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Discussion Starter #1 (Edited)
Thanks to all the Shacksters who have helped inspire me and guide me in this build.

1. I am upgrading my subs from 2 Dayton 12" RS 4cf sealed boxes and 1 Dayton 15" Titanic 6cf sealed box both being driven by 2 - Dayton SA1000 sub amps. The Daytons go non-existent below 18hz. Knowing that some movies and music go into the single digits makes me want to go there and experience more. I am also looking for higher quality bass to match my excellent MTM's.

2. I originally was going to build 4 TC Sounds LMS-R 15" sealed cabs to get the smoothest room response. I went to order them last month on Parts Express and they are out of stock until June. I HAD NO CHOICE but to order 2 TC Sounds LMS Ultra 18" subs! 2 Ultras model about the same as 4 LMS-R's anyways. It feels good to join the Ultra club. I hope they sound as good as everyone raves!

3. I have 7 MTM's in 1cf curved cabinets from Parts Express. I wanted to build subwoofer curved cabinets to match the look of the smaller curved cabs.



4. The cabinet design was inspired by http://www.hometheatershack.com/forums/sealed-subwoofer-build-projects/43177-warpdrvs-custom-funky-waves-18-0-curved-cab-lms-5400-build.html. I will be taking a different approach though. Here is my design in Google SketchUp View attachment 15 sub curved cab braces.skp . Also View attachment 15 sub curved cab ext 2.skp .

5. The drivers and cabinets were modeled both in WinISD Pro and UniBox408. A sealed design was chosen to get the lowest extension possible in smaller cabs that meet the WAF. SPL will be achieved with wattage.

6. 3cf of internal displacement puts the alignment just in between Bessel and Butterworth. Tilo Stompler from TC Sounds emailed me recommending 4cf over 2.1cf as the larger cab would reach deeper and sound better. However, I have to keep the cabinet size down so a compromise had to occur.

7. EQ will be necessary. I need to bump up lowest frequencies a bit. I do have Audyssey MultEQ X32 with my OnkyoNR5008 for. It is good but I am looking for better room correction by using REW. I will be receiving my new UMIK-1 usb microphone any day now. I have several choices to go here and could really use some advice. I have a Behringer DCX2496 that I can use. I also will be powering these monsters with a Crown iTech 4000 amp with built in dsp. I would prefer to use the amp's dsp and forgo the extra Behringer device. Besides room correction, I would also like to add in a room curve with the Crown or Behringer and then let Audyssey do the final touches.

That is the scope of my project. I have already started building. I will post photos and progress soon! :D
 

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Does the DSP in the Crown amp have shelf filters? If so then it will probably do just as good a job as the DCX2496.

Sound like a great build!
 

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Discussion Starter #5
Does the DSP in the Crown amp have shelf filters? If so then it will probably do just as good a job as the DCX2496.

Sound like a great build!
sub_crazy
I have enjoyed your posts and wisdom. You have quite a setup.
Yes the Crown has shelving filters. I have never used them before but I have been reading about them. I have not installed the Crown IQwic software yet or connected my laptop to the amp via Ethernet. I don't think REW has a setting for the Crown. Either I can use the generic setting in REW and/or manually enter REW's suggested filters into IQwic. I will post on this later. First, I am still building the speaker cabs. Thank you.
 

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I think you will find the XT32 in your Onkyo will do an excellent job on the subs, you will just need to adds some boost down low with either the Crown DSP or the DCX2496. I would try that after XT32 and if you don't like the results then add the boost before re-running XT32. Don't do too over board with the boost, you will run out of headroom if you do. Audyssey will sometimes add boost as well from some reports so that is why you might try just running XT32 before using the DSP in the amp or DCX2496.

I had a Onkyo 5508 and still have a 3008 and everytime I ran XT32 I never had to do anymore EQ work on the subs besides some added boost down low.

Thanks for the compliments by the way. To be honest even though I am running a lot of subs right now I still wish I would have kept my LMS Ultra's and just added a couple more, they really are my favorite subs and your gonna be impressed.
 

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Discussion Starter #7 (Edited)
I have begun building cabinets for the 2 Ultras. i live in Thailand and could not obtain any 1" plywood so I am going MDF all the way.

Here are some of the parts after being routered and jigged:



Closeup:



Because the 5400's are powerful beasts, I have chosen to build very strong frames (probably overkill) but that's just me :bigsmile::



Here are the frames with the first layer of front and rear baffles:

 

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Discussion Starter #8
I think you will find the XT32 in your Onkyo will do an excellent job on the subs, you will just need to adds some boost down low with either the Crown DSP or the DCX2496. I would try that after XT32 and if you don't like the results then add the boost before re-running XT32. Don't do too over board with the boost, you will run out of headroom if you do. Audyssey will sometimes add boost as well from some reports so that is why you might try just running XT32 before using the DSP in the amp or DCX2496.

I had a Onkyo 5508 and still have a 3008 and everytime I ran XT32 I never had to do anymore EQ work on the subs besides some added boost down low.

Thanks for the compliments by the way. To be honest even though I am running a lot of subs right now I still wish I would have kept my LMS Ultra's and just added a couple more, they really are my favorite subs and your gonna be impressed.
Thanks for the sage advice. I will give it try in your order.

My experience and listening tastes really match your suggestions. I do like the XT32 with my Dayton subs. It does a great job EQuing things. I do not have an outbound equalizer in my current setup but my Onkyo has a manual equalizer. After I let the XT32 do its adjustments then I set my crossovers at 80hz (XT32 likes to set them at 40hz), and boost the lower frequencies slightly. Unfortunately, the Onkyo crossover only has PEQ adjustments at 25hz, 40hz, 63hz, and 120hz. I now have a rudimentary room curve.

Just as you suggest, the TC Sounds Ultras model with just a small boost needed down low (around 1 or 2db). This is if you are going flat. I am truly looking forward to the better drivers, amplification, and EQ. Thanks.
 

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Wow Michael, that really is some outstanding work your doing :T

It sort of reminds me of the matrix bracing B&W uses on there top of the line speakers.

Did you do all the work on the braces with a handheld router and guides or do you have access to a CNC?
 

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Does your Crown DSP allow for a HPF below 15hz? The only reason I ask is I know the DCX2496's HPF only goes to 20hz so that would be way too high. The only reason I bring up a HPF is that even though you are running a small 3cuft and with 2000 watts you should not reach xmax until about 4hz but when you add boost that figure drops. I like running the LMS Ultra with an 11hz HPF just to be safe and there have been too many reports of people bottoming the LMS Ultra. One guy on here named Notnyt with 8 LMS Ultra's runs a HPF on his set-up after he bottomed all 8 when running them really hard without a HPF. He said he almost had a heart attack from the sound, I know I would have.

If your not planning on running them really hot then you should be fine without a HPF but if you really plan on cranking them hard then you might want to think about it.
 

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Discussion Starter #11 (Edited)
Regarding amplification, I knew that I would need a serious pro amplifier to drive the LMS Ultras.

1. 2000 watts RMS stereo - LMS can go up to 8000 but (2000 watts plus boost at 10hz is enough!) IMHO

2. No clone amp (too unreliable and questionable patent infringement).

3. Universal power supply to work in Thailand or USA.

4. Lightweight - can be shipped in a suitcase.

3. High damping factor and/or slew rate

4. Class H or I - works on a 20amp plug USA - or 15amp 240volt in Thailand.

5. DSP - bonus.

Though expensive, I purchased a used Crown iTech 4000 from an eBay dealer:



I feel like it is an amp worthy of the LMS Ultra's capabilities.

Crown iTech 4000
2000 watt per channel in 4ohms. Capable of 2ohms but not necessary.
No clone here - USA tech - believed to be the #1 pro amp in the world
Universal switch mode power supply - 120-240v/50-60hz
26lbs - brought to Thailand on a plane
Damping Factor - over 5000 - outstanding control - Should sound very tight!
Class I - Runs cool - conserves power
Has DSP - Feature rich - can run multiple amps through software
 

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Discussion Starter #12 (Edited)
These are my ScanSpeak MTM's.



They have some really fine drivers. The were inspired by Zaph Audio Revelators:

http://www.zaphaudio.com/ZRT.html

Drivers and Crossover were custom designed by Madisound.

http://www.madisoundspeakerstore.com/scanspeak-woofers-6-7/scanspeak-revelator-18w/8531g-00-7-mid-woofer-8-ohm/
http://www.madisoundspeakerstore.com/scanspeak-soft-dome-tweeters/scanspeak-revelator-d2904/7100-03-wide-surround-black-face-plate/

Cabinets were from Parts-Express:

http://www.parts-express.com/pe/showdetl.cfm?partnumber=302-751

They are really smooth and flat. The Dayton subwoofers are good but the Revelators deserve better subwoofers to match them. The Revelators can play 115db 80hz and above. My goal is to have subs that can play 115db down to 20hz. The 2 Ultras can play 120db at 20hz and drop to 108db at 10hz. This does not account for room gain. I can't wait to see how the LMS Ultras match up to the rest of my system
 

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Discussion Starter #13 (Edited)
Wow Michael, that really is some outstanding work your doing :T

It sort of reminds me of the matrix bracing B&W uses on there top of the line speakers.

Did you do all the work on the braces with a handheld router and guides or do you have access to a CNC?
I have a CNC in my dreams!
In reality I used a hand held router.



I made a large circle jig for the sides of the horizontal pieces. They are based on a 32" radius curve.

I based this on the size box I modeled (3cf) and shaped like my RCLSB speakers.



After I built the first piece I used it as a pattern for the other pieces using a flush trim bit.





Next was the vertical pieces that go from 1 side to the other.
Again I made a pattern and then flush trim cut the others.
Lastly, I made a jig to do all the smaller rib pieces.

 

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Discussion Starter #14
Does your Crown DSP allow for a HPF below 15hz? The only reason I ask is I know the DCX2496's HPF only goes to 20hz so that would be way too high. The only reason I bring up a HPF is that even though you are running a small 3cuft and with 2000 watts you should not reach xmax until about 4hz but when you add boost that figure drops. I like running the LMS Ultra with an 11hz HPF just to be safe and there have been too many reports of people bottoming the LMS Ultra. One guy on here named Notnyt with 8 LMS Ultra's runs a HPF on his set-up after he bottomed all 8 when running them really hard without a HPF. He said he almost had a heart attack from the sound, I know I would have.

If your not planning on running them really hot then you should be fine without a HPF but if you really plan on cranking them hard then you might want to think about it.
I do not know if the Crown allows a HPF below 15hz. The specs say 20hz - 20khz. Until I get into the software I really don't know. If it only allows an HPF at 20hz or above then I would opt for a shelving filter below 20hz and keep the watts managed. The Crown has lots of protection in terms of limiting watts, etc. I do not plan on driving things too hard. If I do crank it up, it will be for a short tests once in awhile.

I did email Crown Audio about any roll off below 20hz. One of their techs wrote back that Crown measures their amps flat to 20hz and that there would be a slight roll off below 5hz but that their test equipment was not too detailed.

I assume that this built in roll off will take care of any potential over-excursion issues below 10hz. I do not want to bottom out my ears so I am not too concerned with bottoming out the drivers. I will definitely keep your advice in mind.
 

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This is a very cool build! I am looking forward to seeing how it progresses. That bracing is killer (and is going to be killer on your back :) ) Nice work :T
 

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Your build looks fantastic. I'm definitely eager to watch your progress. I'd agree that your frames are overkill, but I don't think that hurts anything :D

The scanspeak MTMs are also very pretty :)
 

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Awesome work, Look forward to seeing your results. I originally wanted to build a curved cabinet for my LMS Ultra, but decided to get some practice building a regular box first. I plan on starting a curved box once I'm done with my current one.

Were you able to get an exact copy of your template with the flush trim bit? I thought of doing it the same way, but wasn't sure what the tolerance would be like.
 

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Your speakers are also outstanding, some of the best speakers in the world use the same drivers you are using.

I really wish I knew more about crossover design to make some speakers like you have.
 

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Discussion Starter #20
Your speakers are also outstanding, some of the best speakers in the world use the same drivers you are using.

I really wish I knew more about crossover design to make some speakers like you have.
Thanks for the encouragement. I did not know they were that good. Don't get me wrong, they sound fantastic to me.

This is what John Krutke had to say about these drivers on http://www.zaphaudio.com/ZRT.html

This is about as good as it gets for a 7" 2-way or 2.5-way. Not exactly cheap, but about as high performance as anyone could hope for. When the drivers like this have incredibly low distortion, and the design is well implemented, you get a non-fatiguing "listen all day" type of sound.
Here is a list of parts on Madisound:

http://www.madisoundspeakerstore.com/2-way-speaker-kits/zaph%7Caudio-zrt-2-way-revelator-tower-parts-only-pair/

John's original design was for a TM or TMM tower or bookshelf. But I just liked the concept of the MTM. I have no acoustical treatments and the MTM design is better with floor and ceiling reflections.

John Roberts at Madisound modified John Krutke's design to work in an MTM configuration. I also went with the better Goertz coil.

Here are the specs for the crossover and some measurements sent to me from Madisound:

View attachment 20100519154351149.pdf

Progress is coming along on the LMS Ultras. I hope they will match nicely with the rest of the setup.
 
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