Help required on 2 way book shelf for a total Noob

[madhukannan]

Hi,
Since i couldn't find any speaker kits in my place and importing drivers form abroad costs a huge sum (transportation + customs duty which some times go more than the cost of Kits ) i am thinking of making a Bookshelf with locally available drivers . i am a total noob to speaker building i hope speaker building Gurus will help me in the process .

these are the two drivers i am offered

Tweeter --- Peerless India T25 AN ( around 18USD)
https://picasaweb.google.com/1046008...45/19March2012


Mid/Woofer ---Peerless India M13NH (around 15USD)
Products - PeerlessAudio.com

i used an online calculator and got these values for the box
internal volume : 7.07 lit
Fb 52.67
port lenght 2.24inch
port dia 1 inch

are these ok ?

and what type of a crossover should i go for ?

[sreten]

Hi,

See the links blow regarding FRD tools and crossover design.
Look at Zaphs designs for methods to suppress the bass-mids peak.

rgds, sreten.

undefinition (see if nothing else, the excellent FAQs)
The Speaker Building Bible - Thread opened for edits/input. - Techtalk Speaker Building, Audio, Video, and Electronics Customer Discussion Forum From Parts-Express.com
Zaph|Audio
Zaph|Audio - ZA5 Speaker Designs with ZA14W08 woofer and Vifa DQ25SC16-04 tweeter
FRD Consortium tools guide
http://web.archive.org/web/200909021...esigningXO.htm
RJB Audio Projects
http://web.archive.org/web/200909022...ve99/Spkrbldg/
Speaker Design Works
HTGuide Forum - A Guide to HTguide.com Completed Speaker Designs.
A Speaker project
DIY Loudspeaker Projects Troels Gravesen
Humble Homemade Hifi
Quarter Wavelength Loudspeaker Design
The Frugal-Horns Site -- High Performance, Low Cost DIY Horn Designs
Linkwitz Lab - Loudspeaker Design
Music and Design

Great free SPICE Emulator : SPICE-Based Analog Simulation Program - TINA-TI - TI Tool Folder

[MCPete]

The peerless M13NH certainly is more suitable in a vented rather than a closed box. That is,

EBP = Fs/ Qes = 45.5 Hz/ 0.41 = 111

An EBP or efficiency bandwidth product close to 100 means more suitable in a vented system.

That said, a vented system is more difficult to make work properly than a closed-box system. This is the case because the Q of the system of woofer in the box is difficult to predict. In the Loudspeaker Design Cookbook it is suggested to make the box 25% larger than what the equations say interior volume should be according to the alignment that you choose. Then you can make the box smaller by filling it to get the correct alignment, if necessary.

If you truly are a beginner, a closed-box system is a lot easier than vented.

For the crossover, I do believe that there is a tutorial available here at DIY-Audio for designing them without making measurements, which I suppose is what you would want.

Regards, Pete

[sreten]

Originally Posted by MCPete

Then you can make the box smaller by filling
it to get the correct alignment, if necessary.

Regards, Pete

Hi,

Unless you've monumentally screwed up reducing box volumes
to hit a "target" is a very bad idea / concept. Simple port retuning
is all that is needed to get the best out of a better bigger box.

The driver will have very restricted bass in a closed box.

rgds, sreten.

[PeteMcK]

I'd go slightly larger, ~ 10L tuned in the high 40s. But this depends on how accurate the given parameters are, ideally you'd break the drivers in for a while in test boxes, then measure the parameters yourself using Arta or some similar software & recalculate.

The tweeter link doesn't work, so can't recommend a xover freq, but looks like the woofer will be good up to ~2-3 Khz, & will need some sort of notch to deal with the peakiness. 2nd order Linkwitz-Riley is probably a good place to start for the xover.

[madhukannan]

Thanks for the suggestions , here are the tweeter parameters

T25AN1 by Madhu_kannan, on Flickr

[madhukannan]

T25AN2 by Madhu_kannan, on Flickr

[MCPete]

Originally Posted by sreten

Hi,

The driver will have very restricted bass in a closed box.

rgds, sreten.

If the OP were to go along with the idea of tackling an easier build, that is, closed box, then I gave him the means for selecting a different woofer that would be more appropriate in a closed-box.

Regards, Pete

[madhukannan]

Another noob question what if i go wrong with the calculations and if the volume becomes larger than actually needed hows its going to affect the sound quality ?

[Moondog55]

Peerless seem to recommend using this as a midrange, 200 and up, so a sealed box and no bass seem inevitable with only one driver.
Vented box is your only real option as a 3-way is more difficult to get right; especially first time, nice specs for a decent midrange tho