1st build: full range sealed for 4 liters

[zgtc]

Hi,

I will build my first pair of speakers. I want something easy, so I would go for a cube sealed box, around 4 liters (so probably max size around 6") and should be 8Ω.

I am seeking guidance on what numbers I should look for in the specs of a full range driver (ie. SPL? F3? etc). Obviously, driver suggestions are welcome, but I'd prefer to understand how to interpret the marketing talking first.

A bit more of background info:
I am also deciding on a design to build the amp (mostly decided for LM3886 Done Right, around 2x45W at 8Ω), and the kind of music I like is Gabriel, Bowie, and symphonic/rock (Pink Floyd, Dream Theater, Marillion, ...). I set the limit on around $150 for a pair of drivers.

Thank you so much

 

[revelator]

I would say ...Why limit the design to sealed ? Generally Bass reflex sounds much better. Consider for example Markaudio drivers....some of these drivers are voiced and designed to the extent of not having to add baffle step compensation circuit (that is an inductor paralleled with resistor connected in series to one lead of the fullrange) to flatten the midrange which brings out the appropriate bass...at the expense of loosing some efficiency.

I don't have any of the newest MA drivers ( I do own A pair of CHR 1st generation 4 inches) in a recommended bass reflex enclosure and the overall sound is good especially the bass.

Here a link to Alpair 6 in 3.3 liter bass reflex for example

https://www.madisoundspeakerstore.com/pdf/markaudio-enclosure-plans/Alpair6M-BR.pdf

I have evaluated a variety of small drivers and fullrange including CSS, Tang band and Peerless but all in bass reflex. I personally don't like sealed for small drivers ..unless you have plans to add subwoofer later. Lets see what others recommend....

Hasta Luego....

 

[zgtc]

Hello,

Sealed: mainly because i want something really small and I (unknowingly) thought vented required much more volume. Well, at the very least you have to account the space for the cone. Also, I like square boxes, but I guess I could get a 4", put it in a 3 liters box and still be able to use vented (will have to design to make sure it all fits)

thank you for the suggestion!

 

[GDO]

A bit more of background info:
I am also deciding on a design to build the amp (mostly decided for LM3886 Done Right, around 2x45W at 8Ω), and the kind of music I like is Gabriel, Bowie, and symphonic/rock (Pink Floyd, Dream Theater, Marillion, ...

Diomío, if you had mentioned Narciso Yepes, Paco de Lucia, Niño Josele con Estrella Morente, or small jazz performances, even barocco or opera, might understand that gear choice...

Now...If i were you i would change my musical program or the project idea...

 

[zgtc]

my current system is an oldish panasonic sc pm01 microshit, i dont think the diy would sound any worse

 

[GDO]

my current system is an oldish panasonic sc pm01 microshit, i dont think the diy would sound any worse

Nor much better. Its more or less the boombox i have in the kitchen when i want to enjoy non critícal pop rock programs...

This kind of music dont sound especially engaging on small systems, even if refined sounding. Minimum bruteforce sizematters required...

 

[suprf1y]

I built these and I'm very happy with them

"Dragon Foals" writeup - Techtalk Speaker Building, Audio, Video Discussion Forum

 

[planet10]

One of the reasons to go vented is because most of the small speakers are designed to be used vented (if you want any bass response). The Aura NS3 is the only counter example i can think of.

My 1st choice would be one of the Alpair 6.2s. My miniOnken alignment tends to generTE smallish boxes relatively). Both A6 fit into a 2.5 litre net volume miniOnken (with vent less than 4 litre), the metal is optimum in 3.6 litre net, the paper in 5 litre.

dave

 

[zgtc]

This kind of music dont sound especially engaging on small systems, even if refined sounding. Minimum bruteforce sizematters required...

I have a space restriction, thus the 4L limit, so I will have to at least get the most efficient drivers I can for the money I have. I would love to have huge speakers but then I would need a second house for them. I am trying to be realistic.

I built these and I'm very happy with them

"Dragon Foals" writeup - Techtalk Speaker Building, Audio, Video Discussion Forum

Noted. I will have a proper look at your detailed post, thank you!

One of the reasons to go vented is because most of the small speakers are designed to be used vented (if you want any bass response). The Aura NS3 is the only counter example i can think of.

My 1st choice would be one of the Alpair 6.2s. My miniOnken alignment tends to generTE smallish boxes relatively). Both A6 fit into a 2.5 litre net volume miniOnken (with vent less than 4 litre), the metal is optimum in 3.6 litre net, the paper in 5 litre.

dave

Great, vented in less than 4 liters! I will definitely have a look at those mini Onken plans, thank you.

Also, in general, what are the key parameters I should look for in a FR speaker (vented or sealed) for such volume below 4 liters? I have a list of 3-6" FR but beyond SPL and F3 I am not so sure how to compare them.

Thank you all again

 

[zman01]

This kind of music dont sound especially engaging on small systems, even if refined sounding. Minimum bruteforce sizematters required...

Would agree with GDO here. Small single driver systems don't to well with complex rock. A small 2 way perhaps can cope a bit better.

That being said the Dragon Foals might fit the bill, as AFAIK the designer likes rock/metal and in the conclusion he says that the speakers work with rock.

 

[zgtc]

OK but, 2 considerations:

1. As far as I know (very little) FR allows for some more build errors. Also, two way are harder to build, xover adds some extra space, etc

2. What I see in those FR Dragon Foals is a port in the back. Is there any list of rules on where the port has to be placed respect back of the driver? Would it be better to have the port in the front below the FR driver?

Thank you again

 

[zman01]

zgtc,

For BR cabinets port placement can be pretty flexible, but I am not sure if Wolf put the port in the back for any particular reason besides keeping the front clean. He's also a diyAudio member - screen name: wolf_teeth. Maybe you can send him a PM with your query.

 

[zgtc]

zgtc,

For BR cabinets port placement can be pretty flexible, but I am not sure if Wolf put the port in the back for any particular reason besides keeping the front clean. He's also a diyAudio member - screen name: wolf_teeth. Maybe you can send him a PM with your query.

Thank you!

Btw already looking into 2way options just in case, but size aside, it will increase cost quite a bit.

 

[midrange]

The key parameters you need are Fs, Vas, and Qt. They are often listed under Thiel/Small parameters in specs. I would suggest you look at Lalena.com and find diy audio and video. Then go to "speaker box enclosure designer", and play around putting the above parameters in. You can try out both closed box and ported designs. You will quickly see how the parameters and box size relate.

 

[GDO]

OK but, 2 considerations:

1. As far as I know (very little) FR allows for some more build errors. Also, two way are harder to build, xover adds some extra space, etc

2. What I see in those FR Dragon Foals is a port in the back. Is there any list of rules on where the port has to be placed respect back of the driver? Would it be better to have the port in the front below the FR driver?

Thank you again

I only wanted to advise against low bass extension of most closed boxes based on small drivers.

Regarding port at the back vs at the front, at these freqs response is omni, so no matter where the port is placed.

Of course it will make a diffrence when the port is placed close to a boundary, and you will get an extra boost if you use a rear ported box close to a back wall.

 

[zgtc]

The key parameters you need are Fs, Vas, and Qt. They are often listed under Thiel/Small parameters in specs. I would suggest you look at Lalena.com and find diy audio and video. Then go to "speaker box enclosure designer", and play around putting the above parameters in. You can try out both closed box and ported designs. You will quickly see how the parameters and box size relate.

GREAT, thank you! I understand those 3 are important for box design "only"? Should i give some importance to others as SPL or F3?

 

[zgtc]

I only wanted to advise against low bass extension of most closed boxes based on small drivers.

Regarding port at the back vs at the front, at these freqs response is omni, so no matter where the port is placed.

Of course it will make a diffrence when the port is placed close to a boundary, and you will get an extra boost if you use a rear ported box close to a back wall.

Thank you! That's a very valuable info for a newbie like me. The speakers will be ~10cm from the wall so a rear port would be the choice if i go ported (modt likely). Now i have to decide FR vs 2way but size and cost will probsbly take me to FR ported.

 

[HumbleDeer]

If the port on he front isn't don't correctly it might cause issues with phase or alike. Thats why, if I have space, I rear port.

Cheers,
Anna

 

[suprf1y]

What I see in those FR Dragon Foals is a port in the back. Is there any list of rules on where the port has to be placed respect back of the driver? Would it be better to have the port in the front below the FR driver?

I put the port in the front as that's typically my preference

I've heard only good things about the NS3 drivers.

 

[midrange]

GREAT, thank you! I understand those 3 are important for box design "only"? Should i give some importance to others as SPL or F3?

If you go to that Lalena site, if trying out the closed box option you should try varying (upwards) Qtc. A raised Qtc means a smaller box, and also a raised bass resonant frequency. (and increases the output around the resonant frequency.)

F3 then gives an indication of where the bass falls away.

0.707 is a theoretically best Qtc, but with very small boxes a more satisfying result usually comes from a higher Qtc giving more mid bass (at the expense of less low bass)