Why not Higher Freq extension out of RSS315 HO ??,Help - Page 2 - AVS Forum
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post #31 of 39 Old 03-22-2013, 06:36 PM - Thread Starter
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Originally Posted by tuxedocivic View Post

But how are you level matching things? The input sensitivity of the SA1000 may be lower compared to the Kef amp. In reality, if both subs were to be getting 2.83V at the woofer terminals, the dayton might have 3db on the Kef even at 100hz (where the difference is largest). That would move the whole line way up showing that the Dayton kills the Kef, except at high frequencies then the battle is a little closer, which is what I'd expect.

I'd suggest doing the same measurements with the same amp. And not because of the low pass, that's all taken care of in your receiver. Keep that at 200hz if you really want to know the high frequency performance of the Daytons.

I ajusted the Kef to 75db with the DB meter in REW with before doing test ,..then ajusted 1 RSS with SA1000 to 75db . If you look at the peak at 50 ,they are very close .

How would i use SA1000 on the Kef cube which has it's own amp ??
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post #32 of 39 Old 03-22-2013, 07:42 PM
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Turn off the filters and level adjust them at 200hz or something instead. You will notice that the Daytons doesnt lack higher frequenzy extension, but have WAY more low end than the KEF..

Do you have more info about the Dayton boxes? Volume and tuning for instance.
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post #33 of 39 Old 03-23-2013, 06:13 AM - Thread Starter
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Originally Posted by eXa View Post

Turn off the filters and level adjust them at 200hz or something instead. You will notice that the Daytons doesnt lack higher frequenzy extension, but have WAY more low end than the KEF..

Do you have more info about the Dayton boxes? Volume and tuning for instance.

My boxes are 3.6 cuft net tuned to 18hz,with a RSS 315HO-4
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post #34 of 39 Old 03-26-2013, 12:59 PM
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Originally Posted by randyc1 View Post

It's a Dayton SA1000 , both Subs together =4ohm load

Not sure it's room reinforcement ,room is 22x23 ?? ,...but RSS definitely go lower,... but not as high as the Single Kef in left corner ??

Randy, how do you get a 4 ohm net load from a pair of 4 ohm nominal subs? I thought you decided to go with the HO-44 when you were planning your build last year. With the HO-44, coils wired in series, drivers in parallel, you could show the amp a net 4 ohm load. No way to get 4 ohms net from a pair of HO-4s. Unless you're using one SA1000 per HO-4, but your text doesn't read that way to me.

Just to cover all of the bases. You are using the LFE input on the SA1000? Even though the LFE input should bypass the adjustable LP, I'd still set the LP to max (200Hz). Either way, the SA1000 likely has a fixed low-pass at 200Hz, based on the frequency reponse graph in the manual. Fairly commong for plate amps, although KEF may have chosen to allow theirs to run higher given the size of the satellites they wanted to mate it with. You might want to remeasure using the adjustable inputs on the SA1000. Similarly, if you can bypass the SA1000 and feed one of the subs directly from a full range main channel to get the SA1000's filter section completely out of the equation.

What's the receiver/processor? Any chance you're running a room correction program (Audyssey, YPAO, etc.)? If you leave room correction on, it could produce some wonky results for the sub it wasn't calibrated with.

-Brent
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post #35 of 39 Old 03-26-2013, 01:13 PM
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Quote:
Originally Posted by randyc1 View Post

I ajusted the Kef to 75db with the DB meter in REW with before doing test ,..then ajusted 1 RSS with SA1000 to 75db . If you look at the peak at 50 ,they are very close .

How would i use SA1000 on the Kef cube which has it's own amp ??

Would be better to measure the voltage at the driver terminals, but you probably can't do that with the Kef...
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post #36 of 39 Old 03-27-2013, 05:07 AM - Thread Starter
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I don't get this paragraph of yours""

With the HO-44, coils wired in series, drivers in parallel, you could show the amp a net 4 ohm load. No way to get 4 ohms net from a pair of HO-4s. Unless you're using one SA1000 per HO-4, but your text doesn't read that way to me. "" ?

Each dayton RSS driver is wired in Series ,... Then both subs are in parallel at the SA1000 for a total of 4ohm load .

I then tested just 1 RSS ( in case of cancellation) at a 8 ohm load and got very similar results.
Yes im using LFE
6 yr old Yam rx-v 657
No dsp
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post #37 of 39 Old 04-01-2013, 03:45 PM
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Quote:
Originally Posted by randyc1 View Post

I don't get this paragraph of yours""

With the HO-44, coils wired in series, drivers in parallel, you could show the amp a net 4 ohm load. No way to get 4 ohms net from a pair of HO-4s. Unless you're using one SA1000 per HO-4, but your text doesn't read that way to me. "" ?

Each dayton RSS driver is wired in Series ,... Then both subs are in parallel at the SA1000 for a total of 4ohm load .

I then tested just 1 RSS ( in case of cancellation) at a 8 ohm load and got very similar results.
Yes im using LFE
6 yr old Yam rx-v 657
No dsp

The point I was trying to make is clarifying which sub drivers you're using. You've said multiple times in this thread and others that you're using the RSS315HO-4. However, the RSS315HO-4 is a single coil 4 ohm sub. If you wire a pair in parallel, you get 2 ohms at the amp; in series you get 8 ohms. A single shows the amp 4 ohms. To achieve the wiring configurations you've described, you must be using the RSS315HO-44, a dual voice coil/4 ohm per coil driver.

To get accurate answers, you must first provide accurate information.

In reality, any 12" subwoofer should easily reach 200Hz without a problem. Thanks to good venting and low distortion motors, the RSS315 drivers would appear to be useful up towards 1kHz if beaming weren't becoming an issue due to the ratio of wavelength to driver diameter. One of the 315HF models, either the 8 or the 4 (can't remember), has been incorporated as the woofer in a 3-way design. You don't see many 12" subwoofer drivers being used in that application.

Unfortunately, as measured, it appears the room is the dominant factor in your current measurements. It looks like both the KEF and HO-44 are showing many of the same peaks/dips, which tells me the room is dominating your measurement. As someone else mentioned, you also probably haven't accurately level matched the two sub amps so the KEF "appears" to have more high frequency by virtue of being louder. The HO-44 might suffer a little more of an inductance hump than the KEF, giving the appearance of a more rolled off high frequency response, but we can't tell from your current measurements. If you want to compare sub to sub, do a close mic'd measurement with the mic 1/2" or so from the dust cap of each driver. This will take the room out of the equation and show you what each driver is actually doing...above tuning in the case of the HO-44. Don't be surprised if the response is still similar since 200Hz should't really be a challenge. If you want to see what the drivers' upper frequency limits are, you're going to need to run them off of full range amps instead of your current amps that have built-in lowpass filters.

And, while I'm writing a book :-). You may want to double check your receiver's settings since you seem to be confusing YPAO with the DSP enhancements. The RX-V657 does have YPAO. YPAO is Yahama's attempt at room correction and is separate from their various DSP enhancement modes. In addition to automatically setting distance and level for all channels, YPAO attempts to equalize the main channels (sub excluded) frequency response using parametric EQ on each channel. If you ever ran the auto-setup routine and didn't go back and manually disable EQ in the setup menu, then you're applying this automatic EQ to your current setup. Even though your version of YPAO doesn't EQ the sub channel directly, depending on how YPAO actually works, the capability of the sub used during the YPAO measurement could influence the EQ applied to the mains.

-Brent
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post #38 of 39 Old 04-02-2013, 03:35 PM - Thread Starter
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You are right riverwolf , i am using the RSS315HO-44 , , i just assumed everyone would know it was the double voice coil , i should have been more specific!

I level matched with REW sound meter ,and thought i was quit accurate ? the peaks are what dominate the sound level, no ?? they seem to peek at the same level ?

I will also check if YPAO is dissactivated correctly and take close mic measurements.
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post #39 of 39 Old 04-04-2013, 07:37 AM
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Well, you didnt really level match the subs... you measured only at 50hz wich clearly have a peak introduced by the room.
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