First 2-way project

[pacoblackxx]

hello guyz,

I finished my LM3886 amp which delivers 40w@8ohm per channel(22v,250va tranformer).

Now, its time to begin building the speakers. After long searching i decided to use peerless woofer and hivi SD1.1-A tweeter(15watt).

I concluded in 2 peerless woofers:

Peerless 830875 6-1/2" Nomex Cone HDS Woofer | Parts-Express.com (50 watt)

and

Peerless 830860 5-1/4" PPB Cone HDS Woofer | Parts-Express.com (30watt)

I like most the first option(50watt) but how will my amplifier(whitch is 40watt/channel @8ohms) go with this option?

It is ok to drive 50watt woofer with a 40watt amp? Or i have to go with the 30watt woofer?

[sreten]

Hi,

Though your drivers are decent choices its best to use the
hard work done by other people for your first louspeaker build.
See the first few links. Powerhandling issues are more complicated
that you think but nearly all designs will be fine with 40W / channel.

rgds, sreten.

Paul Carmody's DIY Audio Projects - undefinition
Zaph|Audio
FRD Consortium tools guide
RJB Audio Projects
Speaker Design Works
HTGuide Forum - A Guide to HTguide.com Completed Speaker Designs.
Humble Homemade Hifi
Click below to go to
Quarter Wavelength Loudspeaker Design
The Frugal-Horns Site -- High Performance, Low Cost DIY Horn Designs
Linkwitz Lab - Loudspeaker Design
Music and Design

[pacoblackxx]

thanks for the links man.

I would like to build the project by my own. Peerless are fairly easy speakers for crossovers i think.. So you said that the 50watt woofer is ok with my amplifier, right?

[sreten]

Originally Posted by pacoblackxx

thanks for the links man.

I would like to build the project by my own. Peerless are fairly easy speakers for
crossovers i think.. So you said that the 50watt woofer is ok with my amplifier, right?

Hi,

the 5OW bass/mid driver will be fine with a 40W amplifier.
If you want to design it yourself you should understand
how all the designs in the first few links are arrived at.

You will have to do the same amount of work yourself.

I you don't / cannot then your design procees will likely be wrong.
Zaphaudio has test info on your tweeter choice and the bass/mid I think.

Your driver choice of the two affects sensitivity, cabinet size and
bass extension, it has little to do with the drivers power handling.

rgds, sreten.

[Helmuth]

I would like to build the project by my own. Peerless are fairly easy speakers for crossovers i think.. So you said that the 50watt woofer is ok with my amplifier, right?

Hi Paco,

The power of a speaker is most mentioned and is only a figure about amount of energy it can bare.

It is more interesting if the driver you choose wil be able to reproduce low frequency in its lineair drive of the loudspeakermotor.

This figure you can find in Xmax. you can have a driver of 100W witch becomes troubles at 20W because it is at his maximum extrusion. So not the power consumption is then the problem but the mechanical limits.

When you simulate your enclosure in Winisdpro (freeware) you can see what the driver xmax does in the box at your given power.

Then again one shout not speak to much about maximum power but about maximum spl at maximum power then at means some thing and what the frequency response.
Because it is interesting how much sound you can create with the loudspeaker.

Why these older peerless drivers. I like the new peerless glasfiber cone 6,5" or aluminium types.


see attachement I did simulate that driver and also at 50W you see it works fine although it can be smart to protect the driver for to much power under 40Hz by a series highpass with the woofer.

[PeteMcK]

either of those drivers will go with your amp, and both are easy to cross over. The 5" has a smoother response up high, the 6" will go lower but require a larger box.

[pacoblackxx]

Thanks guyz.

glasfiber or aluminium types are trickier to crossover i think. so i conclude on the older versions. is there any advantage of the glasfiber over the other? or only just because is a newer version you told me to go for these?

Does any of you know if the lm3886 can handle an impedance of 3.5ohm?

[picowallspeaker]

Does any of you know if the lm3886 can handle an impedance of 3.5ohm?

Nope.Unless you use 18+18 Vac trafo and you are ok with 30 W. Solid state amplifiers are likely to distort under low impedance loads ,you'll need to parallel output devices to have reasonable control of the load

[pacoblackxx]

i didn't get it. the lm3886 wont handle the 3.5ohms?

[picowallspeaker]

As specified on the datasheet ,it will . But that's an extreme condition for the chip ,and to have it working safe it is better to lower the rails .