Help picking drivers for speakers please

[harrisni]

Hi,

Im putting together some speaker boxes below are the details and what type of frequency I am aiming for

They are to be used for Home Theatre only

:

Floorstanding speakers
Drive Units:
1" tweeter
1x6 1/2" midrange
2x6 1/2" woofer

Dimensions (HxWxD): 1004 x 240 x 340(mm)
Sensitivity: 90dB spl
Frequency Response: 35Hz - 22kHz ±3dB


Bookshelf speakers
Drive Units:
1" tweeter
1x5" midrange

Dimensions (HxWxD): 440 x 240 x 335(mm)
Sensitivity: 88dB spl
Frequency Response: 49Hz - 22kHz ±3dB


Centre speaker
Drive Units:
1" tweeter
2x5" Bass

Dimensions (HxWxD): 160 x 440 x 250(mm)
Sensitivity: 90dB spl
Frequency Response: 42Hz - 22kHz ±3dB

[noodle_snacks]

It is definately a bad idea to go building boxes without knowing what drivers go in them, you will end up with incorrect box sizes and or tunings. I would also personally question the requirement for your front speakers to go to 45hz, your rears to 49 and your center to 42. 80hz is a better goal

For home theatre only, I would be aiming for either five to seven identical speakers, or three identical front speakers, then two to four dipole/monopole surrounds. Whilst horizontal center channels have some aesthetic appeal, they have very poor off axis response making them generally a bad choice. Notice how the better center channels from most speaker makers have a tweeter above a midbass in a three way, or some other method to get the tweeter on top. The best match however comes from three identical front speakers (baffle step etc is all matched)

Major brands that you can easily get in australa for speakers are:

Seas
Vifa (Peerless V-Line nowdays)
Peerless
Scan Speak

It is difficult to give you specific driver suggestions without budget constraints. however

http://www.zaphaudio.com/6.5test/

is a good start for woofers, as is:

http://www.zaphaudio.com/tweetermishmash/

for tweeters. There are lots of other test groupings around, use google and see if you can find them.

[harrisni]

Hi,

I have based my specs and boxes on the B&W 800 series

[noodle_snacks]

You are going the wrong way about this, you cant come up with specific roll off frequencies and cabinent sizes and expect to get it with drivers availible on the market, download winISD and simulate some drivers and you will see what i mean, low frequency roll off is effected by box volume and port tuning, not to mention the drivers themselves.

[rabbitz]

Listen to noodle_snacks as there are wise words in his posts.

You may want to consider some kits like the ones at Stones Sound Studio or the LSK or look for some designs on the web.

If it's for HT only you are better off trimming down the main speakers and adding a sub. Best to have all the speakers set to small and let the LFE channel do all the bass, so your front speakers do not need to go down to great depths.

[FullThrottleRic]

Lots of people suggest that but it might not always be the ideal solution.

In my reasonably small room (7'x12.5'x9.5', HxWxD) I get much better results running my main speakers down to their limit of around 40Hz and letting the sub play everything under that + everything under 100Hz from the small rear speakers.

In my experience you want 3 identical full range fronts (40Hz-20kHz) and di-pole rears, full range if you have space for it but it isn't too critical they are able to go much below 80-100Hz. You can always redirect it to the sub and there isn't much LF in the surround channels anyway.

Anyway back to the origonal question...

From your post it looks like this will be the first or one of the first projects you've done harrisni?
If it is it's usually a good idea to keep things simple to start with, a 2-way speaker can be hard enough to get working for the inexperienced, and 3-way's are 10x more work! Remember more drivers doesn't always mean better, normally the more drivers in a design the harder it is to get right.
If I were you I'd start with a well established kit, you'll still learn a lot and save money in the process
Start by building your front pair only, once you've got those done move onto the centre and the surrounds.

Which suppliers can you order from and what's you budget for each speaker?

[noodle_snacks]

Originally posted by FullThrottleRic
Lots of people suggest that but it might not always be the ideal solution.

In my reasonably small room (7'x12.5'x9.5', HxWxD) I get much better results running my main speakers down to their limit of around 40Hz and letting the sub play everything under that + everything under 100Hz from the small rear speakers.

Basically subwoofer crossovers are a tradeoff between distortion, localisation and smoothness of frequency response. Oh, and how much power the mains use up.

[harrisni]

Hi

Floorstanding $3500
Bookshelf $2000
Centre $2000

Ive picked the drivers and the crossovers, I just need to get the box sizes right.

[sreten]

Originally posted by harrisni
Hi

Floorstanding $3500 Bookshelf $2000 Centre $2000

Ive picked the drivers and the crossovers, I just need to get the box sizes right.

Huh ? how can you have proper crossovers if you don't know box sizes ?
Getting the box volume right is trivial with something like winISD.

Carry on by all means, why bother checking if $ 7500 worth of
drivers and crossovers makes any sense to those who know.

/sreten.

[noodle_snacks]

Originally posted by harrisni
Hi

Floorstanding $3500
Bookshelf $2000
Centre $2000

Ive picked the drivers and the crossovers, I just need to get the box sizes right.

harrisni have you listened to _any_ of hte advice offered here?