questions about building a cab.

[retrorocket]

I'm building a cab to run with my Trace Elliot AH100. It's a 4ohm head and I wanna make a 2x10 cab with a horn. My biggest question is a about wiring. Does it make much difference if the drivers are wired series or paralle (given the total impedence is 4ohm)? And does the horn get wired in that mix or seperate with a cross over?

Any advise and or websites to diagrams would be great!

open to speaker and horn suggestions here too.

thanks

 

[M0ses]

You WILL get TOTALLY different impedences depending on whether your drivers are wired series or parallel. Read the stickies.

 

[johnk_10]

I'm building a cab to run with my Trace Elliot AH100. It's a 4ohm head and I wanna make a 2x10 cab with a horn. My biggest question is a about wiring. Does it make much difference if the drivers are wired series or paralle (given the total impedence is 4ohm)? And does the horn get wired in that mix or seperate with a cross over?

Any advise and or websites to diagrams would be great!

open to speaker and horn suggestions here too.

thanks

two 8 ohm speakers wired in parallel will get you an impedance of 4 ohms. the horn must be wired with a crossover and the crossover does not change the cab's impedance. a crossover just splits the frequencies that go to the woofers and tweeters.

 

[retrorocket]

thanks for the reply's, I should have specified I have experience in electronics as it's my trade, unfortunately they don't teach bass cab wiring 101 in school, haha.

So as an example, if I wired two 4 ohm speakers and series would the horn get wire in parallel (with cross over) with those to giving me my 4 ohms? would that be an expectable set up?

 

[johnk_10]

two 4 ohm speakers wired in series will yield an 8 ohm load. and as i previously stated, the horn/crossover doesn't change the cab's impedance.

 

[billfitzmaurice]

I'm building a cab to run with my Trace Elliot AH100. It's a 4ohm head and I wanna make a 2x10 cab with a horn. My biggest question is a about wiring. Does it make much difference if the drivers are wired series or paralle (given the total impedence is 4ohm)? And does the horn get wired in that mix or seperate with a cross over?

Any advise and or websites to diagrams would be great!

open to speaker and horn suggestions here too.

thanks

Please don't try to design your own cab. Your question is the equivalent of 'I want to make my own car, will it need round wheels or will hexagons be close enough?'
There are many existing DIY designs that don't require you to obtain a degree in Acoustical Engineering to get it right, starting with the fEarful here.

 

[retrorocket]

Please don't try to design your own cab. Your question is the equivalent of 'I want to make my own car, will it need round wheels or will hexagons be close enough?'
There are many existing DIY designs that don't require you to obtain a degree in Acoustical Engineering to get it right, starting with the fEarful here.

where's you sense of adventure? great things will never happen if people don't step outside of the box.

 

[seamonkey]

2x10 - that's stepping outside the box?

 

[billfitzmaurice]

where's you sense of adventure? great things will never happen if people don't step outside of the box.

True, but in this case what you're going to step in outside the box is this:

If building a worthwhile speaker was as simple as sticking a couple of drivers in a box everyone would build their own.

 

[majortoby]

That looks human :0

 

[kesslari]

Retrorocket has a great point, and should not be thwarted.
Building a speaker cabinet really IS as simple as building a box and putting two drivers in it, and hoping that you have them wired correctly so you don't blow out your amplifier.

Building a speaker cabinet that works... that's a little harder.
Building a speaker cabinet that SOUNDS GOOD... that is significantly harder, and I too would strongly encourage a would-be first time builder to go with a good set of plans.
He didn't say so himself, but the plans on Bill (Fitzmaurice)'s site are eminently worth looking at.

OTOH, if you don't care about the cabinet sounding good... just build a box!

 

[retrorocket]

2x10 - that's stepping outside the box?

no...building it by ones self would be stepping outside of the box. Thanks for posting your child hood pic tho!

 

[retrorocket]

Retrorocket has a great point, and should not be thwarted.
Building a speaker cabinet really IS as simple as building a box and putting two drivers in it, and hoping that you have them wired correctly so you don't blow out your amplifier.

Building a speaker cabinet that works... that's a little harder.
Building a speaker cabinet that SOUNDS GOOD... that is significantly harder, and I too would strongly encourage a would-be first time builder to go with a good set of plans.
He didn't say so himself, but the plans on Bill (Fitzmaurice)'s site are eminently worth looking at.

OTOH, if you don't care about the cabinet sounding good... just build a box!

thanks for the support,

I'm just taking on a challange.... doing a little research and enjoying a hobby. The internet has a vast amount of information on such a topic. It may be hard to make a good sounding cab but not impossible.

 

[T-Bird]

Hi.

I'm just taking on a challange.... doing a little research and enjoying a hobby. The internet has a vast amount of information on such a topic. It may be hard to make a good sounding cab but not impossible.

The beauty of it is that You probably don't realize whether the cab sounds bad or not.

I'm about the last person to discouradge any DIY approach, but as the world offers shortcuts and advice from experienced DIYers, I'm also about the last one to suggest ignoring them.

Good luck, whatever You decide.

Regards
Sam

 

[devilock76]

There is also a program out there (forget the name) that helps you determine cabinet interior volume and port size depending on your speaker selection and desired cabinet tuning. It is free, someone remind me, the steel trap is rusty.

As for series vs parallel. Well other than the impedance comments...

Here is a site with numerous cabinet wiring diagrams:

http://www.colomar.com/Shavano/4x12wiring.html

It has a 4x12 with crossover and tweeter example that you should be able to transmogrify to your needs.

I will say this most 2x10 enclosures the 10's are wired in parallel (well most any 2 x ???'s are, and 4x???'s are series + parallel, etc). Typically if your desired net impedance is 4 ohms you would select two 8 ohm drivers.

Now the one other difference between series and parallel is what happens on failure. If a speaker was to die/disconnect both speakers in a series connection are dead, no sound. In a parallel configuration the surviving speaker will continue to work. However taking a two 8 ohm driver in parallel example the result would also be the cabinets overall impedance would now jump to 8 ohms as it is only going through the one driver. Theoretically though it would still be getting the same power as the impedance change counteracts the voltage jump. In series there is no sound obviously but in essence there is an ohm jump there, this time to infinity (and beyond).

Now if a speaker was to fail in a way that it short circuited itself where the speaker itself dropped to 0 ohms across it's connection, you would have an ohm drop (by half in a 2x??? example). That is for both parallel and series. Honest truth, I can't say I know of that happening much though. However a short in your wiring could. Especially in a bass cabinet I would recommend shielding and securing all wiring well due to vibration.

Now on another note. You could in theory build a cab with a series parallel switch, not vary common but I debated this once. I was at one point considering rewiring my 2x15 like this with two 4 ohm speakers. It would have been two inputs and a selector knob. The options would have been "normal" speakers in parallel at 2 ohms, series (8 ohm), and dual where each input fed a different speaker, each input 4ohm. Just a crazy idea I had.

As for the DIY approach. If you feel daring and you want to do it because YOU did it, and have an idea you cannot purchase, or whatever, great. Just never do the DIY path with stuff like this to save money. The first outing rarely does and you cannot get the bulk discount on parts major manufacturers do.

Ken