Line Array 15" SUBS

[RaymondFromThePyrénéés]

Happy New Year to all Audio Fans.

Instead of building 12 separate wooden
boxes for 12 subs,

I want to build
2 hugh enclosed columns with no vents
installing 6x 15 inches subs in each column,

each column driven by a class D amplifiers.

Question since I am new to this.

Do I need some kind of filters ?

and if yes, can the filters be installed
between the amplifiers and the column speakers
to avoid installing the filters inside the speakers ?

Thank You. Raymond living in France.

 

[voodooless]

What is this for? How is bass management done?

 

[DVDdoug]

Do I need be some kind of filters ?

Yes... You need a crossover to route the bass to the sub and the higher frequencies to the other speaker(s). Typically the subwoofer crossover is line-level (at the input to the amp). AVRs have low-passed line-outputs for the sub (bass management) and speaker-level outputs for the other speakers.

There are some pro Crown amplifiers with DSP that you can program as high-pass or low-pass. Ot you can buy an active crossover or a lot of people here use the miniDSP.

Sealed active subs often have some built-in EQ because the bass tends to fall-off at a higher frequency than ported subs. (It falls-off more gradually so at some point the curves cross and the sealed version is putting-out more sound.) With EQ/DS{ and enough power sealed subs can put-out more deep-bass.

Most pro subs used live and in dance clubs are ported because they are more efficient and they can fill a large venue with bass you can feel in your body, even if they don't go as-low as good home subs or pro studio subs.

EQ/DSP doesn't work as well with ported designs because below the tuning frequency the speaker ends-up flopping-around without putting-out much sound.

This post shows the general trade-offs between sealed and ported designs..

Also, a single driver in a given box usually goes lower but more drivers can give you more SPL.

Get some speaker design software and plug-in the Thiele-Small parameters for the drivers. That way you can model and predict performance and decide if you want to go sealed or ported, etc. WinISD is free.

 

[Sokel]

I was thinking about the same thing, (no matter the number of drivers) so I can install a floor to ceiling array at each corner of a 5 meter wall and then make them invisible (short off).
I even have the lanes ready hidden in the cement of the floor.

Yes, you'll need a bunch of filters and the gear to run them and you better have planned all the clutter of the cables needed if you want them active and aligned at MLP.
Not very hard if you plan the logistics.

 

[RaymondFromThePyrénéés]

I had a friend living close to Toulouse in France who had about 12 subs, each sub in a closed box. I do not know how he managed the whole thing, but he was a student in sound and other high techs and had powerful software from school he talked about. When he played some jazz or blues, I closed my eyes, and it was as if the musicians were in front of me. Especially the drummer. He did not play loud, but so real, amazing. So I thought I try out the same number of subs, but I must acknowledge that I do not know much about crossovers and so on, but never too late to learn. All the best, Raymond living in France

 

[DVDdoug]

There are 2 reasons for using multiple woofers/subwoofers -

1. To get strong-loud-deep bass. (You can't get the "realistic sound" of a kick drum or bass guitar from a 6-inch woofer...)

In "small rooms" (any room in a house) you get standing wave Room Modes where certain direct and reflected waves combine in-phase at certain frequencies and certain places in the room to make a bump-up in frequency response, and at other frequencies and other places in the room they combine out-of-phase creating cancelation and a dip in frequency response.

The bumps and dips can be evened-out with multiple subs at different locations. (Your column won't help much with that.) ...Not always practical in a home environment. Another solution is bass traps which to absorb the waves that would otherwise be reflected, again smoothing-out the dips and bumps. Bass traps are usually big and bulky and you have to cover a significant amount of wall area. "Regular" acoustic treatment doesn't do much for the bass and it's often unnecessary.

You can fix the bumps with EQ but the dips/cancelation is more difficult. It takes nearly "infinite power" which you may have (considering the home environment) and nearly "infinitely large woofers" which you WILL have! EQ only "works" at one place the room so if you have a home theater situation with several viewers/listeners, some peopel will get "imperfect" bass.

Fortunately, the hard-to-fix dips are less annoying than the "boomy sounding" bumps.

BTW - I forgot to say... I LOVE BIG SPEAKERS! My "speaker stack' in my living room is almost ceiling height (almost 8-feet tall) with the subs on the bottom and tweeters on the top angled-down. Some people would complain about the "imaging" with the tweeters higher than ear-height and higher than the midranges, but I listen to rock, and I'm a bit crazy! ...I "only" have a pair of 15-inch subs in large ported cabinets, and no bass traps or other treatment. ...It's just a normal carpeted living room. I'm satisfied and I can "rattle the walls" or annoy the nearby neighbors... I also built a pair of 8-foot LED "VU meters".

but I must acknowledge that I do not know much about crossovers and so on, but never too late to learn.

You should understand what frequency response is and what a frequency response curve looks like. If you experiment with the speaker design software and make a good design you can make electronic tweaks later. You're pretty-much stuck with the driver & box size, although you can add or block a port, or change port dimensions. With huge well-designed subwoofers you can't go wrong from there!

BTW - Ported boxes are more finicky than sealed boxes... A random ported box is likely to be BAD, whereas a random sealed box is usually OK. But either way, the software can help you to make a good speaker.

If you have an AVR (audio video receiver) the bass crossover ("bass management") is taken care of. That's the most common and easiest way to add a subwoofer.* Normally it's an active sub but you can use your own power amp. Many AVRs also have "room correction" (Software that measures and EQs the frequency response).

Some active (powered) subwoofers have built-in line-level high-pass filters to cut the bass from the main speakers (and low-pass to the internal amplifier). You can also build an active sub and there are "plate amplifiers" with crossovers and other EQ or DSP built-in.

Or there are active line-level crossovers.

All 2-way or 3-way speakers have a crossover inside.

Once you've built your speakers and everything is working you can consider downloading REW (free) getting a measurement microphone (about $100 USD). to measure your speakers and room. ...Especially before acoustic treatment, etc. "Diagnosis before treatment".




* Bass management is an optional setting. You can set your AVR for "large speakers" and the regular speakers will get the regular bass from the stereo and surround channels. In this case, the sub is only used for the "point one" LFE channel, so the sub isn't used with regular stereo at all. Also, without an AVR (or other surround decoder) the LFE channel is lost and you only get the regular bass (It's not used in the stereo down-mix).

 

[Wolf11Man]

You are at a great forum here, but it is not that much about DIYS projects. With DIYS you may get more answers at https://www.diyaudio.com/
There are a whole lot of competend builders getting their hands dirty and you will find any information you ever need.

 

[voodooless]

You are at a great forum here, but it is not that much about DIYS projects. With DIYS you may get more answers at https://www.diyaudio.com/
There are a whole lot of competend builders getting their hands dirty and you will find any information you ever need.

I would really recommend against this if you don’t know what you’re doing. Next to the competent builders there is also a lot of subjective nonsense. If you’re new to the game, this will be a major source of noise you cannot filter out properly. And the building is not what is the first concern here anyway.

I admire the enthusiasm, @DVDdoug, but we really still have nothing to go on here. There is a vague wish to recreate some realistic drumming, nothing more.

At @RaymondEnAriège, we really need more information about what kit you have, and in what room you want to put it.

12 subs will be overkill in the vast majority of cases, and surely a wast of money, time and space.

And realistic drums is not something only achieved with subs. Much of the drum content lives above the 80 Hz where typically drums are crossed. If you don’t fix that, it still won’t sound good. And if the recording isn’t done well, it never will.

So let’s first get some more context:
- current speakers
- room size and layout
- amplification, bass management options
- budget

 

[Azrael]

You are at a great forum here, but it is not that much about DIYS projects.

Well, at least we're in the DIY audio subforum here.

12 subs will be overkill in the vast majority of cases, and surely a wast of money, time and space.

With 12 15-inch drivers and depending on the type of room, a double bass array (DBA) would be a good choice, with a 3x2 matrix on the front and on the rear walls. With a DBA, more total Vd is required for the same output than with - for example - an SBA.

However, for laymen, this is probably the most difficult solution. For the subwoofers alone, two power amplifier channels, a DSP, measuring tools, and the ability to configure the whole system are required.

 

[Flaesh]

There's more than one way to skin a cat place and drive 12 subs. For example, one line array positioned horizontally on the floor in front (Is the room wide enough?), with a single amplification channel. Or MSO system with 12 processing and amplification channels and a random arrangement of 12 subwoofers.
And besides what's already been said, how are you going to move this strong, sturdy 8-foot box?

 

[RaymondFromThePyrénéés]

There are 2 reasons for using multiple woofers/subwoofers -

1. To get strong-loud-deep bass. (You can't get the "realistic sound" of a kick drum or bass guitar from a 6-inch woofer...)

In "small rooms" (any room in a house) you get standing wave Room Modes where certain direct and reflected waves combine in-phase at certain frequencies and certain places in the room to make a bump-up in frequency response, and at other frequencies and other places in the room they combine out-of-phase creating cancelation and a dip in frequency response.

The bumps and dips can be evened-out with multiple subs at different locations. (Your column won't help much with that.) ...Not always practical in a home environment. Another solution is bass traps which to absorb the waves that would otherwise be reflected, again smoothing-out the dips and bumps. Bass traps are usually big and bulky and you have to cover a significant amount of wall area. "Regular" acoustic treatment doesn't do much for the bass and it's often unnecessary.

You can fix the bumps with EQ but the dips/cancelation is more difficult. It takes nearly "infinite power" which you may have (considering the home environment) and nearly "infinitely large woofers" which you WILL have! EQ only "works" at one place the room so if you have a home theater situation with several viewers/listeners, some peopel will get "imperfect" bass.

Fortunately, the hard-to-fix dips are less annoying than the "boomy sounding" bumps.

BTW - I forgot to say... I LOVE BIG SPEAKERS! My "speaker stack' in my living room is almost ceiling height (almost 8-feet tall) with the subs on the bottom and tweeters on the top angled-down. Some people would complain about the "imaging" with the tweeters higher than ear-height and higher than the midranges, but I listen to rock, and I'm a bit crazy! ...I "only" have a pair of 15-inch subs in large ported cabinets, and no bass traps or other treatment. ...It's just a normal carpeted living room. I'm satisfied and I can "rattle the walls" or annoy the nearby neighbors... I also built a pair of 8-foot LED "VU meters".


You should understand what frequency response is and what a frequency response curve looks like. If you experiment with the speaker design software and make a good design you can make electronic tweaks later. You're pretty-much stuck with the driver & box size, although you can add or block a port, or change port dimensions. With huge well-designed subwoofers you can't go wrong from there!

BTW - Ported boxes are more finicky than sealed boxes... A random ported box is likely to be BAD, whereas a random sealed box is usually OK. But either way, the software can help you to make a good speaker.

If you have an AVR (audio video receiver) the bass crossover ("bass management") is taken care of. That's the most common and easiest way to add a subwoofer.* Normally it's an active sub but you can use your own power amp. Many AVRs also have "room correction" (Software that measures and EQs the frequency response).

Some active (powered) subwoofers have built-in line-level high-pass filters to cut the bass from the main speakers (and low-pass to the internal amplifier). You can also build an active sub and there are "plate amplifiers" with crossovers and other EQ or DSP built-in.

Or there are active line-level crossovers.

All 2-way or 3-way speakers have a crossover inside.

Once you've built your speakers and everything is working you can consider downloading REW (free) getting a measurement microphone (about $100 USD). to measure your speakers and room. ...Especially before acoustic treatment, etc. "Diagnosis before treatment".




* Bass management is an optional setting. You can set your AVR for "large speakers" and the regular speakers will get the regular bass from the stereo and surround channels. In this case, the sub is only used for the "point one" LFE channel, so the sub isn't used with regular stereo at all. Also, without an AVR (or other surround decoder) the LFE channel is lost and you only get the regular bass (It's not used in the stereo down-mix).

Thank You for all this useful information. Yes, my friend who had all these subs like to experiment and YES he had lots of absorbing wood fiber insulation pads on the walls, I think almost half the walls were covered with this. My idea to begin easy is to buy a WiiM Ultra Amp, so that I can begin listening to music again after moving into this house last year. Since at the moment I do not have any subs with my Line Arrays, I bought, so that I can start to listen to music again with a WiiM, some vinted speakers yesterday, 350US$ for a pair of french PhonOphone model G1, 20-20.000 Hz, 85db, 8 ohms, 70-100 watts, the subs on them are new.. The person selling them to me yesterday build his own horn speakers and so on, I real technician. He said I should change the condensators and so on but they sounded very nice while at his place yesterday. Once I get this up and going next week, I will begin experimenting, building subs and so on. The idea of several subs was some nostalgia from what I heard at my friends house five years ago. REW, looks pretty complicated to me but perhaps there are som tutorials on youtube. Thank You. Raymond

 

[RaymondFromThePyrénéés]

I would really recommend against this if you don’t know what you’re doing. Next to the competent builders there is also a lot of subjective nonsense. If you’re new to the game, this will be a major source of noise you cannot filter out properly. And the building is not what is the first concern here anyway.

I admire the enthusiasm, @DVDdoug, but we really still have nothing to go on here. There is a vague wish to recreate some realistic drumming, nothing more.

At @RaymondEnAriège, we really need more information about what kit you have, and in what room you want to put it.

12 subs will be overkill in the vast majority of cases, and surely a wast of money, time and space.

And realistic drums is not something only achieved with subs. Much of the drum content lives above the 80 Hz where typically drums are crossed. If you don’t fix that, it still won’t sound good. And if the recording isn’t done well, it never will.

So let’s first get some more context:
- current speakers
- room size and layout
- amplification, bass management options
- budget

I appreciate your feedback voodooless. I will get back tomorrow to tell more about what I have and especially do not have

​

 

[voodooless]

PhonOphone model G1

They are quite old, but if the woofer was replaced, could still be okay. If there are any electrolytic caps in the filter, those might benefit from a replacement after so many years.

A large woofer is probably useful to match the massive subwoofer. But the 4 kHz crossover to the 6.5” is probably going to have directivity issues, and the large distance between woofer and tweeter will cause lobing (different sound when you move around). So that is most probably not ideal.

As to the subwoofer setup. I think it’s better to be smart here. First off, getting good bass will require you to make measurements and dial in the system for best results. This can either be done manually, or using automated systems. The last is especially convenient if you don’t have the knowledge or time to do this.

Also, having multiple subwoofers with a WiiM isn’t ideal without an additional DSP. You’ll have to individually dial in every channel for optimal results. The WiiM just has a single output.

What I might do in your situation: only build 4 subs, 12” is plenty, and distribute them across the room. Get a 4 channel amp for them. Next get an AVR that support Dirac ART. This is not super cheap, but it will basically take care of bass management, alignment, and will eq your speakers and subs in a way that isn’t easily done manually (arguably ). Budget wise, 4 drivers and amps vs 12 will compensate for the AVR and license.

If you want to tinker, get a miniDSP and hook to up to the WiiM AMP. I’m sure people here will be able to help you dial it in.

 

[Flaesh]

Bert Doppenberg)) I don't know if it's one or two channels. Maybe it's just one.

 

[RaymondFromThePyrénéés]

Dear Flaesh, whaooo, that is amazing.

Thank you voodooless. Yes, that is a good idea. 4 subs and an amp for these subs. Thank you.
I will also try my new speaker. The Dirac and the REW intimidates me. I do have the mike for measuring. Perhaps I can find a Dirac how to use guide on the youtube channel.

Very interesting comment on percussion and that they are not so low in frequencies. Yes, it is true. I will start out wisely, trying to find a used sub to begin with.

My room. I am so lucky to have a big room for my hifi, houses where I live in the french Pyrénées are cheap. 1000 us dollars to the square yard, so I have a big room all to myself with a lock for cats and children !
What I wonder is whether I should install the speakers on the long side or the short side. Either way I can get lots of space for the speakers, either behind or on the outer sides.

- 6 meters long = 19.7 feet
- 4 meters wide = 13 feet
- 3 meters high = 9.9 feet

My budget is small because I think that spending hugh amounts is not a guaranty to a good sound.
But I can buy for some 5000 dollars over some years, I prefer to go step by step.

Now I have my old Alientek's that I will change for the WiiM Ultra Amp just to start going
I feel emotionally empty without good music.

The speakers I just bought,
The old fench PhonOphone model G1, 20-20.000 Hz, 85db, 8 ohms, 70-100 watts with new woofers.

And also I have my old line arrays that a friend sold me for 70 dollars that needs
a woofer. They are not pretty but when I went to compare my sound with the sound in a
hifi store with speakers for 2000€, there is no comparison ! But as always, one has to compare
in the same room setting.

 

[diyhobby]

Raymond I suggest you get this speaker made. 2 way BookShelf or / Floor Stander start with this and for extra bass that you want we look at later

Paul Carmody's DIY Speaker Pages - Virage

Home > Bookshelf Speakers > Virage

sites.google.com

regards
anand

 

[Hayabusa]

The bumps and dips can be evened-out with multiple subs at different locations. (Your column won't help much with that.) ..

I think it will, a full height line array will minimize floor and ceiling interaction also for bass!

 

[Flaesh]

minimize floor and ceiling interaction also for bass!

But there may be little benefit from this:

 

[Hayabusa]

But there may be little benefit from this:
View attachment 507768

Is this simulating multiple subs on top of each other?

 

[Flaesh]

Yes