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Multi-Way Conventional loudspeakers with crossovers

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Old 28th February 2018, 07:59 PM   #161
montana1 is offline montana1  United States
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Hi to All,
I attached this screenshot of 2 way standmount speakers that I have
been working on through this thread. This is with both channels driven with xover in place at a distance of 6 feet with mic centered between the speakers in what is the normal listening area. Both speakers were placed facing straight ahead not toed in. That was tried but frequency response was worse. IT is certainly not very pretty as compared to simulations. But, my question would be how does one compensate for the drooping top end? Do I reduce resistor value to raise upper treble? What are tricks/tips that others use in tweaking their speakers at this stage?

Thanks in advance,
Rich
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Old 28th February 2018, 09:23 PM   #162
Draki is offline Draki  Macedonia
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Actually not bad considering that both speakers are driven, at 6 ft LP and as they are straight ahead, you are measuring essentially 30/40 degrees off-axis. It is more-or-less straight up to 2 KHz and then rolls off in a linear fashion.

Do you subjectively feel the highs are missing?

And yes, you can increase (or decrease) the tweeter level with the series resistor (if L-pad, then you adjust both Rs). Rule of the thumb is 1 Ohm equals aprx 1 dB.

Measurement below 400 Hz is not accurate as the room dominates, and you could use say 7 ms gate (right window) to clean up the hash.

The black trace: is that the mic calibration?
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Old 28th February 2018, 10:07 PM   #163
montana1 is offline montana1  United States
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Thanks Draki,
The system actual sounds quite nice. Lojzek, helped me out with some excellent suggestions and now bass is coming through nicely. My impression is these speakers seem balanced very well. I did not know if it was worth pursuing an off axis response that is similar to the on axis response. As for the black line, I am not sure what it represents. I'm still a beginner with REW and still trying to figure some things out but that black line does not coincide with the 88 db level that I calibrated with the onboard spl meter in REW. You could be correct though in that maybe Umik-1 mic is calibrated to that level.

Best,
Rich

Last edited by montana1; 28th February 2018 at 10:16 PM.
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Old 1st March 2018, 07:11 AM   #164
Lojzek is offline Lojzek  Croatia
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Hey Rich, take a shot of measuring one loudspeaker only, on-axis and a few off-axis to the side ( like 10, 20 and 30 deg) not too far from it (1m is enough). It doesn't have to be all that accurate to the last degree. Simply rotate the loudspeaker on a stand. Take care of the impulse to be included in the time window (gating) from start to the end and some more. Set it to 10-15 ms so we can see the floor bounce and some midbass.
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Last edited by Lojzek; 1st March 2018 at 07:14 AM.
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Old 1st March 2018, 02:41 PM   #165
montana1 is offline montana1  United States
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Hi Lojzek,
I took a few measurements this morning as you requested. Attached is screenshot from REW. Measurements were taken at distance of 36 inches @ 0, 10, 20, AND 30 degrees. I gated measurements at 10 ms and applied 1/24th smoothing.

Thanks for your help
Rich
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Old 1st March 2018, 03:59 PM   #166
Lojzek is offline Lojzek  Croatia
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Much obliged, it seems to me that the waveguide is working alright. Now you're left with how much of toeing in speakers to your listening spot will you find most pleasing. Does it feel like there is lack of HF energy in the room?
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Old 1st March 2018, 04:45 PM   #167
montana1 is offline montana1  United States
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Hi Lojzek,
Actually, I find myself turning the treble tone control down just a bit. So, its seems that there is plenty of HF energy in the room. These speakers appear very balanced and neutral sounding (not dark sounding at all). Since expanding the cabs to 38 liters, bass is outstanding. Thanks to you, I now really enjoy listening to them over other loudspeakers in the house. Maybe its time to stop worrying so much about how well the system measures and live with them as they are for some time before considering any adjustments if at all.

Best Regards,
Rich
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Old 1st March 2018, 06:34 PM   #168
Lojzek is offline Lojzek  Croatia
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Hi Rich, I am happy to hear the modifications were successful. Cheers!
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Old 1st March 2018, 06:59 PM   #169
montana1 is offline montana1  United States
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Hi Lojzek,
These loudspeakers now are bassy enough. I would imagine, that if placed in a box 50-60 liters these Peerless 830869 woofers would do even better. Maybe that could be a nice winter project for next year to build floorstander cabs that meet the exact volume requirements. As it is, I am very happy with the outcome. What I really would like to build next is the amplifier you built from The Audiophile's Project Sourcebook on page 137. My wife got me the book as an Anniversary gift a couple days ago. I have read up to about page 120 and cannot say enough good things about this book. It is Awesome! Thanks for the recommendation. Hopefully, if I work up the courage to build that amp it will turn out as nice as yours did.

Best,
Rich
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Old 1st March 2018, 07:49 PM   #170
Lojzek is offline Lojzek  Croatia
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Whoah, awesome gift! Slowly, patiently and eventually it will work out with amp.
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