My Highend 2way floorstander build

[NoSnipeLimit]

So I recently purchased 2 Seas W22NY001 drivers from Xumbug (Thanks Stu). 
Now I'm planning on building two floorstanders with these units.
I however need some input and guidance in selecting a decent tweeter, to match the woofers.

I want to take my time with this one to do a lot of planning.  I'm going to build curved boxes.

So far I've had a listen to Norvals Seas T25CF002, which I really liked.

I've had a look at these, but they seem a tad expensive?

https://www.madisound.com/store/product_info.php?manufacturers_id=173&products_id=1594
https://www.madisound.com/store/product_info.php?manufacturers_id=173&products_id=8169

I'm also looking at this one, which seems like a good candidate for the money, but not sure how it will sound. If anything like the T25CF002, then i'd probably like it

https://www.madisound.com/store/product_info.php?manufacturers_id=173&products_id=778

Any ideas or suggestions would be nice.

[JimGore]

Hi Anton,

I have used the T25CF001, and while not as good as the Millenium, it is still an absolutely fantastic driver. 
Nice thick aluminium faceplate, and you can replace the VC if you damage it.

For the money I would buy this one.

Regards,
Ian.

[NoSnipeLimit]

Ian seeing as you have some experience with the SEAS Prestige 27TBFC/G, what would your opinion be about this tweeter vs the T25CF001?

[NoSnipeLimit]

Also I see a lot of tweeters that have a spike in the 25khz area, what does this effect if anything? As this is not part of the audible range but the sensing.

[bbe22]

what does this effect if anything
  >>>>built in insect repellent   this is WAY past my sensing ability......

[bbe22]

T25CF001   second that one if the budget allows............

[chipwelder]

You get to actually hear those frequencies ;-)

I wanted to suggest the DXT tweeters which have the lil wave-guide, as I saw they get used with larger woofers for a lower xo... but not so sure anymore... the Fs around 900Hz, is not that hot... so maybe it is the cd that work well with them... My https://www.madisound.com/store/product_info.php?manufacturers_id=149&products_id=795 tweeters work well crossing steeply at about 1500Hz... they have the nice low Fs of 550Hz, but obviously not the excursion of the excel tweets...

https://www.madisound.com/store/product_info.php?manufacturers_id=149&products_id=8322

[Hennie]

Also I see a lot of tweeters that have a spike in the 25khz area, what does this effect if anything?

The breakup peak (at 27kHz in the Seas Magnum for example) does two things:

Firstly, harmonic distortion amplification - this results in increased in-band harmonic distortion at 27kHz/2 (second harmonic), 27kHz/3 (third harmonic), 27kHz/5 (fifth harmonic) or 13.5kHz, 9kHz and 5,4Khz respectively. The fifth harmonic at 5.4kHz is the one to watch out for, the lower order ones are probably inaudible.

Secondly, the breakup at 27kHz is highly non-linear and would have caused intermodulation distortion in the pass band IF there were ultrasonic frequencies present in your music. Fortunately, there is very little music content above 12kHz with normal as well as so called Hi-Res recordings (88kHz, 96kHz etc). Depending on the nature of your digital playback equipment low level processing artifacts may exist at 27kHz, but these are probably too low to cause trouble.

[NoSnipeLimit]

The breakup peak (at 27kHz in the Seas Magnum for example) does two things:

Firstly, harmonic distortion amplification - this results in increased in-band harmonic distortion at 27kHz/2 (second harmonic), 27kHz/3 (third harmonic), 27kHz/5 (fifth harmonic) or 13.5kHz, 9kHz and 5,4Khz respectively. The fifth harmonic at 5.4kHz is the one to watch out for, the lower order ones are probably inaudible.

Secondly, the breakup at 27kHz is highly non-linear and would have caused intermodulation distortion in the pass band IF there were ultrasonic frequencies present in your music. Fortunately, there is very little music content above 12kHz with normal as well as so called Hi-Res recordings (88kHz, 96kHz etc). Depending on the nature of your digital playback equipment low level processing artifacts may exist at 27kHz, but these are probably too low to cause trouble.

Very interesting, would a notch filter sort this out?  The other option will be to crossover above 5.5khz, but that is not an option.  So it would be better to get one that doesn't have a peak like that. 

[Hennie]

A notch filter would not help and is also unneccesary.

This effect is not necessarily a problem. Harmonic amplification of 13.5kHz, 9kHz and 5,4Khz tones would not be audible as harmonic distortion, because the harmonics would appear where the breakup peak lie, i.e at 27kHz. They can only present problems if there is something to intermodulate with around that 27kHz breakup peak. Most digital replay systems would be safe I think, I don't know about clicks and other ultrasonic noise in turntable based systems, probably quite suppressed by the RIAA equalization.

You can look at the harmonic distortion graphs for Seas 27TBCDGB-DXT and the Seas 27TBFCG here:

http://www.zaphaudio.com/tweetermishmash/compare.html

They show this effect quite clearly, but keep in mind those peaks are of the fundamental. The corresponding harmonic is at the breakup peak > 20kHz, i.e. inaudible as harmonic distortion.

This effect is of more importance in metal cone mid / bass drivers, where the amplified harmonics are inside the audible band.

[NoSnipeLimit]

Ok So i've set my mind to the T25CF001, now just need to get my hands on them

I've done another sketchup, with the seas woofer i modeled.  To get a better idea of how it will look.

I've designed the box so that midway between the woofer and tweeter's centers are the height of my ear.

[bbe22]

to do a lot of planning
nice to see your rendering show the tweeter real close to the woofer.
for X-over check out
http://www.fortunecity.com/marina/pontoon/3/audio/elliptic/elliptic.html
and http://www.audioheuristics.org/projects_gallery/RS225_RS28A_updates/dayton_reference_rs225.htm

[NoSnipeLimit]

to do a lot of planning
nice to see your rendering show the tweeter real close to the woofer.
for X-over check out
http://www.fortunecity.com/marina/pontoon/3/audio/elliptic/elliptic.html
and http://www.audioheuristics.org/projects_gallery/RS225_RS28A_updates/dayton_reference_rs225.htm

Yep, i'm going to do loads of planning on this one.  Yes, I left a 5 mm gap between the woofer and tweeter, but I'll probably make this less even.

Thanks for the links

Just posting the insides, that i've started working on, still not very happy with the bracing, but it's a start.
Also not sure how the port will be effected in the way i used it.  Might still change this to rather use a lower level for the volume box.  And have the port free air supported by braces.

[NoSnipeLimit]

and the view from the back

[NoSnipeLimit]

Ok So i've set my mind to the T25CF001, now just need to get my hands on them

Seeing as PQSound is running a special i opted to buy the T25C003 tweeters.  They're basically on the way
Really itching now to get started but will take it slow, must take it slow...