yet another PE buyout driver thread...anen't these getting old?

[nerd of nerds]

hello...i'm a bit of a newbie and have been building speakers for a few months now...nothing great really...but i bought some of the parts express 4" pioneer full range drivers and don't know a thing about box design...

so what would the best box size for these be? i would do the open baffle thing but i don't really want all of those wires just hanging there...

i'm going to be using 8 of these...how big should the box size be (internal)

or is open baffle the ONLY way to go with these?

[Sherman]

Open baffle is not the only way to go with these drivers. I've built a few different designs including a line array (well, 6 drivers anyway), a smaller ported box with four drivers and a very small two-way system.

For a single driver in a ported box I think a volume of .11 cu.ft. works pretty well. A circular port of 1" ID and about 1.5" long also seems to work pretty well with that configuration.

[nerd of nerds]

so does the depth and width not matter that much? i thought that it was a pretty important part...but whatever...so for 8 drivers i assume that .88 cubic feet?

i'm smart...

[Sherman]

Originally posted by nerd of nerds
so does the depth and width not matter that much? i thought that it was a pretty important part...but whatever...so for 8 drivers i assume that .88 cubic feet?

i'm smart...

Disclaimer- I am not a speaker design expert. I've only been doing this for a year and have built maybe a dozen pairs. Whatever I say is based on my experience and that of others whose speakers I've actually heard.

OK, the volume I gave, .11 cu.ft. is designed to produce a speaker with an F3 of 85 Hz approximately. That is below the FS of these drivers (105 Hz) meaning the sound below 105 is going to be less than perfectly accurate. A smaller enclosure would give an F3 closer to 105. Of course then you would probably want a sub.

A volume of .88 cu.ft. for 8 drivers would work pretty well I think but you could go a little smaller for less bass.

Shape does matter. Try to avoid having the width and depth the same. Some say using the "golden ratio" to computer width, depth and height minimizes internal standing waves. I use the golden ratio because it looks good. It is a very pleasing aspect ratio.

Other factors that make big differences- stuffing the box, sizing of ports etc..

A decent place to start is with an Excel spreadsheet called "Speaker Designer". You enter the T/S parameters for your driver and it suggests box volumes for both ported and sealed designs. It also shows an estimated frequency response graph.

You can tweak some parameters, like Fb, F3, port diameter or change the box volume and see the frequency response results on the graphs.

Mostly, just have fun and build something. You'll probaby be pleasantly surprised!

[Hybrid fourdoor]

Originally posted by Sherman




Mostly, just have fun and build something. You'll probaby be pleasantly surprised!

Never read Stereophile seriously (aside from getting enclosure ideas ), listen to what the 60% of the poeple say on the internet, all what Sherman said, and this can be a very enjoyable hobby

[nerd of nerds]

i know i'm not going to get earth shaking bass from these...so what i was thinking of doing was just have 8 of the pe buyout drivers and below those 8 have an mcm 55-1870...this thing can go to about 50hz pretty well for a 5" driver...and i was also thinking of doing that in a seperate enclosure...maybe a transmission line? i'll post some pics of my idea later...i have to go to school

ALSO...could i get some info about bipole speakers? i thought that might be another fun thing to try with these...but then again, what do i know

[Chris8sirhC]

just a quick question, does anyone know the spl 1watt 1 meter for 16 of these things is?

[cjd]

I like these dipole best. With an enclosure, I have found bigger is better. For an MTM I'm running .6cu/ft.

If you run them as a mid, you can go more "ideal" and size the box down some (say, tune the box to your crossover point and you gain some extra slope), just expect to cross high. I like 3800hz on the top end, though between 3200 and 3800 is all OK. On the bottom, that gives you room to cross as high as 400hz. Below 200hz becomes troublesome pretty fast unless you go active. ALWAYS use separate mid and bass enclosures.

FWIW, I have some MT dipoles that are very enjoyable (perfect computer speakers), and my HT currently uses MMTMMs across the front and MTMs in the back.

These are perfect for discovering a lot of tricks and having experimentation fun on the cheap. I went through a whole pile of miserable sounding attempts before (seemingly) getting the hang of things. I have not yet tried a 3-way with these though.

C

[Chris8sirhC]

ill answer my own question in case anyone else wants to know, for 16 of these, wired for 8 ohms, its 98db 1watt/1 meter

[nerd of nerds]

hello! i'm back and i finally got my design made in paint...just a REALLY rough draft but it works...haven't started building yet...wanted some opinions...here you go...