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View Full Version : Query on 2245H used in B460 vs 4345



ngccglp
12-13-2013, 10:27 PM
Hi,

just curious, GT commented that the 9 cubic feet of the 4345 contributed to the less than articulate bass of the 4345, why then is the B460 designed with only 8 cubic feet ?

thanks

BMWCCA
12-14-2013, 04:42 AM
Hi,

just curious, GT commented that the 9 cubic feet of the 4345 contributed to the less than articulate bass of the 4345, why then is the B460 designed with only 8 cubic feet ?

I don't recall seeing the comment. I'll have to check The Designer's Note in the thread. Perhaps he meant it was too big?? :dont-know:

ivica
12-14-2013, 09:20 AM
I don't recall seeing the comment. I'll have to check The Designer's Note in the thread. Perhaps he meant it was too big?? :dont-know:

http://www.audioheritage.org/vbulletin/showthread.php?10613-4345-Includes-Designer-s-Post&p=110349&viewfull=1#post110349
GTimbers: "........... It also had a reputation for less than detailed bass, which I have always thought was due to the enclosure not being quite large enough. I haven't thought about these things in years ..."

Regards
Ivica

BMWCCA
12-14-2013, 05:52 PM
http://www.audioheritage.org/vbulletin/showthread.php?10613-4345-Includes-Designer-s-Post&p=110349&viewfull=1#post110349
GTimbers: "........... It also had a reputation for less than detailed bass, which I have always thought was due to the enclosure not being quite large enough. I haven't thought about these things in years ..."

Now I'm curious, too. I guess I never paid much attention to it since I find the bass rather exceptional.
Can't wait to try them with the Crown Studio Reference II.

ivica
12-15-2013, 01:27 AM
Now I'm curious, too. I guess I never paid much attention to it since I find the bass rather exceptional.
Can't wait to try them with the Crown Studio Reference II.

May be our member
ZELJKOR ( http://www.audioheritage.org/vbulletin/member.php?11146-zeljkor )
can give us more words as his 4345 has 340Lit (12ft3) box volume with 2245H installed
http://www.audioheritage.org/vbulletin/showthread.php?33941-My-DIY-clone-of-4345&p=342742&viewfull=1#post342742

regards
ivica

BMWCCA
12-15-2013, 05:58 AM
May be our member
ZELJKOR ( http://www.audioheritage.org/vbulletin/member.php?11146-zeljkor )
can give us more words as his 4345 has 340Lit (12ft3) box volume with 2245H installed
http://www.audioheritage.org/vbulletin/showthread.php?33941-My-DIY-clone-of-4345&p=342742&viewfull=1#post342742
Without both to compare, the words might be moot.

And how is the 340L box volume calculated? If you simply take the inside dimensions of the original 4345 without accounting for mid-bass box, etc, the volume would be closer to 300 liters (10.6 cu.ft.) already.
:cheers:

ivica
12-15-2013, 09:45 AM
Without both to compare, the words might be moot.

And how is the 340L box volume calculated? If you simply take the inside dimensions of the original 4345 without accounting for mid-bass box, etc, the volume would be closer to 300 liters (10.6 cu.ft.) already.
:cheers:

Unfortunately it would be very difficult to manage to get "smaller" and larger 4345 at the same time.
As I have remembered Zeljkor has made depth of the box larger (then the original) so to get about 12ft3 real volume for the bass driver.

Regards
ivica

Ian Mackenzie
12-16-2013, 04:33 AM
The 4345 was an empirical design and the marketing guys had input in term of the passive crossover option and box dimensions.

The first thing to understand is the 4345 won't work well in full passive mode and bass definition suffers.

The L250 on the other hand needed far less volume and was not hurt by passive mode in the sale way.

Greg Timbers designed both so the comments are best viewed in the context of those designs.

To an extent a larger box would help in full passive mode as the Dcr of the Xover raises the total Q and that means a larger box to avoid ripple.

From that point of view a fixed box size is a compromise of trying to be the best of both worlds for passive and active.

I have an 8 cu foot factory sub box tuned to 30 hertz. The tuning is quite aggressive and is great or HT.

The 9 cu ft net 4345 tuned to about 28 hertz is less aggressive but with the woofer being lower to the floor boundary room placement can be an issue because the box is quite bulky.

The 10.3 cu ft tuning to 27 hertz offers two things. The slight fall in the curve does help with placement and IMHO offers a more natural extended response.