Hi
I currently have Eminence Alpha 15's for bass and I was thinking of changing to Jbl K140
Are these suitable for hifi use? Any advice would be really helpful
Thanks
I currently have Eminence Alpha 15's for bass and I was thinking of changing to Jbl K140
Are these suitable for hifi use? Any advice would be really helpful
Thanks
It's an ancient M.I. mid-bass driver that based on published specs requires 25-30 ohms of series resistance to have a similar bass response to the Alphas, so not a practical swap unless you're planning to add a sub system.
Then again, you may find that when hooked to a tube amp, its 'tight' mid-bass 'tone' is preferred over the Alpha's more extended LF, so swapping out one and doing an A-B comparison may be a worthwhile endeavor.
GM
Then again, you may find that when hooked to a tube amp, its 'tight' mid-bass 'tone' is preferred over the Alpha's more extended LF, so swapping out one and doing an A-B comparison may be a worthwhile endeavor.
GM
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Appears to be 3 way system to me so I will move it.
Agree with GM, I don't think you'll get low end you want. But if you can borrow a pair to try, it would be worth a listen.
Looks like SABA green cones up top? Mid and tweeter.
Looks like SABA green cones up top? Mid and tweeter.
Hi,
I agree, with a Qts of 0.21 the JBL is an entirely
different beast to the Alpha, which has Qts 1.26.
The JBL is not suited to OB's, the Alpha is.
rgds, sreten.
I agree, with a Qts of 0.21 the JBL is an entirely
different beast to the Alpha, which has Qts 1.26.
The JBL is not suited to OB's, the Alpha is.
rgds, sreten.
Out of interest I'm not just upgrading the woofer, this is what I am changing my OB's to
Rusinos_Altecus_Maximus_Alnico_Lampizator
I have the monster Altec mid range and horns, but I can afford to buy four Altec bass comes so the the JBLs are not suitable I'll stick with the Eminence Allha 15's
I'm kind of out of my depth with the xover as the bass cones are not the exact ones in the design.
Rusinos_Altecus_Maximus_Alnico_Lampizator
I have the monster Altec mid range and horns, but I can afford to buy four Altec bass comes so the the JBLs are not suitable I'll stick with the Eminence Allha 15's
I'm kind of out of my depth with the xover as the bass cones are not the exact ones in the design.
Some years ago I built Open Baffle with horns. Same Altec horns and drivers, but used Selenium 15" woofers with a Q of about 0.7. No need for a cone midrange. It worked very well, after I finally understood the crossover needed.
Usually with OB you need a BIG inductor on the woofers to fight the rising response caused by the bass wrap around. Basically, you need to attenuate the upper end of the woofer to match the bottom end. The lower the woofer Q, the bigger the inductor you need. Values of 10-20mH are common with this approach.
Most people don't understand this - and I admit that it took me a long time to understand. A woofer with a high Qts like the Alpha, is going to have a bass bump. That bump can help serve as bass EQ, making the rising response tilt not so bad. With low Q woofers. you won't have that bump, so will have to shave off more top end to get an even response. The low Q woofer will generally but more efficient to start with, so you can afford some of that loss.
Of course in the model you linked to, Lukasz is running the Altec woofers in a sealed box. No open,
Usually with OB you need a BIG inductor on the woofers to fight the rising response caused by the bass wrap around. Basically, you need to attenuate the upper end of the woofer to match the bottom end. The lower the woofer Q, the bigger the inductor you need. Values of 10-20mH are common with this approach.
Most people don't understand this - and I admit that it took me a long time to understand. A woofer with a high Qts like the Alpha, is going to have a bass bump. That bump can help serve as bass EQ, making the rising response tilt not so bad. With low Q woofers. you won't have that bump, so will have to shave off more top end to get an even response. The low Q woofer will generally but more efficient to start with, so you can afford some of that loss.
Of course in the model you linked to, Lukasz is running the Altec woofers in a sealed box. No open,
Thanks for you're help chaps , I'm leaning to running the bass Wonfer actively and running the altec horns and midrange passively, that way I can tune the base to suite
That's a good idea. I don't think you really need the Biflex midrange, but It would be fun to play with.
You'll want EQ or some kind of tweak on that active woofer channel.
You'll want EQ or some kind of tweak on that active woofer channel.
Pano your probably correct. The crazy thing is I love the way my speakers sound as they are but I have this crazy urge to upgrade from the DIY Lampizator P17 to the P23
I'm hoping it works out and I don't I don't end up wanting to revert back to what I have now.
I'm hoping it works out and I don't I don't end up wanting to revert back to what I have now.
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