Pls help mod old 3-way closed box...

[Littlebear]

Hello Audio Experts!
My old speakers just aren't thrilling me any more (or else my audio nervousa is kicking in again). Sometimes it seems a bit closed, veiled, etc. You know....
Big sealed box, drivers are:
Dynaudio d28/2,
Peerless 832873, nomex(sometimes 850106 sandwich5.25")
Peerless 850146 (sandwich10")
My BIG idea is to replace the mids since I think they are so important, and maybe not up to the level of the other two. Wouldn't mind going cheap (P13wh?), say <$75.ea.
Then (or maybe instead of above) try to do a 1st order xover.

TIA! Murf

[martinbls]

Just a few thoughts...

- A three way system is quite difficult regarding the crossover. You will need a whole lot of different crossover components to try out what config sounds best. This is expensive AND a lot of work.

- Most of the peerless drivers I saw (and heard) have frequency responses which are hard to handle with a simple 1st order crossover design. Often there is this peak in the range of 3kHz, and then the sound level goes down by around 18db/octave.

- I would consider this: Buy a pair of the very nice Vifa P13W's. These are sooo sweet that they can go without any crossover at all. These will be your "main" drivers for the most important part of the frequency range, say from 100Hz up to 5000Hz, as said, completey crossoverless. Just put them into a small sealed cabinet of around 2-3 litres to prevent extreme cone movement at low frequencies (in a small enclosure these units are "mechanically dampened")

- Then you take the tweeter (normally these dynaudios are quite well suited for a simple 1st order crossover) and use a properly calculated L-pad network for attenuation. This will have three important functions at the same time: You get the desired volume level of the tweeter, the impedance of the whole system (tweeter and L-pad) remains the same as the tweeter (e.g. 8 ohms) and the parallel resistor of the L-pad flatens the impedance of the tweeter, so you won't need a zobel network or a LCR-network to compensate any oddities in the impedance response.

- Then you can take a single capacitor (I would try out 2,2uF and 3,3uF if the tweeter is 8 ohms), to blend in the tweeter with the woofer nicely.

- After all this is finished, you will have a pretty nice sounding two-way system, but without the bass impact. This is when the woofer comes into play.

- Try to find a pair of air coil inductors of around, say, 10mH each, from which you can take off windings. Then you can try to blend in the woofer with 10mH first, and if there is not enough level in the upper bass (or lower mid) section, you can unwind some windings until it sounds "right" to you. Even better would be if you know somebody (or perhaps your local dealer) who is willing to lend you some coils for testing purpose, then I would try out 15mH, 10mH and perhaps 6,8mH.

Well, just a few ideas, but this is what I would probably do.

Regards and good luck ;-)
martin

[Littlebear]

I thought the Peerless drivers were almost as easy to work with as the Vifa p13, advertised as needing no xover if desired. For the present xover I gave the Leap folks freedom to do whatever xover they thought might sound best. They put in lots of stuff!
Would going to a smaller mid, say a TB w4-1720 (!) make it easier to mate with the D28/2 1st order? From looking at specs, I haven't found a 4" that seems to mate higher than the good 5"ers. While the p13 is great, some say it is less detailed & the TB W4(so much newer) cleans it's clock (veil).

Murf

[PeteMcK]

re:'my audio nervousa is kicking in again' - must be this, those are good drivers.
FWIW, the 850146 is best vented, I use it in 70L tuned to the low 30s - sublime bass.
It's crossed over to 850488s at 200Hz 1st order PLLXO, the 5" sandwich version of the driver you've got up to ~3KHz IIRC, 1st order & 2nd order on my Peerless tweeters

[Littlebear]

I'm trying to attach my xover...

[fastbike1]

If your baffle is at least 11 1/2 inches wide, go over to audiokarma and search for Econowave.

Very popular, lots of satisfied owners, me included.