[eikon]

I'm a noob..

I am really intrigued by the DIY sub build idea. I have seen people post over and over about how fantastic a pair of HT-18's in Martysub boxes (or easier pre-cut flat packs) powered by an Inuke 3000dsp amp would be be. I'm on a tight budget and I need to spend more on construction supplies for my room before I start shelling out for subs.. but I can't get it out of my head. The value proposition that everyone keeps talking about here has me really excited.

A few more details. I'm working on my first ever HT build. I'm doing double wall construction with double layer drywall and green glue and a double layer ceiling on clips and channel. This is in my basement, but my house has very poor soundproofing to being with, so I'm going the extra mile on the soundproofing. It's a small room since I'm limited by some structural issues. It will be about 11' wide by 22' long with barely a 7' ceiling. I believe I will have about 24" of space behind a false wall, but I haven't built the wall yet so I could squeeze another 6" inches if needed.
My past experience with subs is very limited. I have a single JBL ES250PBK in my current living room setup. It certainly improves the overall sound by adding some lower notes, but I can't turn it up very loud because the distortion gets really bad.. so it's really just a fill-in. I have a friend with a powered 12" and a passive 10" in separate corners of the room and it's definitely better than my setup.. But nothing like the dual 18" idea that I'm considering.

So, if I could bore the group with a few questions..

1.) The reviews on my JBL are supposed to be pretty good, but since I have no experience with really high end or really large subs I don't know what "good" means. If I get a couple of huge 18's, is it going to be much of the same sound.. only much more distortion? Does anyone have any first hand experience going from a cheap $200 manufactured sub to a "value" DIY build? I know the experience of sound is difficult to put into words, but if anyone has any experiences they could share to help me understand, I'd appreciate it.

2.) I'm really more interested in quality of the sound than sheer decibels. With a wife and two kids and a very demanding job, I'm most likely going to be spending most of my HT time late in the evenings after kids have gone to sleep.. plus my wife is an early to bed and early to rise kind of person.. so even with a reasonably well soundproofed room I still won't be at high volumes. So, if I have to keep the volume at reasonable levels, I want to have very good quality of sound. Not sure i'm using the right terminology here, but I'd rather have very low 20hz extension than 130db volume. Are the 18's overkill? Should I be looking at 12's or 15's instead?

3.) The HT-18's seem like an amazing deal at $174 shipped.. but they come in 2 ohm or 4 ohm.. Through a few searches it seems like the 2 ohm gets you the highest volume, but 4 ohm might be a cleaner sound. Is this true? Should I go for the 4 ohm since i'm looking for lower volume/lower distortion, smoother bass?

4.) Is it overkill to get 2 x 18"? Would a single DIY sub with my current JBL in another part of the room be sufficient?

Thanks in advance for the patience and help of anyone who replies.

 

[Kubbie]

I'm in the middle of my first DIY build, using the SI HT-18. Just a single 18". Not done so I Haven't heard it yet, but really curious to hear what this will sound like. I haven't demo'd even "high-end" commercial offerings. Just a single 15 year old Kenwood 150 watt 12" sub.

I read somewhere here that some people believe 8x 18's is the minimum for serious bass. I wonder what level of crazy this DIY forum does to people that they go from 1x 18" - to 2 to 4 to 8 and multiples of 24's...

 

[Boomassiv]

Due to the price it is better to get two of the 18" subs and have overhead.

 

[eikon]

I'm in the middle of my first DIY build, using the SI HT-18. Just a single 18". Not done so I Haven't heard it yet, but really curious to hear what this will sound like. I haven't demo'd even "high-end" commercial offerings. Just a single 15 year old Kenwood 150 watt 12" sub.

I read somewhere here that some people believe 8x 18's is the minimum for serious bass. I wonder what level of crazy this DIY forum does to people that they go from 1x 18" - to 2 to 4 to 8 and multiples of 24's...

Seems like you are in a similar position as I am.. only you're a little more committed since you're already building.

There is something amazing about AVS forum.. how quickly I spend more money than I planned.

 

[Fatshaft]

There is something amazing about AVS forum.. how quickly I spend more money than I planned.

Something else you will quickly realize...
How much money you save going DIY !

Then next thing you know, you got the bug!
Good luck with that cause there's no known cure!

 

[pgwalsh]

I'm a noob..

I am really intrigued by the DIY sub build idea. I have seen people post over and over about how fantastic a pair of HT-18's in Martysub boxes (or easier pre-cut flat packs) powered by an Inuke 3000dsp amp would be be. I'm on a tight budget and I need to spend more on construction supplies for my room before I start shelling out for subs.. but I can't get it out of my head. The value proposition that everyone keeps talking about here has me really excited.

A few more details. I'm working on my first ever HT build. I'm doing double wall construction with double layer drywall and green glue and a double layer ceiling on clips and channel. This is in my basement, but my house has very poor soundproofing to being with, so I'm going the extra mile on the soundproofing. It's a small room since I'm limited by some structural issues. It will be about 11' wide by 22' long with barely a 7' ceiling. I believe I will have about 24" of space behind a false wall, but I haven't built the wall yet so I could squeeze another 6" inches if needed.
My past experience with subs is very limited. I have a single JBL ES250PBK in my current living room setup. It certainly improves the overall sound by adding some lower notes, but I can't turn it up very loud because the distortion gets really bad.. so it's really just a fill-in. I have a friend with a powered 12" and a passive 10" in separate corners of the room and it's definitely better than my setup.. But nothing like the dual 18" idea that I'm considering.

So, if I could bore the group with a few questions..

1.) The reviews on my JBL are supposed to be pretty good, but since I have no experience with really high end or really large subs I don't know what "good" means. If I get a couple of huge 18's, is it going to be much of the same sound.. only much more distortion? Does anyone have any first hand experience going from a cheap $200 manufactured sub to a "value" DIY build? I know the experience of sound is difficult to put into words, but if anyone has any experiences they could share to help me understand, I'd appreciate it.

2.) I'm really more interested in quality of the sound than sheer decibels. With a wife and two kids and a very demanding job, I'm most likely going to be spending most of my HT time late in the evenings after kids have gone to sleep.. plus my wife is an early to bed and early to rise kind of person.. so even with a reasonably well soundproofed room I still won't be at high volumes. So, if I have to keep the volume at reasonable levels, I want to have very good quality of sound. Not sure i'm using the right terminology here, but I'd rather have very low 20hz extension than 130db volume. Are the 18's overkill? Should I be looking at 12's or 15's instead?

3.) The HT-18's seem like an amazing deal at $174 shipped.. but they come in 2 ohm or 4 ohm.. Through a few searches it seems like the 2 ohm gets you the highest volume, but 4 ohm might be a cleaner sound. Is this true? Should I go for the 4 ohm since i'm looking for lower volume/lower distortion, smoother bass?

4.) Is it overkill to get 2 x 18"? Would a single DIY sub with my current JBL in another part of the room be sufficient?

Thanks in advance for the patience and help of anyone who replies.

Dual 18's in a marty cube will definitely be a huge change from your JBL ES250PBK.

A reasonably soundproofed room? Have you gone to soundproofingcompany.com and followed those steps? You can definitely achieve lower extension and not hit 130db, but bass travels and even at lower levels if you don't have a properly setup room, you could be shaking your wife a kid.

Most people in these forum's will say it's best to have multiple subs. I'd figure out question 2 before moving on.

 

[LTD02]

with large ported enclosures and a pair of 18's, you can tune to 15-17hz and hit that no problem. if you have a smallish room and don't listen loud a pair of sealed 18's might even be enough. down around the tuning frequency, ported give more than a 2:1 output vs sealed, so for most folks looking for bang for the buck, that's the way to go. there are lots of form factors (tall, short, wide, etc.), so all you really need to do is pick what you want and a design probably exists somewhere around here.

 

[Mrkazador]

1.) The reviews on my JBL are supposed to be pretty good, but since I have no experience with really high end or really large subs I don't know what "good" means. If I get a couple of huge 18's, is it going to be much of the same sound.. only much more distortion? Does anyone have any first hand experience going from a cheap $200 manufactured sub to a "value" DIY build? I know the experience of sound is difficult to put into words, but if anyone has any experiences they could share to help me understand, I'd appreciate it.

That JBL sub is good enough for the average joe. I went from a crappy Yamaha sub to 4 sealed 15s... It was such a HUGE difference in sound quality and spl output, even building one quality sub will make you wonder how that crappy sub sounded "good".

2.) I'm really more interested in quality of the sound than sheer decibels. With a wife and two kids and a very demanding job, I'm most likely going to be spending most of my HT time late in the evenings after kids have gone to sleep.. plus my wife is an early to bed and early to rise kind of person.. so even with a reasonably well soundproofed room I still won't be at high volumes. So, if I have to keep the volume at reasonable levels, I want to have very good quality of sound. Not sure i'm using the right terminology here, but I'd rather have very low 20hz extension than 130db volume. Are the 18's overkill? Should I be looking at 12's or 15's instead?

I say get the biggest sub/s you can afford to fit in your space. If you need something small that digs down to 20hz and not crazy loud then look at a 12" ported sub.

3.) The HT-18's seem like an amazing deal at $174 shipped.. but they come in 2 ohm or 4 ohm.. Through a few searches it seems like the 2 ohm gets you the highest volume, but 4 ohm might be a cleaner sound. Is this true? Should I go for the 4 ohm since i'm looking for lower volume/lower distortion, smoother bass?

This depends on the amp you plan to use. If you're going to use a plate amp which are typically stable 4 and 8 ohms, you want to use a sub that is wired as dual 2 ohm (2 + 2 ohm = 4ohms). Some pro amps are stable at 2 ohms per channel, you would need to look at the specification page for the amp.

4.) Is it overkill to get 2 x 18"? Would a single DIY sub with my current JBL in another part of the room be sufficient?

There is no such thing as overkill The JBL is not going keep up with a 18" sub, I would sell it...

 

[rhodesj]

1) There's no comparison between my old Bic sub and my HT18s. The 18s are deeper, cleaner, lower, better. Music is better. Movies are better.

2) You can get low extension with a 12, but the 18s will go lower and cleaner. You don't have to crank them loud.

3) No, the impedance difference has nothing really to do with volume and distortion in this case, it's simply about matching the driver to the amplifier. Generally speaking, if you have an amp that can support 2-ohm drivers, you get the HT18 D4. If your amp can only support 4-ohm drivers, you get the HT18 D2.

4) It would be overkill if you never listen above a whisper, but if you have family movie night and want to listen at a normal volume, you'll use everything a pair of 18s can give you. The biggest reason to get 2 subs is to smooth out room response. Bass naturally has huge peaks and nulls in response as you move around the room.

HT18s get lots of recommendations because they give a ton of performance cheaply. It's a huge bang-for-your-buck sweet spot.

 

[lovinthehd]

Having just built 2 sealed HT18s all I can say is I can't wait to build another The next one I'm pretty sure will be dual opposed using the HT18s again. I used D2s as that was all that was available at the time, and using them in 4ohm mode (wiring the DVC in series) works great with the amps I have (Crown XLS1500s). I like multiple subs in my room which is big and open, if I had a smaller room I'd probably still go multiple. You could always start with one and see how you feel about it....I know when I completed the first one compared to my Empire I was hooked.

 

[eikon]

Dual 18's in a marty cube will definitely be a huge change from your JBL ES250PBK.

A reasonably soundproofed room? Have you gone to soundproofingcompany.com and followed those steps? You can definitely achieve lower extension and not hit 130db, but bass travels and even at lower levels if you don't have a properly setup room, you could be shaking your wife a kid.

Most people in these forum's will say it's best to have multiple subs. I'd figure out question 2 before moving on.

Thanks for the reply!

I have spent considerable time on soundproofingcompany.com, the AVS dedicated theatre build forum, and other sources. I ordered my clips from Ted in fact already.. and will probably be purchasing the door seal kit soon as well.

I am also realistic.. I know that a "room within a room" build with double walls and decoupled ceilings and double layer drywall with green glue in between will help lower my sound-floor and help keep sound in.. but it's just not going to contain all the bass. From what i've read it would take a concrete bunker, which is not in the cards obviously. So it will be good soundproofing for my budget level and should increase the overall STC, but I'm not expecting to be able to play heavy bass at high volumes without annoying the family at night.. Hence my comments that I'm really more interested in quality than quantity of sound.

 

[squiers007]

I went from an SVS NSD-2000 to dual HT18's in Martycube size enclosures and the difference was unbelievable. I don't listen at crazy loud volumes, but these subs hit low notes with ease, so low that I hadn't even noticed them before. It completely changes your movie/music experience, even at low volume. I went with the 18's 1) so that I could have the crazy output on tap if I ever wanted it and 2) so that during my normal viewing they would just be cruising along, not struggling at all, meaning they will last a very long time, meaning I'm saving even more money!

If you have the space and budget then no amount of subs are overkill... if it's too loud for you then just turn it down... but too loud is not a phrase many know around here, especially when it comes to bass!!

 

[cellarnoise]

2 18s in your space would work well to even out the bass. For when you can't turn them up look into bum shackers. They add a lot to the movie and even music experience, especially when you can't shake the whole house. Dual 18s will probably shake most of the house when cranked...

 

[pgwalsh]

Thanks for the reply!

I have spent considerable time on soundproofingcompany.com, the AVS dedicated theatre build forum, and other sources. I ordered my clips from Ted in fact already.. and will probably be purchasing the door seal kit soon as well.

I am also realistic.. I know that a "room within a room" build with double walls and decoupled ceilings and double layer drywall with green glue in between will help lower my sound-floor and help keep sound in.. but it's just not going to contain all the bass. From what i've read it would take a concrete bunker, which is not in the cards obviously. So it will be good soundproofing for my budget level and should increase the overall STC, but I'm not expecting to be able to play heavy bass at high volumes without annoying the family at night.. Hence my comments that I'm really more interested in quality than quantity of sound.

Well I'm in the same boat. I can't do wall within a wall without reducing the room size too much. My room will be started in a few weeks. I haven't ordered mine stuff yet, but will soon. My son's (1.5 year old) is 2 floors above. I'm going with 4 18's for my theater room. I know when he gets a bit older he'll love it and my wife loves huge bass as well, but only when she's taking part in the experience.

 

[nwf477]

Had to reply I use to have the exact same JBL ES250PBK and I thought wow this thing is great but I started reading and then figured out what I had was not going to cut it. There is no comparison between one MartyCube and the JBL. It made the JBL seem weak now watching movies is a whole new experience. I like it so much I built a second just waiting on the 18.

 

[G-Money1572]

You sound a lot like me a year ago. I'm not a basshead nor do I listen to anything at reference levels. I got sucked in by the value proposition and the fact I'm a DIY type of guy naturally. Now I have 2 18"s in my room for the exact reason that I quoted below. It's amazing what I was missing.

1)
4) It would be overkill if you never listen above a whisper, but if you have family movie night and want to listen at a normal volume, you'll use everything a pair of 18s can give you. The biggest reason to get 2 subs is to smooth out room response. Bass naturally has huge peaks and nulls in response as you move around the room.

My system is pretty underwhelming when compared to AVS standards, but mention 2 18 inch subs to the normal person and they get a weird look on their face.... It's kinda fun.

 

[jcwhammie]

Though I'm reiterating what everyone else had already said, but I would go with two 18's in sealed cabinets. I have two right now in a room a little bigger than yours. I just finished them about 6 weeks ago. I had two Outlaw LFM 1 pluses, which I really like. The 18's are leaps and bounds better in output, extension, and lack of distortion. I bought the Inuke 6000dsp because I thought there was a chance I would eventually buy two more. Well I've already gotten the drivers, I'm just waiting 2 more days to order the flat packs.
I agree that when you first think about that much speaker it seems like overkill. But when you feel like you're in the movie it makes it all worth it. Plus you get to tell your friends and family you built them!

 

[AudioJosh]

I am moving up from dual sealed 15s to 4x sealed 18s. I live in an urban apartment (old brick building though) with a downstairs basement theater. I like the ideal of ease of low bass reproduction, multiples for spreading about the room for best bass quality (average out room modes) and hitting a low f3 sealed.

 

[Cryptic1911]

Absolutely go with the 18's. If you want bass, you need to move air.. can't cheat physics. You don't need to play them super loud to experience the difference either.. they are just more full sounding, and they never struggle. It's a much more enveloping sound

 

[bluer101]

Best money spent in a long time and a fun build.

I'm in a open living room to the whole house and with my 2 martycubes / 2 12's it is crazy. I can't wait to build a sealed dedicated room less area to pressurize.

I then added bass shakers and it brings everything together. Every movie now brings a smile without that feeling you need better.