Building a large Low-Tones cabinet to join existing high quality Compact speakers

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Hey Y'All!

I'm new here ...never done forums before! First of all I want to apologize for my English (my speach is OK, but I hardly ever need it to write ...so a lot of mistakes and translating!). I'm a Hifi Adept, with very sensible ears, but very few knowledge about speaker mathematics! Mostly while listening to all wellknown and often very expensive speakers, I'll find my stuff! Then getting the right sound by carefully testing and matching pre- and poweramplifiers, cable and interlinks will be the icing on the cake! Having been working for several Hifi Importing companies in Belgium, I own a lot of good stuff, BUT .....I adapt and upgrade most of it ...when should you be completely happy!?

Sometimes you don't find what you are looking for (or it may be way too expensive). As I have several very, very,very good Compact Speakers (Monitor Audio, Dynaudio, Spendor) I never invested in Big speakers, because I feel they don't do Highs an Mids as good as the compacts! I tried a lot of high quality Subwoofers, but NEVER found it completing the sound ...it just added something not coherent! I play almost any kinds of music (this is why I use several speakers)

So here's the question :
Would it be a (good) solution to build an enclosure of about 100 up to 150 liters, to put in 1 or 2 bassdrivers, which don't play uniquely subbass, but work up to maybe 200 or 300 Hz, and with a filter (Highpass?) that is variable and let the Compacts only play Highs and Mids and then nicely pass over the job?

If I'm right, it would be like the lower cabinet of a separated speaker (seen several High-End speakers that way and also building projects). MONACOR has something like that : the MENHIR ...so could I use such a kit, or build alike with higher quality components?

I also saw from Monacor the SAM-2 amplifier, which seems to do such a job (if I go from my preamplifier to the Sam-2 and from there to the poweramp, it cuts the Compacts up to 150 Hz).This would be an active solution?

So the question stands, and most important is a real high quality blending (active or passive ...I'm still a bit oldfashioned so I won't think about digital variable and/or programmable stuff!) with different Compact speakers! (and playing and testing)

As I'm 'new' in this part of the market, my idea may be ridiculous, very easy, complicated or not possible with a good quality wanted, but I'm excited anyway to see if I will be combining two worlds! (mostly people who buy expensive stuff, just listen, don't touch, and are willing sheep to get slaughtered by commercial guys ...people who build on a decent level, will want to build everything themselves from A till Z!).

Thanks in advance!
 
I tried a lot of high quality Subwoofers, but NEVER found it completing the sound ...it just added something not coherent! I play almost any kinds of music (this is why I use several speakers)

So here's the question :
Would it be a (good) solution to build an enclosure of about 100 up to 150 liters, to put in 1 or 2 bassdrivers, which don't play uniquely subbass, but work up to maybe 200 or 300 Hz, and with a filter (Highpass?) that is variable and let the Compacts only play Highs and Mids and then nicely pass over the job?

So the question stands, and most important is a real high quality blending (active or passive ...I'm still a bit oldfashioned so I won't think about digital variable and/or programmable stuff!) with different Compact speakers! (and playing and testing)
Crossing over at 200 to 300 cycles needs a lot more fine tuning to accomplish a smooth crossover and alignment from the lows to the mids than the more usual "sub" crossover around 100 Hz, below most vocal range.
Crossing at 200-300 is right in the middle of the vocal fundamental range, if the transition is not really smooth, the speaker system will not sound very good, even though it has more LF extension.
Bass reflex or sealed will make the transition the easiest, but by far the hardest part of the project is the crossover.
To "do it right" you need to cut the lows out of the high speakers as well as the highs out of the lows.
This is not a matter of simply putting a few capacitors, coils and resistors together.

Alignment is by far easier to do with DSP than passively, especially if you don't have detailed impedance curves of all the drivers.

If you want to do the crossovers passively, there is a good sticky about building passive crossovers without measurement at the top of the full range section.
http://www.diyaudio.com/forums/mult...designing-crossovers-without-measurement.html

Good luck!
 
You will probably need to get a pair of the best possible subwoofers money can buy to get a good match with a pair of top class mini monitors.

If you were in the US I was going to recommend a pair of JL Audio f112 Fathoms or try to build something similar using JL Audio 12W6 or 12W7 drivers but since you are in Europe look for Peerless XXLS, Dayton, or SEAS top of the line 12" or 15"subs. Pair them with good plate amps and you may get there. Also if you are brave enough look at TC Sounds and RE audio subs if you don't mind braking the bank.
 
OK weltersys, vacuphile, spirosZ ...gratefull for the input! I'm adapting my view already about crossing over (red some about the freq.range of human voice and critical range) and I may build a heavy, well braced towerlike cabinet as a sub, with a good amplifier, based on 2x12" drivers. I looked at them all : Peerless, Seas, ScanSpeak, JL Audio, TC Sounds, ...about 280-4OO euro per driver should get me there (I first will read all the tests I can get my hands on!).

I'll try it out with Compact monitors ...do I get the right sound, then I build a second one for Hifi ....am I not satisfied, then the sub goes to the surround system (which need another sub anyway!).

I also glanced at the thread about building crossovers ...interesting! Will study it! Just red the book of David B. Weems ...ordered 3 Visaton brochures and book, two Monacor LS building brochures and the Loudspeaker Design Cookbook of Dickason (Salute! to the Internet!). I also may get the book from Joe D'Appolito! I'll be armed ...and try to get dangerous! ...learn about filters!

Another question :

For now, knowing it's purpose, with an enclosure of about 100-130 liters, would I use 1 driver, 2 identical active drivers or 1 active and 1 passive driver and will I get the best Hifi sound with a closed or BR enclosure?

See y'all!
 
For HIFI I would say two (left-right) active closed boxes.
As to frequency, they should start at 27,5hz. (one of the reason for the 'active' part)
That's the lowest note on a grand piano. But this depends on your music taste.
If you want to go the organ route, your in trouble (16hz or even 8hz!)
 
Hey Bart,

Yes, 2 active boxes is what I will build, and 27,5 Hz is good enough (I love Piano and Harp / I don't like Organ in general, but will play some Albinoni (Adagio), and Zarathustra only for demonstrations) ...But then the question is whether I will use in each enclosure :
1 active driver
1 active + 1 passive driver
or 2 active drivers ?
 
Hey Bart,

Yes, 2 active boxes is what I will build, and 27,5 Hz is good enough (I love Piano and Harp / I don't like Organ in general, but will play some Albinoni (Adagio), and Zarathustra only for demonstrations) ...But then the question is whether I will use in each enclosure :
1 active driver
1 active + 1 passive driver
or 2 active drivers ?
Driver count, size, and Xmax are dependent on your desired SPL.
Some members here desire 120 dB at 20 Hz, others are satisfied with 95 dB at 30 Hz.

A pair (two cabinets) of sealed long throw 12" (around 13mm Xmax) should take care of your needs.
If you go with larger, low tuned (20-30Hz) you can get by with less than half the power required for sealed, and may not need compensating EQ.
 
My personal preference, when price is not as important, would be to use two drivers per closed cabinet and active filtering between mains and subs. So active all the way. I can't comment on driver choice. To much variables and subjective comment on the net.
Even if you don't want furniture shaking effects, it's good to have a lot of headroom for compression's and distortion's sake.
If you go the bass reflex route and tune at 27,5hz, the drivers will have less strain and you could go with one driver per box instead of two, but the box will be about the same I guess.

Basically the same comment as weltersys, only difference is, he really knows what he's saying, I'm just repeating from memory. 😀
 
Hey Everybody!

I'm almost reading and studying every day about this stuff!! I'll get there!

For testing and combining with different High End Monitors (which reach about 40Hz easily) I may have to go digital and active indeed! If that's the best, I 'll do it and just get 'modern'.

As I have access to Monacor directly, I guess I'll will build a big enclosure, based on their speakers first, with their amplifier Sam2. This will be a testcase for getting more and better afterwards (I could build an extra Satellite for it afterwards, to complete a system for popular music ...bad recordings played on a Super system always sound bad. That's the reason I always kept several pairs of speakers. Or as said before, it will serve for Surround). In the process I'll learn about building, bracing, stuffing and dampening, and experience if a big enclosure adds what I'm looking for (and don't find in compact subwoofers with a forced sound!).

Ideas are always welcome, but I probably have to do some more homework first, and get a more specific idea of what I want! Pretty shure is a large volume, a pair, 12", closed, active ...I will look into DSP!
 
Hey Bart!

What would you think about this : I just red in Hobby Hifi about the Reckhorn A-404 Amplifier. It gets good critics and the price is not too high (I don't mind spending some money on Hifi, and building a speaker combination that doesn't sound good enough is not a terminal faillure ...you can always re-use the stuff in another combination or project! But I won't spend 500eu on a woofer, 1000eu on an amplifier ....maybe up to 1000eu per enclosure, all in!).

I gues I could develop enclosures which hold a Reckhorn 404, built in visible in the front (horizontally), (the Reckhorn is 43cm wide and 10cm high) ...but then I would need long signal cables from the Pre-Amplifier to the Reckhorn and back to the Power-Amps + the existing long speaker cables? Maybe better to keep the Reckhorns with the Pre-Amplifier (very short signalcable) and build a space for the Power-Amps (Monoblocs) in the Bass-enclosure (=long signalcable + very short speakercable).

What do you think about that :
1) The Reckhorn?
2) Is 1000eu per enclosure OK for good quality Hifi (or way too high or low)?
3) The arrangement of all the units?
 
1) Doesn't look bad but you might need two of these, so I would say, have a look at a Beringer iNuke 1000DSP or a 3000DSP, you would spend less money and have a DSP controller, programmable from you computer.
2) Yes 1000€ per box should be OK for a DIY sub. You gave the example of 500€ on a woofer and 1000€ for the amp, I would reverse that and spend the larger part on the driver. 😉
3) I prefer long speaker cables instead of long signal cables, less chance of noise pick-up along the way.
2,5mm² should be enough for what you need, sub frequency's need power leads, so you could play save and use 4mm², more then enough!

Oh one more thing, since you're not aiming for <25hz, like HT 'demands', a good woofer might not be that expensive, so another benefit to your goal. 🙂
I bought two Monacor SPH450TC's a while back (18" woofers)
If you like I can sim a BR and a sealed box for 27,5hz and up or whatever freq you like.
 
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Hey guys!

I have been reading a lot about building speakers (all the Mathematics)...also took a look at Behringer, Monacor and Rane external DSP Crossovers, Equalizers, Speaker Management Modules, Programable Hypex mono and stereo modules.

...so now I know much less then before!!! Or I should say : too many possibilities!

So as I'm a complete novice in building, I decided to go easy : it will be 2 huge closed enclosures (120-200 liters each, about 115x40x 60cm, not rectangular and few parallel sides, against standing waves), with 2 x 12" drivers in each speaker(I guess parallel) and driven by 2 pretty normal Plate amps or by 2 external Reckhorn amps A-406 (gets good tests and seems to adjust the compacts and basses fine). It will be just for Hifi.

Can anyone tell me how I choose the drivers ? I can look at all the drivers and start calculating, but is there a way to do a PRESELECTION :

What I mean is : what KIND of driver do I need, given
120-200 liters
closed
2 x 12" drivers in an enclosure, I guess parallel is ok ?)
I want a deep clean bass (I may play very loud, but not all the time)
I'll brace the cabinets very well
I can get Monacor, Peerless, Vifa, Scan Speak, Seas, Eton, Morel, P-Audio and SB Acoustics, and I'm willing to spend up to 300 euro (about 375$?) per driver.

Thanks!
 
Will you use them as subs (<100Hz) or as woofers?
What use? Music? Home theater?
I am not familiar with the Reckhorn amplifier but it looks like a competitor to the Behringer iNuke 1000DSP.
How does it compare?
The Behringer seems to be more powerful, has build in fully adjustable High & Low pass filters and digital equalizer. With a pair of those you can drive both the subs and the main speakers and have total control over them.

Also it seems that you plan to build those boxes because you have a specific place for them in mind. However low frequency room modes may need experimentation with the sub position to avoid nulls and peaks at listening position. Sometimes just a small position change forward or backward can make a big difference. I would opt for an enclosure that allows me some movement.

Among the brands you listed Peerless XXLS12 is a safe bet (and will work fine with a relatively small enclosure) but I am sure that there are other good options as well.
If you play very loud you may want to look at 15" or 18" options as well.
 
Hey SpirosZ!

Well, as the compacts I refer to (Monitor Audio Studio 2 an 6 / Spendor / Dynaudio/ ..there were more, there will be more!) go down deep to 40-45 Hz, and sound very, very well, I just want to add more low (in a big room 7x8m), and let the compacts play only their beautifull Highs and Mids. So I want to have a variable crossover between 100 and 40 Hz.

The bas enclosures will only serve for Music / Hifi. With 120-200 liter I guess I can go very low (the amplifiers give the posibility to cut at 15-60 Hz Subsonic, Low Pass at 40-300 Hz and High pass at 40-400 Hz). There seems to be a lot of space to experiment there?

A closed enclosure with 2 drivers will probably be less dependant on the room than BR's? And they may go as deep as they can (without forcing for an extra Hz ...just what they can reach, stressless, easy going!).
 
Well, a sealed enclosure will be less efficient but more forgiving as well. I am a big fan of sealed subs but they need lots of power and probably some DSP work.
Twin 12s, one sitting on top of the other also helps with room modes so you are on the right track.
Do some modeling on WinISD and see which one suits the sealed box you are after.
Peerless XXLS12, Dayton 12"Titanic or Reference, Eminence Lab12, are some of the most popular choices and they have being used in some great commercial subs.
According to WinISD two 12" XXLS will need at least 200lts for a Qtc 0.77 (WinISD recommended 282lt), two Lab 12s will yield a little higher SPL and will go a little deeper on a 105lt box with a Qtc of 0.7. I don't have the T/S of the Dayton drivers but if I remember well they will also be fine in a not too big sealed enclosure.
 
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