Peerless HDS 6.5in vs Vifa P17

[noodle_snacks]

I am new to designing crossovers, but plan to buy a microphone and preamp to aid in my first complete speaker design (I have built some kits). I want to build either floorstanding or large bookshelf sized speakers in a MTM configuration.

For the tweeter i am considering either the Vifa XT25TG or the Vifa D25AG at the moment, but am open to other options from vifa, peerless and seas (within a similar sort of cost)

What i am really wondering about is using the Peerless HDS 6.5in woofer(s) (and if i should get the one with the phase plug or not) vs playing hte safe route with a P17 or something.

I am wondering what those with more experiance think i should use out of those drivers.

[5th element]

From what I have heard the Peerless HDS will wipe the floor with the P17. The HDS without phase plug should be nice and easy to work with. Other tweeters are thee 27TDFC & 27 TFFC from seas. The vifa XT25 I have read can be quite tricky to get sounding right. Whereas the seas above are a doddle.

[barn]

I am just an amateur but I believe that quality wise scanspeak comes first then peerless then vifa, I have no experience with seas.
As mid range I tried a vifalogic series 5 inch then upgraded to a peerless HDS 5 inch (850488) with a definate improvement and am about to upgrade to a Scan-speak 2.5 inch (13m8640), I hope that the sound will improve again.

I have gone through similar steps with Tweeters and woofers.

Check out a supplier in Sydney if you haven't already, they can send to Tassie - wes.net.au / speakers and for some prices - citysouthelectronics.com.au
Happy hunting.

[noodle_snacks]

What are the 27TDFC & 27 TFFC tweeters like compared to the D25 in quality etc (My supplier only seems to have the 27TFFC in the price list, would the lower resonance of the TDFC be important for crossing over to the 6.5in) ?

[HiFiNutNut]

I have used the HDS 5" with good result. But the tweeter I use is the expensive Dynaudio T330D, the best tweeter ever made by Dyanudio that would beat most other tweeters. The sound is very nice. My audiophile friends who have listened to numerous systems commented that my speaker / system sounds better than the JM Lab Grand Utopia driven by the MF Kilo Watt amp. That should give you some confidence on the HDS 5".

However, the HDS is not easy to work with. Its response curves looks pretty easy but it is not. It can sound pretty bad if the XO is not done properly. I have tried everything: 1st order, 2nd order, 3rd order (electrical, higher order accoustic), parrallel, serial, Butterworth, Bessel, LR, textbook like formulas, computer software similation, etc, you name it. Most of them didn't work well and the sound was pretty ordinary. For some configurations, I added or subtracted 1 uF on the caps to fine tune the XO. After a few months hard work, eventually, I got the XO right. It competes with commercial speakers with 4 or 5 digit price tag in sound quality.

My tip here is that don't use the 5" HDS for anything lower than 150Hz-200Hz as it won't do it well. You can check this from computer software. Have a sharp cut off at the HP as this driver sounds nasty above 3-6k. The difficult part is that with deep roll-off, which is required by this driver to sound its best, would make the phase response design of the XO very difficult to do. If you follow this, the HDS sounds as good as any high end, high price drivers.

I found the HDS 8" is rather hopeless.

Hope this help.

[HiFiNutNut]

Sorry. The above HP in the last paragraph should be LP.

[bzdang]

I find the 6.5" HDS [without phase plug] just right. It is the safe route. Big enough to make some bass [well, the tall thin WAF kind of bass], well behaved enough to not go nuts at upper end of its range. Have a look at the published curves, the phase plug version is less well behaved, meaning more crossover education for you.
Look hard at tweeter published curves too, you might be better off spending more on them and getting better results with less work and frustration. Then again, you will learn more by getting tweeters with some character to them
Getting a measurement system at home is a very good plan, I was surprised to see how far each driver put out beyond it's nominal crossover point, even with 24dB/oct slopes. Having a big peak in each driver to deal with in the overlap region would suck.
One last thing, Never listen to Mangers or good horn systems, it will ruin your project.

[noodle_snacks]

Bass down to 40hz or so will do my fine as i have already built a Tempest subby. However I don't want them to be guttless without a sub either.

[rabbitz]

noodle snacks

The SEAS 27TFFC is a great tweeter and IMO better than the Vifa D25AG and is easy to work with. I've got it used with the Peerless CSX 850122 which is very similar to the HDS driver. A great match. I think this combo was used on some of the later Peerless pipes with the SEAS replacing the Peerless tweeter.

HiFiNutNut

I've used quite a few Peerless 850488 mid/woofers and didn't have the problems with the crossover you mentioned....... maybe a difference in batches. Used a 1st order series xo with stunning results but must admit it did take a while and a lot of testing to get the sweet spot.

Have to agree with you on the 8" HDS...... a strange driver. Couldn't get it to work well at all, nice mid bass but........ stick with the 6.5".

[paulspencer]

Apparently the Seas 27TFF is fairly similar to the D25AG. I heard of an independant comparison of tweeters, in the budget range the Morel MDT 30 (or was is 33?) was the winner, but the Vifa D24 and Seas 27TFF were also rated very well. I like the sound of the D25 but I don't like the look of it that much.

From what I have heard the Peerless HDS will wipe the floor with the P17

I think on these forums the differences are most of the time overstated. I have heard both and I can't say a clear winner presents itself. I'd say it's more a matter of implementation in fact.

One day I heard my speakers compared with an AB instant switch to two other TL speakers, one with the same midbass MTM (P17) with a SS 9300 tweeter instead of my D25 and the other was the Seas Odin Kit. In switching, differences in tonal balance were immediately apparent, however I found it difficult to decide which I liked better. You might think this is bias on my part, but I was expecting the other two to show up my speakers, but I'm not sure they did.

On another day I heard VAF's top of the range speaker using Seas Excel drivers and it was immediately apparent that they were in another league. Very refined speakers, I did not need a side by side comparison to know they were more accurate with "audiophile music." However, the moment I put on some rock music, it sounded very ordinary! A little bit too revealing!

A few things you might consider with driver choice:

* poly, paper and other similar materials are a bit more forgiving and good all round speakers
* metal cones and kevlar tend to have lighter cones, higher resolution and are less forgiving - better on good recordings, worse on poor recordings (most rock, pop music and anything but "audiophile stuff")
* look for a smooth response up past where you want to crossover, no nasty breakup modes

If you only want to get down low enough to cross to your sub at say 80 Hz then midrange is definately the focus and the P13 is one of the best mid drivers you can get. If you want to get down lower then a 6.5" like Vifa P17, HDS or CSX are good choices with a good balance of extension and smoothness.