Mach 5 18"ixl build up

**wkhanna** · 23 August 2007, 11:59 Thursday

Hi Mike!

400+ Litre!!!!!!
Dude.........use the Sono tube (concrete form tubes from the local BB hardware) and save yourself all that needless cutting and bracing. Remember all the 'Fun' :M you had cutting all the swiss cheese holes for POK (Project Over Kill)!

Just my 2 cents, FWIW & trying to make things easier on you!

**ThomasW** · 23 August 2007, 12:19 Thursday

Image not available

Doesn't do any good to have a 12Hz tuning when you run out of Xmax at 23Hz. (see where the red line crosses the black one.)

That said the current trend to model using Pmax as the input power is unrealistic...

**Gir** · 23 August 2007, 12:24 Thursday

That tunning is a little low; you may want to go for something along the lines of 14-16Hz. I have a 340l (effective volume w/ sub) sonotube with the IXL-18.4 tuned to 16.5Hz. Not the most ideal tuning, but it works wonders in my opinion. I'll tell ya' what, the sonotube was awesome. Like wkhanna said, cutting all those swiss cheese holes sucks!

**ThomasW** · 23 August 2007, 14:05 Thursday

I have a little spare time while I taste test some "full-city" roasted Guatemalan coffee beans, so here are some thoughts....

Above Fb there's minimal performance difference between sealed and vented alignments...

The 'advantage' of vented alignments is their +3dB greater efficiency and the added output at Fb.

I realize it's all the rage to create these very low Fb designs, but I wonder 'to what end?'

In-room one will not "hear" any difference between a 12Hz, 15Hz, or 18Hz tuning. The 12Hz tuning will provide somewhat lower protection from unloading, but all are vunerable to destruction from very low frequencies (single digits) like those found in WotW or the ring drop in LotR..

This means one might as well take advantage of the 'free' 'usable' output a from a higher Fb, and protect the bottom end with a high-pass...

BTW ports should be 36" or less to avoid issues with port resonances. And no a port resonance has nothing to do with the port itself vibrating....

Ciao' for now,
Thomas

**JaxLax** · 23 August 2007, 18:16 Thursday

Originally posted by Gir

I have a 340l (effective volume w/ sub) sonotube with the IXL-18.4 tuned to 16.5Hz. Not the most ideal tuning, but it works wonders in my opinion.!

then what might be the ideal tuning?

**kingpin** · 23 August 2007, 20:12 Thursday

Originally posted by wkhanna

Hi Mike!

400+ Litre!!!!!!
Dude.........use the Sono tube (concrete form tubes from the local BB hardware) and save yourself all that needless cutting and bracing. Remember all the 'Fun' :M you had cutting all the swiss cheese holes for POK (Project Over Kill)!

Just my 2 cents, FWIW & trying to make things easier on you!

Hey Bill.

Not much into the sono subs. I don't like that I can't see the driver. Ine of my hang-ups of hidden drivers. Although it would be less work in cutting mdf it wouldn't be by much. I would still need the triple thick bottom plate, top plate which are all mdf.

I will be using window bracing instead of all the holes. My drill press still hasn't recovered from P.O.K. :T

**cobbpa** · 23 August 2007, 20:20 Thursday

Who doesn't love a good sub / suggestion thread? - HTGuide Forum

https://www.htguide.com/forum/showthread.php?p=355370#post355370

It hasn't been the most active week on the board & the Mach Audio presale is enticing to me, but I want to be sure that if I purchase one of those subs that it's the best for me in the long run. Here's my scenario. I'll live in a smallish apartment until May of 2008, then move out hopefully to a little bigger place and

There's my build with the IXL in an all-wood enclosure. I'm verrrry happy; gets plenty loud & I haven't heard it complain at all. I don't push it really hard with movies and the loud music isn't so tough, but it's very impressive to me. I didn't do enough bracing (poor planning on my part), but might fix that next summer.

**kingpin** · 23 August 2007, 20:56 Thursday

Here is the driver with a 15 hz tune.

Image not available

Maybe 2 opposing drivers in a 700l box, with an 8"port will be better tuned to 11.5hz wired in parallel being fed with 1200watts.
Cone excursion never goes past xmax.

Images not available

Suggestions?

**kingpin** · 24 August 2007, 12:34 Friday

Oooops. Just noticed the first graph I posted in the above post was with the 12 hz tune.

Fixed it to show the 15 hz tune.

Oh yeah and Bump. haha

**soho54** · 25 August 2007, 15:32 Saturday

I don't think I want to build just a regular box,

What exactly do you have in mind here?

The Le is actually 2.3 at the standard 1K, the 6.09 is for 100Hz.

You are also using a 7" Diameter port there.

:

Here are a few things to get the ball rolling.
All level matched to 110dB at 80Hz, on the Unibox 10-1K scale.
All using a 6" port under 36" long. To use an 8" port all volumes have to be increased by 90l or more to get the length down to acceptable levels. :twisted:
Red----------Orange--------Gray-----------Yellow
Two RS 12"-- One IXL 18Hz--One IXL 13Hz--One IXL 15Hz
115l--------- 190l-----------320l-----------240l
150w-------- 135w--------- 150w----------144w
SPL

Cone Excursion

Port Velocity

This is the same subs, but power increased until 1000w or xmax before Fb.
Red=1000w Orange=1000w Gray=730w Yellow=970w

**kingpin** · 25 August 2007, 18:40 Saturday

Thanks Jacob.

What I mean by just a regular box is, it may not end up being square or rectangular in shape. I may be placing the sub on a side wall between the tv and the couch. I understand that you don't want to put subs behind the listening position otherwise I would put it in an area behind or more to the side of the couch. Don't know what shape yet.

I think I am going to use 2 drivers though in a front and rear firing configuration. Although the thought of stereo subs(1 per box on each side of the room may be more appropriate and provide better sound.

Would the preference be to put both subs in one box or 2 seperate boxes?
Does this mean I have to double the size of the box if using 2 drivers?
Would I then go to an 8" port with 2 drivers?
Would I bridge the ep2500 or run 1 off each channel?

I am going to try Unibox again with dual drivers with the new numbers that you listed and post them so you can see what I get.

Appreciate your efforts Jacob.
Thank goodness for PM's. PM's should be changed to S.O.S. :B

**kingpin** · 25 August 2007, 19:10 Saturday

How does this look for 1 640l box with dual opposing subs. 1 in front and 1 in rear, tuned to 13hz with 1 8" flared port. Each sub seeing 600 watts.

Images not available

**soho54** · 25 August 2007, 21:24 Saturday

I think I am going to use 2 drivers though in a front and rear firing configuration.

What I can't figure out is how you are going to do this in a non-rectangular enclosure. I am intrigued.

Would the preference be to put both subs in one box or 2 seperate boxes?
Does this mean I have to double the size of the box if using 2 drivers?
Would I then go to an 8" port with 2 drivers?
Would I bridge the ep2500 or run 1 off each channel?

That is up to you. Both have pros and cons.
Yes.
No, you would need two 6" ports.
One off each channel.

To use an 8" port lets look at the 18Hz sub. At 190l a 6" port is 30.5" long. An 8" port would have to be 56" long. In order to get an 8" port under 36" you have to bump the enclosure up to 250l. For the 15Hz sub the bump is up to 406l. 8O

Think of what I posted more as a guide. Just something to get a feel for the different options available. I'm starting to think a slotted port would be a better idea with this driver. An 8" port would be a no brainer if you could get it into the enclosure. As things are it won't, so a slot could be a better option than the 6" port.

**kingpin** · 25 August 2007, 21:42 Saturday

Originally posted by soho54

What I can't figure out is how you are going to do this in a non-rectangular enclosure. I am intrigued.

That is up to you. Both have pros and cons.
Yes.
No, you would need two 6" ports.
One off each channel.

To use an 8" port lets look at the 18Hz sub. At 190l a 6" port is 30.5" long. An 8" port would have to be 56" long. In order to get an 8" port under 36" you have to bump the enclosure up to 250l. For the 15Hz sub the bump is up to 406l. 8O

Haha. Remember I am working night shift these days, so I am a little more confused than normal. The girl at the bank on Friday morning told me point blank.

"You look like sh!t".
I got a good laugh at that.

So help me understand the pros and cons of each.
Is it not better overall to have 2 subs on either end of the room than one.

I think that I am starting to like the idea of 2 seperate enclosures each tuned to 13hz. :T

320l seems like a manageable size.

Oh Mr. Ogowski(Mach 5) hold a couple of those 18's for me. I will be calling you next week. :B

I should have some drawings soon.

Jacob, could you alsp give me some do's and don'ts for port placement.

Thanks

**soho54** · 25 August 2007, 21:47 Saturday

How does this look for 1 640l box with dual opposing subs. 1 in front and 1 in rear, tuned to 13hz with 1 8" flared port. Each sub seeing 600 watts.

One 8" port is not going to cut it, and two will not fit at 65.5" each. Two 6" ports is a little better than one 8". A slot is a little better still by 5-6m/s more than the 6".

I think you missed the edit in my last post.

**soho54** · 25 August 2007, 22:00 Saturday

So help me understand the pros and cons of each.
Is it not better overall to have 2 subs on either end of the room than one.

You could end up with better or worse response. It depends on how they play off the room.

You could go stereo bass with a separate pair, and it might be worth it to you. Two mono subs in different locations is a crap shoot. Unless you have a lot of placement options I wouldn't recommend this route.

could you alsp give me some do's and don'ts for port placement.

That's easy, the further away from anything the better. At a minimum keep the openings away from anything, at least the distance of the port diameter. More is better.

**kingpin** · 25 August 2007, 22:12 Saturday

Originally posted by soho54

You could end up with better or worse response. It depends on how they play off the room.

You could go stereo bass with a separate pair, and it might be worth it to you. Two mono subs in different locations is a crap shoot. Unless you have a lot of placement options I wouldn't recommend this route.

Well, depending on the width of the subs and depth of the subs(would rathr have them taller than anything=top port) if I put one IXL each in their own enclosure I would probably be able to put them to the sides of the tv between the speakers. I will be moving my audio rack across the room.

**kingpin** · 25 August 2007, 22:21 Saturday

Here is a pic of my old place where I am moving back to.
The audio rack won't be there so there should be plenty of room between the speakers and the tv to put each sub.
It seems like you are hinting that putting them both in one enclosure would be more beneficial?

Image not available

**soho54** · 25 August 2007, 23:40 Saturday

It seems like you are hinting that putting them both in one enclosure would be more benefiscial?

Nah, no hints. I'm just telling it like it is. You have already seen how room position can muck things up first hand. One enclosure or two you still take your chances. I just wanted to make sure you understood that two isn't always better than one.

If you go with a dual option, try to make them so that if it doesn't work you can put them together. One on top of the other, side by side, or something. That is what I would do anyway.

Also remember that one IXL by itself without an enclosure will be as wide as the EP2500 in that pic. :B

**kingpin** · 26 August 2007, 00:05 Sunday

What kind of effects does placing the sub on a side wall have. More negative or positive. Also could you place the sub with the driver pointing up along the wall. I am sure that the driver facing into the room is better.

So let's say for poops and giggles that with 320l enclosure with a 6"port, the port itself would be 35.5".

Suggestions taken.

**soho54** · 26 August 2007, 00:12 Sunday

I want to add something else for you to think about.

What SPL do you listen at. (if you had that SPL meter you would know

: ) If you really listen at high SPL levels. Do your ears ring a little or feel funny after playing a CD/DVD? Are guest always commenting on how loud you have the volume? Do you have to raise your voice to carry on a conversation with someone next to you, even during the non-action scenes in a movie most of the time? Do you ask "huh?" or "what?" a lot? :B

If so, I would really consider a higher tuning (Fb) point. The several dB of headroom at extreme SPL levels would be a big plus. Of course if you do listen at these levels I would be in the market for another EP2500 as well.

Again I'm not trying to tell you what to do here. Only to get you to think about your needs, so that you get the best fit. Since I don't know you personally, and can't pop over for a visit you have to decide on the best fit on your own. :T

**Hdale85** · 26 August 2007, 00:13 Sunday

So your moving back to your old place?

**soho54** · 26 August 2007, 00:17 Sunday

What kind of effects does placing the sub on a side wall have. More negative or positive.

It just changes the peaks and valleys throughout the room. Can be a plus or minus. Sorry, a lot of this stuff is up in the air until you get it in room.

Also could you place the sub with the driver pointing up along the wall. I am sure that the driver facing into the room is better.

It's not a problem. Most people here lately have been aiming them at the floor remember.

So let's say for poops and giggles that with 320l enclosure with a 6"port, the port itself would be 35.5".

Sounds about right, for 13Hz :B

**kingpin** · 26 August 2007, 00:37 Sunday

Originally posted by Dougie085

So your moving back to your old place?

Yup. It is actually my parents place. I can help them with bills and in turn my bills go down.

It kinda sucks but that's the way life goes for now.

**kingpin** · 26 August 2007, 00:46 Sunday

Originally posted by soho54

I want to add something else for you to think about.

What SPL do you listen at. (if you had that SPL meter you would know

: ) If you really listen at high SPL levels. Do your ears ring a little or feel funny after playing a CD/DVD? Are guest always commenting on how loud you have the volume? Do you have to raise your voice to carry on a conversation with someone next to you, even during the non-action scenes in a movie most of the time? Do you ask "huh?" or "what?" a lot? :B

If so, I would really consider a higher tuning (Fb) point. The several dB of headroom at extreme SPL levels would be a big plus. Of course if you do listen at these levels I would be in the market for another EP2500 as well.

Again I'm not trying to tell you what to do here. Only to get you to think about your needs, so that you get the best fit. Since I don't know you personally, and can't pop over for a visit you have to decide on the best fit on your own. :T

I have wanted to say for the past few threads that I have an spl meter on order. I just kept forgetting.

No ear ringing.
Yes, it's tough to carry on a conversation with others when I have it turned up.
Movies I play extremely loud, but find myself turning the volume down cause things can get uncomfortable.

No. I am not buying another amp. :B

Next time you are in Toronto Canada tell me. I am sure you could improve any setup I have greatly.

In essence, just because I have a car that goes 200mph it doesn't mean that I always drive at that speed. Cruising is awesome, but flying in a car is a totally different thrill ride. :W

**kingpin** · 11 September 2007, 09:35 Tuesday

Still trying to decide on an enclosure.
What I am thinking is the tv stand idea. Yup its rectangle but I don't think I can do anything else.

So we are back at using 2 ixl's in one enclosure.

28"deep x 64"wide x 20" high
2 x 6" ports
tuned to 13hz
This will give me 33 280 cu inches or 545 litres.
This is about the biggest I can go.
How much am I suffering without using the whole 640 l.
Unibox shows that I lose 1db at 13 hz. This I can live with. Or am I missing something here.

Here is what I got from Unibox

Images not available

thanks

**kingpin** · 11 September 2007, 11:14 Tuesday

This is what I am thinking for design.
The PORT sizes aren't worked out yet. This is just a quick rendering.

What you see are just the basic design and ideas that I want to incorporate.
A slot in the middle for the amplifier.
5 anti-vibration pods per side with a finished piece of wood or something on top.

Images not available

**cjd** · 11 September 2007, 12:15 Tuesday

Late to the conversation, but.

Harman did a *superb* paper on sub placement. I'll try to find the link, if osmeone else doesn't beat me to it. Worth a read.

Make sure you have a filter in place to chop out frequencies below your tuning frequency or your loud movie watching will toast those drivers. Sealed is nice too and a little more native driver protection, though if you use any kind of transform to bring up the low end you're back to the same place as far as excursion troubles.

I'd build two boxes. Lighter, easier to move. More flexible as far as layout (can put on opposite sides of the room, next to each-other, on top of each-other, etc) which can do a ton to tame room nodes.

C

**kingpin** · 12 September 2007, 07:47 Wednesday

I forgot to mention that the above design was going to be my new tv stand. Hence the anti vibration pads which are to help stop any vibration going to my DLP's bulb.

I don't want to go sealed because I am not willing to buy any more electronics at this time like an eq.

So I will go ported.

If you look at the pic I am ordering some new longer cables so I can get the equipment rack outta there and give the speakers something breathing room. I would hate to put the sub in place of the stand.

What about setups like KGVeterans where his sub is basically in the same place as to where I would like to place it. This is the thought I was going with.

Another thing is that the room is about 15 x22 with a fireplace in the corner to the right of where I am sitting in the pic. To my left is an open wall that goes to my bedroom. I am actually sitting at my desk which is against the wall a few feet behind the couch. The couch is 11" from the face of the speakers. Not really any other places I can place the subs.

This is my dilemma.

Image not available

**---k---** · 12 September 2007, 09:22 Wednesday

Mike,
I'm not the resident expert here, but I think it looks good. Two things though. You room could always screw you on placement. So, unless you have a way to find the best sub location prior to building, you might want to size your subs in seperate boxes or atleast in a shape that if under the TV doesn't work, you can move it somewhere else. Trust me, rooms can really screw you if you're limited on positioning. Every room is different.

Second, your Unibox models look good except for the first port resonance. See the squiggle around 157hz. That may be audiable, depending on your crossover and such. If you use a 50-60hz cross, less likely, but maybe. (And remember that there isn't a crossover on the LFE track in movies) Back when I was building my ported sub, we discussed it a bit. Everyone has an opinion. Most say keep it above 200hz, mine is at like 180hz. To be on the anal safe side, I would try and move that up. The smaller diameter ports and the higher tuning frequences will raise the port resonance.

It is a balancing act, with smaller diameter ports, because then you raise the port speed and chuffing. But, exceeding the theoritcal good port speed limit below 20hz, like your graph shows, isn't a big deal if you ask me.

**dlneubec** · 12 September 2007, 11:20 Wednesday

I agree with the others. Make them in two boxes. Not necessarily so you can move them around the room you have now, but for future flexibility should you move to a different location. When I suggested the TV stand concept to you in the other thread, I posted a conceptual pdf plan for what I've been thinking of doing. It has been designed as two boxes all along (two 12's per box in mine, 4 total, however).

What product do you plan to use for the vibration reduction?

**BobEllis** · 12 September 2007, 11:51 Wednesday

In a former business life I gathered a touch of knowledge about vibration isolation. To be effective you really need to design your isolation system to the frequency(ies) that are problematic based on the mass (center and position) of the object to be isolated.

Throwing some random rubber pucks at the problem is almost as likely to make it worse as better. Too hard and the LF gets through. Too soft and you risk compressing it to ineffectiveness or bottoming, which causes a shock spike.

Of course I cannot remember how to size the isolator, but IIRC, Lord Industries should have some information on their website if you want to try to do it scientifically.

IMHO, a better solution would be a table like stand that completely isolates the TV from the subs underneath it.

**Mike P.** · 12 September 2007, 17:09 Wednesday

As stated, all rooms are different. My HT room is 15 by 26 and I tried the "TV stand" with 2 Atlas 15's in seperate enclosures (10 cubic feet each) and it did not work for me. My couch is 13 feet back and the bass was almost non existent due to a cancellation problem. The best placement for me wound up being on either side of the couch ( woofers facing the couch) and the improvement was tremendous. I suggest you skip the amp shelf and build 2 seperate enclosures. If it works, fine. If not you have the option to try another placement. It will also give you greater flexibility should you move in the future. Next week I'm starting to build a pair of IXL-18.4's in 12 cubic feet each tuned to 16.5hz. I'll be placing them along the back wall for some "major reinforcement".

**---k---** · 12 September 2007, 19:56 Wednesday

Another option I was just thinking about, what about making the sub your sofa and just put some cushions over it. Think about it, you would get a sub, bass shakers, and pants flappers all in one!

Probably should just build a small sealed box, stick the driver in it, move it around the room, cross your fingers and hope under the tv works decent enough, determine what is acceptable, then build for that location. If that is too much work, go with under the tv and live with the room. 99% of the population does that. It is only us crazy forum people that do the bass crawl.

**kingpin** · 12 September 2007, 21:19 Wednesday

:scratchhead: :scratchhead: :scratchhead: :rollhead: :rollhead: :rollhead: :unsure: :unsure: :unsure:

This is always much easier when you think you know everything, but really know nothing.

Mike

**WillyD** · 12 September 2007, 21:23 Wednesday

Second, your Unibox models look good except for the first port resonance. See the squiggle around 157hz. That may be audiable, depending on your crossover and such. If you use a 50-60hz cross, less likely, but maybe. (And remember that there isn't a crossover on the LFE track in movies) Back when I was building my ported sub, we discussed it a bit. Everyone has an opinion. Most say keep it above 200hz, mine is at like 180hz. To be on the anal safe side, I would try and move that up. The smaller diameter ports and the higher tuning frequences will raise the port resonance.

Keep in mind the inductance roll off inherent to the IXL well act as an extra lowpass filter.

**audioslave** · 12 September 2007, 22:32 Wednesday

go with two subs....

have a read of some of these white papers....

http://www.harman.com/wp/pdf/multsubs.pdf

Are you planning on using an EQ on the sub? I would highly recommend it (BFD or something like that). There is a good white paper on using a parametric EQ there too. The chances of you getting a good even un-EQ’d response is pretty slim.

I would also second the recommendation to nix the TV stand option…..looks like a nice DLP HDTV, hate to blur that picture or shorten the life of the bulb.

**kingpin** · 13 September 2007, 11:04 Thursday

I have to go to bed. So I don't mean to be short with you guys.
Thanks for all the info and I started to read the white papers but will do so more when I am wide awake.

Here is a video of my room(turn down volume as there is a screeching nose) where I plan on putting them. 1 on each side wall facing to the middle of the room.

Image not available

So this is where I am at today.
2x320l enclosures tuned to 13 hz.
Here is a picture of what I am considering. To be made of sonotube and a birch ply front top and bottom baffle.
Front ported incase they have to be stacked. Can't be more than 39" total height. Depth and width are open.
this picture is just an example. Nothing to scale. Mark from Mach5 Built something similar with 5 or 6 of his 12's. Am waiting for a picture from him.

Comments.

Image not available

**BobEllis** · 13 September 2007, 12:15 Thursday

A little OT, MIke, but you probably should apply some absorption to the right side wall since your speaker is so close to it. The standard OC703 a few inches off the wall will make a big difference. I had a similar setup and was amazed at the change in imaging and detail even 2" of eggcrate foam made. The idea is to kill the early reflections that smear the image.

**BigJim_inFLA** · 13 September 2007, 18:11 Thursday

To be made of sonotube and a birch ply front top and bottom baffle.

Not sure that would be a good way to go. I thought (could be wrong) that sonotube works so well because its a complete circle, can't be distorted. Once you make it a flat front the sonotube walls will flop all over the place, very thin walls. I'm sure someone else with more knowledge can confirm or dispute that.

**kingpin** · 13 September 2007, 20:38 Thursday

Here are the pics Mark sent me.

Images not available

**---k---** · 13 September 2007, 20:56 Thursday

it will probably still work as long as you can transfer the tension through the baffle to keep it a ring-link structure.

**Gir** · 14 September 2007, 01:44 Friday

If there's plenty of glue I wouldn't see anything wrong with it. It just has to be guaranteed that it won't slip out of the hold, and like Ryan said, as long as the tension can transfer through the baffle it'll work. If you wanted to be extra sure, a few brads to hold it in just in case probably wouldn't be a bad idea (if they're on hand).

**ahaik** · 14 September 2007, 08:14 Friday

Originally posted by BigJim_inFLA

Not sure that would be a good way to go. I thought (could be wrong) that sonotube works so well because its a complete circle, can't be distorted. Once you make it a flat front the sonotube walls will flop all over the place, very thin walls. I'm sure someone else with more knowledge can confirm or dispute that.

Two problems that I see here:
1. It’s not a full circle. Think of an egg, it’s very strong when its elliptical, now if there was one side that was flat, it will break in a sec.

2. In a sonotube the driver/s is on the bottom (or top, or both) which gives you equal pressure on the walls of the tube all the way around, so the only way for it to warp is to stretch the tube, very hard to do, so its strong. here you have the drivers on the walls pressure is not equalized on walls and the "tube" will warp (the back wall will surely get pushed back and forth.

IMO this is a no no.

Just my opinion though.

Asi.