6L Sealed Enclosure - 6.5" Woofers!

[Veloxy]

HI! I was hoping to find some answers before I make some decisions I might regret

I am planning on building a sealed boombox. For this I already have a box that has a 12L enclosure, which makes it 6L for each speaker in stereo. The purpose of the boombox is to take it with me over to friends apartments for small partys. So by having very sensitive speakers is not the main goal, but to get something that sounds very audiophile at the same time as I am getting enough low bass and loudness. I have found 2 woofers that fullfill these requirements, but I CANNOT decide which one to buy! PLEASE let me know what you guys think I should go with. Sealed Enclosure it is.

Monacor SPH-176 VS Monacor SPH-170

Sensitivity: 90dB (1W/1m)
Qts: 0.37 | 0.44
Fs: 39Hz | 38Hz
Vas: 27L | 37L
Xmax: 5.5mm | 3.0mm
BxL: 7.7Tm | 5.9Tm
Moving mass: 14g | 12.5g
Sd: 140cm2 | 137cm2

Vb: 5L (Calculating out 1+1L cus of electronic stuff + magnets.)
Qtc: 0.93 | 1.27
F3: 79.8Hz | 79.4Hz
F10: 53.0Hz | 56.7Hz
Fb: 98.0Hz | 109.6Hz

Monacor SPH-176:


Monacor SPH-170:

[mdocod]

I would go with 5" drivers and a BR design personally.

Of the 2 you are debating between, the 176 looks far better to me.

[Veloxy]

The problem is that the box I be using is a suitcase... A bass reflex port is not really that good considering I wont be able to open the case after I have sealed it good enought... BUT if I tend to go BR, which other speaker would you prefer me to use?

[mdocod]

As far as specific drivers go.. I don't know where intend to order from so can't really say specifically. Just thinking that there are a lot of ~5" drivers out there that would provide a flatter response down into the lower bass ranges in that limited box size.

The 6.5" drivers in sealed are just going to require more EQ and amplification power to play down to ~50hz, which is what I would suggesting shooting for as your bottom end.

[Veloxy]

Deep bass isnt really what I am looking for, what I seek is actually more of a punchy bass which I believe u get more from 6.5" elements... And the speakers has to have a minimum of 90dB sensitivity. I cant seem to find anything better than the Monacor SPH-176 for this kind of small enclosure that still performs good in a sealed enclosure!

[Veloxy]

What about SB Acoustics SB15NRXC30-04 with BR VS SPH-176 in sealed enclosure?

[mdocod]

The adjectives we use to describe bass performance will vary from person to person dramatically. What some call "tight," will be another persons "lacking bottom end." Some people will say it sounds "smooth" which usually means it doesn't have a peaky or "boomy" effect in a certain frequency range. Some people will use the word "fast" or the words "good transient response" to describe bass that can slam those "tighter" complex notes with greater precision. While onother might use that same term "fast" to describe a system that simply lacks the deep stuff. Someone might say "deep," while another might say "muddy."

To make matters worse, all of these words are apt to get used interchangeably to describe all of the various circumstances listed above with those terms I have listed depending on the persons personal preferences and experience.

Having said all that, if the bottom end is not truly important for the build, then whether you go with 5" or 6.5" woofers really isn't going to matter much on that aspect....

In your original post, it sounded to me like you were not interested in efficiency, (translation issue I suspect). Now I understand you are looking for good efficiency. If I were personally building a portable boom box, especially if I intended to run it on a portable power source (not sure what your plans are for that), I would use sound reinforcement style 6.5" drivers for the mid-bass, and a high efficiency dome, ribbon, or planar for the high end. (just try to match the drivers for efficiency so that you don't have to pad a driver, adding unnecessary complication).

[Veloxy]

Are there any 90+ dB sensitivity 6.5" midbass woofers that works good in a 6L enclosure?

[AllenB]

Hi Veloxy. Interesting project. While reading about your challenge it seems to have conflicting needs. It would be good to know how important getting loud is with this. It would be tempting to suggest something like this woofer because it would allow you to go louder and even to equalise the bass a little. Except that it isn't known for its great upper midrange and you'd need a special tweeter or three way to do it, so a 6.5" would be preferrable to you but only if it is capable of meeting your volume levels and bass requirements.

There doesn't seem to be a great deal of difference between the woofers so far. I think as long as you achieve a flat response down to at least 100Hz, you'll be achieving something. It is beneficial that you have a somewhat wide surface to mount them on, although I think that room placement will play an important part in a successful end result. You'll want to find a place near a wall or corner that can sound good once you build these.

I have a reservation about you using a suitcase. What is it made of? I am concerned the 'front' panel will vibrate and give or take a lot from the woofer. To this end it might be worth lining the woofer panel with something to stiffen it. Due to the fact that it will still vibrate like this I'd also go to some lengths to dampen it from vibration.

I am also thinking that the whole cabinet would 'breathe' (expand etc.) with the woofer causing it to perhaps act similarly to a port in a vented enclosure. Who knows that this might be a good thing but be prepared to throw a little damping material around if it doesn't bode well in your case. To this end I would try to leave the case openable for the time being, maybe finding something you could line the rim with to form a gasket.

[Veloxy]

The suitcase is pretty much the only case I got, already bhought it for the boombox purpose and its dimensions are 45x35x10 cm. I have calculated that the inner volume is 12L to be precise, which makes it into 6L for each speaker in stereo...

Even though my plan was to go sealed theres some that have recommended me to go bass reflex. I currently have a amp6 from 41hz ready, so there are some limitations in power. I kinda feel lost... My main goal was to build a speaker that could give VERY nice punchy bass! Being able to play loud would also be cool! For that reason, I believe 90db (1w/1m) is a minimum require?

For sealed purposes I have searched for the whole internet after a valiable speaker and after ALOT of simulations I have come to a conclusion that either the Monacor SPH-170 or SPH-176 are the best picks for a 12L enclosure.

However, I havent been looking into every speaker that is suitable for bass reflex in such a small enclosure which is why I ask you here at DIYaudio if you have any valid ideas?

There's one candidate I have found which is the SB15NRXC30-4