My experiences with the Alpha 15A to do not match those of InclinedPlane and fakamada. I have found that the bass from the Alphas in an OB has been excellent. However I don't have any experience with Jenson or Pyle drivers with a lower Qts (I have played with Eminence drivers with a lower Qts and Goldwood ones with a higher Qts). I wonder whether their descriptions of "speed" and "detail" relate more to having "lean" bass such as peterbrorsson suggests.
When I first started using and measuring the Alphas in my livingroom, I had to reduce the level of the driver given the room nodes present. Until I did that the bass sounded "bloated" (the opposite of "lean"!). I suspect that drivers with a lower Qts won't have quite the same problem because there is not as much bass output to excite room nodes.
I really think the choice comes down to better level matching of a high Qts woofer vs. equalization of a low Qts woofer (so that it has any reasonable output below say 60Hz).
When I first started using and measuring the Alphas in my livingroom, I had to reduce the level of the driver given the room nodes present. Until I did that the bass sounded "bloated" (the opposite of "lean"!). I suspect that drivers with a lower Qts won't have quite the same problem because there is not as much bass output to excite room nodes.
I really think the choice comes down to better level matching of a high Qts woofer vs. equalization of a low Qts woofer (so that it has any reasonable output below say 60Hz).
Question, have any of you low qts submitters wondered why, a so called book shelf speaker, sound faster than a floor stander? I'm getting OT here now but can't help it.
I've heard so many times from hifi dealers that big drivers are slower than smaller ones. It is soo wrong according to me, this debate about
low Q/high Q seem to be the same b******t.
Application rules, with or without EQ/multiple amplication.....
I've heard so many times from hifi dealers that big drivers are slower than smaller ones. It is soo wrong according to me, this debate about
low Q/high Q seem to be the same b******t.
Application rules, with or without EQ/multiple amplication.....
I have to admit that I do not fully understand group delay, but is strongly connected to mass and magnet strenght.
On the other hand Group Delay is just one of the speed factors. It doesn't tell everything. There are also moving mass, fs, size, suspension stiffness, power etc.
I'm not saying that Alpha is too slow. But please don't tell me that it is an ultimate high-end and that you cannot imagine it being better in terms of speed and accuracy. It is faster than most bass reflex systems anyway.
I bet that most of listeners wouldn't like too quick bass in their systems. It is not suitable for modern music at all. Only acoustic music sounds right, but is my subjective opinion.
I'm not an ezpert. I just want you guys to consider that there are some issues about high QTS drivers that we should be aware of.
Now just compare these divers:
Alpha 15a (red)
Selenium 15PW3 (orange)
Altec 416-8a (yellow)
First graph are charactreistics in 99999 liter closed box (smth like infinite baffle)
Second are Group Delay graphs.
On the other hand Group Delay is just one of the speed factors. It doesn't tell everything. There are also moving mass, fs, size, suspension stiffness, power etc.
I'm not saying that Alpha is too slow. But please don't tell me that it is an ultimate high-end and that you cannot imagine it being better in terms of speed and accuracy. It is faster than most bass reflex systems anyway.
I bet that most of listeners wouldn't like too quick bass in their systems. It is not suitable for modern music at all. Only acoustic music sounds right, but is my subjective opinion.
I'm not an ezpert. I just want you guys to consider that there are some issues about high QTS drivers that we should be aware of.
Now just compare these divers:
Alpha 15a (red)
Selenium 15PW3 (orange)
Altec 416-8a (yellow)
First graph are charactreistics in 99999 liter closed box (smth like infinite baffle)
Second are Group Delay graphs.
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That is a really interesting observation. Since the dipole woofers in OBs or H frames are typically only playing below 200 Hz, room reinforcement of the bass would make a higher Qts driver bloom and sound tubby while a lower Qts driver that provides less low end input to the room modes might sound just right. Different people's rooms will play a strong role in the selection of the optimum Qts value for their dipole speaker's woofer(s). Hence the significant difference in the driver preferences and reported bass performance, a dipoler difference in the feedback about drivers like the Alpha 15A. This makes a lot of sense.
Fakamada,
if the Selenium and the Altec were EQed to the same response curve as the Alpha, their group delay curves would be identical to the Alpha's too. That can be clearly derived from your comparison. If your comparison is not based on identical prerequsites, it does not qualify as a comparison IMHO. It is roughly like peterbrorsson is saying:
Well, it could be right. Does anyone know any better simulation program than mine that would show us Group Delay dependently of driven power ?
That could show us how equalisation would influences Group Delay.
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Could it be possible that the Alpha + your room is inadequate? In your case a lower Qts driver + your room are the best combination. In somebody else's room maybe the Alpha works much better. I think you need to look at the total picture of driver, OB size, type of amp (tube vs. SS), and the room. I think focusing on the magnet is too simplistic.
Do you have a certain track you use to test this? I use the Alpha and don't experience the same with general listening, if anything I think the kick is right. Martin makes a good point above being my speakers would sound allot differant and have before my room is set up like is is now.
Brad
Yes they Kick, but it's all about their lack of resolution. Try to listen to any QUICK drum Solo.
The longer I listen to Selenium 15PW3 (QTS 0,6) the more I realise that they're still to slow...
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Brad,
Please send me those pictures so I can add them to the gallery. That has to be one of the wildest builds of this speaker design on the Internet. Are you happy with the performance?
Whoa!!! that means alllot, HAPPY
is an understatement. I have to say the Jordan's are as smooth as they report. They handle allot of rock from the loudness wars time like I never heard. The hot S as we call it has tamed allot of recordings. Comparing them to the FE87e and 15a OB I would say they are smoother with more detail and extend a little lower on the bottom.
I am driving them with the HK CII and have to say if they had any more bottom end it would be to much, I may try them in triode soon. I will send some pics in a bit.
Thanks,
Brad
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Hi Brad,
Got the pictures, thanks. I will try to add them to the gallery this week.
Thanks again,
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