Maurbacs NS6 MTM

[donradick]

Re: Maurbacs NS6 MTM

Quick question ...

I bought all the parts to build the AURBACS but never got the cabinets together.

I am now thinking of the MAURBACS .. so I would like to reuse as many parts as possible.


The coils for the MAURBACS are 1.0mH and .15mH ... the AURBACS use a 1.2 and a .2.

How big a difference would I see (or hear) by using the AURBACS coils?

I don't have a DCR meter but I could unwrap each coil a few turns to get close.

Thanks

Yeah, unwrap a bit from each coil. If you don't it'll be close, but this way it will be better.
You can build an impedance box for a couple of bucks and use it with the free LIMP software
to get very accurate readings.

[rhubarb9999]

Re: Maurbacs NS6 MTM

Tell me more of the impedance box of which you speak ...

[greywarden]

Re: Maurbacs NS6 MTM

Actually check out one of icor's threads. You can use it with LIMP and ARTA to measure LCR and FR and Impedance

[donradick]

Re: Maurbacs NS6 MTM

Tell me more of the impedance box of which you speak ...

Best (simplest explanation) of the jig:
http://zobsky.blogspot.com/2008/01/s...t-jig-for.html

Slightly different form factor, same schematic:

https://sites.google.com/site/amateuraudio/projects-1/arta-limp-and-or-room-eq-wizard-impedance-jig

As far as I know, most LCR meters will give you one measurement for the device under test at
1 KHz (since impedance varies with frequency). The jig and LIMP will give you a complete
graph. Measure a couple of PE coils and you should see the listed impedance in the graph
at 1K.

regards,

[donradick]

Re: Maurbacs NS6 MTM

Listening update.
While reworking the Targas, I moved the Maurbacs to our bedroom, and we gave some Bob Marley a serious listen.
Wow. Even in the current 34 liter box, the 2 NS6 woofers play with real authority, and they image VERY well,
with a perfect balance from bass through mids, to the highs. (Driven by a lowly Lepai 20 watt amp)
I can recommend these without hesitation for music.

[photoprashanth]

Re: Maurbacs NS6 MTM

Hi Don,
I am a newbie to the speaker building and do not understand too much of technical terms. So I would just try to replicate your design.
I want to build a complete HT system for movies.
I would like to know which one do you suggest me to build,

1. 2 Pairs of Aurbacs + 1 Maurbac as center (my preference) OR
2. 3 Maurbacs (L/C/R) + 1 Pair Aurbac for surround.

I will import only drivers and try to procure other crossover components in my place.

-Prashanth

[donradick]

Re: Maurbacs NS6 MTM

Hi Don,
I am a newbie to the speaker building and do not understand too much of technical terms. So I would just try to replicate your design.
I want to build a complete HT system for movies.
I would like to know which one do you suggest me to build,

1. 2 Pairs of Aurbacs + 1 Maurbac as center (my preference) OR
2. 3 Maurbacs (L/C/R) + 1 Pair Aurbac for surround.

I will import only drivers and try to procure other crossover components in my place.

-Prashanth

Hi Prashanth

I would strongly advise building the Maurbacs as your front LCR - the cost is only a little more
than the Aurbacs, and the crossover is significantly simpler and less costly.
If you can, build the L + R into 1.5 cubic feet boxes (42 liters) for a better low end.
The center channel will be fine in a 28 liter box.
The port length will need to be a bit longer, I can provide that value if you decide on this option.
the Aurbacs will make good rear surrounds - you can build them into .5 cubic feet boxes (14 liters)
for a good match to the usually surround low end of about 80 Hz.
Let me know if you need more assistance.

[Geniuss_dad]

Re: Maurbacs NS6 MTM

Don, have you tried the Maurbacs in near field? Im thinking of computer speakers.

[donradick]

Re: Maurbacs NS6 MTM

Don, have you tried the Maurbacs in near field? Im thinking of computer speakers.

I ran them as my computer / desktop speaks for a few months (DTA-100a), they sounded very good from 3 feet or so -
but when I listened to them from 8-9 feet, they really seemed to "open up" with imaging. I've no idea whether you
would or could design a different crossover for near-field vs far-field. They will be able to get very loud and deep for
your use - not something you could say about very many desktop builds.

[photoprashanth]

Re: Maurbacs NS6 MTM

Hi Prashanth

I would strongly advise building the Maurbacs as your front LCR - the cost is only a little more
than the Aurbacs, and the crossover is significantly simpler and less costly.
If you can, build the L + R into 1.5 cubic feet boxes (42 liters) for a better low end.
The center channel will be fine in a 28 liter box.
The port length will need to be a bit longer, I can provide that value if you decide on this option.
the Aurbacs will make good rear surrounds - you can build them into .5 cubic feet boxes (14 liters)
for a good match to the usually surround low end of about 80 Hz.
Let me know if you need more assistance.

Hi Don,
I have got all the drivers and built the crossovers. It took sometime for me to do it because I had to wound the inductors myself.
Now I connected the crossovers and checked with a dummy box and they sound clear. I am sure they should sound better when I build the actual enclosure.
As per your suggestion I am building about 1.5 cubic feet enclosure for fronts. I will first finish the fronts then start with center and surrounds.
Actual measurement of the box is (W=9 1/2" H=26" and D=15") 1.53 cubic feet.

This picture shows more or less how my box would look like.


I would like to know
What should be the port dimension and position?
I would like to position the port in the front baffle and at left or right side of the tweeter (like horizontal mirrored) or bottom.
What would you suggest for best sound.

Also, Whether the tweeter has to be at the right side for the right speaker and left side for the left speaker?

Regards,
Prashanth

[Adam_G]

Re: Maurbacs NS6 MTM

Here's the progress on my Maurbacs' boxes.

Looks pretty close to the CAD Drawing.

[donradick]

Re: Maurbacs NS6 MTM

Hi Don,
I have got all the drivers and built the crossovers. It took sometime for me to do it because I had to wound the inductors myself.
Now I connected the crossovers and checked with a dummy box and they sound clear. I am sure they should sound better when I build the actual enclosure.
As per your suggestion I am building about 1.5 cubic feet enclosure for fronts. I will first finish the fronts then start with center and surrounds.
Actual measurement of the box is (W=9 1/2" H=26" and D=15") 1.53 cubic feet.

This picture shows more or less how my box would look like.
[ATTACH=CONFIG]29322[/ATTACH]

I would like to know
What should be the port dimension and position?
I would like to position the port in the front baffle and at left or right side of the tweeter (like horizontal mirrored) or bottom.
What would you suggest for best sound.

Also, Whether the tweeter has to be at the right side for the right speaker and left side for the left speaker?

Regards,
Prashanth

Excellent!
1.5 cubic feet will give you an F3 of 46 Hz - use a 3 inch inside diameter port (in the U.S. I like to use PVC SCH40 plastic pipe) - 5.5 cm long. Tweeters must be offset to one side from the woofers. Later you can swap your speakers from left to right and decide if you prefer the tweeters on the inside or the outside. Clear?

Put the port on the front or back, close to the floor. If you are going to place them close to the back wall, then put the port on the front.
Line the box with 1 inch thick or thicker open cell foam (mattress or pillow).

Here are the simulation graphs:

[donradick]

Re: Maurbacs NS6 MTM

Here's the progress on my Maurbacs' boxes.[ATTACH=CONFIG]29325[/ATTACH][ATTACH=CONFIG]29326[/ATTACH][ATTACH=CONFIG]29327[/ATTACH]

Looks pretty close to the CAD Drawing.

Wow! gotta dig that slanted top. Nice work.
With your woodworking skills, how are you going to finish them?
Thanks for the post, Looking forward to your listening impressions.

[bkeane1259]

Re: Maurbacs NS6 MTM

Hi Don.

I've been looking into a high-sensitivity design to run off of my COUGAR Boom Box and after mulling over several drivers, I circled back to the Aura NS6 and then figured why not just build the Maurbacs???

So that's my intention, but I have a few questions. I don't need real deep bass extension. I'm more concerned with sensitivity as these will be running off of a 50-watt/channel (total) head unit amp. If I may ask, how much BSC is factored into the design? I know you mentioned that these get very loud very quickly.....do you have an idea of the design sensitivity?

I'm not looking to alter the design -- just want to make sure my application is appropriate. Thanks for any info you can provide.

[donradick]

Re: Maurbacs NS6 MTM

Hi Don.

I've been looking into a high-sensitivity design to run off of my COUGAR Boom Box and after mulling over several drivers, I circled back to the Aura NS6 and then figured why not just build the Maurbacs???

So that's my intention, but I have a few questions. I don't need real deep bass extension. I'm more concerned with sensitivity as these will be running off of a 50-
watt/channel (total) head unit amp. If I may ask, how much BSC is factored into the design? I know you mentioned that these get very loud very quickly.....do you have an idea of the design sensitivity?

I'm not looking to alter the design -- just want to make sure my application is appropriate. Thanks for any info you can provide.

These should work well for you. Factory specs and my T/S testing shows 91 db / 1 W - and with the MTM that makes 97 - factor out
3 dB of BSC, and you get 94. I can tell you that I am driving them off a Lepai 20W amp, and have never truned them up past about
"9 o'clock" - they would drive us out of the room!