Mocking up with cardboard

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Mocking up with cardboard, and other newbie questions

So I'm just starting out in speaker building and I have received a pair of Monacor SPX-30M and mocked up some basic ~3L enclosures from cardboard.

Firstly, is this what everyone did when they first started out?!

Secondly, how will the cardboard actually affect the sound negatively, when compared to the future "proper" wooden efforts? I'm hoping they're going to sound a bit more "weighty" once I build the boxes.

Obviously the Monacors are bass-light but they're also a little bit shouty in the mid range. I don't know if this is a characteristic of the drivers, or that of the thin cardboard enclosures.

Also, when building small full range units like this, is it normal to have a high pass filter at all? I have the speaker size on the AV receiver I'm using to power them set to "small" but I think that crosses over at about 80hz which is a bit low for these little'uns.

Lastly, with the T&S parameters of the driver, how do you go about ascertaining the correct volume of sealed enclosure for single full range drivers like this one? Shove them in WinISD like you would a sub? Does the enclosure size affect anything other than the bass response particularly?

I have some HiVi B3Ns on the way too, which I'm hoping will fit in the same holes and I know work well in 2.5-3L enclosures judging by information available online.


As you can see I'm a big n00b so any answers to my questions and general advice are greatly appreciated.
 
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re the HP question - most modern AV receivers will allow a fair degree of flexibility of XO points - especially those with Audyssey or similar software. Allocating the speakers as "small" will probably set the XO much higher than 80 - ie. more likely in the 120 - 150 Hz range. Those settings of course can be overridden, but not all menus or remotes are intuitive - sometimes at least 4 levels deep to the specific function you need.
 
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Welcome to your new addiction of diy speaker building :) The cardboard will resonate like a guitar body and produce quite a bit of sound. But it is not always bad as these speakers can sound quite nice.

My first DIY speaker was a made from a postal cardboard box. I then discovered that foam core boards work infinitely better more precise to cut and is nicer looking than the brown corrugated cardboard. We discussed foam core vs cardboard at length in this thread: http://www.diyaudio.com/forums/full-range/223313-foam-core-board-speaker-enclosures.html#post3239367

This is one of my best sounding cardboard speakers - it helps if the box is high quality double wall stuff. http://www.diyaudio.com/forums/full-range/223313-foam-core-board-speaker-enclosures-109.html#post3335376

325364d1358742082-foam-core-board-speaker-enclosures-p1030849.jpg


The inside:

325363d1358742082t-foam-core-board-speaker-enclosures-p1030847.jpg


Have fun and good luck.
 
XRT,
Is that the little Peerless 3"er? Last Spring I put them into just-over-1-liter sealed boxes and they perform beyond expectations...maybe not the best highs but dynamic and punchy and capable of decent SPLs....they'll do even better in yours when they're made of wood:)
Mario
 
Founder of XSA-Labs
Joined 2012
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XRT,
Is that the little Peerless 3"er? Last Spring I put them into just-over-1-liter sealed boxes and they perform beyond expectations...maybe not the best highs but dynamic and punchy and capable of decent SPLs....they'll do even better in yours when they're made of wood:)
Mario

Vifa or Peerless TC9FD and they sound really nice. The high Qts generally requires a larger volume. I think 2 to 3 liters is as small of a volume I would go with for sealed box. For vented you need about 9 to 10 liters. Doubling them up for dual drivers at 4 ohms sounds great too. Can get pretty sensitive this way.
 
Well, high-pass and wattage applied are just vague considerations.

The HP is needed when a subwoofer is used together, because little cones express themselves better when not charged of very LF content. Otherwise you have to limit (...that enough ! ) the excursion of the driver by not pushing it to the limit.

About cardboard and wood...they're not perfect for enclosure making.

The enclosure purpose is to limit ( again !) the drawbacks of the acoustical short circuit . If you let the panels of which the box is made to resonate or vibrate, you'll introduce again another extra source of sound >coloration, masking .

Heavy cardboard ( 1 cm thick) might be good, and the usual combination of multi layering techniques and kinds of acoustic stuffing. I suggest the ever good car supplies for the combination of tar foils+ waste felt. Very cost effective, adds lots of mass;)
 
Second question is yes the cardboard will have a negative effect compared with wood. You will perceive less bass and it may sound a little muddled.

High pass filters are used when you have an auxiliary woofer and you wish to increase the power handling of the FR and separating the drivers so they are not covering the same bandwidth.

Are those the questions?
 
In regards to my crossover question, I meant do many people who build small full range speakers fit some sort of passive crossover to restrict the lower frequencies or do they mostly rely on some sort of solution when amplifying them, ie the receiver's crossover settings?

Also I'm wondering how to determine the best enclosure volume, do I need to model with the t&s parameters in some way?

Thanks so far guys!
 
If your room is not too big and you use the right cabinet, you can get satisfying sound from a FR driver, no need for an auxiliary woofer. If you like your bass, then it's pretty common to hang a cap on your FR driver to increase the power handling and keep the drivers from covering the same bandwidth. I don't rely on the XO in the amp. No to say you can't but I don't.
 
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