building a crossover

[GranteedEV]

As a further remark, I note you seem to be setting your sites on pro drivers. In general pro drivers make for very poor domestic speakers. They are intended for active designs in large spaces.

Hmm...

here's a really long thread over at DIYaudio worth a read for all of us:

http://www.diyaudio.com/forums/multi-way/147514-pro-vs-hifi-drivers-pros-cons.html

 

[TLS Guy]

Hmm...

here's a really long thread over at DIYaudio worth a read for all of us:

http://www.diyaudio.com/forums/multi-way/147514-pro-vs-hifi-drivers-pros-cons.html

In pro drivers high efficiency and robustness are paramount.

This results in high flux densities, stiff suspensions and not very lossy surrounds.

So this in general tends to high Fs low Qt drivers, and therefore poor bass response. Also as a group they are know for a lot of edge reflections causing peaks and nulls.

These units do fine in a big building and concert venues, but fall short as a rule in home audio.

 

[GranteedEV]

So this in general tends to high Fs low Qt drivers, and therefore poor bass response. Also as a group they are know for a lot of edge reflections causing peaks and nulls.

erm? I thought for a transmission line a lower Qts from .25 to .4 is preferable.

So I presume you would never use a pro sound driver such as the Acoustic Elegance TD15H?

Fs 21.0 Hz
Qms 4.23
Qes 0.27
Qts 0.26
Vas 467 Liters
Cms 0.45 mm/N
Mms 129 grams
Sd 855 cm2
Rms 4.0 Kg/S
Bl 20.1 T/m
Re 6.5 ohms
Z 8ohms
Le 0.3 mH
Pe (max) 500 Watts
Pe (transient) 1000 Watts
"no" 1.51 %
1WSpl 94.0 dB
Linear Xmax 14 mm (peak)
Mech Xsus 20 mm (peak)

Or the a compression driver mid such as the JBL 476Be?

Personally I feel that you're being too general. Certainly I would not use just any pro sound driver in home application, but finding the right ones (cost notwithstanding), I don't know if I would just "stick to domestic drivers" which of course run into sensitivity and thermal compression issues sooner, even with regards to in-house SPLs.

I definitely think there's some intruiging "pro" speakers somewhat used in-home, such as the Danley SH-50, JTR Triple 8, Seaton Catalyst, JBL Everest, and Gedlee Abbey so I wonder if each of them would be lacking to your ears. Certainly none of them is a transmission line, but each of them (with the exception of the Everest) is designed to roughly be crossed to a subwoofer around 80hz or so. I do respect you because your reference is of course an unamplified orchestra unlike many, but I'm skeptical at the idea that none of those speakers would be "any good" in a domestic application.

 

[TLS Guy]

erm? I thought for a transmission line a lower Qts from .25 to .4 is preferable.

So I presume you would never use a pro sound driver such as the Acoustic Elegance TD15H?

Fs 21.0 Hz
Qms 4.23
Qes 0.27
Qts 0.26
Vas 467 Liters
Cms 0.45 mm/N
Mms 129 grams
Sd 855 cm2
Rms 4.0 Kg/S
Bl 20.1 T/m
Re 6.5 ohms
Z 8ohms
Le 0.3 mH
Pe (max) 500 Watts
Pe (transient) 1000 Watts
"no" 1.51 %
1WSpl 94.0 dB
Linear Xmax 14 mm (peak)
Mech Xsus 20 mm (peak)

Or the a compression driver mid such as the JBL 476Be?

Personally I feel that you're being too general. Certainly I would not use just any pro sound driver in home application, but finding the right ones (cost notwithstanding), I don't know if I would just "stick to domestic drivers" which of course run into sensitivity and thermal compression issues sooner, even with regards to in-house SPLs.

I definitely think there's some intruiging "pro" speakers somewhat used in-home, such as the Danley SH-50, JTR Triple 8, Seaton Catalyst, JBL Everest, and Gedlee Abbey so I wonder if each of them would be lacking to your ears. Certainly none of them is a transmission line, but each of them (with the exception of the Everest) is designed to roughly be crossed to a subwoofer around 80hz or so. I do respect you because your reference is of course an unamplified orchestra unlike many, but I'm skeptical at the idea that none of those speakers would be "any good" in a domestic application.

I was not being too general. I was pointing out characteristics you were more likely to find than not. There are certainly pro drivers around that could be used well in a domestic situation, but they tend to the exception rather than the rule.

As far as a TL. You need a Qts of at least 0.3 for decent bass response and best between 0.35 and 0.45. TLs do not model well with low Qts drivers.

Horns are best with low Qts drivers.

 

[GranteedEV]

what about the TD15S?

fs might be a hz or two too high but it seems to model better in a TL while still having 93db sensitivity:

Fs 22.8 Hz
Qms 3.87
Qes 0.41
Qts 0.37
Vas 467 Liters
Cms 0.45 mm/N
Mms 108 grams
Sd 855 cm2
Rms 4.0 Kg/S
Bl 14.1 T/m
Re 5.3 ohms
Z 8 ohms
Le 0.3 mH
Pe (max) 500 Watts
Pe (transient) 1000 Watts
"no" 1.31 %
1WSpl 93.4 dB
Linear Xmax 14 mm (peak)
Mech Xsus 20 mm (peak)

What are your thoughts on that driver in a TL and home usage, then?

 

[TLS Guy]

what about the TD15S?

fs might be a hz or two too high but it seems to model better in a TL while still having 93db sensitivity:

Fs 22.8 Hz
Qms 3.87
Qes 0.41
Qts 0.37
Vas 467 Liters
Cms 0.45 mm/N
Mms 108 grams
Sd 855 cm2
Rms 4.0 Kg/S
Bl 14.1 T/m
Re 5.3 ohms
Z 8 ohms
Le 0.3 mH
Pe (max) 500 Watts
Pe (transient) 1000 Watts
"no" 1.31 %
1WSpl 93.4 dB
Linear Xmax 14 mm (peak)
Mech Xsus 20 mm (peak)

What are your thoughts on that driver in a TL and home usage, then?

Those parameters look excellent. VAS is high, so as well as being long Lp it will also be a reltively large volume pipe Vp.