Ricci's Skhorn Subwoofer & Files

[peniku8]

2 hours ago, pazo said:

I have 2 pieces RCF 21n401  .Any suggestions?

That is a fairly high Qts driver, which is not ideal for "small" cabs like this. The sims don't look good either. Voltage sensitivity is really rough and hornresp says it has 5db less headroom than a 21DS115.

[pazo]

Thanks for suggestions.

[lawbadman]

Hello all,

 

What are you guys thoughts on the new Dayton PSS555-8 21" sub?

It seems to be a nice budget friendly option for the skhorn.

https://www.parts-express.com/dayton-audio-pss555-8-21-pro-subwoofer-with-45”-voice-coil-8-ohm--295-050

 

[OldMan]

These look amazing! I have a CNC and would love to take a go at making a pair. @Ricciis this something you still share and if so may I pretty please

[Ricci]

On 4/5/2021 at 10:56 PM, OldMan said:

These look amazing! I have a CNC and would love to take a go at making a pair. @Ricciis this something you still share and if so may I pretty please

Sure. All of the files are available in the first couple of posts. 

Welcome to the forum. 🙂

[OldMan]

36 minutes ago, Ricci said:

Sure. All of the files are available in the first couple of posts. 

Welcome to the forum. 🙂

Thank you boss! 

[M88@FL450]

Hi Gang. After considering this monster I’m debating a driver. 

The IPals unless I can get a vendor to slash the price is a non starter for me. 

Would you all agree the next best is the Eminence NSW21? 

 

Beyond that the DS and Lavoce are third in terms of performance by my analysis here. 

In terms of most economical of output per dollar, would the Lavoce be the pick or the Eminence? My intended bandwidth is 35-100 with emphasis on kick drum (66-90hz)

 

 

[peniku8]

On 9/25/2021 at 9:11 PM, M88@FL450 said:

Hi Gang. After considering this monster I’m debating a driver. 

The IPals unless I can get a vendor to slash the price is a non starter for me. 

Would you all agree the next best is the Eminence NSW21? 

 

Beyond that the DS and Lavoce are third in terms of performance by my analysis here. 

In terms of most economical of output per dollar, would the Lavoce be the pick or the Eminence? My intended bandwidth is 35-100 with emphasis on kick drum (66-90hz)

 

 

I'd say you have a pretty good overview already. I have 4 21ds115, but if you want some 1-2db more headroom, go for the Eminence. Your call if you wanna spend the extra on that. For me (in Germany), the Eminence is twice the price than the 21ds115. It's actually almost the same price than the 21IPAL here. In the states it's more like 500 vs 700$ between LaVoce and Eminence I think. I'd personally go for the latter there.

[chrapladm]

Its funny because IPAL is about 300 more than SW152 but still hundreds less that Eminence 21 at least for me.

 

What was the lowest impedance for the IPAL and this cab? Does a clone 20Q still work with a pair of these in series wiring?

[Ricci]

The Eminence NSW and the Beyma drivers are a little better match for the SKRAM cab due to the extra air volume behind the driver. 

Impedance for the SKHORN with dual Ipal's is available in the measurements section for it. 

I do not have experience with the clone amps but I do not think it would like dual Ipal's in series on sustained bass notes near tuning. It's a 2ohm load with those drivers. That's why I use the SP6000

[M88@FL450]

Thanks. Good info. Ricci second to the ultimate k20 and iPal rig, what would be your second recommendation amp/driver combo for a bit more of an affordable build with max bang for the buck. 

 

Thanks much. 

 

Anyone have any recommendations on a supplier that can help with the cost of an iPal (qty of 4-8) if I went that direction? VIP?

[peniku8]

My Sanway clone amp handled 2R (one channel) sustained without issues. I let it pump out 4KW (again, one channel; sine wave) into my loadbank for over a minute, but kinda forgot it was fan modded, so it overheated and blew up on me.

I'd be pretty confident with the newer and sturdier version (mainly power supply changes with an additional fan next to the parts which blew up) when it's not fan modded. It muted the output pretty quickly into 1R (matter of milliseconds; SC protection kicked in), so it might not like it if the impedance of the actual cab dips below 2R.

[chrapladm]

Ricci was a single SP6000 enough for a pair of IPALs?

 

I was looking at using them in Skhorns. Would have a pair of SW512's and a pair of IPALS.

[Ricci]

SP6000 is great for 1 or 2 ohm loads. It doesn't have the peak voltage of the LG/PS amps but it can cook your drivers with sustained power. 

[Ricci]

On 9/29/2021 at 5:51 PM, peniku8 said:

My Sanway clone amp handled 2R (one channel) sustained without issues. I let it pump out 4KW (again, one channel; sine wave) into my loadbank for over a minute, but kinda forgot it was fan modded, so it overheated and blew up on me.

I'd be pretty confident with the newer and sturdier version (mainly power supply changes with an additional fan next to the parts which blew up) when it's not fan modded. It muted the output pretty quickly into 1R (matter of milliseconds; SC protection kicked in), so it might not like it if the impedance of the actual cab dips below 2R.

What frequency was it doing 4kw? 1kHz is easy peasy...30Hz not so much. The magic smoke strikes again! No doubt those amps make power. 

Load banks are purely resistive, speakers are not. Dual 21Ipal does drop below 2ohms. 1.6 ohms at certain frequencies or thereabout. Not too bad with dynamic music. Long sustained notes near the impedance min gets tough on the amp. 

[peniku8]

4 hours ago, Ricci said:

What frequency was it doing 4kw? 1kHz is easy peasy...30Hz not so much. The magic smoke strikes again! No doubt those amps make power. 

Load banks are purely resistive, speakers are not. Dual 21Ipal does drop below 2ohms. 1.6 ohms at certain frequencies or thereabout. Not too bad with dynamic music. Long sustained notes near the impedance min gets tough on the amp. 

It was 1khz, which meant maximum heat development in the amp, which was the cause for its failure.

It sustained over 7khz (single channel) into 2R for 260 milliseconds at 1khz. That's 260 cycles. Wouldn't that means it's able to do 2.6 cycles at 10Hz at 7khz or does it behave differently? I was planning on measuring at different frequencies as well, but I have so many things on my plate at the moment, I can't tell when that'll happen.
I was also pretty pissed when the amp went up in smoke, which is why I stopped testing. But I think it should be fine if I limit it to 10 second tests instead of 'seeing what will happen' (I left the amps running at max for 2 minutes). The amp threw my 16A 230V breaker after 16 seconds anyways, I should've left it at that instead of plugging it into a 32A circuit.

[M88@FL450]

If iPals were no longer available in the marketplace (theoretically speaking) which current driver would you choose to run in the SKH?

[Murmel]

On 9/29/2021 at 6:47 PM, Ricci said:

The Eminence NSW and the Beyma drivers are a little better match for the SKRAM cab due to the extra air volume behind the driver. 

Impedance for the SKHORN with dual Ipal's is available in the measurements section for it. 

I do not have experience with the clone amps but I do not think it would like dual Ipal's in series on sustained bass notes near tuning. It's a 2ohm load with those drivers. That's why I use the SP6000

I can find a ferrite (21QLEX1600FE) and neo (21LEX1600ND) 21" in beyma site, are both suitable or one better than the other? The ferrite seem to like a little bigger enclosures and a few other parameters are a little different. Do you mean they (or one of them?) are a better match than lavoce & B&c aswell? Also for ckram and Skram if so? I've not seen them recommended here before, interesting. The ferrite version is attractively priced in Europe.

[m_ms]

Don't know if this video (in Norwegian) has been shared already - I presume not due to the different-language "barrier" - but it shows what can only be the Skhorn with IPAL drivers at some Norwegian fella who specializes in building (and buying) horns speakers, big subs and the likes. He describes the Skhorn sound as (freely translated) "effortless, dynamic and airy." Attributes any serious (true) audiophile should aspire to from subs, I gather, but in reality few would ever get to experience their sound for, well.. obvious reasons when speaking of audiophiles in general. 
 

I take it the Skhorn is designed with the B&C 21SW152 and/or its IPAL sibling in mind? 

[M88@FL450]

Ok. Just found out that the SKHorn is dependent on the iPal in its entire design concept. Usually we think of a cab and then figure which driver would best suit it. in this case it seems its the other way around and if you want to use other drivers, see the Skram. 

 

So, seems like I’ll be trying again to negotiate prices on iPals. The guy from VIP pretty much hung up on the Saturday so maybe I’ll try again on a weekday during business hours. He was clueless on what an iPal was. I think he just gave up to be honest and had better things to do. 

[chrapladm]

9 hours ago, M88@FL450 said:

Ok. Just found out that the SKHorn is dependent on the iPal in its entire design concept. Usually we think of a cab and then figure which driver would best suit it. in this case it seems its the other way around and if you want to use other drivers, see the Skram. 

 

So, seems like I’ll be trying again to negotiate prices on iPals. The guy from VIP pretty much hung up on the Saturday so maybe I’ll try again on a weekday during business hours. He was clueless on what an iPal was. I think he just gave up to be honest and had better things to do. 

Ricci designed the sub after the IPAL but there are still many other drivers that work in this design.

[Ricci]

Skhorns in Norway...Nice. Thanks for the video link. 

I would use the Eminence or the 21DS115 as alternatives to the 21Ipal in this cab. 

[Ricci]

On 10/5/2021 at 5:00 PM, peniku8 said:

It was 1khz, which meant maximum heat development in the amp, which was the cause for its failure.

It sustained over 7khz (single channel) into 2R for 260 milliseconds at 1khz. That's 260 cycles. Wouldn't that means it's able to do 2.6 cycles at 10Hz at 7khz or does it behave differently? I was planning on measuring at different frequencies as well, but I have so many things on my plate at the moment, I can't tell when that'll happen.
I was also pretty pissed when the amp went up in smoke, which is why I stopped testing. But I think it should be fine if I limit it to 10 second tests instead of 'seeing what will happen' (I left the amps running at max for 2 minutes). The amp threw my 16A 230V breaker after 16 seconds anyways, I should've left it at that instead of plugging it into a 32A circuit.

Yes things behave much differently towards the frequency extremes. 1kHz is the defacto standard test for amps a lot of the time. Where the power ratings are measured. Testing at 20Hz or 20kHz is a lot rougher on the amplifier many times. It depends though. Some amps behave differently than others. The best amplifier testing I recall was the Bink's tests from something like 15 years ago. 

10 seconds is more than plenty IMHO. Hell I think 3 seconds 100% duty cycle would be enough. Those types of signals simply aren't in 99.99% of music, broadcast or, movie soundtrack.

[peniku8]

19 hours ago, Ricci said:

Yes things behave much differently towards the frequency extremes. 1kHz is the defacto standard test for amps a lot of the time. Where the power ratings are measured. Testing at 20Hz or 20kHz is a lot rougher on the amplifier many times. It depends though. Some amps behave differently than others. The best amplifier testing I recall was the Bink's tests from something like 15 years ago. 

10 seconds is more than plenty IMHO. Hell I think 3 seconds 100% duty cycle would be enough. Those types of signals simply aren't in 99.99% of music, broadcast or, movie soundtrack.

I agree on the 3 seconds part. Amps either drop off from burst power to sustained power within a fraction of a second or they're burst power=sustained power type of amps. Looking at my Sanway test reveals that nothing much changes after the cap banks are drained (after just shy of a second). After 2 seconds it ended up on its sustained power level, which would happen even faster when driving two channels.

I think I'll go with 3 seconds at 1k, 100, 60, 30, 15 and 8Hz. It cuts down on my testing time, is less hard on the amps and my breakers are unlikely to trip like this. Looking back at my initial test, the 90 seconds test was pretty stupid. 90 seconds 100% duty cycle into 2R of a fan modded amp...

I will fool around with REW and stepped sine wave tests as well, maybe that reveals some interesting results (It can step level now and not just frequency)

 

[Ricci]

Sounds like a plan and I agree. Save the time and the wear and tear on all of the above. There simply aren't any common scenarios where the content calls for 100% duty cycle signals for any length of time. Perhaps an SPL competition for a few seconds.