# LAT Home Sub Goodness



## SSSnake (Mar 8, 2007)

A few pics of a Tymphany LAT 700 home project I did recently. Tuned to 22hz with 9 cubic feet total volume (less bracing, ports, sub it comes in a little over 8 cubes). It was designed to go behind a couch and that dictated the odd shape. It has been in the house and playing for a little less than one month and still sounds sweet.




























The next one goes behind the other couch and then I start working on the 18" Avalanches in an isobaric bandpass enclosure. Fun things are brewing...


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## stereojnky (Mar 17, 2008)

What is the purpose/design goal of having these plus the 18"s? 

Are these for music and the avalanches for theater? Or will they all be played together?


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## SSSnake (Mar 8, 2007)

Yes they will all be playing together There are several studies indicating multiple room Placement for subs helps to equalize in room response and reduce localization. Check out the diyaudio forum.


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## req (Aug 4, 2007)

that will be some serious LFE in your house :uhoh:


did you inform the neighbors? LOL

sweet though, i always wanted to play with those LATs. but i didnt have money to throw around.


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## stereojnky (Mar 17, 2008)

SSSnake said:


> Yes they will all be playing together There are several studies indicating multiple room Placement for subs helps to equalize in room response and reduce localization. Check out the diyaudio forum.


I'm aware of that, but usually they are the same type/size of subs. 

That's why I thought maybe you were using two separate sub systems (one for music and one for HT). 

Now that would have been awesomer!


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## SSSnake (Mar 8, 2007)

Stereojnky,

I certainly could use that type of approach but I wanted to try this. Most of the studies I read didn't indciate that using different types of subs was prohibited and the FR and output capabilities should be similar when considering sub locations, boudary loading etc. Once I get the others in place I will provide an update.

Req,

The output capabilities are pretty good on the LATs down to about 18-19hz (anechoic) but roll off a little quicker than I would like below this point. The Avalanches should get down to about 15hz with authority. Given the room placements I am using (LATs along walls and AVAs in the center of the room - more or less) the LATs should come pretty close to the AVAs FR curve and maximum output capabilites even with much less power. This is all good in theory, I'll just have to measure and see what happens with all of these going at once. 

Neighbors shouldn't be too much of a problem. I live on about three heavily wooded acres and as long as the bass is coming from in the house I don't have too many complaints. Now demoing the car systems has generated a few complaints...


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## SSSnake (Mar 8, 2007)

I forgot to mention that I picked up these LATs from a forum member and friend for a good price. I was too curious not to add them to the collection. Now I just have to figure out what I am going to do with a pair of the Pioneer PRS 12s. Maybe under the pool table in the bonus room, hmmm...


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## ErinH (Feb 14, 2007)

stereojnky said:


> I'm aware of that, but usually they are the same type/size of subs.
> 
> That's why I thought maybe you were using two separate sub systems (one for music and one for HT).
> 
> Now that would have been awesomer!


I would imagine crossover points and location dictate size requirements more than anything.
I believe most people using multiple subs use staggered crossover points. That's my understanding, at least.

Think about it like this... you run 7's for midbass and 15's for subs in the car.


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## captainobvious (Mar 11, 2006)

I guess I dont get the whole "localization" thing with multiple subs. Assuming your room is treated properly and your crossing the subs over low enough, how would one have localization issues? Isnt bass no longer directional at that point to your ears? 

In regards to the LAT driver- is it more of a tactile bass driver or actual sound?


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## ErinH (Feb 14, 2007)

it's not so much about localization. it's about response smoothing.

Using multiple subs in various locations (testing determines these locations) helps to smooth the overall response and rid the nulls you get when using singular placed subwoofers. 

Multiple Small Subs - Geddes Approach - diyAudio


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## SSSnake (Mar 8, 2007)

I find if the sub level gets too high I can typically locate the sub. Now does this mean it is producing distortion products that I am hearing or just rattling things in the room. I really don't know. I have just always felt that a single sub mounted to a far side of a room (where mine typically were) could be located. It is typically not a situation where I can point dierctly to the sub but just the music seems more full and impactful in one are versus another (hard to explain). 

Right now I have the sub mounted on the left side of the room and that side definitely seems to have more bottom. THis is not a good test case right now as we still have the Xmas tree up and it obscures my right full range. However, I am hard pressed to believe that a Xmas tree would black much bass...


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## SSSnake (Mar 8, 2007)

Erin,

You are absolutely right about the response smoothing but Geddes makes comments about localization as well (or maybe it was the JBL article). Either way that was my goal, smooth the response and hopefully get rid of a left side bias on the bass. If this does nothing else it should help distribute the rattles in the room and prevent localization from that standpoint. 

Charles


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## stereojnky (Mar 17, 2008)

bikinpunk said:


> I would imagine crossover points and location dictate size requirements more than anything.
> I believe most people using multiple subs use staggered crossover points. That's my understanding, at least.
> 
> Think about it like this... you run 7's for midbass and 15's for subs in the car.


Yeah but at all but the lowest frequencies, it seems that he's going to be running these together.



SSSnake said:


> If this does nothing else it should help *distribute the rattles in the room *and prevent localization from that standpoint.
> 
> Charles


That's what my goal is for my home theater!

Anyway great build so far! Subscribed and eagerly waiting.


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## SSSnake (Mar 8, 2007)

After a few weeks of living with these I thought I would provide some commentary. So far the bass has been outstanding. With the wall loading reponse is stout sub 20hz. They do well on music and LFE (although I am again noticing how much difference there is in sub bass levels on different TV broadcasts). The biggest thing is that they don't shake the things around them as much as other subs. You can sit on the couch these things are mounted behind and you never find yourself looking back. The bass draws you to the mains (with a little left side bias - the side they are mounted on). So far I am really impressed.


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## sq civic (Jul 21, 2009)

Just alot of laughs here!!!! 
Using 7 inch subs to get to to 20hz, and 18's to get to 15hz.
funny stuff


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## sq civic (Jul 21, 2009)

I knew that you would like the LAT's if you gave them a try


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## SSSnake (Mar 8, 2007)

How's it going Ricky? Yeah the LATs are definitely sweet. Once I get the other set in I might forget about putting the 18s in... 








Nah!

FYI - Still no word on contract awards. Hopefully we will hear something soon.


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## sq civic (Jul 21, 2009)

You are just running one of them now and you are impressed with output!!!
Both of them with a 1000 watts would shake my car around no doubt.

I hope to hear something soon.
Ready for a new career path


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## ErinH (Feb 14, 2007)

Ricky, email me your resume. I'll keep it in mind. 

Charles, I still have a hard time figuring out enclosures for those dang subs. They're just awkward. I fail.


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## subwoofery (Nov 9, 2008)

SSSnake said:


> I find if the sub level gets too high I can typically locate the sub. Now does this mean it is producing distortion products that I am hearing or just rattling things in the room. I really don't know. I have just always felt that a single sub mounted to a far side of a room (where mine typically were) could be located. It is typically not a situation where I can point dierctly to the sub but just the music seems more full and impactful in one are versus another (hard to explain).
> 
> Right now I have the sub mounted on the left side of the room and that side definitely seems to have more bottom. THis is not a good test case right now as we still have the Xmas tree up and it obscures my right full range. However, I am hard pressed to believe that a Xmas tree would black much bass...


I don't think it has to do with the sub level being to high. It's because the transition of the bass through the midrange is not good anymore. Also try to make sure there's no huge peak around 45Hz. 
Just make sure 60 to 160Hz is smooth. 

Kelvin


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## SSSnake (Mar 8, 2007)

> You are just running one of them now and you are impressed with output!!!
> Both of them with a 1000 watts would shake my car around no doubt.


Right now I am only running about 250W to it and it slams. The eventual setup will be 250W to each LAT and then 1000W to the iso pair of Avalanches.



> Charles, I still have a hard time figuring out enclosures for those dang subs. They're just awkward. I fail


I don't get it... Do you mean just how to orient/mount everything or the modeling. If you model these things you will find that Tymphany lied. Even with cabin boost their figures are too low. You need more airspace.



> I don't think it has to do with the sub level being to high. It's because the transition of the bass through the midrange is not good anymore. Also try to make sure there's no huge peak around 45Hz.
> Just make sure 60 to 160Hz is smooth.


I believe that we are saying the same thing with different words. When the sub level is high (assuming the same XO point) then the midbass output from the sub increases. This typically screws around with the integration but I don't believe that this is the only factor (could be wrong). I think there are several things that contribute (increased midbass output as a result of the increased sub level, increased distortion generating audio products into the midbass passband and beyond, more rattles [I, like most, have to live within the WAF and that means damn nick nacks scattered all over a bunch of glass table tops - soon to be replace with stone  ]), and room nodes (which can give you additional gains in the midbass ranges). So what I am saying is that I don't believe that I localize sound below about 80 hz but I localize subs crossed over at 80hz if there level is too high compared to the mains. This tends to be a pretty tough balancing act to get the sub output I want and the integration as well.


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