  United States
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Has anyone built this yet? I'm very close to building a pair of these cabinets just for fun to put my Epic 12s in just to see how they compare to the TH.
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Old 20th December 2012, 05:18 PM   #68
tb46 is offline tb46  United States
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Hi Y'all,

Post #65: "...anyone see a problem with folding these in this configuration?"

Don't see any problems, but the 45 degree duct opening to the room does not seem to be helpful in AkAbak. I didn't enter these particular enclosures, but an MLTL build around the LAB15, and tried the same duct modification without seeing any benefit. The angle at the inside can be evalutated in Hornresp, and may be helpful.

Regards,
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Old 20th December 2012, 07:02 PM   #69
DrDyna is offline DrDyna  United States
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Quote:
Originally Posted by tb46 View Post
Hi Y'all,

Post #65: "...anyone see a problem with folding these in this configuration?"

Don't see any problems, but the 45 degree duct opening to the room does not seem to be helpful in AkAbak. I didn't enter these particular enclosures, but an MLTL build around the LAB15, and tried the same duct modification without seeing any benefit. The angle at the inside can be evalutated in Hornresp, and may be helpful.

Regards,
Do you think it's harmful in any way?

It certainly looks cooler, at least imo.
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Old 20th December 2012, 09:05 PM   #70
tb46 is offline tb46  United States
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Hi DrDyna,

Don't think it'll do any harm. I just dug out the scripts, and set up a comparison w/ straight duct ends, and angled duct ends (again, this is not for the box in this thread, but a similar MLTL) :

Regards,
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