The great leap forward! I have just installed an Behringer cross-over and
now want to
build/buy a sub to run off the low channel (variable crossover from 44 Hz
up). I've got
a 500W (genuine rms) amp to drive a sub. I should say that my listening room
is large:
7m x 5m x 2.5m so the power is not over the top. I am using a redundant car
sub as I'm
still in the experimental stage.

Results are quite good but not what I want. It really isn't up to the room
size and is a bit
flabby in its control. I'm not after a 'boom-box' sound, but need to extend
the
power response down to bowed double bass, electric bass guitar and
electronic deep
bass.

I would prefer to build rather than buy. Question is which sub driver to buy
and what
constraints are there on the design of the box. Has anyone got experience or
suggestions?
Is there a recommendable site where I can find box designs or design
suggestions? I've
had a google but its difficult to know which are sheep and goats.

Anyone's ideas, especially negative ones, gratefully received. BTW my first
impressions
of the Behringer CX3400 are very positive. Tonally neutral, very quiet, no
audible
distortion and highly controllable. For those into active speakers this
could be a good
choice. Each device can be used as 2 or 3 way stereo or mono 4 way. Only
possible
drawback for domestic users is that all connectors are XLR.
--
__________________________________________________ _______________

Peter Scott
__________________________________________________ _______________

Peter Scott wrote:

I would prefer to build rather than buy. Question is which sub driver
to buy and what
constraints are there on the design of the box. Has anyone got
experience or suggestions?

Sealed box. 18 or bigger driver. Precision Devices will be your friend if
you want to go low with big power and presence -

http://www.precisiondevices.co.uk/showdetails.asp?id=17

should be capable - your room should be big enough to hide it...

--
We are the keepers of the sacred words: Ni, Pang,
and Ni-wom!

"Tim S Kemp" wrote in message
news
Peter Scott wrote:

I would prefer to build rather than buy. Question is which sub driver
to buy and what
constraints are there on the design of the box. Has anyone got
experience or suggestions?

Sealed box. 18 or bigger driver. Precision Devices will be your friend if
you want to go low with big power and presence -

http://www.precisiondevices.co.uk/showdetails.asp?id=17

should be capable - your room should be big enough to hide it...

Thanks. Have you actually used one of these or know someone who
has? They look impressive and there is a UKdealer near to me.

Peter Scott

Peter Scott wrote:

Sealed box. 18 or bigger driver. Precision Devices will be your friend if
you want to go low with big power and presence -

http://www.precisiondevices.co.uk/showdetails.asp?id=17

should be capable - your room should be big enough to hide it...


Thanks. Have you actually used one of these or know someone who
has? They look impressive and there is a UKdealer near to me.

Fs30Hz does not a subwoofer make!

--
Eiron.

Eiron wrote:

Fs30Hz does not a subwoofer make!

Stick it in a big sealed enclosure and drive it below Fs?


--
We are the keepers of the sacred words: Ni, Pang,
and Ni-wom!

Peter Scott wrote:
Thanks. Have you actually used one of these or know someone who
has? They look impressive and there is a UKdealer near to me.

PD are used in many professional applications. Definitely do the job.

--
We are the keepers of the sacred words: Ni, Pang,
and Ni-wom!

"Tim S Kemp" wrote in message
...
Peter Scott wrote:
Thanks. Have you actually used one of these or know someone who
has? They look impressive and there is a UKdealer near to me.

PD are used in many professional applications. Definitely do the job.


Thanks. That's useful

Peter Scott

Peter Scott wrote:

BTW my first impressions of the Behringer CX3400 are very positive.
Tonally neutral, very quiet, no audible distortion and highly
controllable.
For those into active speakers this could be a good choice. Each device
can be used as 2 or 3 way stereo or mono 4 way. Only possible
drawback for domestic users is that all connectors are XLR.

That looks an interesting bit of kit. What adapters are needed to turn it
into all phono sockets? Like, male or female XLR plug, how many (8?)?


--
Wally
www.artbywally.com/FiatPandaRally/index.htm
www.wally.myby.co.uk

"Wally" wrote in message
...

For those into active speakers this could be a good choice. Each device
can be used as 2 or 3 way stereo or mono 4 way. Only possible
drawback for domestic users is that all connectors are XLR.

That looks an interesting bit of kit. What adapters are needed to turn it
into all phono sockets? Like, male or female XLR plug, how many (8?)?

XLR is new to me so I am going on what it says in the Behringer
user manual. You can download these from B's site at
www.behringer.com. Unit is Super-X Pro CX3400.

The manual makes an interesting read as it also covers the theory of
loudspeaker alignment and insertion of time delays to avoid cancellation
in multiple speaker setups.The cross-over allows time delays to be put in
and gives you separate control of gain for low/mid/high bands
and control of the limiters.

If my understanding is correct you can make up a cable that connects the
balanced XLR end to an unbalanced phono or jack socket. All that happens
is the output impedance halves from 60 to 30 ohms. This should not
matter from the cross-over into the kilohm input impedances of the amps.

Please ignore if this is all known to you. XLR has a conductor for both
live and return (L and R) and they are twisted together like cat5 to cancel
out
magnetic interference. There is a separate screen connected to the third pin
called X for external. For XLR to XLR the screen is broken at the receiving
end to avoid hum loops. For XLR to unbalanced the screen and return are
joined at one end. XLR signals go in the direction the pins point, so
outputs
have pins sticking out, that is they are male plugs even though on the
chassis.
I find this weird, the opposite of mains practice.

I am inputting from the XLR output from a Cyrus Pre pre-amp. If you were
sending from an unbalanced phono pre-amp output then you would need
another cable the reverse of what I've said above. Alternatively you could
use
Direct Injection (DI) boxes like the ones the pros use for unbalanced
mikes and guitars.

The cross-over has two input XLRs and six XLR outputs, two for bass
(one used if summed), two for mid/high and two for high if a three way
set-up is used. Four of the six are used for four-way mono use.

By the way I can recommend www.studiospares.com. They are a
Behringer dealer and are friendly, reliable and speedy. Good source
connectors and cables and stuff like DI boxes.

The low price of Behringer stuff 80-some ukp plus VAT for the
Xover makes it possible to buy one to play with perhap? I am also
moving to professional power. I am trying the InterM devices. At
present an R500plus in stereo mode driving Mordaunt Short 55Ti
speakers of some vintage and a bridged R500 to give the oomph
for the sub. So far very pleasing.

Peter Scott

Peter Scott wrote:

XLR is new to me so I am going on what it says in the Behringer
user manual. You can download these from B's site at
www.behringer.com. Unit is Super-X Pro CX3400.

Thanks for that - I'll have a read.


... so outputs
have pins sticking out, that is they are male plugs even though on the
chassis.
I find this weird, the opposite of mains practice.

I'm glad you mentioned that - I found a place that does XLR-to-phono
adapters, and thought the signal ends would have sockets...


I am inputting from the XLR output from a Cyrus Pre pre-amp. If you
were sending from an unbalanced phono pre-amp output then you would
need another cable the reverse of what I've said above. Alternatively
you could use Direct Injection (DI) boxes like the ones the pros use
for unbalanced mikes and guitars.

Doesn't a DI box convert the unbalanced phono signal to a balanced one with
the correct impedance? Unless it also works in reverse, it wouldn't help
with the connections from crossover to amps. Consdering the cost of DI boxes
(about a tenner per signal), I think adapters is probably the way to go. I
was wondering about the connection from unbalanced preamp to the crossover,
but the manual says the input impedance is 50K balanced, 25K unbalanced,
which I think should be okay.


The cross-over has two input XLRs and six XLR outputs, two for bass
(one used if summed), two for mid/high and two for high if a three way
set-up is used. Four of the six are used for four-way mono use.

Yup. So, inputs are sockets, requiring a connector with pins, and outputs
have pins, requiring a connector with sockets, yes?


By the way I can recommend www.studiospares.com. They are a
Behringer dealer and are friendly, reliable and speedy. Good source
connectors and cables and stuff like DI boxes.

The low price of Behringer stuff 80-some ukp plus VAT for the
Xover makes it possible to buy one to play with perhap?

If it's as clean as you suggest, it sounds like a much easier way for me to
try out my tri-amping idea. I was going to cobble something together by
attempting to make my own filters (ie, tweak standard circuits, because I
don't really know what I'm doing), but, at that price, it just isn't worth
the effort.


I am also
moving to professional power. I am trying the InterM devices. At
present an R500plus in stereo mode driving Mordaunt Short 55Ti
speakers of some vintage and a bridged R500 to give the oomph
for the sub. So far very pleasing.

These R500 thingies are PA amps?


--
Wally
www.artbywally.com/FiatPandaRally/index.htm
www.wally.myby.co.uk