dayton 7" alum - dayton neo Project

[unknownuser]

i've been thinking of building an 8" 2-way speaker for a friend of mine that is looking for a relatively cheap pair of mains. it's possible, and the theoretical response (using Passive Crossover Designer) looks pretty good, but he doesn't have a sub and he wants to do it on the cheap, which means ported (for a little extra low end) and we are stuck using a pair of cabs that he already has (1.25 cu.ft.)

so with 1.25 cu.ft. to work with i was looking at the the dayton 7" alum and the dayton neo tweet. modeling with unibox it should get to about f3=35hz, which is good. and using both Passive Crossover Designer and LspCAD i think that i've got a decent response of +/- 4db at about 83db using a 3rd order xover on both the woofer and the tweet. but man is it difficult to to keep the impedence above 4 ohms with these drivers! and the tweet is still playing at about 73db at 2000hz (using LspCAD).

woofer: L1 = .68mH

C1 = 18uF

L2 = .56mH

Zobel

C4 = 22uF

R1 = 6.8ohms

tweet: (Polarity Inverted)

C2 = 8.2uF

L3 = .18mH

C3 = 15uF

LPad

R2 = 2.7ohms

R3 = 2.2ohms

These are about the best values that i have been able to come up with. when i try to optimize with LspCAD it always wants to bump the output of the tweeter up to compensate for a dip in response at about 2000hz, but then the tweet plays at about 75db @ 2000hz. there is also a peak in the impedence at about 2300hz to ~10ohms. i know its not much, but i'd like it to be flatter.

My main concerns are that the tweet is playing too low (and that there will be distortion), and that the spike in impedence at about 2300hz will be an issue; although i'm less worried about the spike.

i know you are all busy people, and budget projects are usually trivial, but i think that this 2-way has some serious potential if the Neo tweet is as good as people have been saying it is, especially considering the total cost for drivers and xovers would be about $75.00.

what are you're thoughts? Concerns? Experiences?
any input would be greatly appreciated.
thanks in advance.




(Originally posted by: some kid)

[unknownuser]

This is all using the front mounted (version A) tweet


(Originally posted by: some kid)

[thenoid]

Provided Link: theNoid's DIY Raffle


While I have not used the neo tweets yet from Dayton I would stay away from them unless using smaller drivers for the midrange so you can cross themhigher than you are wanting to go. I am sure there are other folks that have used the drivers you are contimplating so be patient, and someoen will chime in for ya here...

Noidster

________
How to roll blunts

[jkrutke]

> This is all using the front mounted (version
> A) tweet

As the Noidster suggested, that driver combo is not ideal. Both of those drivers have broad distortion peaks in the area you're trying to cross over, and it's going to sound pretty edgy and harsh.

<A HREF="http://www.zaphaudio.com/tweetermishmash/ND20TA6-HD.gif">http://www.zaphaudio.com/tweetermishmash/ND20TA6-HD.gif</A>
<A HREF="http://www.zaphaudio.com/6.5test/DA175-8-HD.gif">http://www.zaphaudio.com/6.5test/DA175-8-HD.gif</A>

They are both great drivers, but don't mate well. Consider the Hi-Vi K1 tweeter, it's only $10 and can go down to 2khz a little easier. The Vifa D27 would be another cheap choice. Cross steep at 2khz and it might sound good.

John


(Originally posted by: jkrutke)

[rudyjakubin]

Whoa! That tweeter won't go lower than 3500 hz, any lower and it starts screaming like a banshee.
That 7" Dayton Aluminum shouldn't go any higher than 1800 hz.
2 - 7 inchers and 2 - Dayton Planars crossed at 1700 hz sound very nice or you could try and build this set;
<A HREF="http://www.jupiter-audio.com/pages/europa.html">http://www.jupiter-audio.com/pages/europa.html</A>

You can get the SilverFlutes at Madisound;
<A HREF="http://madisound.com/">http://madisound.com/</A>
Another safe bet on 8" 2 ways are using Peerless woofers with Seas Tweeters.

[unknownuser]

Thanks for the insight. I'll try modeling with the K1 and see what kind of results I can get.

I kind of figured that the neo tweet wouldn't be able to make it that low. That's why I wanted to ask around here first.

These are not going to be audiophile quality speakers; like I said, he wants to do it on the cheap (we're re-using a pair of cabs he already has!) He's never owned even a decent set of speakers, and i'm sure that these will be of a quality that is quite acceptable for him.

Thanks again


(Originally posted by: some kid)

[Chris Roemer]

> i've been thinking of building an 8"
> 2-way speaker for a friend of mine that is
> looking for a relatively cheap pair of
> mains. it's possible, and the theoretical
> response (using Passive Crossover Designer)
> looks pretty good, but he doesn't have a sub
> and he wants to do it on the cheap, which
> means ported (for a little extra low end)
> and we are stuck using a pair of cabs that
> he already has (1.25 cu.ft.)

Try modelling Dayton's Classic 8" (-310) and the silky (-070). While the optimum box would be a tad larger (1.7) it should still perform well enough to impress your friend. Tuned to around 32-33 Hz its F3 should still be in the mid 30's. Cross 2nd order around 2K and things should be fine.

> so with 1.25 cu.ft. to work with i was
> looking at the the dayton 7" alum and
> the dayton neo tweet. modeling with unibox
> it should get to about f3=35hz, which is
> good. and using both Passive Crossover
> Designer and LspCAD i think that i've got a
> decent response of +/- 4db at about 83db
> using a 3rd order xover on both the woofer
> and the tweet. but man is it difficult to to
> keep the impedence above 4 ohms with these
> drivers! and the tweet is still playing at
> about 73db at 2000hz (using LspCAD).

> woofer: L1 = .68mH

> C1 = 18uF

> L2 = .56mH

> Zobel

> C4 = 22uF

> R1 = 6.8ohms

> tweet: (Polarity Inverted)

> C2 = 8.2uF

> L3 = .18mH

> C3 = 15uF

> LPad

> R2 = 2.7ohms

> R3 = 2.2ohms

> These are about the best values that i have
> been able to come up with. when i try to
> optimize with LspCAD it always wants to bump
> the output of the tweeter up to compensate
> for a dip in response at about 2000hz, but
> then the tweet plays at about 75db @ 2000hz.
> there is also a peak in the impedence at
> about 2300hz to ~10ohms. i know its not
> much, but i'd like it to be flatter.

> My main concerns are that the tweet is
> playing too low (and that there will be
> distortion), and that the spike in impedence
> at about 2300hz will be an issue; although
> i'm less worried about the spike.

> i know you are all busy people, and budget
> projects are usually trivial, but i think
> that this 2-way has some serious potential
> if the Neo tweet is as good as people have
> been saying it is, especially considering
> the total cost for drivers and xovers would
> be about $75.00.

> what are you're thoughts? Concerns?
> Experiences?
> any input would be greatly appreciated.
> thanks in advance.

[jonpike]

> <A HREF="http://www.zaphaudio.com/6.5test/DA175-8-HD.gif">http://www.zaphaudio.com/6.5test/DA175-8-HD.gif</A>
> They are both great drivers, but don't mate
> well. Consider the Hi-Vi K1 tweeter, it's
> only $10 and can go down to 2khz a little
> easier. The Vifa D27 would be another cheap
> choice. Cross steep at 2khz and it might
> sound good.

> John

Looks like they've got you covered on the limits of the Dayton Neo...

And allright John, on another great driver comparison posted!

Hmmm, the the Dayton 7" Al looks better than I thought. Maybe I'll keep mine (bought 1 ea of it and the 6.5" 4ohm classic for Bitty Boom experiments) and buy another, rather than return it..