Peerless HDS Exclusive 6"5 or 8" ?

[youyoung21147]

Hello guys !

I'm currently building a 3-way project, with the midrange driver operating from 200Hz to 2kHz. Filtering is 24dB/oct.

SPLmax will be around 110dB

I've looked at the Peerless Exclusive range, which seems to offer a good price/quality ratio.


My problem is that I hesitate between the 6"5 inch midwoofer (830883) and the 8" woofer (830884).

The 8" has a flatter response, and a better efficiency combined with higher Xmax. Unfortunately, no test is available for it...


What I'd like to know is if the 8" will be as clean up to 2kHz as the 6"5 inch.


Thx in advance !!

[MJL21193]

What type box are you building? There are other factors at play here. The 830883 is better suited to a small sealed box (higher Qts, low VAS) The 830884 works well in a larger vented enclosure. Low frequency response is going to be vastly different between these also as the fs of one is 20Hz lower then the other.

With that said the 830884 should have no problem with 2kHz as seen here:http://www.tymphany.com/datasheet/pdf/pl/830884.pdf

Have fun.

[youyoung21147]

The driver will be mounted on open baffle, crossed to a 15" subwoofer.

Considering only the frequency response, yes, no problem up to 2kHz.

But what I'm more skeptical about is energy storage issues...

I'm wondering if the tone bursts at 2kHz look clean enough to be acceptable...

[MJL21193]

The 830884 has very similar specs and frequency response to the Seas W22EX001 selected by Siegfried Linkwitz for his open baffle Orion speaker. Whenever I am in doubt about OB design, I go there:http://www.linkwitzlab.com/orion_challenge.htm
Also the Seas driver is about 2.5 times more expensive, so probably a wise choice.

[rabbitz]

If you are going from 200Hz up, I'd go with the 830883 as it would make a better mid and less beaming. The higher Qts will help the lower frequencies. I've ran trials using a 830875 Nomex in an OB and works very well. The baffle in the pic was a test one for some Scan Speaks but managed to do the Peerless as well.

[youyoung21147]

MJL21193 : well, the frequency response looks the same, but I hope distorsion is better controlled, because the Seas has huge peaks in HD due to the cone breakup. That's why I don't choose them...
On the other side, I was wondering if the linear distorsion performance is on par with the metal cone...


rabbitz : you've understood my point : on the one hand, the small driver has less beaming and is maybe cleaner, but on the other hand, its low end distorsion must be worse, and its lower efficiency would mean power compression (or even destruction) at high levels...

Do you have any measurements of the 830875 ?


BTW, what exactly is Nomex ? And does anyone have an idea of the Peerless drivers power handling ?

[pjpoes]

Nomex is a dupont developed light weight plastic fiber which is used in fire retardent suits such as race car driving suits and also fire fighter suits. It is also similar to Kevlar when used in a specific weave, which makes it bullet proof. I also just looked it up, its an aromatic fiber, that can be considered aromatic nylon. Its the meta- variante of para-aramid aka Kevlar.

I used to get runoffs and over-runs of kevlar cloth to make car speaker enclosures so I could save weight. I hated taking a sporty car and throwing even 100 extra pounds worth of car audio, let alone the 500+ that isn't uncommon with more extreme systems. I also quickly figured out that a vacuum bagging system will save a ton of weight over the paint it on method, but have never been able to afford the setup for my personal use, that and I don't do much with installs anymore. Everyone seems to be using Carbonfiber now for this, but when I was doing this about 7-10 years ago, and I was around 15-16 years old, Carbon Fiber was extremely expensive and not available like Kevlar, which wasn't so envogue.

[youyoung21147]

Ok thanks a lot for explanation ! I thought it was specially impregnated cellulose fiber

I'm interested in what you say about building things from fiber, but for radio controlled planes, not car audio. The vacuum bag seems a widely employed method nowadays for this purpose. Well, that's rather off-topic...

[MJL21193]

"Tone Bursts"... "Beaming"... What are we doing, calling the mother ship or designing a speaker? The Seas driver suffers from harsh cone breakup, of course, it's a magnesium cone. Thats where you design the crossover to compensate. Same applies to the Peerless, though not to the same extent.
What have you decided on for the tweeter?
You said three way, then refered to a 15" sub. Is that the LF driver?

[tinitus]

Allthough you are able to dampen/attenuate frequencies with breakup, the cone breakup is still there and dealing with it in xo, you might introduce phase issues