First build options

[RWB]

Widebander?

I like the idea of getting some measuring equipment and so I can tune a system properly, play with new speakers etc. Is it just a microphone, a preamp and some software?

Can anyone recommend some light reading as an introduction to science behind all this?

Also, can the CHP-70s take being driven hard for several hours or are are they likely to get damaged? Assuming I'm using a crossover and a sub.

[zman01]

RWB,

"Widebander" or Wide Band driver unit would be probably a more tehcnically correct term (guys don't shoot me) for a "Full-range" driver unit - as to many, a full range unit is not truly capable of doing real bass and HF extension. So the driver and covers a wide band if not the full range of 20-20 Khz. Cabinet design can help wideband (aka FR) units to get some more LF extension out, but HF is pretty much what you get in the first place.

You can visit this link for more info and reading:

FullRangeDriver.com

What do you mean by driven hard?? Hard question...

If my understanding is correct, if cone movement is well within tolerable limites set by manufacturer and their is no amp clipping, the a FR unit like the CHP-70 can play for long hours. Amp clipping results in voice coil heating, so it's bad for drivers. Over driving drivers can damage the suspension and components of a driver too.

The other thing to consider here is SPL - at low volumes even with material that has some low frequencies, you will not see much cone movement. As you raise the volume, it is likely that cone movement will increase a lot. If you cut off frequencies below a certain level, then it is likely you can play louder with the same FR driver without stressing it too much.

How loud do (would) you like to play? Do you have a SPL meter?

[RWB]

It's not going to happen a lot and I plan on building a stereo pair of subs (probably peerless sls 10" or 8") , but they will have a DJ playing through them for small house parties and I love just turning it up and basking in it every now and then....well, fairly frequently actually.

Using them with subs means that a lot of the damaging frequencies will be taken up. But, using a pair of subs, does that mean the frugal horns are a bit overkill? Seeing as they are designs for bass extension. Would I be better of using a smaller pair bookshelf speakers?

I can build a sub and a pair of bookshelf speaker out of one sheet of ply, If I build the FHs I'll have to buy two sheets of ply. Which is an extra £50. I could buy another set of CHP 70 for that and have 4 full range drivers and two subs

[zman01]

RWB,

2 driver/cab vs 1 driver/cab can reduce excursion by 4 times at same SPL (if I got my calculation right) - others please chime in. I love the CHP-70 gen1 (I am assuming you are talking about gen 1 CHP-70 here, as gen 2 will need tweetwers anyway) for its natural sounding vocals, but MA metal cones like the CHR-70.3 will give you more treble...

With stuff like dance and prog house you might prefer something that will give you "air" and HF extension - Alp 7 comes to mind...I found the Alp 7.3 to be a treat at dealing with progressive house music when assisted by helper subs. I crossed at 110 Hz using an ASIO plug-in for Foobar. Did not do a SPL check though. Crossing slightly higher should be possible depending on the sub-woofers you have.

BTW, you will need to amps for this set up - the subs will draw a lot more power vs the FR unit. This will add to cost - are you still sticking to 250 quid?

[RWB]

Sticking to around £250. An amp will cost around £50-60 to drive the subs. I was going to use Behringer crossover @ £60 ish. A pair of Peerless 10" SLS driver is £130, CHP 70's come in at £65 which already put me over my £250.

I have a pair of Q acoustics 2020s which will be part exchanged for an amp which brings the cost down closer to the £250 mark.

[tvrgeek]

Originally Posted by rjbond3rd

Widebander DIY is easier than multi-way, by far. You start from the midrange and work outward. It's easier to augment bass and treble, but very hard to impossible to fix a defective midrange.

For about $100 or so, you can build a set of excellent stand-mount / satellites which only need a sub. These can be world-class at (let's say) clarity and imaging, while sacrificing ultimate SPL, slam, orchestral, dynamics, etc.

For me, DIY is about being able to understand and manage the results. The alternative is to live on the hifi upgrade mery-go-round, where you have to keep buying the latest thing based on reviews, etc.

We'll just have to agree to disagree. Pushing the limits of a wideband is far more problematic for me than doing a two way. I'll give you the sub for either. Even my tiny Fountek full-rangers fall all over the place in the treble even after I spent considerable time modifying their breakup issues. It turns out the old decade rule is still pretty good. A driver can work well for about a decade. When you push wider than that, you are too close to LF resonance issues and to close to HF breakup. You get excursion issues on the bottom and beaming issues on the top. Granted, I have not tried full range driver that cost as much as a car. Maybe they can design their way out of a bad idea with unlimited money. $100 for a set of "excellent" speakers. Sorry, can't agree there at all. Not for my hearing.

Now, TRYING to work with a full range is very educational. No question there. You can learn a lot about measurements, balance, cabinets etc without being confused with crossover integration. My argument is making a midrange try to be a woofer and a tweeter is harder than just using a woofer and a tweeter.

I very much like the idea of using a wide band driver to push the HF crossover up from 2K-ish to 5K-ish so it is out of the most sensitive range where your brain makes most of the spatial decisions. Just have not found a driver that can do it yet and still get down to the 60 to 80 where I can bring in the sub. My merry-go-round is self-induced. I learn. I build. I have not bought a reviewer publication in 20 years.

[zman01]

tvrgeek,

Alpair 7.3 perhaps?

Alp 7.3 should get you down to 110-120... But would your subs go up there?

Would love to hear (more like read about) what you hear.

[sippy]

My thoughts:
Why use hifi 'speakers if you'r going to thrash them?
one of your friends will get over ecxited and turn up the wick and POOF, there goes a wee delicate flower.
£98 will get you a pair of Eminence Beta 12LTA's
Build a 3cubic foot box for them OR find/design a box of your own.
My 12Lta's are in the Beta EmKen build, more of a design for PA than hifi...... they do have their flaws, as will all wide range drive units / enclosures, but at 97db/1w/1m and 225w peak (?) power handling, they will will rip your ears, arms and most probably destroy your neighbours as well.
For less than £250.
Just remove the dust cap (only mod needed).
They do 'hifi' things well.

[rjbond3rd]

Greetings, tvrgeek. Actually, we don't disagree at all.

A driver pushed past its limits will not please. So the trick is simply to use it within its limits, where it is ear-pleasing. This often means sacrificing high SPL's (and ultimate dynamics) so they're not for every application, and they definitely have their own sets of tradeoffs.

Personally, I like a very small non-beamy, non-peaky, non-whizzered driver which can play nicely down to about 80-100Hz at polite levels. This is what works for me, because I'm lazy, but there's nothing wrong with working a bit harder to get the benefits / tradeoffs a nice two-way.

[planet10]

Originally Posted by tvrgeek

The amp is 5% of the sound. Source 45%, speaker the other half.

I will disagree strongly. Synergy between amp & speakers is very important. The wrong amp can move a system from enjoyable to absolute trash.

dave