Modifiying an existing design.

[Ouch_my_ears]

Hello everyone,

Assuming I have the know-how (don't laugh) and the equipment... If I wanted to modify Zaph's Waveguide TMM design to use the newer Seas ER18 or the Peerless 830883, would the gain be worth the effort? With the ER18, would I be giving up some low end? Has anyone tried this? Does anyone have feedback on Zaph's TMM stock or modified?

Sorry to sound so arrogant as to assume I can do better then Zaph, just wondering if there is anything to be gained as he mentions the woofers could be easily changed for a different model... If it's worth the time that is.

Regards,
Joe

[Jed]

I doubt the stock crossover would work given the different impedance and FR profiles of the CA18 versus the ER18. So you wouldn't gain anything even though the ER18 has lower distortion. It would need a crossover redesign.

[Ouch_my_ears]

I guess the Peerless is worst in terms of impedance as well?

But IF I could re-design the crossover, would it be worth the gain? If yes, then Peerless or ER18?

[ThomasW]

If I wanted to modify Zaph's Waveguide TMM design to use the newer Seas ER18 or the Peerless 830883, would the gain be worth the effort?

The answer to your question is.....it depends, it depends entirely on whether or not the rest of the equipment in the signal path is adequate to the task of revealing these differences.

Posted test plots showing one driver being 'better' than another are one thing. Being able to take advantage of those differences is something completely different...

[Ouch_my_ears]

My amp will be changed eventually, specially since it's not rated at 4ohms. So it's not an issue. Just want one pair of good speakers and then work my way from there.

Joe

[ThomasW]

IMO, it's going to take a pretty substantial amp to distinguish the differences in these speakers, considering the passband where they're typically used...

Seas CA18RNX



830883



ER18



CA18



830883



ER18

[Ouch_my_ears]

Thomas,
thanks for taking the time and the graphs. I am just not sure what you mean by substantial? Aren't speakers usually the weakest links in a Hifi gear? What would make an amp substantial by your standard?

I just saw Zaph's THD graphs and noticed lower THD on the newer drivers ER18 and Peerless.... Compared to the CA18rnx, the ER18 has less THD anywere bellow the 1500hz mark, and the Peerless has less THD everywhere... Is it a significant improvement?

Note: Ok I'll stop editing this post to avoid any confusion.

[Dennis H]

From Zaph's distortion curves in Thomas's post, the differences aren't enough to make it worth changing the design IMO.

[ThomasW]

Typically yes speakers are considered the weak link in the chain. But these speakers are all so closely matched it, would be extremely difficult to differentiate between them in a normal listening room using standard electronics.

Someone with bizillion dollars worth of electronics and a fantastic room setup one 'might' hear a difference, but no one with that setup would be building these speakers. (no offense intended to Zaph.... :B )

My recommendation is to build Zaph's design as published. It will be a long time before you'd be buying electronics that would allow you to hear the difference in the stock design vs a modded one, unless of course you win the Lotto....

[Ouch_my_ears]

It will be a long time before you'd be buying electronics that would allow you to hear the difference in the stock design vs a modded one, unless of course you win the Lotto....

LOL, if I win the Lotto, it will be nothing but live music for me baby!!! Craps, what do I do for artists that have passed on? Dam you Newman :M

But seriously I see your point. Maybe I am juts envious of that ER18 being the newest thing from Seas. I guess newer is always perceived as better by default.

Thanks guys,

[cjd]

Besides, remember that this is only the FIRST set of speaks you're going to be building.

In this case, the quality of the crossover will probably contribute MORE than the subtle differences in distortion level in these drivers. Zaph does great work. So... yeah.

C

[Ouch_my_ears]

Well I've experimented with the Hivi B3N to test my wood working skills and I knew I was going to want more as it was just to get warmed up... I just thing there are more important thing in life and want to more on after that.... Did I just say that out loud???

But seriously, only reason I would build something after the TMM would be to give as a house/wedding gift... I don't know anyone who would appreciate it to it's value... or at the very least not look at me eyes that say "where am I going to put this thing?".