crossover point for a 10"

[Pbassred]

Back again doing the wrong things with speakers again!

I'm running a pair of "full range" cabs as mid/tops in a small PA rig. These Carlsborough Alphas are ok except for bass. Luckilly the bass is covered by another amp/cab, so they never see below 500Hz. I'd like to sweeten them by changing the piezo for a compression driver - possably with an extra piezo for the very highest. So before I start swapping the wrong stuff. I though that I should get a grip on what I'm aiming for.

The existing driver is a no-name 10" 8ohm The flare hole is 10.5 X 4. Its suppossed to handle 150W. But I want anything that goes in to be more substancial.
However first thing first. What crossover point should I use between the 10" and the horn?

[mike.e]

Before asking what xover frequency to use between the unknown 10" and as yet unbought Compression driver.
Consider the following

The 10" could be completely useless for this use.

The 10" should work happily up to 3khz. Most compression drivers of 1" throat can have a xover frequency as low as 2khz.

So now,are you interested in making your own cab and fudging the xover values etc,tinkering...or do you want to buy something 2nd hand which will probably do the job simply?

See the X15 at speakerplans.com.

[Pbassred]

This is where real learning begins. The JBL logo suggests that you have the right expertise.

The 10" could be completely useless for this use

Why is a 10" useless here, given that there are many systems that have: - a single sub and a pair of 10"s. What are we all missing out on ( or did you mean my particular driver.) Right now its doing the job, and the only one who notices is me.

The 10" should work happily up to 3khz. Most compression drivers of 1" throat can have a xover frequency as low as 2khz.

From what I read, a nice crossover would want more overlap than that. Is that the problem?

are you interested in making your own cab

What's wrong with the Carlsboro cabs? Essentially what I am doing IS tinkering. I haven't ruled outchanging the 10" for something better. I havent ruled out anything except possibly buying a set of shagged cabs and learning nothing.

Why would I want to augment my 15"s with another set of 15"s?

[Cameron Glendin]

Why would I want to augment my 15"s with another set of 15"s?

sorry to sound ignorant, but why not? as long as one is cone shaped and the other a curvlinear.

ps beware of how much louder a compression driver is to a pizzo, I learnt the hard way!

[Pbassred]

Are smaller drivers not more suited to high frequencies (without beaming for instance)?
So aren't 10" more suited to upper mid than 15"s?

Thats why I questioned a second set of 15"s.

Horns being louder than Peizos is not a problem as long as they sound better!

[Cameron Glendin]

personally Ive heard great sounding 15s for mid bass,

I find a good 2" horn covers the mids and upper by far the best , but thats only my opinion! crossed over from 500 to 800 hz they can be extremly flat up to 8k with a good sounding extended response up to 15k.

I have found that by crossing over low and not in the more sensitive part of our hearing has some merrit. often these drivers are 108db per watt @ 1 metre, twice as loud as the woofer and the sound level is cut back with L pads ect.

The shape of the woofers cone has a lot to do with its ability to smoothly cover the midrange sound (curvlinear shaped cone usually light weight). Speakers for deep bass often have nasty peaks in the mids (cone shaped heavy cone)

what shape and style is your no name speakers cone ?

[mike.e]

I have the JBL logo because I owned a 2226 for several years in my lounge.

Buy these and be happy ;-)

http://www.behringer.com/B1520/index.cfm?lang=ENG

Problem solved!
+ youl have resale value.

There are a number of reasons why people use 12"s and 15"s with horns.


What you want is CONTROLLED coverage
two cones, a woofer and a tweeter do NOT give that.

A large woofer,which narrows in coverage -until it meets the horns coverage at the xover point results in a nice even sound!

Believe me - at your level,you dont want to be playing with xovers and getting a sound ,with good drivers,that is only half as good as it could be. Buy some value 2ways,then learn.

[Pbassred]

Reassesing my knowledge which is based on conventional wisdom. i.e. :- big , small, tweet. There is another concideration. This is mobile. It needs to fit in a car, not a truck!

Meanwhile, pic of Carlsboro "powertone" driver. They used to use Eminence. I would think that there is a cost saving.

[Cameron Glendin]

Well if small is what you need? to fit into a car, well a 2" horn is the best sounding unit for the job. JBL make a brillant one and P audio make an affordable one, bm-d 750 with a flare PH 2380, at 30cm high 45cm wide in total, it should fit and do the job better than the 10" and a 1" horn

In australia these 2 items will set you back Au$350 per channel (US$1= Au 75 cents) you already have a crossover at 500 hz?
you will need a l pad to cut the volume to match your 15"bass driver. Much smaller, lighter and better sounding in all probability.

Sorry I cannot make out from the photo your style of cone

38 p = A1$

[Pbassred]

flat, but ribbed to excite!