Enclosure for a 3.25" driver

Hello,
I just took out my old pair of mini speakers from an old JVC UX-2000 system.
Each speaker is tiny with only one 3.25" driver and a small port behind, but the sound is lovely and enjoyable.
I am just thinking of putting the drivers in a new enclosure, but i don't really know the science and math behind all the complex calculations.
I am not looking for big sound or deep bass, just want them to sound more like a pair of bookshelf speakers. Probably considering letting them firing at 45 degrees like the Shahinian Larcs / Elf or the Neat Iota Alpha.
Anyone have tried building a pair of full range speakers with just 3.25" drivers? Maybe I can still some ideas in terms of the enclosure volume and port size.
Thanks.
 
Those 3.5" drivers are some of the best things in that category of size and source (from a mini system), I had many thoughts in the past about making some transmission lines for them; the cherry (looking) enclosures came with 3 models of speakers, the most interesting being the woodcone variant, but it's rare. I almost bought the other two in several occcasions but never really had enough motivation. My enclosure of choice would have been a TABAQ. Now that's not a bookshelf design, in fact a bookshelf is limited to closed of bass reflex and yours is a bass reflex so if you rebuild it in closed box you will have less bass. There is not that much of options in the world of bass reflex, yo can make it bigger and get deeper bass but that's about it... or just make it similar in size but with fancy esthetics.
 
When you say 3.25”, what are you measuring, the baffle, the cone or cabinet cutout?

3.25" is the dimetre of the cone.

Those 3.5" drivers are some of the best things in that category of size and source (from a mini system), I had many thoughts in the past about making some transmission lines for them; the cherry (looking) enclosures came with 3 models of speakers, the most interesting being the woodcone variant, but it's rare.

So glad you remember them. The speakers are very nice especially in a small environment. I have the paper cone and honestly I prefer them over the woodcones.
 

perceval

Member
2014-02-21 8:17 am
Taiwan
I had that little system a long time ago, it is still playing at my mom's house.
It's true that for the size, they sound pretty good.

Why would you take them out of their little enclosure?

Without any kind of measuring software and hardware, you will not be able to design something better than JVC own enclosure.

Enjoy them as they are, and get some other little drivers to play around with DIY boxes, and hopefully drivers that you will know their specs!
 
There is always the option to make some maze type enclosures (ex: https://img.alicdn.com/imgextra/i4/20303713/O1CN011dIb3WVOL5cvLU1_!!20303713.png) but in my opinion those are always undersized but with some transparent lateral panels you get some fancy looks, at least, and maybe some better mid bass if they end up having transmission line type of sound. Add some nice decorative art to the thing and you will smile every time you see them.
Or buy a second pair and make a double TABAQ floor standing enclosure and you will get the maximum out of these, serious bass for their size and more powerhandling/sensitivity.
 
No, I don't own a pair (I almost owned several) but if I would have I would have published the measured specs here already, however any 3 incher that does not have a Fs too high - like 180hz should be ok in a TABAQ in therms of good response bellow 100hz. The creator of TABAQ uses a 4 incher in exactly the same enclosure and he was satisfied.
 
The designer of the TABAQ originally used a 3" that was suited for the design.

You can't just say that it is a 3" driver so it will fit in a TABAQ.

The driver has to match the specs required for such a design, otherwise it is a waste of time, effort and money.

Without measurements, it is a shot in the dark, and it usually ends up in disappointment.
 
The designer of the TABAQ originally used a 3" that was suited for the design.

You can't just say that it is a 3" driver so it will fit in a TABAQ.

The driver has to match the specs required for such a design, otherwise it is a waste of time, effort and money.

Without measurements, it is a shot in the dark, and it usually ends up in disappointment.

You know what? I' m going to contradict that without hesitation due to what I discovered in practice, I know I have to throw in the garbage the book of acoustics but I don't care, a book does not contradict practice. Let me give you an example - since last year I actually have a means of measuring TS parameters (DATS 2) and I had two (a pair) 5 incher fullrangers made by Videoton in the 80s I think, the surrounds were completely rotten so I replaced one of them with leather resulting in a fs=85.4 hz and Qts of 1.19, the other one I made a surround out of extremely thin almost transparent paper resulting in fs=45.1 hz and Qts of 0.47. I put them (first one then the other) in an enclosure of 27 liters with same architecture of a TABAQ and guess what? the difference in bass output was almost not noticeable, the lower Fs unit had a bit of extra deep bass but easily ignorable. The difference in stiffness when pressing (by hand) the cone in is very large so it's not a measurement error. The purpose was to hear the difference in sound from one surround material to the other the bass situation was a surprise I did not expect.
Experience tells me stay away from high Fs (>100hz) with high Qts (>1) when it comes to natural sounding bass in a transmission line, other than that you will be fine. And! those JVC units are capable of playing bellow 100 hz that's why I did not hesitate to recommend them for TABAQ... I know because I have heard one and I was pleasantly surprised by how much bass there was from such a small enclosure.
 
Congratulations on getting DATS. I mean it. It's an invaluable tool for DIY and the many drivers out there with not much information on them.

Now, maybe you could go as far as to download HornResp and simulate those drivers to find the best enclosure for them... not just plug them into any enclosure laying around and say:"eh! they sound ok!"
 
I have Hornresp and not much else but I noticed practice weighs much much more, obviously when I get good results I ignore what simulations show. I honestly don't like this perception that measurement tools tell a better story than a listening experience, at the end of the day we listen to audio equipment, not measure, so if the listening experience is good then why bother measure anything? Do we really want to optimize the system for good measuring or for enjoyable listening?
My reaction to the difference in parameters but lack of difference in sound is that the two speakers have much more in common - everything is the same except the surround - so speaker construction gives sound not necessary the sterile perception of the engineer that wrote the book on acoustics ... you know! that somehow the speaker has a set of physical parameters (such as stiffness of suspension, damping of the cone material, mass, geometry, frequency response plot etc) which define it... however practice shows something else - let me put it this was, I started to call the coloration of each fullrange sound character as accent, much like we all know to distinguish accent in the language we learned as children, they are very real and I don't even want to begin a discussion how a scientist would try to quantify the differences between accents, that's not the right mind set for these things.
Anyway, I am 99% sure that the driver in question will perform in a TABAQ enclosure as intended by the designer of the enclosure... and there are many other drivers that fit in the same box because it's a transmission line and it's more flexible with these things.
 
Do we really want to optimize the system for good measuring or for enjoyable listening?

eh..... both.

It's the only way to not regard audio as some kind of voodoo magical thing.

We measure to come up with optimal designs that we enjoy listening to.

And that's how commercial companies, and DIY people, don't throw away time and money in fruitless tries.

When JVC designed those little drivers and their little ported enclosure, they measure everything about them over and over to make sure they would get the best sound possible.

You seem to be happy with the idea that it "kinda works and sounds good enough."

That was in 1930... We are in 2020 and we have wonderful tools to get out of that voodoo era.

But, to each his/her own.
 
You know the food industry has people who's taste is particularly refined and these are the ones that give the final taste of let's say a ketchup's aroma - what I am saying is that if the equivalent of such people in the audio industry would do the voicing of speakers and other all sorts of components you would end up with a natural sounding system. However that's not the tradition in audio industry - they go by the book of acoustics!
And this is my final statement on the matter: hear it from the mouth of a driver designer by the name of Mark Fenlon - YouTube - 4:37 to 5:24 - (in case the link will no longer be available in the future - he said the paper cone versus the metal cone - they measure so close but sound so different). And in the same presentation he says somewhere that he does not know what sounds good, he only knows parameters if you give him the parameters for good sounding he will do it... to me this sounds hilarious, the people who suppose to give is the good sounding stuff say they don't know know what sounds good... I rest my case.