High Efficiency Speaker Asylum Need speakers that can rock with just one watt? You found da place.

---

[ Follow Ups ] [ Post Followup ] Thread: [ Display  All  Email ] [ High Efficiency Speaker Asylum ]

---

[ Alert Moderator ]

---

RE: Help needed with BMS compression driver horn experiment

Posted by kurt s on June 18, 2007 at 12:42:34

In Reply to: RE: Help needed with BMS compression driver horn experiment posted by stuck.wilson@gmail.com on June 18, 2007 at 10:27:48:

>what is your current crossover topology? are you using an active, or a passive?<

After a lot of messing around, here is the present condition of this system:

I have an active biamped system between the bassbins and the horn. The bass amp receives an active crossover of 3rd order at about 400 Hz (the frequency is dial-able by a pot.) This bassbin is only about 90 dB sensitive and is powered by 100W of SS power. Gain is adjusted to match the horn's output.

The horn assembly receives its power from an active-filtered HF tube amp, from 400 Hz on up, 2nd order. Within the horn assembly is a first order crossover somewhere below 250 Hz to the mid driver and then passively crosses over to the tweeter driver at about 6.5 KHz. This assembly with its own passive crossover is an unknown beyond that since it is sealed up and is proprietary to BD-Design.

There is a mismatch between the low frequency direct radiator and the horn in two respects. The horn loading or lack thereof and the type of amp that is driving it. The higher this crossover goes, the worse the sound is at low volume levels due to this lack of matching. At 250 Hz it's not as bad as 400 Hz. Now the midband is starting to be heard directly from the SS powered woofer which is simply not as clean, dynamic, nor detailed as the horn with tube amplification.

>i wouldn't get too hung up on single point source or crossover points as concepts-- they're nice ideals-- but that ain't the problem, i'd suspect. most bass drivers'll get your north of 500hz (although i'm not certain as to what you're using), to my knowledge, and crossovers aren't necessarily evil either! even if you're running a bass driver up 'that high'-- it's sonic penalties can't be any worse than running a compression driver 'that low'!<

I'm not hung up on the point source issue at all which is why I thought of midrange horn plus tweeter horn separately as the solution to making a clean high SPL system. I was thinking bassbin 30 - 300 Hz or maybe 30 - 400 Hz, then compression midrange horn 300 Hz? - 6 KHz, then bullet tweeter 6 KHz - 20 KHz. The bassbins would be either 3rd or 4th order low pass. The midrange would be maybe 4th order high pass to 1st order low pass, and the tweeter 2nd order high pass.

Then the question would be what drivers? I don't want to buy too expensive drivers yet and I don't want to buy another expensive horn to replace the one I have. The one I have is a good round 250 Hz horn with good wideband response and no honkiness.


>throw out to the forum what you have-- maybe there's an amenable answer to be found, if not 'nirvana'.<

Well, there you have it. I hope someone can be creative in thinking up a solution that's appropriate and will work. I think what I propose is a decent start, if not the ultimate. The bass is the weakness here IMO. I also am space constrained and that's why this "Onken" is a small cheap 10" Vifa paper cone woofer. It can go to higher frequencies and all that, but when you're listening to solid state on the bottom to low mids and single-ended tube on the low mids on up, it's definitely another compromise in terms of "seamlessness".

This system used to be a 150 Hz horn for a Lowther driver which made for a very full range horn and the bassbins were truly just for bass. It's creeping up to be for bass and low mids.

Kurt

This post is made possible by the generous support of people like you and our sponsors:

VH Audio

---

[ Top of Page ] [ Contact Us ] [ Support/Wish List ] [ Copyright © 2024, Audio Asylum, all rights reserved ]

---

[ General ] [ Speakers ] [ Tubes ] [ Vinyl ] [ Digital ] [ Hi-Rez ] [ Video Asylum ] [ Cables ] [ Tweaks/DIY ] [ Music ] [ Films ]

---