[db_bloke]

Time to build a sub. I know a fair bit about them and have done a few in the past, but I can't seem to get winisd pro working for me. It complains about parameters (screen shot's below) when I try and manually enter the info from the affordable drivers ixl-18 page (can't do a link - noobie here)

I just ordered a single IXL 18.2.2 (dual 2 ohm) from affordable drivers Australia. I want pretty much the smallest box I can with a response down to 20hz as I guess I'll get an in room boost to 10hz or so.
I already own a Behringer ep2500 which even with a RScomponents spec - 21db fan - is still a bit noisy (I might have to reverse it to vent out the back rather than push air in). Also it is a complete pain to get the screws in on the top section of the back plate - anyone know the trick?

I was thinking 24-27" cube sealed to make it easy (taller slimmer shallower might be good as well if I move). I've always found ported boxes sound less tuneful and would be annoying to make the port anyhow, but perhaps with this limited quality sub it won't matter much. I might use it for hifi if it sounds any good, my warehouse flat is huge (30'x60'x22' !!) and my transmissions line speakers can't cope. It would just be nice to get some opinions or help with ISD so I can see what I might be expecting before I start covering everything in MDF dust. Also I'd be keen to know the 'minimum - read easiest' amount of bracing required. Dacron / Dynamat / fitting binding posts sealing tips also appreciated.

I'm pretty surprised there isn't a decent sealed IXL 18 project here already (I've searched a fair bit).

 

[Mike P.]

Re: IXL 18.2.2 - Project Advice Sought

Welcome to the Shack! The WinISD Pro file for the IXL-18.2.2 can be found here:

http://www.hometheatershack.com/forums/diy-subwoofers/14410-downloadable-winisd-pro-files.html

Most IXL-18 builds have been for HT applications, big ported cabinets are the norm. There is a sealed build, 24 inch cube, 6 cu.ft. net, started by a member. Cabinets are built and pics will be posted soon.

http://www.hometheatershack.com/forums/diy-subwoofers/14558-ready-build-my-first-two-subs-help.html

Not sure what you mean by "limited quality sub". It will definitely hold its own against more expensive subs. Read Post 10, 11 and 12 in this thread.

http://www.hometheatershack.com/for...ported/13635-first-acoupower-18-complete.html

 

[db_bloke]

Re: IXL 18.2.2 - Project Advice Sought

Thanks for the links and in particular the location of the WinIsd file. :bigsmile:

I'll follow the maelstrom cutting guide, it seems 2' square was about right. Looks like a weekends work or two and hopefully I'll find a mate with a paint shop.

I just gotta get myself a deq2496, replace some (39) capacitors in my class A amp :sweat: and I should have decent sound again. Hopefully one sub will be enough.

The other thing I'll try is wiring the voice coils by running the amp in stereo to each coil / mono to both. I do this in the car to great effect. Diamond D912D2 / DLS A3, with the stereo setup sounding much better making it possible to identify 3 or 4 sounds rather than just 1 or 2, lower distortion from no bridging. I guess it depends how it fills my large space as to whether or not I need the extra few db's.

Look forward to posting some pics / details and in room measurements (finally a use again for my ECM8000).

 

[Mike P.]

Re: IXL 18.2.2 - Project Advice Sought

The other thing I'll try is wiring the voice coils by running the amp in stereo to each coil / mono to both

As long as the amp is 2 ohm stable, as that is what the coils are.

 

[db_bloke]

Re: IXL 18.2.2 - Project Advice Sought

From what I've found on the Measured Performance of the EP2500 it should be alright, I guess I'm assuming the coils are indeed 2 ohm and not worrying about impedance drops.

For the mono option I'll wire the DVC's on the driver in series so my ep2500 is seeing 4 ohms or thereabouts. Hopefully the driver will have -ve / +ve clearly marked.

 

[Mike P.]

Re: IXL 18.2.2 - Project Advice Sought

If memory serves me correctly the positive terminal has a red band around it. Post some build pics when you get started. :T

 

[salvasol]

Re: IXL 18.2.2 - Project Advice Sought

If memory serves me correctly the positive terminal has a red band around it. Post some build pics when you get started. :T

You're correct, red band on positive and black on negative (I just saw it on the IXL 15.2.2) :yes:

 

[db_bloke]

Re: IXL 18.2.2 - Project Advice Sought

OK, after much deliberation and trying to think about inside panels and stressing over internal volumes, I've come up with a 22" cube which has an internal volume of 125litres.

The braces should deduct about 4l and driver 11l. My final volume will be 110l.

For all you Melbourne people, Plyco up the road in Clifton Hill do 25mm MDF for $58.67 and a cutting service at $65 p/h. So < $100 for wood n glue without too much effort and nice square edges. They also offer veneered MDF for not a lot more. I'll find out when I get there.

This is the cutting sheet I'm giving them hopefully tomorrow, 1 day turnaround. Might manage to get it done pretty soon assuming I can work out how to cut a nice circle.

Maybe time to buy a cheap router / jig... I've never had much luck getting exact holes with a jigsaw before. Is it really worth getting one or should I just go slow with the jigsaw?

Large clamps I guess req. as well.

What kind of plaster / cement is best to make the seams really airtight.

No idea about binding posts yet though. Thinking four posts on the outside so I can wire how I like once it's all sealed. How do you attach them so you can make them really really air tight though?
One other thing I'm pondering is whether to fire the driver at the floor or into the room?

Any input / advice welcome.

Use - 80% music (or just parties), 20% av(until I get a projector). 40k cu/ft room.
I've had 4 similar drivers before in a 1.2k cu/ft room and it was insane :hide: but I was like 19yrs old or so. I read about all the people here with 2 of them to 15hz in a tiny room also and just wonder why on earth do you need that much air movement. Do you like to be kicked out of the chair or something. I'll probably be eating my words when I find out I need 2 of the above :R

 

[Mike P.]

Re: IXL 18.2.2 - Project Advice Sought

Is it really worth getting one or should I just go slow with the jigsaw?

I've used a jigsaw before and it works well if you take your time and don't force it.

What kind of plaster / cement is best to make the seams really airtight.

Wood glue works the best, LaPages and Elmers wood glue are popular here. Not sure what available to you over there.

One other thing I'm pondering is whether to fire the driver at the floor or into the room?

Down firing would ensure the safety of the sub since you mentioned parties.

......40k cu/ft room.........
I'll probably be eating my words when I find out I need 2 of the above

Start munching! :bigsmile:

 

[db_bloke]

Re: IXL 18.2.2 - Project Advice Sought

I'm wondering what the best thing is to do processing wise.....?
I've got a behringer ep2500 and soonish the Sub.
I have my surround unit which powers everything apart from the main speakers. I run a pre-out from the surround unit to a hifi amp to run the mains. I connect my cd player / record player directly to the hifi amp, otherwise it sounds distinctly average if I go through the surround unit.
What's the best way to connect my sub? I was thinking tape line out and then a DEQ2496 but this wouldn't really be using the LFE channel on the surround unit, the manual says if you select main speakers as large then bass goes to the mains instead of the LFE output. How else could I do it? Is there something cheaper than the DEQ? The other option is a DCX + DEQ or just a DCX between the surround / hifi amp. Not really thought about it much thus far.

Cheers for all your feedback / help so far. It's a lot easier with people spurring you on to actually achieve something. BTW the sub turned up, pic of it next to some guitars for scale.

Big aren't they. The surround is interesting, reminds me of RE XXX's. The binding posts rather subtly have black / red rings for each voice coil.

 

[salvasol]

Re: IXL 18.2.2 - Project Advice Sought

I have my surround unit which powers everything apart from the main speakers. I run a pre-out from the surround unit to a hifi amp to run the mains. I connect my cd player / record player directly to the hifi amp, otherwise it sounds distinctly average if I go through the surround unit..

Why don't you use the LFE/Sub pre-out from AVR (surround unit) to BFQ then to EP2500??? ...LFE/bass signals are non directional so you don't have to worry about a hi-fi audio.

 

[thxgoon]

Re: IXL 18.2.2 - Project Advice Sought

What kind of receiver are you using?

The subwoofer output is the best bet. You'll get the LFE and you won't need any additional crossover. Even if you have large floor standing speakers it is a good idea to set them to small (adjust the crossover point lower if the receiver has the option) so the burden of bass duties is relieved from them. The result is lower distortion.

 

[shogo33]

Re: IXL 18.2.2 - Project Advice Sought

How do you wire the EP2500 into 2 ohms?

Do you connect the (+) and (-) terminals of one voice coil ONLY to ONE channel of the (+) and (-) terminals of the EP2500? OR

Connect the (+) and (-) terminals of one voice coil to the LEFT channel of the (+) and (-) terminals and the other voice coil terminals to the RIGHT channel?

i know its a silly question but i'd rather ask and know then to fry my amp or sub! :crying: thanks

 

[shogo33]

Re: IXL 18.2.2 - Project Advice Sought

Yeah, that is a big sub! :sweat: I showed it to the misus and she freaked out saying " I hope its not going to :hsd:!!.. And "naturally" i said, "No..course not!"... I dont think she bought that..lol

 

[thxgoon]

Re: IXL 18.2.2 - Project Advice Sought

You'd be best off wiring the sub in series for a 4 ohm load and running either off of one channel of the EP2500 or bridging it. Bridging the amp might be a bit much for a single 18...

Take the positive output from the amp, run it to the positive input for the first voice coil. Take a wire from the negative connection on the first voice coil and run it to the positive connection on the second voice coil. Connect the negative connection on the 2nd VC and connect it to the negative connection on the amp. Make sense?

 

[db_bloke]

Re: IXL 18.2.2 - Project Advice Sought

Thanks for all of the advice. The thing is, ATM I want to use for say 80% music if it sounds any good (on account of a huge room). If I use the LFE output on the AVR, I will only get a signal when I watch movies / TV as I plug my CD / TT into the HiFi Amp due to the fact that if I plug it via the AVR it sounds average.

As far as 2kw in bridged mode and there were some really good hyperlinks in an earlier post of mine as to how to wire a sub with DVC for bridged operation, it 'might ' be a bit much BUT...
although xmax is 22mm, xmech is 30mm+ if I remember correctly.
I very seriously doubt I'm going to be giving it that much power, I'm not deaf of need a massage when I play music / watch TV. I don't have a sound deadened house or live in the middle of nowhere. Last time I had something similar to 4 of these, you could hear it reasonably well about a half mile away (it accidentally came on once at full pelt whilst I was outside!). I'm sure the cops will come aroud before I blow the sub asking me to turn it down.
If it turns out I am giving the sub too much power, then I'm going to hear it bottoming out and just turn it down and consign myself to having to build another one to get another few db. As far as 2kw in a 1kw sub goes then that's fine (sort of). As long as it doesn't clip I should be alright, that's my reasoning anyhow, not blown up a speaker yet. It's normally underpowered amps running dc that blow speakers up, not overpowered ones. You'de only be hitting 2kw on transients and as I said it's mostly for music, also at 2kw I expect the behringer to have quite high distortion (which is not as noticeable on bass). I appreciate HT does have different kinds of bass (sustained for 4-10 seconds) which is probably quite a lot. Is there any analysis of HT bass? Do people run their subs at 100% always?

Anyway, still wondering about how to wire up / processing. The annoying option is manually switching the input from tape loop / LFE output each time I change source media. Perhaps building myself a 2 input switching box / buying a QED one might be the go..?

I would still like advice on processing though, is the DEQ the tool or will a FBD do? There isn't a great deal of difference in price over here and you do get room eq which I'm told can do amazing things even in a hifi world. Interesting article on HTPC's / sound using ACXO.

MY AVR is a Yamaha DSPA5 which I read is the same as the processing from a DSPA1. More than fine for my purposes until I get a huge screen and need 3 channels for speech. Blu-ray sounds quite good through it. 7.1 is a nice idea but I don't find it any better than 5.1 (other than 3 ch for front with a huge screen). That's just my opinion though I mean how often do you get sound out the surrounds surely you need to spend all your cash on the centre where you get 99% of the sound from, I guess the AVR people need a reason to try and get people to spend money on the latest kit. If I ever get my hands on a Sanyo Z3000 I might have to make a change, but then only for HDMI & 7.1 with low end Yammy unit and I would then wonder if it would sound as good as the A5. When is someone going to bring out a low end 7.1 HDMI AVR with a Scaler. I'd rather go cinamascope than ultimate SQ. Perhaps Sony will update my PS3 with the scaler feature :yes:

 

[thxgoon]

Re: IXL 18.2.2 - Project Advice Sought

As far as 2kw in a 1kw sub goes then that's fine (sort of). As long as it doesn't clip I should be alright, that's my reasoning anyhow, not blown up a speaker yet. It's normally underpowered amps running dc that blow speakers up, not overpowered ones. You'de only be hitting 2kw on transients and as I said it's mostly for music, also at 2kw I expect the behringer to have quite high distortion (which is not as noticeable on bass).

The EP2500 is actually very linear up to max output which is about 1600 watts continuous. I agree you should be fine as program material rarely demands high levels of continuous output. The point on underpowered amps blowing up speakers is true in multi-driver speakers, but not subwoofers.

 

[shogo33]

Re: IXL 18.2.2 - Project Advice Sought

Thanks DB and Thxgoon for the wiring options. Hmm..i think i might take your advice and wire it in series to accept a 4ohm load from one channel of the EP2500.

Btw DB, did you find the fan on the EP2500 loud? Been looking into a postie on swapping the factory fan on the amp. If its not that loud, then i wont do it..if it is then i'll prob have to look at getting a replacement fan for it.

I think i might hold off on building a ported design just yet..my neighbours are in thier 60's - 70's and i dont want them to freak out.. I think i'll do a similar build to yours and see how i like it first. If i'm not happy then i'll do a ported design next year. From what u're saying SQ wise partnering it with the EP2500, i think that will do me good for the moment.

Off to Bunnings I go!

 

[db_bloke]

Re: IXL 18.2.2 - Project Advice Sought

The fan on the EP2500 is loud. Even when you swap in a quiet one it's still noticable. I think it's to do with it sucking the air in, the metal cowling is restricting the airflow somehow and causing turbulance or something making the fan a lot louder.
When I had the replacement fan running free-air it was silent (21db) but when I put it in the case it became noisy. That said, it's a lot quieter than what was in there before. Think really loud computer and you'll be close. If you're not going to put it in a seperate room / enclosure then you'll need the fan mod for sure.
The best 24v fan I could find from a local supplier was from RS Australia. I think there might be cheaper options though.

RS Stock No. Qty Unit Price Goods Value Description
541-5283 1 $28.00 $28.00 Fan,axial,DC,80mm sqx 25mm,2000rpm,37.4cu.m/h,24V

BTW, I'm not a speaker guru (well I know a good one when I hear one), I've built a few sub boxes though. I think my figures add up and I reckon my sealed design should be OK, but you never really know until you hear it after it's been run in for a bit. I've just taken delivery of the pre-cut wood anyhow. Just saying it might be re-assuring for someone here to confirm my design as good before two of us stuff up, I guess it's only wood and time which is all good blokey fun anyhow.


Also, in my design I've used 25mm MDF, I didn't think 18mm would really be dense enough and it made the figures seem just right as well, also it was only like $10 more. The downside is that the sub won't sit flush with the outer baffle, I'm not sure this is so critical for bass frequencies and does give grille options. The other thing is it make the box heavier (which is probably a good thing for such a mad sub project) just weighed it on the bathroom scales - high tech huh - wood 45kg, driver 17kg so 62 all up. I just wanted an easy build to be honest, I'm not sure there will be a lot of difference between sealed and Ported other than what we've already discussed. And of course a smaller cubed box is a lot easier to place.

Other than binding posts, I think the tricky bit is going to be the psychedelic Bridget Riley paint job I'm hoping to pull off.

 

[db_bloke]

Re: IXL 18.2.2 - Project Advice Sought

Still wondering what to do with binding posts, EQ and how to wire up to sources.

I just had to sit the wood together to make sure it fitted and I didn't stuff up. Fortunately everything looks good. Just gotta try and have a steady hand with the jigsaw now. Gettinmg there

It does look quite small considering the sub size. Oh well, most 12" sealed power monsters I've seen are 1cuft or less so I guess it's ok.

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