ND90-8 desktop enclosure Help

[MrDragon1]

Hi all,

I just ordered a pair of Dayton ND-90 3.5" full range speakers to use as a desktop speaker set. Has anyone used these yet? The reviews looked really good for the price. They will be played at mainly low volume, but I still want a full sound from them. Music will be almost anything from electronic to rock to rap. I was thinking of a small ported enclosure, but am not sure how to calculate the proper volume/port size I need for them.

I have some 1" PVC that I would like to use as the port unless it is too big to be useful. I think most are tuning these to 50Hz.

Sealed is an option as well, if someone has tried both and thinks that would be better.

Here is the link/specs:
Dayton ND90-8

Specifications: *Power handling: 20 watts RMS/40 watts max *VCdia: 3/4" *Le: 0.54 mH *Impedance: 8 ohms *Re: 6.9 ohms *Frequency range: 80-15,000 Hz *Fs: 80 Hz *SPL: 82.1 dB 1W/1m *Vas: 0.05 cu. ft. *Qms: 4.25 *Qes: 0.85 *Qts: 0.71 *Xmax: 4 mm *Dimensions: A: 3-1/2", B: 3", D: 2-1/4".

Thanks!!

[Tom V]

These threads should help. I ended up building a desktop computer soundbar with 2 liter bass reflex cabinet using the Aurasound driver which should be functionally equivalent.

-Tom-

indoor/outdoor and Dayton ND90-8

Can it be that simple? 3/8" hole in cab lowers F3 by half an octave?

[MrDragon1]

Thanks Tom,

I had seen one of those links. How did your sound bar turn out? did you change anything lately or just living with it?

Does it sound like it would be better with a tweeter in a 2 way system?

[Tom V]

They are working well. I did stuff cotton balls in the BR vents which tightened up things somewhat.

I didn't want to get into the complexity of a two way system. It is just a box with speakers and a wire leading to the T-amp, nothing fancy. As it is, it is very pleasant listening in the nearfield, and good for background music in a small room.

[MrDragon1]

Sounds like I may be better off with a sealed enclosure for them, or maybe a smaller diameter port than you used, or maybe some polyfil.

[hyperlite]

I'm interested in this. I love the look and bass capability of the ND's. I keep bouncing back and forth between a build with those and this build.

[MrDragon1]

Sorry I didn't reply to this sooner.. I made one set of speakers with these and they sounded so good I made another..

If you don't already have WinISD, get it.. It will help greatly.

WinISD will recommend a large box, I shrunk it a little to about the best low end response I could with a smaller enclosure. I ended up settling with a 6L (366 Cu.In.) enclosure tuned to 50Hz. (Port was 1" doa PVC, rounded internal edges, 3.2" long)

They surpassed my expectations, especially now that they are broken in. They are powered by a LM1876TF chip amp. The surprising part is they probably could use a separate tweeter, though I would couple them with a small one (maybe crossover ~8-10k as a guess).

I use them as computer speakers at work and the guys find it hard to believe there is no sub..

[MrDragon1]

Here are pictures.. The graph from WinISD, the computer speakers I made (which are ugly but sound great) and the iPod dock I built after I knew they would sound good. Note, the dock is almost finished in that picture.

[azneinstein]

Holy MrDragon, that's exactly sort of the thing I'm looking to do, though you're look more like a dock I had bought, I'm turning an old sony speaker box into an all-in-one dock with a metal handle- sorta like a wooden boombox. But kudos to your project!

[borispm]

I guess they would sound even better if the ports are stuffed. WinISD sim shows the group delay is terrible if ported, and this may create some problems. Stuffing it may help a bit and bring better control in the bass.